Effects of low sodium diet versus high sodium diet on blood pressure, renin, aldosterone, catecholamines, cholesterol, and triglyceride

  • Conclusions changed
  • Review
  • Intervention

Authors

  • Niels Albert Graudal,

    Corresponding author
    1. Copenhagen University Hospital, Rigshospitalet, Dep. of Rheumatology TA4242/Internal Medicine, Copenhagen, Denmark
    • Niels Albert Graudal, Dep. of Rheumatology TA4242/Internal Medicine, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, Copenhagen, DK-2100, Denmark. graudal@dadlnet.dk.

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  • Thorbjorn Hubeck-Graudal,

    1. Bispebjerg University Hospital, Department of Clinical Pharmacology, Copenhagen, Denmark
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  • Gesche Jurgens

    1. Bispebjerg University Hospital, Department of Clinical Pharmacology, Copenhagen, Denmark
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Abstract

Background

In spite of more than 100 years of investigations the question of reduced sodium intake as a health prophylaxis initiative is still unsolved.

Objectives

To estimate the effects of low sodium versus high sodium intake on systolic and diastolic blood pressure (SBP and DBP), plasma or serum levels of renin, aldosterone, catecholamines, cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL) and triglycerides.

Search methods

PUBMED, EMBASE and Cochrane Central and reference lists of relevant articles were searched from 1950 to July 2011.

Selection criteria

Studies randomizing persons to low sodium and high sodium diets were included if they evaluated at least one of the above outcome parameters.

Data collection and analysis

Two authors independently collected data, which were analysed with Review Manager 5.1.

Main results

A total of 167 studies were included in this 2011 update.

The effect of sodium reduction in normotensive Caucasians was SBP -1.27 mmHg (95% CI: -1.88, -0.66; p=0.0001), DBP -0.05 mmHg (95% CI: -0.51, 0.42; p=0.85). The effect of sodium reduction in normotensive Blacks was SBP -4.02 mmHg (95% CI:-7.37, -0.68; p=0.002), DBP -2.01 mmHg (95% CI:-4.37, 0.35; p=0.09). The effect of sodium reduction in normotensive Asians was SBP -1.27 mmHg (95% CI: -3.07, 0.54; p=0.17), DBP -1.68 mmHg (95% CI:-3.29, -0.06; p=0.04). The effect of sodium reduction in hypertensive Caucasians was SBP -5.48 mmHg (95% CI: -6.53, -4.43; p<0.00001), DBP -2.75 mmHg (95% CI: -3.34, -2.17; p<0.00001). The effect of sodium reduction in hypertensive Blacks was SBP -6.44 mmHg (95% CI:-8.85, -4.03; p=0.00001), DBP -2.40 mmHg (95% CI:-4.68, -0.12; p=0.04). The effect of sodium reduction in hypertensive Asians was SBP -10.21 mmHg (95% CI:-16.98, -3.44; p=0.003), DBP -2.60 mmHg (95% CI: -4.03, -1.16; p=0.0004).

In plasma or serum there was a significant increase in renin (p<0.00001), aldosterone (p<0.00001), noradrenaline (p<0.00001), adrenaline (p<0.0002), cholesterol (p<0.001) and triglyceride (p<0.0008) with low sodium intake as compared with high sodium intake. In general the results were similar in studies with a duration of at least 2 weeks.

Authors' conclusions

Sodium reduction resulted in a 1% decrease in blood pressure in normotensives, a 3.5% decrease in hypertensives, a significant increase in plasma renin, plasma aldosterone, plasma adrenaline and plasma noradrenaline, a 2.5% increase in cholesterol, and a 7% increase in triglyceride. In general, these effects were stable in studies lasting for 2 weeks or more.

Résumé scientifique

Effects of low sodium diet versus high sodium diet on blood pressure, renin, aldosterone, catecholamines, cholesterol, and triglyceride

Contexte

Malgré plus de 100 ans d’études, la question de la diminution de l’apport en sodium à titre prophylactique sur la santé n’a pas encore été résolue.

Objectifs

Estimer les effets d’un apport faible en sodium comparé à un apport riche en sodium sur la pression artérielle systolique et diastolique (PPAS et PPAD) ainsi que sur les niveaux de rénine, d’aldostérone, de catécholamines, de cholestérol, de lipoprotéine de haute densité (HDL), de lipoprotéine de faible densité (LDL) et de triglycérides dans le sérum ou le plasma

Stratégie de recherche documentaire

Une recherche a été effectuée dans PUBMED, EMBASE et le registre Cochrane des essais contrôlés (CENTRAL) ainsi que les références bibliographiques des articles pertinents de 1950 à juillet 2011.

Critères de sélection

Les études randomisant les personnes selon les régimes faibles en sodium et riches en sodium ont été incluses si elles évaluaient au moins l’un des critères de jugement ci-dessus.

Recueil et analyse des données

Deux auteurs ont extrait de manière indépendante les données, qui ont été analysées avec Review Manager 5.1.

Résultats principaux

Au total, 167 études ont été incluses dans cette mise à jour de 2011.

La diminution du sodium chez les Caucasiens normotendus a produit une PAS de -1,27 mmHg (IC à 95 % -1,88, -0,66 ; p = 0,0001) et une PPAD de -0,05 mmHg (IC à 95 % : -0,51, 0,42 ; p = 0,85). La diminution du sodium chez les Noirs normotendus a entraîné une PPAS de -4,02 mmHg (IC à 95 % -7,37, -0,68 ; p = 0,002) et une PPAD de -2,01 mmHg (IC à 95 % -4,37, 0,35 ; p = 0,09). La diminution du sodium chez les Asiatiques normotendus a donné une PPAS de -1,27 mmHg (IC à 95 % -3,07, 0,54 ; p = 0,17) et une PPAD de -1,68 mmHg (IC à 95 % -3,29, -0,06 ; p = 0,04). La diminution du sodium chez les Caucasiens hypertendus a produit une PPAS de -5,48 mmHg (IC à 95 % -6,53, -4,43 ; p<0.00001), et une PAD de -2,75 mmHg (IC à 95 % -3,34, -2,17 ; p<0.00001). La diminution du sodium chez les Noirs hypertendus a entraîné une PAS de -6,44 mmHg (IC à 95 % -8,85, -4,03 ; p = 0,00001) et une PAD de -2,40 mmHg (IC à 95 % -4,68, -0,12 ; p = 0,04). La diminution du sodium chez les Asiatiques hypertendus a donné une PAS de -10,21 mmHg (IC à 95 % -16,98, -3,44 ; p = 0,003) et une PAD de -2,60 mmHg (IC à 95 % -4,03, -1,16 ; p = 0,0004).

Une augmentation significative de la rénine (p<0.00001), l'dosterone (p<0.00001), de la noradrénaline (p<0.00001), de l’adrénaline (p<0.0002), du cholestérol (p<0.001) et des triglycérides (p<0.0008) a été notée dans le plasma ou le sérum en cas d’apport faible en sodium à un apport riche en sodium. En général, les résultats étaient similaires dans les études durant au moins 2 semaines

Conclusions des auteurs

La diminution du sodium a entraîné une baisse de 1 % de la pression artérielle chez les personnes normotendues, une baisse de 3,5 % chez les personnes hypertendues, une augmentation significative de la rénine, de l'aldostérone, de l'adrénaline et de la noradrénaline dans le plasma, une augmentation de 2,5 % du cholestérol et une augmentation de 7 % des triglycérides. En général, ces effets étaient stables dans les études durant 2 semaines ou plus.

摘要

低鈉飲食對比高鈉飲食在血壓、腎素、醛固酮、兒茶酚胺、膽固醇和三酸甘油酯上的影響

背景

僅管有超過100年以上的調查,降低鈉攝取做為健康預防方法倡議的問題仍未解決。

目的

想要估計低鈉對比高鈉攝取在收縮與舒張壓(SBP與DBP)、血漿或血清腎素、醛固酮、兒茶酚胺、膽固醇、高密度脂蛋白(HDL)、低密度脂蛋白 (LDL)與三酸甘油酯水準上的效果。

搜尋策略

搜尋1950年到2011年7月的PUBMED、EMBASE及考科藍Central與相關文章的文獻參考清單。

選擇標準

若研究至少有評估上述成果參數之一,則包含有隨機排列民眾到低鈉與高鈉飲食的研究。

資料收集與分析

兩位作者獨立蒐集數據,數據使用Review Manager 5.1分析。

主要結果

總計有167個研究被包含在此2011年的更新中。

減鈉在血壓正常的白種人身上的效果為SBP -1.27 mmHg (95% CI: -1.88, -0.66; p=0.0001), DBP -0.05 mmHg (95% CI: -0.51, 0.42; p=0.85)。減鈉在血壓正常的黑人身上的效果為SBP -4.02 mmHg (95% CI:-7.37, -0.68; p=0.002)、DBP -2.01 mmHg (95% CI:-4.37, 0.35; p=0.09)。減鈉在血壓正常的亞洲人身上的效果為SBP -1.27 mmHg (95% CI: -3.07, 0.54; p=0.17), DBP -1.68 mmHg (95% CI:-3.29, -0.06; p=0.04)。減鈉在高血壓白種人身上的效果為SBP -5.48 mmHg (95% CI: -6.53, -4.43; p<0.00001), DBP -2.75 mmHg (95% CI: -3.34, -2.17; p<0.00001)。減鈉在高血壓黑人身上的效果為SBP -6.44 mmHg (95% CI:-8.85, -4.03; p=0.00001)、 DBP -2.40 mmHg (95% CI:-4.68, -0.12; p=0.04)。減鈉在高血壓亞洲人身上的效果為SBP -10.21 mmHg (95% CI:-16.98, -3.44; p=0.003), DBP -2.60 mmHg (95% CI: -4.03, -1.16; p=0.0004)。

以低鈉攝取與高鈉攝取相比,在血漿或血清中,腎素 (p<0.00001)、醛固酮 (p<0.00001)、去甲腎上腺素 (p<0.00001)、腎上腺素(p<0.0002)、膽固醇 (p<0.001)與三酸甘油酯(p<0.0008) 中有顯著增加。一般而言,維持在至少為期2周,所有研究中結果類似。

作者結論

減鈉導致血壓正常人身上1%的血壓降低、高血壓者降低3.5%,顯著的於血漿腎素、血漿醛固酮、血漿腎上腺素與血漿去甲腎上腺素中增加,2.5%的膽固醇增加以及三酸甘油酯增加7%。一般而言,這些效果於研究中穩定持續2周或以上。

アブストラクト

低ナトリウム食と高ナトリウム食が血圧、レニン、アルドステロン、カテコールアミン、コレステロール及びトリグリセリドに与える影響の比較

背景

100年を超える研究が行われてきたにもかかわらず、予防的健康法としてのナトリウム摂取量の抑制に関する疑問は依然として解決されていない。

目的

低ナトリウム摂取と高ナトリウム摂取が、収縮期血圧と拡張期血圧(SBPとDBP)、並びにレニン、アルドステロン、カテコールアミン、コレステロール、高比重リポ蛋白(HDL)、低比重リポ蛋白(LDL)及びトリグリセリドの血漿濃度や血清濃度に与える影響を比較、推定する。

検索戦略

1950年から2011年7月まで、PUBMED、EMBASE、Cochrane Central及び関連性のある論文の参考文献リストを検索した。

選択基準

低ナトリウム食と高ナトリウム食にランダムに割り付けている研究を、少なくとも1つの上記アウトカムパラメーターを評価している場合に組み入れた。

データ収集と分析

2名のレビューアが別々にデータを抽出し、このデータをReview Manager 5.1で解析した。

主な結果

この2011年の更新では、計167件の研究を対象とした。 正常血圧の白人における低ナトリウム摂取は、SBPを-1.27 mmHg(95%CI:-1.88~-0.66)低下させ(p = 0.0001)、DBPを-0.05 mmHg(95%CI:-0.51~0.42)低下させた(p = 0.85)。正常血圧の黒人における低ナトリウム摂取は、SBPを-4.02 mmHg(95%CI:-7.37~-0.68)低下させ(p = 0.002)、DBPを-2.01 mmHg(95%CI:-4.37~0.35)低下させた(p = 0.09)。正常血圧のアジア人における低ナトリウム摂取は、SBPを-1.27 mmHg(95%CI:-3.07~0.54)低下させ(p = 0.17)、DBPを-1.68 mmHg(95%CI:-3.29~-0.06)低下させた(p = 0.04)。高血圧の白人における低ナトリウム摂取は、SBPを-5.48 mmHg(95%CI:-6.53~-4.43)低下させ(p<0.00001)、DBPを-2.75 mmHg(95%CI:-3.34~-2.17)低下させた(p<0.00001)。高血圧の黒人における低ナトリウム摂取は、SBPを-6.44 mmHg(95%CI:-8.85~-4.03)低下させ(p = 0.00001)、DBPを-2.40 mmHg(95%CI:-4.68~-0.12)低下させた(p = 0.04)。高血圧のアジア人における低ナトリウム摂取は、SBPを-10.21 mmHg (95%CI:-16.98~-3.44)低下させ(p = 0.003)、DBPを-2.60 mmHg (95%CI: -4.03,~-1.16)低下させた(p = 0.0004)。 高ナトリウム摂取と比較して低ナトリウム摂取により、血漿あるいは血清中のレニン(p<0.00001)、アルドステロン(p<0.00001)、ノルアドレナリン(p<0.00001)、アドレナリン(p<0.0002)、コレステロール(p<0.001)及びトリグリセリド(p<0.0008)に有意な増加がみられた。概して、この結果は、少なくとも2週間継続した研究の結果と同等であった。

著者の結論

低ナトリウム摂取は、正常血圧者における血圧の1%低下、高血圧者における血圧の3.5%低下、血漿中レニン、血漿中アルドステロン、血漿中アドレナリン、血漿中ノルアドレナリンの有意な増加、コレステロールの2.5%増加、トリグリセリドの7%増加をもたらした。概して、これらの効果は、2週間以上継続した研究で一定していた。

訳注

監  訳: 吉田 雅博,2012.3.13

実施組織: 厚生労働省委託事業によりMindsが実施した。

ご注意 : この日本語訳は、臨床医、疫学研究者などによる翻訳のチェックを受けて公開していますが、訳語の間違いなどお気づきの点がございましたら、Minds事務局までご連絡ください。Mindsでは最新版の日本語訳を掲載するよう努めておりますが、編集作業に伴うタイム・ラグが生じている場合もあります。ご利用に際しては、最新版(英語版)の内容をご確認ください。

Plain language summary

Effects of low salt diet on blood pressure, hormones and lipids in people with normal blood pressure and in people with elevated blood pressure

We are commonly advised to cut down on salt. The previous version of this review looked at mostly short-term strategies to reduce salt intake. In the present updated version separate analyses of studies with a duration of 2 to 4 weeks or longer were performed. Low salt diets reduced systolic blood pressure by 1% in white people with normal blood pressure and by 3.5% in white people with elevated blood pressure. The effect was similar in trials of 4 weeks or longer. There were increases in some hormones and lipids which could be harmful if persistent over time. However, the studies were not designed to measure long-term health effects. Therefore we do not know if low salt diets improve or worsen health outcomes.
Most of the people who took part in the studies were whites, but in the small number of non-whites the blood pressure reduction was, if anything, greater. More research on reduced salt intake is required, particularly in non-white populations.

Résumé simplifié

Effets d'un régime pauvre en sel sur la pression artérielle, les hormones et les lipides chez les personnes ayant une pression artérielle normale et chez les personnes présentant une pression artérielle élevée

Il est couramment conseillé de réduire la consommation de sel. La précédente version de cette revue a examiné les stratégies principalement à court terme visant à réduire l’apport en sel. Dans la version mise à jour actuelle, des analyses séparées des études durant entre 2 et 4 semaines ou plus ont été effectuées. Les régimes pauvres en sel ont réduit la pression artérielle systolique de 1 % chez les caucasiens ayant une pression artérielle normale et de 3,5 % chez les caucasiens ayant une pression artérielle élevée. L’effet était similaire dans les essais durant 4 semaines ou plus. Des augmentations de certaines hormones et de certains lipides susceptibles d’être nuisibles si elles persistent au fil du temps ont été notées. Les études n’étaient toutefois pas conçues pour mesurer les effets à long terme sur la santé. Nous ne savons donc pas si les régimes pauvres en sel améliorent ou aggravent les résultats sur la santé.
La plupart des personnes qui ont participé aux études étaient des caucasiens, mais la baisse de la pression artérielle était, le cas échéant, supérieure chez le petit nombre de personnes non caucasiennes. Des recherches supplémentaires doivent être menées sur l’apport réduit en sel, tout particulièrement auprès des populations non blanches..

Notes de traduction

Traduit par: French Cochrane Centre 1st December, 2011
Traduction financée par: Ministère du Travail, de l'Emploi et de la Santé Français

淺顯易懂的口語結論

低鈉飲食對血壓正常者和高血壓者的血壓、荷爾蒙和脂質影響

我們通常會建議人們降低鈉的攝取量。本次文獻回顧的前一版本,主要檢視降低鈉攝取量的短期策略。目前這份更新版本,則分別分析持續2至4週以上的試驗。低鈉飲食可使血壓正常的白人收縮壓降低1%;血壓偏高的白人收縮壓降低3.5%。持續4週以上的試驗,所得結果相似。有些荷爾蒙和脂質若長時間持續增高,可能使身體受損,不過這些試驗並非專為測量長期健康影響而設計,因此我們無法得知低鈉飲食會使健康結果改善或惡化。
這些試驗的受試者大部分為白人,但所納入的非白人受試者,血壓的降低幅度較大。仍需進行更多關於低鈉飲食的研究,尤其是針對非白人族群的研究。

譯註

翻譯: East Asian Cochrane Alliance
翻譯補助: 台灣衛生福利部/台北醫學大學實證醫學研究中心

Background

In the later years, population studies associating sodium intake with morbidity and mortality have contributed to the evidence of sodium reduction as a prophylaxis initiative, although not unambiguously, as the interpretation of the population studies have been conflicting (Aldermann 2010, Strazzulo 2009). In addition, recent studies have showed a direct harmful effect of sodium reduction on patients with established heart failure (Paterna 2008, Paterna 2009) and diabetes (Thomas 2011, Ekinci 2011), questioning the advisability of a general recommendation of reduced sodium intake.

Hitherto, the recommendation to reduce sodium intake is based on the effect on a surrogate marker, i.e. blood pressure (BP), and on the hypothetical benefits in terms of reduction in cardiovascular morbidity and mortality (Collins 1990, Law 1991, Bibbins-Domingo 2010). There is evidence from several published reviews of randomised studies (Grobbee 1986, Midgley 1996, Cutler 1997, Ebrahim 1998, Graudal 1998, He 2002, Hooper 2002) and other Cochrane reviews ( He 2004, Taylor 2011) of the effects of reduced sodium intake on BP. In addition sodium intake has been shown to affect other surrogate markers, such as the renin-angiotensin-aldosterone system, catecholamines and serum lipids. Since some of these effects are expected to be mutually dependent, the investigation of more than one effect makes it possible to detect the consistency of the results between the studies. The present review represents a second update of the first cumulative meta-analysis that includes an analysis of hormones and lipids in addition to blood pressure (Graudal 1998), first updated in 2003 (Jürgens 2004).

Objectives

The purpose of the present review was to estimate the influence of low versus high dietary sodium intake on systolic blood pressure (SBP), diastolic blood pressure (DBP), mean blood pressure (MBP) and blood concentrations of renin, aldosterone, catecholamines, cholesterol, HDL, LDL and triglyceride to contribute to the evaluation of the possible suitability of sodium reduction as a prophylaxis initiative and treatment of hypertension.

Methods

Criteria for considering studies for this review

Types of studies

Randomised controlled trials (RCTs) allocating patients to either a low or a high sodium diet and in which the sodium intake was estimated by the 24-h urinary sodium excretion (either measured on the basis of a 24-h urine collection, or estimated from a sample of at least 8 hours).

Types of participants

Persons with normal or elevated blood pressure irrespective of race and age were included. Studies systematically investigating unhealthy patients with other diseases than elevated blood pressure, for instance diabetes or heart failure, were excluded.

Types of interventions

The intervention was changed sodium intake, randomly dividing the investigated population into a group eating a low sodium diet and a group eating high sodium diet. Confounding was not allowed, i.e. studies treating persons with a concomitant intervention such as an antihypertensive medication, potassium supplementation or weight reduction were only included if the concomitant intervention was identical during the low and the high sodium diet.

Types of outcome measures

Outcome measures were effects on SBP, DBP, MBP, renin, aldosterone, adrenaline, noradrenaline, triglyceride, cholesterol, LDL and HDL MBP was analysed separately in Caucasians. In studies of Blacks and Asians reporting BP only as MBP, SBP was estimated from MBP + 1/3 of MBP and DBP was estimated from MBP - 1/3 of MBP. Separate meta-analyses were performed for each outcome measure. Concerning blood pressure, participants were stratified according to race (Caucasians, Blacks and Asians) and according to level of blood pressure (hypertension or normotension). In studies, which investigated different races and different blood pressure levels, the first priority was to separate these subgroups. If separate data were not given, the study data would be analysed according to the biggest subgroup. Concerning all other outcome variables, no stratifications were performed. 

Search methods for identification of studies

Trial search: Parijs et al. published the first RCT of the effect of sodium reduction on BP in 1973 (1000 P SE Parijs 1973). In our first meta-analysis (Graudal 1998), a literature search in “MEDLINE” (1966-through December 1997) was performed using the following combinations of search terms: 1) salt or sodium, 2) restriction or dietary, 3) blood pressure or hypertension, 4) randomized or random. We combined 1, 2, 3 and 4 and found 291 references. Of these, 76 randomized trials from 60 references met the inclusion criteria. From the reference lists of these articles and from 4 previous meta-analyses (Grobbee 1986, Law 1991, Cutler 1991, Midgley 1996) additional 23 references reporting on 39 trials were identified, resulting in a total of 83 references.

Similar searches were made for hormones and lipids changing the third search term (blood pressure or hypertension) with the hormone or lipid term resulting in additional 5 sub-studies dealing with hormones and lipids (1086 P Jula 1992, 1087 P Jula 1992(2), 1025 Koolen 1984, 1104 Overlack 1993, Ruppert 1994). Of these 88 references, three dealing exclusively with diabetes patients were excluded in the 2003 update (Dodson 1989, Mühlhauser I 1996, Miller JA 1997).

In January 2002 a repeated search was performed through December 2001, revealing additional 12 references, of which one was excluded because it only included patients with diabetes (Imanishi M 2001). Accordingly, the 2003 updated review included a total of 96 references.

In December 2009 a literature search for the present update was performed from 1950 through December 2009. This search revealed a total of 511 references in PUBMED, 282 in EMBASE and 1428 in CENTRAL. Headlines and abstracts were read and 44 articles from PUBMED (26 included), 8 from EMBASE (1 included) and 129 from CENTRAL (45 included) were retrieved as full-papers for further review. A total of 72 new references investigating at least one of the effect variables met the inclusion criteria for this review. The search was not limited to English language studies. Two studies in Italian were identified and included. During the present revision we discovered that in a few of the previously included studies some subgroup data were published in two papers. To avoid duplication due to including subgroup data from several papers, we included them from the main paper only. As a result, 3 previously included references were excluded (Steegers 1991, Ruppert 1991, Ruppert 1994). A last search was performed on July 21, 2011, revealing 293 additional references. After screening of titles and abstracts, 4 full papers were retrieved of which 2 contained data to be included.

Consequently a total of 167 studies are included in this updated version of this systematic review.

Data collection and analysis

Selection of studies

See Search methods for identification of studies.

Data extraction and management

Two authors independently recorded the following data from each trial:

  1. the sample size (N);

  2. the mean age of participants;

  3. the fraction of females, males; Caucasians, Blacks and Asians;

  4. the duration of the intervention;

  5. the sodium reduction measured as the difference between 24-h urinary sodium excretion during low -sodium and high - sodium diets and standard deviation (SD);

  6. SBP (SD) and DBP (SD) before and after intervention;

  7. difference between changes in SBP and DBP obtained during low-sodium and high sodium diets and the SD of these differences;

  8. for cross-over studies, when possible, the overall effect estimate and SE;

  9. levels of hormones and lipids in the blood and their standard deviations during low-sodium and high-sodium diets. Concerning lipids, cholesterol units of mmol/l were transformed to mg/dl by means of the factor 38.6 and triglyceride units of mmol/l were transformed to mg/dl by means of the factor 88.4.

If there were discrepancies between reviewers they looked at the data together and came to an agreement.

Assessment of risk of bias in included studies

This was performed using the Cochrane Risk of bias tool, including recording of allocation, blinding, incomplete outcome data and selective reporting.

Measures of treatment effect

This was defined as the mean difference (MD) between the changes from baseline to end of treatment during a low and a high sodium diet. When units within an analysis were different the standardized mean difference (SMD) was used.

Unit of analysis issues

Blood pressure: 

Combined analyses were performed including both parallel and cross-over studies. The generic inverse variance data type was used to analyse the effect in order to ensure that the weight of the cross-over studies was not underestimated compared with the parallel studies. For parallel studies SE was calculated in the usual way as follows: SE (diff) = sqrt SE1 2 + SE2 2. For cross-over studies the given SE (difference) was used. A linear regression equation linking the given SE to the calculated SE (sqrt SE1 2 + SE2 2) was calculated by means of the studies which reported both SE (difference) and SE on blood pressure during both intervention periods. This equation was used to transform all calculated SEs to estimated “true” SEs (difference) in cross-over studies that did not report SE (difference). In this way it was ensured that cross-over studies were attributed proper weight compared with the parallel studies. There were not enough studies to calculate separate equations for Blacks and Asians and therefore the equations calculated in the white populations were used to transform these SEs when necessary.

Hormones and lipids:

The very few parallel studies were excluded and the large fraction of cross-over studies were analysed separately. As the large majority of cross-over studies reported separate data for each intervention period instead of overall estimates of effect, the continuous data type was used in the separate analyses of the cross-over studies.

Dealing with missing data

If SD was not reported it was calculated from a given SE, 95% confidence interval, p-value or t-value, estimated from a figure or imputed from the formula SD (change) = sq root (SD1sq + SD2sq), SD1 is SD on blood pressure before intervention and SD2 is SD on blood pressure after intervention.

Assessment of heterogeneity

A chi-squared test included in the forest plot was used to assess whether observed differences in results are compatible with chance alone. A low P value (or a large chi-squared statistic relative to its degree of freedom) provides evidence of heterogeneity of intervention effects (variation in effect estimates beyond chance).

Assessment of reporting biases

Funnel plots were assessed for asymmetry.

Data synthesis

The weighted mean difference (WMD) was calculated for outcome measures with identical units in the included studies (BP, adrenaline, and lipids, after transformation). The standardized mean difference (SMD) was calculated for outcome measures with different units (renin, aldosterone, and noradrenaline). With this method, the difference in effect between two treatments is divided by the standard deviation of the measurements. By that transformation the effect measures become dimensionless and the outcomes from trials, which have used different units, can consequently be combined. If p was less than 0.05 in the test for heterogeneity, a random effect analysis was carried out. In the homogeneous meta-analyses the fixed effect model was used.

Level of significance: In case of multiple independent comparisons it is important to avoid coincidental significance. Twenty meta-analyses were performed. However, the blood pressure comparisons are not independent of each other and the blood pressure depends on renin and aldosterone as well as catecholamines. Concerning lipids these are mutually dependent, whereas the dependency on blood pressure and hormones is not obvious. Consequently the 20 meta-analyses could be sub-classified into a group of meta-analyses of mutually dependent blood pressures and hormones and an independent group of meta-analyses of mutually dependent lipid fractions. Consequently, the level of significance was reduced by means of the formula 1-0.951/N = 1-0.951/2 = 0.025, (N = number of independent investigations = 2).

Subgroup analysis and investigation of heterogeneity

All analyses: subgroup analyses were performed for studies with a duration of 2 weeks or more (hormones and lipids) and 4 weeks or more (all).

Lipids: subgroup analyses were performed for studies reducing sodium chloride intake to moderate levels (45 mmol or more).

Sources of bias: subgroup analyses were performed for contrasting sources of bias appearing from the risk of bias analysis.

Sensitivity analysis

Sensitivity analyses were performed excluding studies giving rise to asymmetry in the funnel plots.

Results

Description of studies

See: Characteristics of included studies; Characteristics of excluded studies.

Results of the search

See Search methods for identification of studies.

Included studies

See Characteristics of included studies.

167 references were included in the review. When results were reported by subgroup, the subgroup results were used. In the studies of persons with elevated BP the median of the mean ages was 51 years (range 23-73); the median duration was 28 days (4-365). The mean of the mean 24-hour sodium excretions in the high salt intake groups was 196 mmol and in the low salt intake groups was 71 mmol, corresponding to a mean sodium reduction of 125 mmol, and the median of mean sodium reductions was 94 mmol/24 hours (10-90 percentiles: 46-236). In the studies of persons with normal BP, the median of mean ages was 27 years (range 13-67); the median duration was 7 days (4-1100). The mean of the mean 24-hour sodium excretions in the high salt intake groups was 201 mmol and in the low salt intake groups was 50 mmol, corresponding to a mean sodium reduction of 150 mmol, and the median of mean sodium reductions was 146 mmol/24 hours (10-90 percentiles: 56-246). In 100 studies including 7005 participants there was information of the baseline 24 hour sodium excretion, not influenced by diets. This was 157 mmol (10-90 percentiles: 125-192).

Excluded studies

See Characteristics of excluded studies.

Risk of bias in included studies

See Characteristics of included studies and additional Table 1.

Table 1. Risk of Bias
  1. SG: Sequence generation; AC: Allocation concealment; B: Blinding; P: Performance; D: Detection; IOD: Incomplete outcome data; SR: Selective reporting; HR: High risk; LR: Low risk; UR: Unclear risk.

 SGACB (P+D)IODSRB (P)B (D)
HR2210514310763
LR396011915660103
UR162156234801
Total167167167167167167167

The obligatory trial quality criterion was randomization. Double blind, single blind or open studies with a parallel or a cross-over design were accepted. A study was defined as single blind if an investigator measured BP without knowledge of the diet or by a computerized manometer and as open if precautions to decrease observer bias were not mentioned. Only 10 studies (1034 SE Watt 1985, 1078 MBP SE Egan 1991, 1081 P TOHP I 1992, 1135 P TOHP II 1997, 1197 Dickinson 2009, 1198 SE He 2009, 1195 SE Jessani 2008, 1142 P Knuist 1998, 1107 SE MacFadyen 1994, 1136 P van Buul 1997) sufficiently explained the allocation concealment and only two studies use the intention to treat principle (1081 P TOHP I 1992; 1135 P TOHP II 1997).

We found two important contrasts: General blinding and blinding of outcome detection (additional Table 1). We performed sub-analyses of blood pressures in Whites, both normotensive and hypertensive populations, but not in Blacks and Asians due to the small numbers of trials. We did not perform sub-analyses on the biochemical outcomes (hormones and lipids) as they are supposed to be performed blindly in 100% of cases. The results of the sub-analyses are shown in the following section.

Effects of interventions

See Data and analyses.

Blood pressure in Whites

In the meta-analyses of 62 trials (71 comparisons) of Caucasians with normal BP, the mean weighted difference (WMD) was a change in SBP of -1.27 [95% CI: -1.88, -0.66] mmHg (p = 0.0001) and in DBP of -0.05 [95% CI: -0.51, 0.42] mmHg (p = 0.85) (Figure 1 Figure 2). In sub meta-analyses of 16 trials (19 comparisons) with duration of at least 4 weeks, the WMD was a decrease in SBP of -1.29 [-1.96, -0.62] mmHg (p = 0.0002) and in DBP of -0.45 [95% CI: -0.90, 0.00] mmHg (p = 0.05).

Figure 1.

Forest plot of comparison: 1 Effect of salt reduction on systolic bloodpressure (SBP) and diastolic blood pressure (DBP) in whites, outcome: 1.2 Whites, normotensive, SBP.

Figure 2.

Forest plot of comparison: 1 Effect of salt reduction on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in whites, outcome: 1.1 Whites, normotensive, DBP.

In a meta-analyses of 28 normotensive trials (31 comparisons) in which MBP was measured, the mean weighted difference (WMD) of MBP was 0.00 [95% CI: -0.34, 0.33] mmHg (p = 0.99). In 13 trials (14 comparisons) in which only MBP was measured, the change was +1.01 [95% CI: 0.39, 1.63] mmHg (p = 0.001).

In the 74 trials (76 comparisons) of Caucasians with elevated BP, WMD was a decrease in SBP of -5.48 [95% CI: -6.53, -4.43] mmHg (p < 0.00001) and in DBP of -2.75 [ 95% CI: -3.34, -2.17] mmHg (p < 0.00001) (Figure 3; Figure 4). In sub meta-analyses of 47 trials (49 comparisons) with duration of at least 4 weeks, WMD was a decrease in SBP of -5.18 [-6.43, -3.94] mmHg (p = 0.0001) and in DBP of -2.59 [95% CI: -3.32, -1.85] mmHg (p = 0.00001).

In a meta-analyses of 21 hypertensive trials (23 comparisons) in which MBP was measured, the mean weighted difference (WMD) of MBP was -3.56 [95% CI:-4.07, -3.06] mmHg (p = 0.00001). In 5 trials (7 comparisons) in which only MBP was measured, the change was -2.03 [95% CI:-3.00, -1.06] mmHg (p = 0.0001).

Blood pressure in Blacks

In the meta-analyses of 6 trials (7 comparisons) of blacks with normal BP, WMD was a decrease in SBP of -4.02 [95% CI:-7.37, -0.68] mmHg (p = 0.02) and in DBP of -2.01 [95% CI:-4.37, 0.35] mmHg (p = 0.09).

In the meta-analyses of 8 trials (9 comparisons) of blacks with elevated BP, WMD was a decrease in SBP of -6.44 [95% CI:-8.85, -4.03] mmHg (p = 0.00001) and in DBP of -2.40 [95% CI:-4.68, -0.12] mmHg (p = 0.04).

Blood pressure in Asians

In the meta-analyses of 3 trials (3 comparisons) of Asians with normal BP, WMD was a decrease in SBP of -1.27 [95% CI: -3.07, 0.54] mmHg (p = 0.17) and in DBP of -1.68 [95% CI:-3.29, -0.06] mmHg (p = 0.04).

In the meta-analyses of 7 trials (7 comparisons) of Asians with elevated BP, WMD was a decrease in SBP of -10.21 [95% CI:-16.98, -3.44] mmHg (p = 0.003) and in DBP of-2.60 [95% CI: -4.03, -1.16] mmHg (p = 0.0004).

Renin

Two parallel trials were excluded (1087 P Jula 1992(2), 1155 P Heer 2000).

In the remaining 70 cross-over trials of measurement of renin (81 comparisons), the standardized mean difference (SMD) of sodium reduction was 1.15 [95% CI: 0.99, 1.30] (Z= 14.81, p<0.00001) (Figure 3). In comparisons with a duration of at least 2 weeks (n = 29) the SMD was 0.67 [95% CI 0.53, 0.82], p = 0.00001 and in comparisons with a duration of at least 4 weeks (n = 14) the SMD was 0.47 [95% CI: 0.35, 0.60], p = 0.00001.

Figure 3.

Forest plot of comparison: 6 Effect of salt reduction on hormones, outcome: 6.1 Renin.

Aldosterone

Three parallel trials were excluded (1087 P Jula 1992(2), 1111 P Howe 1994, 1155 P Heer 2000).

In the remaining 51 cross-over trials of measurement of aldosterone (59 comparisons), SMD was 1.36 [95% CI: 1.15, 1.57] (Z = 12.79, p<0.00001) (Figure 4). In comparisons with a duration of at least 2 weeks (n = 20), SMD was 0.99 [95% CI: 0.70, 1.28], p = 0.00001 and in comparisons with a duration of at least 4 weeks (n = 9), SMD was 0.70 [95% CI: 0.37, 1.04], p = 0.0001.

Figure 4.

Forest plot of comparison: 6 Effect of salt reduction on hormones, outcome: 6.2 Aldosterone.

Noradrenaline

One parallel trial was excluded (1086 P Jula 1992).

In the remaining 31 cross-over trials of measurement of noradrenaline (39 comparisons), SMD was 0.52 [95% CI: 0.37, 0.67], (z = 6.67, p = 0.00001) (Analysis 6.4). In comparisons with a duration of at least 2 weeks (n = 12) the SMD was 0.17 [95% CI: 0.00, 0.33], p = 0.04 and in comparisons with a duration of at least 4 weeks (n = 6) the SMD was 0.06 [95% CI: -0.19, 0.32], p = 0.62.

Adrenaline

One parallel trial was excluded (1086 P Jula 1992).

In the remaining 14 cross-over trials of measurement of adrenaline (16 comparisons), SMD was 0.30 [95% CI: 0.13, 0.46], (z = 3.58, p = 0.0003) (Analysis 6.3). In comparisons with a duration of at least 2 weeks (n = 8) the SMD was 0.21 [95% CI: -0.00, 0.43], p = 0.05 and in comparisons with a duration of at least 4 weeks (n = 5) the SMD was 0.24 [95% CI: -0.04, 0.52], p = 0.10.

Cholesterol

Three parallel trials were excluded (1015 P Bulpitt 1983, 1085 P Sciarrone 1992, 1199 P Meland 2009).

In the remaining 24 cross-over trials of measurement of cholesterol (25 comparisons), WMD was an increase of 5.76 mg/dl [95% CI: 2.29, 9.24], p = 0.001 (Figure 5). In comparisons with a duration of at least 2 weeks (n = 13) WMD was 2.48 mg/dl [95% CI: -2.18, 7.14], p = 0.30 and in comparisons with a duration of at least 4 weeks (n = 9), WMD was 3.21 mg/dl [95% CI: -2.51, 8.93], p = 0.27.

Figure 5.

Forest plot of comparison: 8 Effect of salt reduction on lipids, outcome: 8.1 Cholesterol.

LDL

One parallel trial was excluded (1085 P Sciarrone 1992).

In the remaining 15 cross-over trials of measurement of LDL (16 comparisons), WMD was a non-significant increase of 2.88 mg/dl [95% CI: -1.03, 6.79], p = 0.15 (Analysis 8.4). In comparisons with a duration of at least 2 weeks (n = 8), WMD was 2.45 mg/dl [95% CI: -3.15, 8.06], p = 0.39 and in comparisons with a duration of at least 4 weeks (n = 6), WMD was 3.72 mg/dl [95% CI: -2.67, 10.11], p = 0.25.

HDL

Two parallel trials were excluded (1085 P Sciarrone 1992, 1199 P Meland 2009).

In the remaining 17 cross-over trials of measurement of HDL (18 comparisons), there was no effect of sodium reduction on serum HDL: WMD:  0.09 mg/dl [95% CI: -1.44, 1.62] p = 0.91 (Analysis 8.3). This result did not change in comparisons with duration of at least 2 weeks (-0.61 mg/dl [-2.70, 1.47] (n=10)) or at least 4 weeks (-0.14 mg/dl [-2.58, 2.30] (n = 8)).

Triglyceride

Two parallel trials were excluded (1085 P Sciarrone 1992, 1199 P Meland 2009) .

In the remaining 18 cross-over trials of measurement of triglyceride (19 comparisons), WMD was an increase of 6.78 mg/dl [95% CI: 2.81, 10.75], p = 0.0008 (Figure 6). In comparisons with a duration of at least 2 weeks (n = 11) the effect was 7.78 mg/dl [95% CI: 2.23, 13.34], p = 0.006 and in comparisons with a duration of at least 4 weeks (n = 7) the effect was 8.37 mg/dl [95% CI: -1.43, 18.18], p = 0.09.

Figure 6.

Forest plot of comparison: 8 Effect of salt reduction on lipids, outcome: 8.2 Trigyceride.

Subanalyses

Blood pressure

Significance of general blinding and blinding of outcome detection for blood pressure outcomes in white normotensives and hypertensives, low bias risk versus high bias risk: details reported in "Data and analyses: 11 Bias analyses".

Hormones and lipids

Inclusion of the few parallel studies did not change any of the results (data not shown).

Cholesterol

The mean increase in se-cholesterol during sodium reduction to a moderate level (median 81mmol/24 hours, range 47-132) in 15 studies was 3.86 [95% CI: -0.74, 8.46] (p=0.10).

Triglyceride

The mean increase in se-triglyceride during sodium reduction to a moderate level (median 81mmol/24 hours, range 47-132) in 12 studies was 8.03 [95% CI: 2.06, 14.01] (p=0.0008).

HDL and LDL

No significant differences were detected during sodium reduction to moderate levels.

Sensitivity analyses

The funnel plots of all analyses were investigated. For each funnel plot all studies giving rise to asymmetry were eliminated. The resulting effect was compared with the original analysis. All these analyses showed only marginal effects without significance (not shown).

Discussion

The intake of sodium in the low sodium group was above 150 mmol in six studies, between 120 and 150 mmol in 3 studies and below 120 mmol in all other studies. Consequently, this meta-analysis in general compares the effects of a dietary sodium intake which is lower than normal (120 mmol) with a sodium intake which is either normal or above normal (150 mmol). The mean and the range of the baseline 24 hour sodium excretion of the included populations before diet manipulation (157 mmol/24(10-90 percentile: 125-192)) hours was within the range, which recently has been hypothesized to be physiologically determined (McCarron 2009, McCarron 2010). This sodium reduction from a generally normal to a subnormal level resulted in a 1% decrease in systolic blood pressure in normotensives a 3.5% decrease in hypertensives, a significant increase in plasma renin, plasma aldosterone, plasma adrenaline and plasma noradrenaline, a 2.5% increase in cholesterol and a 7% increase in triglyceride.

Short-term studies have been assumed to reduce the blood pressure effect size to a lesser degree than longer-term studies (He 2002, He 2004). From a statistical point of view this is marginally true for normotensives, as the effect increased from -1.27/-0.05 mmHg to -1.29/-0.45 mmHg, when only studies with duration of 4 weeks or more were included. However, from a clinical point of view this mean difference of about 0.4 mmHg is probably unimportant. In the analysis of hypertensive persons there was no difference between the analysis of all studies versus the analysis of studies with duration of at least 4 weeks (-5.41/-2.68 mmHg vs. -5.03/-2.47 mmHg).

A similar objection has been directed against the possible adverse effects on hormones and lipids. In the previous analysis these effects were not significant in the longer-term studies, of which, however, there were very few. In the present analysis more studies are included and due to the increased statistical power the adverse effects on hormones and lipids are now significant or borderline significant also in the longer-term studies of at least 4 weeks (renin, aldosterone, adrenalin, and triglyceride). The long-term effect of sodium reduction on renin and aldosterone is in accordance with the findings of Oliver et al. in Yanomamo Indians, who ingest extremely small amounts of sodium. They had a 3 times higher level of renin in the blood and a 10 times higher excretion of aldosterone in the urine, than did normal controls (Oliver 1975). Thus, the present meta-analysis provides a possible explanation for the relatively small effect of reduced sodium intake on blood pressure: Compensatory activation of the renin-aldosterone system is proportional to the degree of sodium reduction. Furthermore, the increases in noradrenaline and adrenaline may contribute to this counter-regulation (Warren 1980).

The DASH study (1160 SE DASH 1, 2001) found a significantly higher effect of sodium reduction on blood pressure than the present meta-analysis. However, the majority of persons in this study were non-whites or they suffered from hypertension. In a later publication (1164 SE DASH 2, 2001) sufficient data was given to estimate the effect on DBP in Whites to be 1.4 mm Hg (Jürgens 2002). Considering that the DASH study only includes persons from the upper 50 percentile of normotension, this effect would probably have been smaller, if the whole spectrum of normotension had been investigated like in the meta-analysis. The DASH finding of a higher effect in Blacks prompted us to make a separate analysis on Blacks and Asians. The analysis of Blacks showed that the effect of sodium reduction in normotensive Blacks corresponded to the one found in hypertensive Blacks. This was in contradiction to the analyses of Whites and Asians in whom the effect was smaller in normotensives than in hypertensives. However, compared with previous analyses (Graudal 1998; Jürgens 2004), the diverging results within the black populations and between the black and white populations are smaller. Our cumulative meta-analysis (Graudal 1998) showed that up to 11 studies should be included before the result of the meta-analysis was stable, and in the beginning the effect was higher than the final effect. Consequently, it is probably too early to draw final conclusions about the effect of a low versus high sodium diet in Blacks and Asians. In Whites the results are still similar to the results from 1983 (Graudal 1998).

The blood pressure analyses were in general heterogeneous due to very big differences in the effect sizes. The heterogeneity of the hormone meta-analyses could in part be ascribed to the use of different units. No heterogeneity was detected in the lipid meta-analyses in which identical units were used in the included studies. Concerning sources of bias there was a general trend towards smaller effects in the low risk blinded groups than in the high risk open groups. These differences were, however, small and insignificant. Elimination of studies giving rise to asymmetry in the funnel plots did not change the results.

Previous meta-analyses of RCTs with other selection criteria have shown similar results of sodium reduction on blood pressure. In 1986, Grobbee and Hofman combined 13 studies of persons with normal and elevated BP in a meta-analysis and found a significant hypotensive effect of reduced sodium intake on SBP of -3.6 mmHg and a non-significant effect on DBP of -2.0 mmHg (Grobbee 1986). In 1991, a second meta-analysis of 24 RCTs showed an effect of -4.0/-2.5 mmHg for persons with elevated BP and -1.0/-0.2 for persons with normal BP (Cutler 1991). This was verified in an update from 1997 (Cutler 1997). In 1996, a meta-analysis of 53 RCTs showed an effect of -3.7/-0.9 mmHg in persons with elevated BP and -1.0/-0.1 in persons with normal BP (Midgley 1996). In a meta-analysis including 26 RCTs with a sodium reduction of at least 40 mmol lasting for more than 4 weeks, the effect was -4.2/-2.4 mmHg in persons with elevated BP and -1.6/-0.6 mmHg in persons with normal BP (He 2002). In an analysis of 8 RCTs lasting for at least 6 months the effect was -2.9/-2.1 mmHg for persons with elevated BP and -1.3/- 0.8 mmHg for persons with normal BP (Ebrahim 1998). These results were confirmed in an update (Hooper 2002) and a Cochrane Review (Taylor 2011,). All these results are very similar to the results of the present meta-analysis. Consequently, they confirm that selection of RCTs based on magnitude of sodium difference or duration of the intervention does not significantly change the overall effect size estimate.

As these almost identical meta-analyses have been performed by sceptics as well as by sodium reduction supporters, major disagreements about this effect size no longer seem to exist. However, there is still significant disagreement regarding the relevance of the effect size, and the political salt conflict (Taubes 1998) is still going strong. Two recent papers exemplify this (Strazzulo 2009, Aldermann 2010). In the meta-analysis of population studies by Strazzulo et al., a statistically significant 20% increased risk of cerebrovascular death was found in persons with a high salt intake compared with a low salt intake. However, in a response letter to a critical comment (Cohen 2010) Strazzulo et al. accepted that the statistical significance depended on the inclusion of incomplete data from one of the population studies. Another review of the same studies comes to the conclusion that low salt intake in population studies is not associated with an improved morbidity or mortality (Aldermann 2010). This has recently been verified in a population study, which showed an inverse relationship between sodium intake and cardiovascular mortality (Stolarz-Skrzypek 2011). Furthermore, the meta-analysis by Strazzulo et al. included two Asian population studies, in which the sodium intake in the high intake group was much higher than usually seen in Caucasians. If only American and European population studies had been included, there would be no difference between the high salt intake and low salt intake groups concerning strokes and other cardiovascular disease.

In a recent paper based on computer simulations of assumptions on associations between salt intake and blood pressure, and between blood pressure and mortality, it was concluded that a daily teaspoonful of salt (3g) was a bigger health risk than cigarette smoking (Bibbins-Domingo 2010). The sense of this conclusion can be judged by estimating the lack of accordance of these simulated projected effects with the above-mentioned observed effects in populations. The reason for this lack of accordance is probably that the authors overestimated the assumed linear relationship between salt intake and blood pressure and ignored the possibility that salt reduction may induce adverse effects. The present meta-analysis indicates that the adverse effect on lipids, especially triglyceride, is not just an acute effect as previously assumed (He 2002), but may be persistent also in longer-term studies. Furthermore, reduced sodium intake seems to harm patients with heart insufficiency and diabetes type 1 and 2. In all three patient groups reduced sodium intake is associated with increased mortality (Paterna 2008, Paterna 2009,Thomas 2011, Ekinci 2011).

The blood pressure effect of reduced sodium intake has been related to age. Freedman and Petitti analysed data from Intersalt (Intersalt 1988) and found the paradox that along with the significant association between increase in blood pressure with age and the salt excretion in urine, there was an inverse relationship between estimated blood pressure and salt excretion in urine at age 20. Freedman stated that unless you preferred to conclude that salt should be eaten in high doses by youngsters and in reduced amounts by the elderly, the findings were probably due to uncontrolled confounding, not to variation in salt intake (Freedman 2001). Furthermore, it is not clear whether the blood pressure of different age cohorts in a cross-sectional study like Intersalt is representative of each other, and therefore the age/blood pressure relationship may not be verified in a longitudinal study (Graudal 2000). This position is confirmed by a study showing that recent birth cohorts attained lower blood pressure than did earlier birth cohorts in the period 1887-1994 (Goff 2001). According to this study based on data from more than 50,000 persons, it can be estimated that the median blood pressure is about 15 mmHg lower in a 50 year old person from a recent birth cohort compared with a birth cohort from the late 19th century. Consequently there has been a dramatic fall in blood pressure during the 20th century. In this context the possible effect of sodium reduction of less than 1 mmHg in normotensive persons calls for reflection (Folkow 2011). Finally, it has been very difficult to maintain a significant sodium reduction in longer-term studies which should be taken into consideration when recommending sodium reduction. One reason for this could be that the sodium intake may be regulated by physiological mechanisms (McCarron 2009).

Authors' conclusions

Implications for practice

The present meta-analysis shows that low versus high sodium diet in Caucasians with normal BP decreases BP less than 1%. A significant concomitant and persistent increase in plasma renin, plasma aldosterone and to a lesser degree of plasma adrenaline and plasma noradrenaline may contribute to the small effect of sodium reduction on blood pressure. Furthermore, sodium reduction resulted in a significant increase in plasma cholesterol and plasma triglyceride, which expressed in percentage, was numerically larger than the decrease in blood pressure. The increase in triglyceride was numerically unchanged in studies with a duration of at least 2 weeks and in studies with sodium reduction to moderate levels of sodium intake. Due to the relatively small effects and due to the antagonistic nature of the effects (decrease in blood pressure, increase in hormones and lipids), these results do not support that sodium reduction may have net beneficial effects in a population of  Caucasians.

In Caucasians with elevated BP, short-term sodium reduction decreases BP by about 2-2.5%, indicating that sodium reduction may be used as a supplementary treatment for hypertension. In Asians and Blacks the effect of sodium reduction was greater, but at present too few studies have been carried out to conclude different from that above.

Implications for research

Trials are needed to determine the effects on BP and other parameters of long-term reductions in sodium intake. The data suggesting that Blacks and Asians are more sensitive to sodium reduction than Caucasians requires further studies. In future studies of mixed populations, it is important that the effects on Caucasians, Blacks, and Asians are reported separately. Long-term RCTs with mortality and morbidity outcomes would be desirable to determine whether the benefits of sodium reduction outweigh the harms. However, such studies may not be practicable and instead well-designed prospective population studies could be an alternative. After more than 150 RCTs and 13 population studies without an obvious signal in favour of sodium reduction, another position could be to accept that such a signal may not exist.

Acknowledgements

Jacob Riis, Rasmus Moustgaard and Dr Peter C Gøtzsche, The Nordic Cochrane Center, are kindly thanked for assistance during the elaboration of the original review. Doug Salzwedel, The Cochrane Hypertension Review Group, is kindly thanked for his assistance in designing and running a complete literature search during the update of this review. Doris Christiansen and Johanne Worm are kindly thanked for their assistance in the acquisition of literature.

Data and analyses

Download statistical data

Comparison 1. Effect of salt reduction on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in whites
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Whites, normotensive, DBP717299Mean Difference (Random, 95% CI)-0.05 [-0.51, 0.42]
2 Whites, normotensive, SBP707035Mean Difference (Random, 95% CI)-1.27 [-1.88, -0.66]
3 Whites, hypertensive, DBP764903Mean Difference (Random, 95% CI)-2.75 [-3.34, -2.17]
4 Whites, hypertensive, SBP744879Mean Difference (Random, 95% CI)-5.48 [-6.53, -4.43]
Analysis 1.1.

Comparison 1 Effect of salt reduction on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in whites, Outcome 1 Whites, normotensive, DBP.

Analysis 1.2.

Comparison 1 Effect of salt reduction on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in whites, Outcome 2 Whites, normotensive, SBP.

Analysis 1.3.

Comparison 1 Effect of salt reduction on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in whites, Outcome 3 Whites, hypertensive, DBP.

Analysis 1.4.

Comparison 1 Effect of salt reduction on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in whites, Outcome 4 Whites, hypertensive, SBP.

Comparison 2. Effect of salt reduction on mean blood pressure (MBP) in whites.
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Whites, normotensive, MBP311790Mean Difference (Fixed, 95% CI)-0.00 [-0.34, 0.33]
2 Whites, hypertensive, MBP231511Mean Difference (Fixed, 95% CI)-3.56 [-4.07, -3.06]
Analysis 2.1.

Comparison 2 Effect of salt reduction on mean blood pressure (MBP) in whites., Outcome 1 Whites, normotensive, MBP.

Analysis 2.2.

Comparison 2 Effect of salt reduction on mean blood pressure (MBP) in whites., Outcome 2 Whites, hypertensive, MBP.

Comparison 3. Effect of salt reduction on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in whites, study duration at least 4 weeks
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Whites, normotensive, DBP204047Mean Difference (Random, 95% CI)-0.45 [-0.90, 0.00]
2 Whites, normotensive, SBP193753Mean Difference (Random, 95% CI)-1.29 [-1.96, -0.62]
3 Whites, hypertensive, DBP493748Mean Difference (Random, 95% CI)-2.59 [-3.32, -1.85]
4 Whites, hypertensive, SBP463543Mean Difference (Random, 95% CI)-5.18 [-6.43, -3.94]
Analysis 3.1.

Comparison 3 Effect of salt reduction on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in whites, study duration at least 4 weeks, Outcome 1 Whites, normotensive, DBP.

Analysis 3.2.

Comparison 3 Effect of salt reduction on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in whites, study duration at least 4 weeks, Outcome 2 Whites, normotensive, SBP.

Analysis 3.3.

Comparison 3 Effect of salt reduction on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in whites, study duration at least 4 weeks, Outcome 3 Whites, hypertensive, DBP.

Analysis 3.4.

Comparison 3 Effect of salt reduction on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in whites, study duration at least 4 weeks, Outcome 4 Whites, hypertensive, SBP.

Comparison 4. Effect of salt reduction on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in Asians
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Asians, normotensive, DBP3393Mean Difference (Fixed, 95% CI)-1.68 [-3.29, -0.06]
2 Asians, normotensive, SBP3393Mean Difference (Fixed, 95% CI)-1.27 [-3.07, 0.54]
3 Asians, hypertensive, DBP7477Mean Difference (Random, 95% CI)-2.60 [-4.03, -1.16]
4 Asians, hypertensive, SBP8477Mean Difference (Random, 95% CI)-10.21 [-16.98, -3.44]
Analysis 4.1.

Comparison 4 Effect of salt reduction on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in Asians, Outcome 1 Asians, normotensive, DBP.

Analysis 4.2.

Comparison 4 Effect of salt reduction on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in Asians, Outcome 2 Asians, normotensive, SBP.

Analysis 4.3.

Comparison 4 Effect of salt reduction on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in Asians, Outcome 3 Asians, hypertensive, DBP.

Analysis 4.4.

Comparison 4 Effect of salt reduction on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in Asians, Outcome 4 Asians, hypertensive, SBP.

Comparison 5. Effect of salt reduction on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in Blacks
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Blacks, normotensive, DBP7506Mean Difference (Random, 95% CI)-2.01 [-4.37, 0.35]
2 Blacks, normotensive, SBP7506Mean Difference (Random, 95% CI)-4.02 [-7.37, -0.68]
3 Blacks, hypertensive, DBP9674Mean Difference (Random, 95% CI)-2.40 [-4.68, -0.12]
4 Blacks, hypertensive, SBP9674Mean Difference (Random, 95% CI)-6.44 [-8.85, -4.03]
Analysis 5.1.

Comparison 5 Effect of salt reduction on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in Blacks, Outcome 1 Blacks, normotensive, DBP.

Analysis 5.2.

Comparison 5 Effect of salt reduction on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in Blacks, Outcome 2 Blacks, normotensive, SBP.

Analysis 5.3.

Comparison 5 Effect of salt reduction on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in Blacks, Outcome 3 Blacks, hypertensive, DBP.

Analysis 5.4.

Comparison 5 Effect of salt reduction on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in Blacks, Outcome 4 Blacks, hypertensive, SBP.

Comparison 6. Effect of salt reduction on hormones
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Renin814078Std. Mean Difference (IV, Random, 95% CI)1.15 [0.99, 1.30]
2 Aldosterone593348Std. Mean Difference (IV, Random, 95% CI)1.36 [1.15, 1.57]
3 Adrenaline16608Std. Mean Difference (IV, Fixed, 95% CI)0.30 [0.13, 0.46]
4 Noradrenaline391570Std. Mean Difference (IV, Random, 95% CI)0.52 [0.37, 0.67]
Analysis 6.1.

Comparison 6 Effect of salt reduction on hormones, Outcome 1 Renin.

Analysis 6.2.

Comparison 6 Effect of salt reduction on hormones, Outcome 2 Aldosterone.

Analysis 6.3.

Comparison 6 Effect of salt reduction on hormones, Outcome 3 Adrenaline.

Analysis 6.4.

Comparison 6 Effect of salt reduction on hormones, Outcome 4 Noradrenaline.

Comparison 7. Effect of salt reduction on hormones, study duration at least two weeks
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Renin291650Std. Mean Difference (IV, Random, 95% CI)0.67 [0.53, 0.82]
2 Aldosterone201170Std. Mean Difference (IV, Random, 95% CI)0.99 [0.70, 1.28]
3 Adrenaline8338Std. Mean Difference (IV, Fixed, 95% CI)0.21 [-0.00, 0.43]
4 Noradrenaline12576Std. Mean Difference (IV, Random, 95% CI)0.17 [0.00, 0.33]
Analysis 7.1.

Comparison 7 Effect of salt reduction on hormones, study duration at least two weeks, Outcome 1 Renin.

Analysis 7.2.

Comparison 7 Effect of salt reduction on hormones, study duration at least two weeks, Outcome 2 Aldosterone.

Analysis 7.3.

Comparison 7 Effect of salt reduction on hormones, study duration at least two weeks, Outcome 3 Adrenaline.

Analysis 7.4.

Comparison 7 Effect of salt reduction on hormones, study duration at least two weeks, Outcome 4 Noradrenaline.

Comparison 8. Effect of salt reduction on lipids
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Cholesterol251546Mean Difference (IV, Fixed, 95% CI)5.76 [2.29, 9.24]
2 Trigyceride191334Mean Difference (IV, Fixed, 95% CI)6.78 [2.81, 10.75]
3 High density lipoprotein, HDL171210Mean Difference (IV, Fixed, 95% CI)0.09 [-1.44, 1.62]
4 Low density lipoprotein, LDL161172Mean Difference (IV, Fixed, 95% CI)2.88 [-1.03, 6.79]
Analysis 8.1.

Comparison 8 Effect of salt reduction on lipids, Outcome 1 Cholesterol.

Analysis 8.2.

Comparison 8 Effect of salt reduction on lipids, Outcome 2 Trigyceride.

Analysis 8.3.

Comparison 8 Effect of salt reduction on lipids, Outcome 3 High density lipoprotein, HDL.

Analysis 8.4.

Comparison 8 Effect of salt reduction on lipids, Outcome 4 Low density lipoprotein, LDL.

Comparison 9. Effect of salt reduction on lipids, study duration at least two weeks
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Cholesterol13848Mean Difference (IV, Fixed, 95% CI)2.48 [-2.18, 7.14]
2 Trigyceride11732Mean Difference (IV, Fixed, 95% CI)7.78 [2.23, 13.34]
3 High density lipoprotein, HDL11684Mean Difference (IV, Fixed, 95% CI)-0.61 [-2.70, 1.47]
4 Low density lipoprotein, LDL8546Mean Difference (IV, Fixed, 95% CI)2.45 [-3.15, 8.06]
Analysis 9.1.

Comparison 9 Effect of salt reduction on lipids, study duration at least two weeks, Outcome 1 Cholesterol.

Analysis 9.2.

Comparison 9 Effect of salt reduction on lipids, study duration at least two weeks, Outcome 2 Trigyceride.

Analysis 9.3.

Comparison 9 Effect of salt reduction on lipids, study duration at least two weeks, Outcome 3 High density lipoprotein, HDL.

Analysis 9.4.

Comparison 9 Effect of salt reduction on lipids, study duration at least two weeks, Outcome 4 Low density lipoprotein, LDL.

Comparison 10. Effect of moderate salt reduction on lipids
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Cholesterol15820Mean Difference (IV, Fixed, 95% CI)3.86 [-0.74, 8.46]
2 Trigyceride12688Mean Difference (IV, Fixed, 95% CI)8.03 [2.06, 14.01]
3 High density lipoprotein, HDL11660Mean Difference (IV, Fixed, 95% CI)-0.40 [-2.22, 1.42]
4 Low density lipoprotein, LDL9568Mean Difference (IV, Fixed, 95% CI)0.04 [-4.96, 5.04]
Analysis 10.1.

Comparison 10 Effect of moderate salt reduction on lipids, Outcome 1 Cholesterol.

Analysis 10.2.

Comparison 10 Effect of moderate salt reduction on lipids, Outcome 2 Trigyceride.

Analysis 10.3.

Comparison 10 Effect of moderate salt reduction on lipids, Outcome 3 High density lipoprotein, HDL.

Analysis 10.4.

Comparison 10 Effect of moderate salt reduction on lipids, Outcome 4 Low density lipoprotein, LDL.

Comparison 11. Bias analyses
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Whites, normotensive, DBP perf-detec-high49 Mean Difference (Random, 95% CI)-0.05 [-0.59, 0.49]
2 Whites, normotensive, DBP perf-detec-low21 Mean Difference (Random, 95% CI)-0.03 [-0.99, 0.92]
3 Whites, normotensive, DBP outc-asses-high29 Mean Difference (Random, 95% CI)0.04 [-0.78, 0.86]
4 Whites, normotensive, DBP outc-asses-low414966Mean Difference (Random, 95% CI)-0.11 [-0.68, 0.46]
5 Whites, normotensive, SBP perf-detec-high496012Mean Difference (Fixed, 95% CI)-1.01 [-1.28, -0.74]
6 Whites, normotensive, SBP perf-detec-low201003Mean Difference (Fixed, 95% CI)-1.35 [-1.97, -0.74]
7 Whites, normotensive, SBP outc-asses-high271965Mean Difference (Fixed, 95% CI)-1.32 [-1.79, -0.85]
8 Whites, normotensive, SBP outc-asses-low425050Mean Difference (Fixed, 95% CI)-0.97 [-1.26, -0.67]
9 Whites, hypertensive, DBP perf-detec-high412827Mean Difference (Fixed, 95% CI)-2.56 [-3.05, -2.07]
10 Whites, hypertensive, DBP perf-detec-low331747Mean Difference (Fixed, 95% CI)-2.61 [-3.03, -2.19]
11 Whites, hypertensive, DBP outc-asses-high241805Mean Difference (Fixed, 95% CI)-2.49 [-3.12, -1.87]
12 Whites, hypertensive, DBP outc-asses-low502808Mean Difference (Fixed, 95% CI)-2.62 [-2.99, -2.24]
13 Whites, hypertensive, SBP perf-detec-high392803Mean Difference (Fixed, 95% CI)-4.94 [-5.65, -4.23]
14 Whites, hypertensive, SBP perf-detec-hlow321673Mean Difference (Fixed, 95% CI)-5.80 [-6.43, -5.16]
15 Whites, hypertensive, SBP outc-asses-high241805Mean Difference (Fixed, 95% CI)-5.18 [-6.14, -4.22]
16 Whites, hypertensive, SBP outc-asses-low482784Mean Difference (Fixed, 95% CI)-5.60 [-6.14, -5.06]
Analysis 11.1.

Comparison 11 Bias analyses, Outcome 1 Whites, normotensive, DBP perf-detec-high.

Analysis 11.2.

Comparison 11 Bias analyses, Outcome 2 Whites, normotensive, DBP perf-detec-low.

Analysis 11.3.

Comparison 11 Bias analyses, Outcome 3 Whites, normotensive, DBP outc-asses-high.

Analysis 11.4.

Comparison 11 Bias analyses, Outcome 4 Whites, normotensive, DBP outc-asses-low.

Analysis 11.5.

Comparison 11 Bias analyses, Outcome 5 Whites, normotensive, SBP perf-detec-high.

Analysis 11.6.

Comparison 11 Bias analyses, Outcome 6 Whites, normotensive, SBP perf-detec-low.

Analysis 11.7.

Comparison 11 Bias analyses, Outcome 7 Whites, normotensive, SBP outc-asses-high.

Analysis 11.8.

Comparison 11 Bias analyses, Outcome 8 Whites, normotensive, SBP outc-asses-low.

Analysis 11.9.

Comparison 11 Bias analyses, Outcome 9 Whites, hypertensive, DBP perf-detec-high.

Analysis 11.10.

Comparison 11 Bias analyses, Outcome 10 Whites, hypertensive, DBP perf-detec-low.

Analysis 11.11.

Comparison 11 Bias analyses, Outcome 11 Whites, hypertensive, DBP outc-asses-high.

Analysis 11.12.

Comparison 11 Bias analyses, Outcome 12 Whites, hypertensive, DBP outc-asses-low.

Analysis 11.13.

Comparison 11 Bias analyses, Outcome 13 Whites, hypertensive, SBP perf-detec-high.

Analysis 11.14.

Comparison 11 Bias analyses, Outcome 14 Whites, hypertensive, SBP perf-detec-hlow.

Analysis 11.15.

Comparison 11 Bias analyses, Outcome 15 Whites, hypertensive, SBP outc-asses-high.

Analysis 11.16.

Comparison 11 Bias analyses, Outcome 16 Whites, hypertensive, SBP outc-asses-low.

What's new

Last assessed as up-to-date: 4 October 2011.

DateEventDescription
5 October 2011New citation required and conclusions have changedAdded one new author, re-run searches and included 74 new studies, updated and refined the methodology.
5 October 2011New search has been performed

1) Seventy-four new references were included. Three previously included references with subgroup data were excluded.

2) The analysis on blood pressure in Blacks were stratified in subgroups of normotensives and hypertensives.

3) New analyses of blood pressure in Asians stratified in subgroups of normotensives and hypertensives were added to the previous analyses of Whites and Blacks.

4) Two separate analyses of mean blood pressure (MBP) in Whites with normal blood pressure and with hypertension were performed.

5) Sub analyses of studies with a duration of 4 weeks or more were added.

6) Subanalyses of lipid studies with sodium reduction to moderate levels were added.

7) Two studies of children with a mean age of 13 years were included.

History

Protocol first published: Issue 1, 2003
Review first published: Issue 1, 2003

DateEventDescription
17 November 2002New citation required and conclusions have changedSubstantive amendment

Contributions of authors

Graudal NA: Study design and definition of selection criteria; Data collection and analysis; Formulation of manuscript.

Hubeck-Graudal T: Data collection and analysis; Revision of manuscript.

Jürgens G: Data collection and analysis; Revision of manuscript.

Declarations of interest

None known.
All authors are employed at public institutions. None of the authors has any connection with or receives funds from the food and salt industries or has commercial interests that might bear on this article.

Sources of support

Internal sources

  • No sources of support supplied

External sources

  • The A.P. Møller Foundation for the Advancement of Medical Science , Denmark.

    The A.P.M. foundation is a non-profit funding source, which donated a grant for the pay of Niels Graudal

Characteristics of studies

Characteristics of included studies [ordered by study ID]

1000 P SE Parijs 1973

MethodsOp
CO
ParticipantsN15
Hyp
Age41
InterventionsSR98
Dur28
OutcomesSBP
DBP
NotesLoFo: 5
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)High risk 
Allocation concealment (selection bias)High risk 
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1001 Mark 1975

MethodsOp
CO
ParticipantsN6
Hyp
Age28
InterventionsSR305
Dur10
OutcomesSBP
DBP
Renin
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1002 P Morgan 1978

MethodsS
BP
ParticipantsN62, M/F:62/0
Hyp
Age60
InterventionsSR23
Dur90
OutcomesSBP
DBP
NotesLoFO: 3
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1003 Sullivan 1980

MethodsS
CO
ParticipantsN27
Norm
Age29
InterventionsSR146
Dur4
OutcomesSBP
DBP
Aldo
Renin
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)High risk 
Allocation concealment (selection bias)High risk 
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1004 Sullivan 1980 b

MethodsOp
CO
ParticipantsN19
Hyp
Age27
InterventionsSR153
Dur4
OutcomesSBP
DBP
Aldo
Renin
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)High risk 
Allocation concealment (selection bias)High risk 
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1005 MBP SE Rankin 1981

MethodsOp
CO
ParticipantsN 8 (M/F:8/0)
Normotension
Age 30
InterventionsSR 776 (796-20)
Dur 6
OutcomesMAP, NE
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskSequence generation not described
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High riskOpen study
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High riskOpen study
Blinding of outcome assessment (detection bias)
All outcomes
High riskOpen study

1006 Skrabal 1981

MethodsOp
CO
ParticipantsN20
Norm
Age23
InterventionsSR150
Dur14
OutcomesSBP
DBP
Aldo
Renin
NA
A
NotesLoFo:0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High riskOpen study
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High riskOpen study
Blinding of outcome assessment (detection bias)
All outcomes
High riskOpen study

1007 P Morgan 1981

Methods

SB

P

ParticipantsN12
Hyp
Age38
InterventionsSR67
Dur56
OutcomesDBP
NotesLoFo:0
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskSequence generation not described
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)High risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risknot blinded
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1008 P Morgan 1981b

Methods

SB

P

ParticipantsN12
Hyp
Age40
InterventionsSR92
Dur56
OutcomesDBP
NotesLoFo:0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)High risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1009 Ambrosioni 1982

MethodsSB
CO
ParticipantsN25
Hyp
Age23
InterventionsSR60
Dur 42
OutcomesSBP
DBP
NotesLoFo:1
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskSequence generation not described
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1010 SE Myers 1982

MethodsOp
CO
ParticipantsN136
Norm
Age39
InterventionsSR130
Dur14
OutcomesSBP
DBP
NotesIncluded 182
LoFo: 46
IT: yes (results not shown, but reported to be "similar")
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1011 MacGregor 1982

MethodsDB
CO
ParticipantsN19
Hyp
Age49
InterventionsSR76 Dur28
OutcomesSBP
DBP
Aldo
Renin
NotesLoFo:0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1012 P Beard 1982

MethodsOp
P
ParticipantsN90
Hyp
Age48
InterventionsSR124
Dur 84
OutcomesSBP
DBP
NotesIncluded 113
LoFo:23
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1013 P Puska 1983

MethodsSB
P
ParticipantsN38
Norm
Age40
InterventionsSR90
Dur72
OutcomesSBP
DBP
NotesLoFo: 4
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1014 P Puska 1983 b

MethodsSB
P
ParticipantsN34
Hyp
Age40
InterventionsSR90
Dur72
OutcomesSBP
DBP
NotesLoFo: 4
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1015 P Bulpitt 1983

MethodsOp
P
ParticipantsN 65 (M/F29/36)(B/W/A.0/65/0)
Hypertension
Age 54.6
InterventionsSR 59 (161-102)
Dur 90
OutcomesSBP, DBP, chol
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1016 P Silman 1983

MethodsOp
P
ParticipantsN28
Hyp
Age55
InterventionsSR 63
Dur 90
OutcomesSBP
DBP
NotesLoFo: 5
IT: No
Weighted average of BP effects obtained ar 1,2,3,6 and 12 months.
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1017 Sowers 1983

MethodsOp
CO
ParticipantsN 9 (M/F:9/0)
Normotension
Age 23
InterventionsSR 154 (196-42)
Dur 5
Outcomesrenin, Aldo
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1018 SE Watt 1983

MethodsDB
CO
ParticipantsN18
Hyp
Age52
InterventionsSR 56
Dur 28
OutcomesSBP
DBP
Renin
NotesIncluded 20
LoFo:2
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskrandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1019 SE Cooper 1984

MethodsSB
CO
ParticipantsN59
Norm
Age16
InterventionsSR55
Dur 24
OutcomesSBP
DBP
NotesIncluded 124(1984+1984b)
LoFo: 11
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskB - Unclear
Blinding (performance bias and detection bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1020 SE Cooper 1984 b

MethodsSB
CO
ParticipantsN54
Norm
Age16
InterventionsSR72 Dur 24
OutcomesSBP
DBP
NotesIncluded 124(1984+1984b)
LoFo: 11
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1021 Skrabal 1984

MethodsOp
CO
ParticipantsN30
Norm
Age23
InterventionsSR137
Dur14
OutcomesSBP
DBP
Aldo
Renin
NA
A
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1022 Skrabal 1984 b

MethodsOp
CO
ParticipantsN22
Norm
Age23
InterventionsSR167
Dur14
OutcomesSBP
DBP
Aldo
Renin
NA
A
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 

1023 Gillies 1984

MethodsOp
CO
ParticipantsN 24 (M/F:14/10)(B/W/A.0/24/0)
Hypertension
Age 56.7
InterventionsSR 77 (169-92)
Dur 42
OutcomesSBP, DBP
NotesLoFo:4. 24 of 28 completed the study. IT:No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1024 P Erwteman 1984

MethodsS
BP
ParticipantsN94 (22 blacks)
Hyp
Age46
InterventionsSR58
Dur28
OutcomesSBP
DBP
NotesIncluded 107
LoFo: 13
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1025 Koolen 1984

MethodsOp
CO
ParticipantsN20
Hyp
Age41
InterventionsSR213
Dur14
OutcomesSBP
DBP
Aldo
Renin
NA
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1026 Koolen 1984(2)

MethodsS
CO
ParticipantsN25 Caucasians
Hyp
Age41
InterventionsSR 208
Dur 14
OutcomesNA
NotesLoFo:0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1027 P Fagerberg 1984

MethodsOp
P
ParticipantsN30
Hyp
Age51
InterventionsSR99
Dur63
OutcomesSBP
DBP
NotesIncluded 34
LoFo: 4
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskB - Unclear
Blinding (performance bias and detection bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1028 P Maxwell 1984

MethodsOp
P
ParticipantsN30
Hyp
Age 46
InterventionsSR161
Dur 84
OutcomesSBP
DBP
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1029 Richards 1984

MethodsSB
CO
ParticipantsN12
Hyp
Age36
InterventionsSR100
Dur28
OutcomesSBP
DBP
Aldo
Renin
NA
NotesIncluded 16
LoFo: 4
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1030 Resnick 1985

MethodsOp
CO
ParticipantsN12
Hyp
Age
InterventionsSR190
Dur5
OutcomesSBP
DBP
Renin
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1031 P Tuthill 1985

MethodsDB
P
ParticipantsN 191 (M/F:0/191)
Normotension
Age 17
InterventionsSR 14 (600 mg)
Dur 56
OutcomesSBP, DBP
NotesLoFo: 13. 191 of 204 completed the study. IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1032 SE Skrabal 1985

MethodsSB
CO
ParticipantsN34
Norm
Age23
InterventionsSR144
Dur14
OutcomesSBP
DBP
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1033 SE Skrabal 1985 b

MethodsSB
CO
ParticipantsN28
Norm
Age23
InterventionsSR163
Dur14
OutcomesSBP
DBP
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1034 SE Watt 1985

MethodsDB
CO
ParticipantsN31
Norm
Age23
InterventionsSR60
Dur28
OutcomesSBP
DBP
NotesIncluded 75 (1985+1985b)
LoFo: 9
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Low risk 
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1035 SE Watt 1985 b

MethodsDB
CO
ParticipantsN35
Norm
Age22
InterventionsSR75
Dur28
OutcomesSBP
DBP
NotesIncluded 75 (1985+1985b)
LoFo: 9
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Low risk 
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1036 Richards 1986

MethodsSB
CO
ParticipantsN 8 males
Norm
Age36
InterventionsSR181
Dur4
OutcomesSBP
DBP
Aldo
Renin
NotesLoFo:0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1037 Teow 1986

MethodsOp
CO
ParticipantsN9
Norm
Age25
InterventionsSR 200
Dur 14
OutcomesSBP
DBP
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1038 P Logan 1986

MethodsOp
P
ParticipantsN86
Hyp
Age47
InterventionsSR43
Dur180
OutcomesSBP
DBP
NotesLoFo: ?
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1039 P ANHMRCDS 1986

MethodsSB
P
ParticipantsN100
Hyp
Age53
InterventionsSR70
Dur 84
OutcomesSBP
DBP
NotesIncluded 108
LoFo:8
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1040 El Ashry 1987

MethodsSB
CO
ParticipantsN13
Norm
Age24
InterventionsSR222
Dur14
OutcomesSBP
DBP
Renin
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1041 El Ashry 1987 b

MethodsSB
CO
ParticipantsN13
Norm
Age27
InterventionsSR232
Dur 14
OutcomesSBP
DBP
Renin
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1042 Fuchs 1987

MethodsOp
CO
ParticipantsN6
Norm
Age20
InterventionsSR99
Dur9
OutcomesSBP
DBP
NotesLoFo:0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1043 Fuchs 1987 b

MethodsOp
CO
ParticipantsN11
Norm
Age20
InterventionsSR93
Dur9
OutcomesSBP
DBP
NotesLoFo:0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1044 P Morgan 1987

Methods

SB

P

ParticipantsN20
Hyp
Age58
InterventionsSR57
Dur60
OutcomesSBP
DBP
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1045 SE Kurtz 1987

MethodsDB
CO
ParticipantsN5
Hyp
Age58
InterventionsSR217
Dur7
OutcomesSBP
DBP
NotesIncluded 7
LoFo: 2
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1046 Grobbee 1987

MethodsDB
CO
ParticipantsN40
Hyp
Age24
InterventionsSR72 (129-57)
Dur42
OutcomesSBP
DBP
Renin
NA
A
Chol
NotesIncluded 42
LoFo: 2
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1047 MacGregor 1987

MethodsDB
CO
ParticipantsN15
Hyp
Age52
InterventionsSR100
Dur30
OutcomesSBP
DBP
NotesLoFo:0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1048 Lawton 1988

MethodsOp
CO
ParticipantsN13
Norm
Age24
InterventionsSR313
Dur6
OutcomesSBP
DBP
Renin
NA
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1049 Lawton 1988 b

MethodsOp
CO
ParticipantsN9
Hyp
Age25
InterventionsSR328
Dur6
OutcomesSBP
DBP
Renin
NA
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1050 Morgan 1988

MethodsSB
CO
ParticipantsN16
Hyp
Age63
InterventionsSR50
Dur14
OutcomesSBP
DBP
Renin
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1051 SE Morgan 1988,2

MethodsDB
CO
ParticipantsN 8
Hypertension
Age 63
InterventionsSR 67 (135-68)
Dur 14
OutcomesSBP, DBP
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1052 Shore 1988

MethodsSB
CO
ParticipantsN6
Hyp
Age
InterventionsSR 97
Dur5
OutcomesSBP
DBP
Aldo
Renin
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1053 MBP SE Sudhir 1989

MethodsOp
CO
ParticipantsN 6 (M/F:6/0)(B/W/A.0/6/0)
Normotension
Age 35
InterventionsSR 134 (163-29)
Dur 12
OutcomesSBP, DBP, renin
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1054 Hargreaves 1989

MethodsDB
CO
ParticipantsN8
Norm
Age23
InterventionsSR106
Dur14
OutcomesSBP
DBP
Aldo
Renin
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1055 P ANHMRCDS 1989

MethodsOp
P
ParticipantsN103
Hyp
Age58
InterventionsSR63
Dur 48
OutcomesSBP
DBP
NotesIncluded 111
LoFo:8
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1056 MacGregor 1989

MethodsDB
CO
ParticipantsN20
Hyp
Age57
InterventionsSR150
Dur30
OutcomesSBP
DBP
Aldo
Renin
NA
NotesLoFO: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1057 SE Dimsdale 1990

MethodsOp
CO
ParticipantsN19 (White)
Norm
Age34
InterventionsSR183
Dur5
OutcomesSBP
DBP
Renin
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1058 SE Dimsdale 1990 b

MethodsOp
CO
ParticipantsN23 (Black)
Norm
Age34
InterventionsSR178
Dur5
OutcomesSBP
DBP
Renin
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1059 SE Dimsdale 1990 c

MethodsOp
CO
ParticipantsN16 (Black)
Hyp
Age34
InterventionsSR178
Dur5
OutcomesSBP
DBP
Renin
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1060 SE Dimsdale 1990 d

MethodsOp
CO
ParticipantsN17 (White)
Hyp
Age34
InterventionsSR 198
Dur 5
OutcomesSBP
DBP
Renin
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1061 Schmid 1990

MethodsSB
CO
ParticipantsN9
Norm
Age32
InterventionsSR190
Dur7
OutcomesSBP
DBP
NotesAllocation: random numbers
LoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1062 Schmid 1990 b

MethodsSB
CO
ParticipantsN9
Hyp
Age36
InterventionsSR
Dur
OutcomesSBP
DBP
NotesAllocation: random numbers
LoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1063 P HPTRG 1990

MethodsS
P
ParticipantsN228 (45 blacks)
Norm
Age40
InterventionsSR23
Dur 1100
OutcomesSBP
DBP
NotesIncluded 252
LoFo: 24
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1064 Bruun 1990

MethodsOp
CO
ParticipantsN10
Norm
Age46
InterventionsSR341
Dur4
OutcomesSBP
DBP
Aldo
Renin
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1065 Bruun 1990 b

MethodsOp
CO
ParticipantsN12
Hyp
Age47
InterventionsSR331
Dur4
OutcomesSBP
DBP
Aldo
Renin
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1066 Sharma 1990

MethodsSB
CO
ParticipantsN15
Norm
Age24
InterventionsSR192 (210.7-18.7)
Dur 7
OutcomesSBP
DBP
Chol
HDL
LDL
TG
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1067 Sharma 1990,2

MethodsSB
CO
ParticipantsN 40 (M/F:40/0)(B/W/A.0/40/0)
Normotension
Age 25
InterventionsSR 214 (239-25)
Dur 7
OutcomesSBP, DBP, renin, aldo
NotesLoFo: 5. 40 of 45 completed the study. IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1068 SE Friberg 1990

MethodsOp
CO
ParticipantsN10
Norm
Age33
InterventionsSR117
Dur 13
OutcomesSBP
DBP
Renin
NA
NotesLoFo:4
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1069 Del Rio 1990

MethodsDB
CO
ParticipantsN 15 (B/W/A 0/15/0)
Hypertension, Age 49
InterventionsSR 100 (190-90)
Dur 14
OutcomesSBP, DBP, chol, trig
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1070 P Parker 1990

MethodsDB
P
ParticipantsN31
Hyp
Age50
InterventionsSR73
Dur28
OutcomesSBP
DBP
Notes1990 + 1990 b Included 63
LoFo: 4
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1071 P Parker 1990 b

MethodsDB
P
ParticipantsN28
Hyp
Age54
InterventionsSR49
Dur28
OutcomesSBP
DBP
Notes1990 + 1990 b Included 63
LoFo: 4
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskB - Unclear
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1072 MBP P Mtabaji 1990

MethodsOp
P
ParticipantsN30 (Black)
Norm
Age
InterventionsSR272
Dur7
OutcomesSBP (MBP +1/3MBP)
DBP (MBP-1/3MBP)
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1073 Sharma 1991

MethodsSB
CO
ParticipantsN13
Norm
Age25
InterventionsSR 246
Dur6
OutcomesSBP
DBP
Aldo
Notes1991 + 1991b
included 25
LoFo. 2
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1074 SE Howe 1991

MethodsOp
CO
ParticipantsN 100 (M/F:52/48)(B/W/A.0/100/0)
Normotension
Age 13
InterventionsSR 81 (179-98)
Dur 28
OutcomesSBP, DBP
NotesLoFo:10. 90 of 100 completed the study. IT:No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1075 SE Mascioli 1991

MethodsDB
CO
ParticipantsN 48 (M/F:38/10)
Norm
Age52
InterventionsSR70
Dur28
OutcomesSBP
DBP
Notesincluded 50
LoFo. 2
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1076 Carney 1991

MethodsDB
CO
ParticipantsN11
Hyp
Age54
InterventionsSR102
Dur 42
OutcomesSBP
DBP
Renin
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1077 SE Singer 1991

MethodsDB
CO
ParticipantsN21(6 blacks)
Hyp
Age54
InterventionsSR91
Dur30
OutcomesSBP
DBP
Aldo
Renin
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1078 MBP SE Egan 1991

MethodsDB
CO
ParticipantsN27
Hyp
Age39
InterventionsSR194 (214-21)
Dur7
OutcomesSBP (MBP+1/3MBP)
DBP (MBP-1/3MBP)
Renin
NA l
Chol
LDL
NotesEandomisation schedule
LoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Low riskA - Adequate
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1079 Gow 1992

MethodsOp
CO
ParticipantsN 9
Norm
Age not given
InterventionsSR 94 (111-17)
Dur7
OutcomesSBP
DBP
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1080 Huggins 1992

MethodsDB
CO
ParticipantsN 9 (M/F:7/2)(B/W/A.0/9/0)
Normotension
Age 25
InterventionsSR 97 (170-73)
Dur 14
OutcomesSBP, DBP, renin, aldo
NotesLoFo:0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1081 P TOHP I 1992

MethodsSB
P
ParticipantsN744 (131 blacks)
Norm
Age43
InterventionsSR 47
Dur 550
OutcomesSBP
DBP
NotesLoFo: 50
IT: yes
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Low riskA - Adequate
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1082 P Cobiac 1992

MethodsDB
P
ParticipantsN52
Norm
Age66
InterventionsSR75
Dur28
OutcomesSBP
DBP
NotesIncluded 114(1992+1992b)
LoFo: 8
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1083 P Cobiac 1992 b

MethodsDB
P
ParticipantsN54
Norm
Age67
InterventionsSR73
Dur28
OutcomesSBP
DBP
NotesIncluded 114(1992+1992b)
LoFo: 8
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1084 Benetos 1992

MethodsDB
CO
ParticipantsN20
Hyp
Age42
InterventionsSR78
Dur 28
OutcomesSBP
DBP
Aldo
Renin
NA
A
NotesIncluded 22
LoFO: 2
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1085 P Sciarrone 1992

MethodsDB
P
ParticipantsN91
Hyp
Age54
InterventionsSR82
Dur 56
OutcomesSBP
DBP
Chol
HDL
LDL
TG
Notes95 included
LoFO: 4
IT: No
Lipid values were estimated on the basis of initial values(table 2) and changes (figure 4)
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1086 P Jula 1992

MethodsSB
P
ParticipantsN35
Hyp
Age43
InterventionsSR146
Dur180
OutcomesNA
A
NotesIncluded 91
Hormones available in a subgroup
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1087 P Jula 1992(2)

MethodsSB
P
ParticipantsN36
Hyp
Age45
InterventionsSR82
Dur180
OutcomesRenin
Aldosterone
NotesIncluded 91
Hormones available in a subgroup
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1088 Ruppert 1993

MethodsSB
CO
ParticipantsN30
Norm
Age46
saltsensitive
InterventionsSR270
Dur7
OutcomesSBP
DBP
Aldo
Renin
NA
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1089 Ruppert 1993 b

MethodsSB
CO
ParticipantsN108
Norm
Age36
saltresistant
InterventionsSR275
Dur7
OutcomesSBP
DBP
Aldo
Renin
NA
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1090 Ruppert 1993 c

MethodsSB
CO
ParticipantsN25
Norm
Age35
counteresulatory
InterventionsSR280
Dur7
OutcomesSBP
DBP
Aldo
Renin
NA
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1091 Burnier 1993

MethodsOp
CO
ParticipantsN16
Norm
Age29
InterventionsSR186
Dur6
OutcomesSBP
DBP
Aldo
Renin
NotesLoFo:0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1092 Burnier 1993 b

MethodsOp
CO
ParticipantsN7
Norm
Age29
InterventionsSR218
Dur 6
OutcomesSBP
DBP
Aldo
Renin
NotesLoFo:1
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1093 Sharma 1993

MethodsSB
CO
ParticipantsN16
Norm
Age24
InterventionsSR 224
Dur7
OutcomesSBP
DBP
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1094 Sharma 1993,2

MethodsOp
CO
ParticipantsN 15 (M/F:15/0)(B/W/A.0/15/0)
Normotension
Age 25
InterventionsSR 198 (219-21)
Dur 6
OutcomesRenin, aldo, NE
NotesLoFo: 5. 15 of 20 completed the study. IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation according to a Latin-Square design
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1095 MBP Fliser 1993

MethodsSB
CO
ParticipantsN8
Norm
Age25
+Doxazosin
InterventionsSR190 (211-21)
Dur8
OutcomesSBP (MBP+1/3MBP)
DBP (MBP-1/3MBP)
NA
Chol
HDL
LDL
TG
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1096 MBP Fliser 1993 b

MethodsSB
CO
ParticipantsN8
Norm
Age26
-Doxazosin
InterventionsSR181(199-18)
Dur8
OutcomesSBP (MBP+1/3)
DBP (MBP-1/3)
NA
Chol
HDL
LDL
TG
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1097 P Nestel 1993

MethodsDB
P
ParticipantsN36
Norm
Age66
InterventionsSR56
Dur42
OutcomesSBP
DBP
NotesIncluded 70 (1993+1993b)
LoFo: 4
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1098 P Nestel 1993 b

MethodsDB
P
ParticipantsN30
Norm
Age65
InterventionsSR73
Dur42
OutcomesSBP
DBP
NotesIncluded 70 (1993+1993b)
LoFo: 4
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1099 Donovan 1993

MethodsSB
CO
ParticipantsN8
Norm
Age36
InterventionsSR152
Dur5
OutcomesSBP
DBP
Aldo
Renin
NotesLoFo. 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1100 SE Fotherby 1993

MethodsDB
CO
ParticipantsN17
Hyp
Age73
InterventionsSR79
Dur 35
OutcomesSBP
DBP
Aldo
Renin
NotesIncluded 18
LoFo. 1
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1101 P Redon-Mas 1993

MethodsOp
P
ParticipantsN418
Hyp
Age55
InterventionsSR104
Dur28
OutcomesSBP
DBP
Notes574 included
LoFo: 156
IT: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1102 P Ruilope 1993

MethodsDB
P
ParticipantsN19
Hyp
Age
InterventionsSR69
Dur21
OutcomesSBP
DBP
NotesLoFo. 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1103 Del Rio 1993

MethodsDB
CO
ParticipantsN30
Hyp
Age49
InterventionsSR151 (198-47)
Dur 14
OutcomesSBP
DBP
Renin
Chol
HDL
TG
NotesIncluded 47
LoFo. 17
IT: no
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1104 Overlack 1993

MethodsSB
CO
ParticipantsN30
saltsensitive
Norm
Age46
InterventionsSR270
Dur7
OutcomesAldo
Renin
NA
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1105 Overlack 1993b

MethodsSB
CO
ParticipantsN108
saltresistant
Norm
Age36
InterventionsSR275
Dur7
OutcomesAldo
Renin
NA
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1106 Overlack 1993c,

MethodsSB
CO
ParticipantsN25
counterregulatory
Norm
Age35
InterventionsSR279
Dur7
OutcomesAldo
Renin
NA
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High riskoutcome detection blinded

1107 SE MacFadyen 1994

MethodsDB
CO
ParticipantsN 12 (M/F:12/0)(B/W/A.0/12/0)
Normotension
Age 24
InterventionsSR 40 (165-115)
Dur 4
OutcomesSBP, DBP, renin
NotesLoFo:0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Low riskIndependently prepared schedule by Department of Pharmacy
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1108 Buckley 1994

MethodsSB
CO
ParticipantsN12 (3 blacks)
Hyp
Age49
InterventionsSR 296
Dur 5
OutcomesSBP
DBP
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1109 Zoccali 1994

MethodsSB
CO
ParticipantsN 15
Hyp
Age 45
InterventionsSR 163
Dur 7
OutcomesSBP
DBP
Aldo
Renin
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskrandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1110 P Jula 1994

MethodsOp
P
ParticipantsN76
Hyp
Age44
InterventionsSR57
Dur365
OutcomesSBP
DBP
Aldo
Renin
NA
A
NotesIncluded 91
LoFo: 15
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1111 P Howe 1994

MethodsDB
P
ParticipantsN 56 (M/F:31/25)(B/W/A.0/56/0)
Hypertension
Age 55
InterventionsSR 80 (158-78)
Dur 42
OutcomesSBP, DBP, aldo
NotesLoFo:5. 56 of 61 completed the study. IT:No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1112 Iwaoka 1994

MethodsOp
CO
ParticipantsN 31 (M/F:17/14)(B/W/A.0/0/31)
Hypertension
Age 48
InterventionsSR 266 (298-32)
Dur 7
OutcomesSBP, DBP
NotesLoFo:0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1113 Miller 1995

MethodsDB
CO
ParticipantsN 36 (M/F:36/0)(B/W/A.0/36/0)
Normotension
Age 23
InterventionsSR 58 (191-133)
Dur 14
OutcomesSBP, DBP, NE
NotesLoFo: 4. 36 of 40 completed the study. IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1114 MBP Fliser 1995

MethodsOp
CO
ParticipantsN 14 (M/F:14/0)(B/W/A.0/14/0)
Normotension
Age 26
InterventionsSR 180 (203-23)
Dur 7
OutcomesMAP, renin, NE
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1115 Doig 1995

MethodsDB
CO
ParticipantsN 81(M/F 81/0 (B/W/A 0/81/0)
Normotension, Age 25
InterventionsSR 112 (130-18)
Dur 4
OutcomesSBP, DBP
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1116 Stein 1995

MethodsOp
CO
ParticipantsN 7 (M/F:7/0)(B/W/A.0/7/0)
Normotension
Age 33.7
InterventionsSR 183 (201-18)
Dur 5
OutcomesSBP, DBP, renin, NE
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1117 P Arrol 1995

MethodsOp
P
ParticipantsN 181 (M/F:95/86)(B/W/A.0/181/0)
Hypertension
Age 55
InterventionsSR 16 (122-106)
Dur 182
OutcomesSBP, DBP
NotesLoFo: 27. 181 of 208 completed study. IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1118 Draaijer 1995

MethodsOp
CO
ParticipantsN 10 (M/F:10/0)(B/W/A.0/10/0)
Hypertension
Age 41
InterventionsSR 131 (283-24)
Dur 7
OutcomesSBP, DBP, renin, aldo
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1119 MBP Overlack 1995

MethodsDB
CO
ParticipantsN11
Hyp
Age61
InterventionsSR240
Dur7
OutcomesSBP (MBP+1/3MBP)
DBP (MBP-1/3MBP)
Aldo
Renin
NA
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1120 MBP Overlack 1995 b

MethodsDB
CO
ParticipantsN27
Hyp
Age40
InterventionsSR249
Dur7
OutcomesSBP (MBP+1/3MBP)
DBP (MBP-1/3MBP)
Aldo
Renin
NA
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1121 MBP Overlack 1995 c

MethodsDB
CO
ParticipantsN8
Hyp
Age43
InterventionsSR234
Dur7
OutcomesSBP (MBP+1/3MBP)
DBP (MBP-1/3MBP)
Aldo
Renin
NA
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1122 P Dubbert 1995

MethodsP
SB
ParticipantsN 122 (B/W/A.67/55/0)
Hypertension
Age 62
InterventionsSR 45 (187-142)
Dur 90
OutcomesSBP, DBP
NotesLoFo: 36. 122 of 158 completed the study. IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low riskrandom number table
Allocation concealment (selection bias)Unclear riskRandomisation procedure stratified by race
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1123 SE Weir 1995

MethodsSB
CO
ParticipantsN11 (8 black)
Hyp
Age60
sodium sensitive
InterventionsSR146
Dur14
OutcomesSBP
DBP
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskrandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1124 SE Weir 1995 b

MethodsSB
CO
ParticipantsN11 (6 black)
Hyp
Age60
sodium resistent
InterventionsSR127
Dur14
OutcomesSBP
DBP
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskrandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1125 Grey 1996

MethodsDB
CO
ParticipantsN34
Norm
Age23
Interventions

SR133 (185-52)

Dur7

OutcomesSBP
DBP
Chol
HDL
LDL
TG
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1126 MBP Feldman 1996

MethodsDB
CO
ParticipantsN5
Norm
Age27
Interventions

SR176

Dur7

OutcomesSBP (MBP+1/3MBP)
DBP (MBP-1/3MBP)
NA
A
Chol
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1127 MBP Feldman 1996 b

MethodsDB
CO
ParticipantsN8
Hyp
Age27
InterventionsSR178
Dur7
OutcomesSBP (MBP+1/3MBP)
DBP (MBP-1/3MBP)
NA
A
Chol
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1128 Schorr 1996

MethodsDB
CO
ParticipantsN16
Norm
Age 64
InterventionsSR 74 (175.2-104.8)
Dur28
OutcomesSBP
DBP
Aldo
Renin
Chol
HDL
LDL
TG
NotesIncluded 21
LoFo: 5
IT: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1129 Bellini 1996

MethodsDB
CO
ParticipantsN 43 (M/F:43/0)(B/W/A.0/43/0)
Hypertension
Age 46
InterventionsSR 121 (233-112)
Dur 14
OutcomesSBP, DBP, renin, aldo, NE
NotesLoFo: 12. 43 of 55 completed study. IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1130 Inoue 1996

MethodsDB
CO
ParticipantsN 14 (M/F:8/6)(B/W/A.4/7/3)
Hypertension
Age 46
InterventionsSR 293 (329-36)
Dur 7
OutcomesSBP, DBP
NotesLoFo:0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1131 Ferri 1996

MethodsDB
CO
ParticipantsN61
Hyp
Age47
InterventionsSR264
Dur14
OutcomesSBP
DBP
Aldo
Renin
Notes79 were included.
65 were randomised.
LoFo: 4
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1132 SE Ishimitsu 1996

MethodsOp
CO
ParticipantsN HT: 23 (M/F:11/12) NT 7 (M/F:3/4)(B/W/A.0/0/30)
Hypertension and normotension
Age 54
InterventionsSR 194 (217-23)
Dur 7
OutcomesSBP, DBP, renin, aldo
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1133 SE Ishimitsu 1996 b

MethodsOp
CO
ParticipantsN HT: 23 (M/F:11/12) NT 7 (M/F:3/4)(B/W/A.0/0/30)
Hypertension and normotension
Age 54
InterventionsSR 194 (217-23)
Dur 7
OutcomesSBP, DBP, renin, aldo
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1134 SE Cappuccio 1997

MethodsDB
CO
ParticipantsN47
Hyp
Age67
InterventionsSR83
Dur 30
OutcomesSBP
DBP
NotesIncluded 52
randomised 48
LoFo: 1
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1135 P TOHP II 1997

MethodsSB
P
ParticipantsN1190 (203 blacks)
High norm
Age 42
InterventionsSR40
Dur 1100
OutcomesSBP
DBP
NotesLoFo: 99
IT: yes
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Low risk 
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1136 P van Buul 1997

MethodsOp
CO
ParticipantsN 232 (M/F:0/232)(B/W/A.0/232/0)
Normotension
Age 28
InterventionsSR 65 (140-75(week 28))
Dur 196
OutcomesSBP, DBP
NotesLoFo: 28.. 242 of 270 completed the study. IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Low riskRandomisation by a closed envelope system
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1137 SE Schorr 1997

MethodsSB
CO
ParticipantsN27
Norm
Age25
sodium sensitive
InterventionsSR208
Dur7
OutcomesSBP (MBP+1/3MBP)
DBP (MBP-1/3MBP)
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1138 McCarron 1997

MethodsDB
CO
ParticipantsN99 (24 blacks)
Hyp
Age52
InterventionsSR 55.4 (175.9-120.5)
Dur28
OutcomesSBP
DBP
Chol
HDL
LDL
TG
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1139 Meland 1997

MethodsDB
CO
ParticipantsN 16 (M/F:13/3)(B/W/A.0/16/0)
Hypertension
Age 50
InterventionsSR 66 (191-125)
Dur 56
OutcomesSBP, DBP, chol, HDL
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1140 Fotherby 1997-BP

MethodsDB
CO
ParticipantsN 17 (M/F:4/13)(B/W/A.0/17/0)
Hypertension
Age 73
InterventionsSR 79 (174-95)
Dur 35
OutcomesChol, HDL, LDL, Trig
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1141 Ferri 1998-BP

MethodsDB
CO
ParticipantsN, HT: 39; NT 8 (B/W/A.0/47/0)
Hypertension and normotension
Age 45
InterventionsSR 170 (200-30)
Dur 14
OutcomesChol, HDL, LDL, trig
NotesLoFo: 8 . 39 of 46 randomised hypertensives + 8 controls completed the study.
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1142 P Knuist 1998

MethodsOp
P
ParticipantsN 361 (80% Caucasian)
Pregnant women, Normotension
Age 27.5
InterventionsSR 40 (124-84)
Dur 35 (mean duration)
OutcomesDBP
NotesLoFo: 67 (35 LowSalt, 32 NormalSalt) IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Low riskBlock randomisation. Treatment allocation in opaque sealed envelopes.
Blinding (performance bias and detection bias)
All outcomes
High risk 
Selective reporting (reporting bias)High risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1143 MBP Bech 1998

MethodsOp
CO
ParticipantsN 12 (M/F:6/6)(B/W/A.0/12/0)
Normotension
Age 23.8
InterventionsSR 235 (273-38)
Dur 5
OutcomesMAP
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1144 Foo 1998

MethodsDB
CO
ParticipantsN 18, (8 males, 10 females)
Normotensive
Mean age 51
InterventionsSR 149 (227-78)
Dur 6
OutcomesSBP
DBP
Renin Aldosterone
Notes

LoFo: 0

SDs estimated on the basis of p-values

Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not desribed
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1145 SE Wing 1998

MethodsDB
CO
ParticipantsN17
Hyp
Age61
InterventionsSR59
Dur42
OutcomesSBP
DBP
Notes39 included
19 randomised
LoFo: 2
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskrandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1146 Herlitz 1998

MethodsDB
CO
ParticipantsN 6 (M/F 6/0)(B/W/A 0/6/0)
treated hypertension (from150/106 to 124/82)
Age 46
InterventionsSR 98 (325-227)
Dur 6
OutcomesSBP
DBP
Renin
NotesIncluded 8
LoFO: 2
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1147 MBP Feldman 1999

MethodsOp
CO
ParticipantsN 8 (M/F:8/0)(B/W/A.0/8/0)
Normotension
Age 33
InterventionsSR 159 (207-48)
Dur 7
OutcomesSBP, DBP, chol, NE
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1148 MBP Damasceno 1999

MethodsDB
CO
ParticipantsN 39 (19HT and 20NT) (M/F:19/20)(B/W/A 39/0/0)
Hypertension and normotension
Age HT 43; NT 38
InterventionsSR HT: 81 (114-33); NT: 180 (210-30)
Dur 7
OutcomesSBP, DBP, renin, aldo
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1149 Davrath 1999

MethodsSB
CO
ParticipantsN 8
Norm
Age 25
InterventionsSR 95
Dur 5
OutcomesSBP
DBP
Renin
NA
A
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskrandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1150 SE Schorr 1999

MethodsSB
CO
ParticipantsN 187 (M/F:187/0)(B/W/A.0/187/0)
Normotension
Age 25
InterventionsSR 206 (225-19)
Dur 7
OutcomesSBP, DBP, renin, aldo
NotesLoFo: 13. 187 of 200 completed study. IT: No.
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1151 Uzu 1999

Methods

SB

CO

ParticipantsN70 (Japanese)
Hyp
Age50
InterventionsSR173 (204-31)
Dur7
OutcomesSBP
DBP
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskrandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1152 MBP SE Chiolero 2000

MethodsOp
CO
ParticipantsN Hyp: 38 (M/F:21/17); Norm: 12 (M/F:6/6) (B/W/A.0/50/0)
Hypertension and normotension
Age 43 and 40
InterventionsSR 183 (255-72) and 201 (265-64)
Dur 7
OutcomesSBP, DBP, renin, aldo
NotesLoFo: 5. 38 of 43 and 12 of 12 completed study. IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1153 Bruun 2000

MethodsOp
CO
ParticipantsN 42 (M/F:34/8)(B/W/A.0/42/0)
Normotension
Age 26
InterventionsSR 237 (273-36)
Dur 4
OutcomesSBP, DBP, renin, aldo, NE, E, chol, HDL, LDL, Trig
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1154 SE Burnier 2000

MethodsOp
CO
ParticipantsN 15 (M/F:15/0)(B/W/A.0/15/0)
Hypertension and normotension
Age 22.7
InterventionsSR 131 (144-13)
Dur 7
OutcomesSBP, DBP, renin, aldo, NE, E
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1155 P Heer 2000

MethodsOp
CO
ParticipantsN 32 (M/F:32/0)(B/W/A.0/32/0)
Normotension
Age 25
InterventionsSR139 (226-87)
Dur 7
OutcomesSBP, DBP, renin, aldo
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1156 MBP SE Barba 2000

MethodsDB
CO
ParticipantsN 7 (M/F:7/0)(B/W/A.0/7/0)
Normotension
Age 32
InterventionsSR 154 (177-23)
Dur 7
OutcomesMAP
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1157 Boero 2000

MethodsOp
CO
ParticipantsN 13 (M/F:10/3)(B/W/A.0/13/0)
Hypertension
Age 51
InterventionsSR 209 (270-61)
Dur 14
OutcomesSBP, DBP, Chol, HDL, LDL, Trig,
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 

1158 Suzuki 2000

MethodsOp
CO
ParticipantsN 20 (M/F:9/11)(B/W/A.0/0/20)
Hypertension
Age 59
InterventionsSR 116 (167-51)
Dur 7
Outcomesnocturnal MAP, NE and E
NotesLoFo:0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1159 Ames 2001

MethodsSB
CO
Participants13 (M/F: 6/7)
Hyp
Age 60
InterventionsSR 133 (265-132)
Dur 28
OutcomesSBP
DBP
NA
A
TG:
Chol:
HDL:
LDL:
Notes21 patients included
8 diabetes patients excluded
LoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskrandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1160 SE DASH 1, 2001

MethodsDB
CO
ParticipantsN54
Norm
Non-black
Age 48
InterventionsSR55
Dur30
OutcomesSBP
DBP not mentioned, see DASH 2
NotesLoFo: 5%
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskrandomisation procedure not described
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1161 SE DASH 1b, 2001

MethodsDB
CO
ParticipantsN37
Hyp
Non-black
Age 48
InterventionsSR 55
Dur 30
OutcomesSBP
DBP not mentioned, see DASH 2b
NotesLoFo: 5%
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskrandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1162 SE DASH 1c, 2001

MethodsDB
CO
ParticipantsN68
Norm
Black
Age 48
InterventionsSR55
Dur30
OutcomesSBP
DBP not mentioned, see DASH 2c
NotesLoFo: 5%
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskrandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1163 SE DASH 1d, 2001

MethodsDB
CO
ParticipantsN46
Hyp
Black
Age 48
InterventionsSR 55
Dur 30
OutcomesSBP
DBP not mentioned, see DASH 2d
NotesLoFo: 5%
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskrandomisation procedure not described
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 

1164 SE DASH 2, 2001

MethodsDB
CO
ParticipantsN54
Norm
Non-black
Age 48
InterventionsSR 55
Dur 30
OutcomesDBP: Table 4: referent+ 50% of female+50% of age = -1.3+0.3+(-0.4) = -1.4
NotesLoFo: 5%
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskrandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1165 SE DASH 2b, 2001

MethodsDB
CO
ParticipantsN37
Hyp
Non-black
Age 48
InterventionsSR 55
Dur 30
OutcomesDBP: -1.2 + hypertensive = -1.4 + (-1.3) = -2.7
NotesLoFo: 5%
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskrandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1166 SE DASH 2c, 2001

MethodsDB
CO
ParticipantsN68
Norm
Black
Age 48
InterventionsSR 55
Dur 30
OutcomesDBP: -1.4 + African American = -1.4 + (-2.5) = -3.9
NotesLoFo: 5%
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskrandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1167 SE DASH 2d, 2001

MethodsDB
CO
ParticipantsN46
Hyp
Black
Age 48
InterventionsSR 55
Dur 30
OutcomesDBP: -1.4 + African American + hyperetnesive = -1.2 + (-2.5) + (-1.3) = -5.2
NotesLoFo: 5%
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskrandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1168 Cuzzola 2001

MethodsDB
CO
ParticipantsN 19
Hyp
Age 47
InterventionsSR 161
Dur: 14
OutcomesSBP
DBP
Aldo
Renin
NotesData available in patients in upper tertile of sodium excretion (19 of 55 patients)
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskrandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
High risk 
Selective reporting (reporting bias)High risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1169 P Seals 2001

MethodsOp
P
ParticipantsN 35 (M/F:0/35)(B/W/A.0/34/1)
Hypertension
Age 64
InterventionsSR 46 (132-86)
Dur 90
OutcomesSBP, DBP, Chol, HDL, LDL, Trig
NotesLoFo: 4. 35 of 39 completed the study. IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1170 P TONE 2001

MethodsSB
P
ParticipantsN 471
(non-blacks)
Hyp
Age 66
InterventionsSR 40
DUR: 105
OutcomesSBP
DBP
Notes2001 + 2001b
included 681
LoFo. 68
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskrandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1171 P TONE 2001 b

MethodsSB
P
ParticipantsN 142 (blacks)
Hyp
Age 66
InterventionsSR 40
DUR: 105
OutcomesSBP
DBP
Notes2001 + 2001b
included 681
LoFo. 68
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskrandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1172 Johnson 2001

MethodsDB
CO
ParticipantsN 40
Hypertension
Age 69
InterventionsSR 73 (185-112)
Dur 14
OutcomesSBP, DBP
NotesLoFo:6; 40 of 46 completed the study. IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskSequenced treatments in Latin square design
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1173 Manunta 2001

MethodsSB
CO
ParticipantsN20 (M/F: 16/4)
Hyp
Age 48
InterventionsSR 110
Dur 14
OutcomesRenin
Aldosteron
Notes138 included in acute study. 20 with SR> 100 mmol included in 14 day study. LoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskrandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low riskoutcome detection blinded

1174 MBP Kleij 2002

MethodsOp
CO
ParticipantsN 27 (M/F:20/7)(B/W/A.0/27/0)
Norm
Age 24.8
InterventionsSR 186 (236-50)
Dur 7
OutcomesMAP
Ren, Aldo
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1175 MBP SE Kerstens 2003

MethodsOp
CO
ParticipantsN 28 (M/F:21/7)(B/W/A.0/28/0)
Norm
Age 24
InterventionsSR 202 (248-42)
Dur 7
OutcomesMAP
Ren, Aldo
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1176 SE Dishy 2003

MethodsOp
CO
ParticipantsN 25 (2 blacks, 23 whites)
Norm
Mean age 34 (18-50)
InterventionsSR 300 (321-21)
Dur 6
OutcomesSBP
DBP
Renin A
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskrandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1177 SE Nowson 2003

MethodsOp
CO
ParticipantsN 108 (M/F:44/64/20 dropouts)(B/W/A.0/108/0)
normotension
Age 47
InterventionsSR 90 (140-50)
Dur 28
OutcomesSBP, DBP, renin
NotesLoFo: 20. 108 completed study
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1178 Perry 2003

MethodsOp
CO
ParticipantsN 15 (M/F:15/0)(B/W/A.0/15/0)
Normotension
Age 26
InterventionsSR 105 (175-70)
Dur 5
OutcomesSBP, DBP, renin, aldo, NE, Chol, trig
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1179 P Nakamura 2003

MethodsDB
P
ParticipantsN 65 (M/F:41/24)(B/W/A.0/0/65)
Hypertension and normotension
Age 46.6
InterventionsSR 20 (1.4g)
Dur 42
OutcomesSBP, DBP,
NotesLoFo: 0. 71 tested, 46 included.
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1180 Palacios 2004

MethodsOp
CO
ParticipantsN 40 (M/F:0/23/17 dropouts) (B/W/A.15/8/0)
Normotension
Age 13
InterventionsSR 86 (120-34)
Dur 21
OutcomesSBP, DBP, renin, aldo
NotesLoFo: 17. 23 completed study
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1181 Beeks 2004

Methods

OP

CO

ParticipantsN 117 (M/F:67/50)(B/W/A.0/117/0)
Hyp
Age 54
InterventionsSR 99 (171-72)
Dur 7
OutcomesSBP
DBP
Aldo
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1182 Berge-Landry 2004

MethodsOp
CO
ParticipantsN 48 (M/F:38/10)(B/W/A.12/34/2)
Hyp
Age 51
InterventionsSR 285 (309-24)
Dur 28
OutcomesSBP
DBP
Cho Trig
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1183 Gates 2004

MethodsDB
CO
ParticipantsN 12 (M/F:6/6)(B/W/A.0/12/0)
Hyper
Age 64
InterventionsSR 95 (155-60)
Dur 28
OutcomesSBP
DBP
Chol, HDL, LDL, Trig, Renin, NE, E
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1184 Harsha 2004

MethodsDB
CO
ParticipantsN 193 (M/F:89/104)(B/W/A.57/136/0)
Mixed Hyper/Norm
Age 49
InterventionsSR 77 (141-64)
Dur 30
OutcomesChol, HDL, LDL, Trig, Renin, NE, E
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1185 Zanchi 2004

MethodsDB
CO
ParticipantsN 10 (M/F:10/0)(B/W/A.0/10/0)
Normotension
Age 25
InterventionsSR 250 (270-20)
Dur 7
OutcomesSBP, DBP, renin, aldo
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1186 SE Forrester 2005

MethodsOp
CO
Participants56 Jamaicans (M/F: 34/22)
Norm (125.9/76.3)
Mean age 40.8 (25-55)
InterventionsSR 78.8
Dur 21
OutcomesSBP
DBP
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskBlock randomisation
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1187 SE Forrester 2005 b

MethodsOp
CO
Participants58 Nigerians (M/F: 34/24)
Norm (114.6/72.9)
Mean age 46.6 (25-55)
InterventionsSR 72.2
Dur 21
OutcomesSBP
DBP
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskBlock randomisation
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1188 SE Swift 2005

MethodsDB
CO
ParticipantsN 40 (M/F:17/23)(B/W/A 40/0/0)
Hypertension
Age 50
InterventionsSR 78 (167-89)
Dur 28
OutcomesSBP, DBP, renin, aldo
NotesLoFo: 7. 40 of 47 completed study. IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1189 MBP Damgaard 2006

MethodsOp
CO
ParticipantsN 14 (M/F:14/0)(B/W/A.0/14/0)
Norm
Age 57
InterventionsSR 129 (188-59)
Dur 7
OutcomesSBP
DBP
NE and E
NotesLoFo: 2 excluded because of side effects
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1190 SE Takahashi 2006

MethodsOp
CO
ParticipantsN 448 (M/F:145/303)(B/W/A.0/0/448)
Hypertension (107) and normotension (341)
Age 56.4
InterventionsSR 38 (237-199)
Dur 365
OutcomesSBP, DBP
NotesLoFo: 102. 448 of 550 completed study. IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation: computer generated random number
Blinding (performance bias and detection bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1191 SE Melander 2007

MethodsDB
CO
ParticipantsN 39 (M/F: 20/19)
Mixed hypertensive and normotensive (144/90.6)
Age 53
InterventionsSR 89 (140-51)
Dur 28
OutcomesSBP
DBP
renin
NotesLoFo: 7. 39 completed. IT: No Diet + salt capsules/placebo
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1192 Townsend 2007

MethodsOp
CO
ParticipantsN 20 (M/F:12/8)(B/W/A.10/9/1)
Norm
Age 30
InterventionsSR 171 (194-23)
Dur 6
OutcomesSBP
DBP
Aldo
Renin
Notes

LoFo: 2

IT: No

Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskPrespecified randomised blocked table
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1193 Dengel 2007

MethodsDB
CO
ParticipantsN 28, 10 males, 18 females, 5 blacks, 23 whites
Hypertension
Mean age 63
InterventionsSR 155 (191-36)
Dur 8
OutcomesSBP -10
DBP -4
Renin 1.64 ng/s Aldo 334.2
Notes

LoFo: 0

Blood pressure effects estimated from figure 1. The effects of two genotype groups were added to one group and calculated as simple means.

Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskrandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1194 Tzemos 2008

MethodsDB
CO
ParticipantsN 16 (M/F:16/0)(B/W/A.0/16/0)
Normotension
Age 27
InterventionsSR 149 (225-76)
Dur 5
OutcomesSBP, DBP, renin, aldo, chol, HDL, LDL, Trig,
NotesLoFo: 0
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1195 SE Jessani 2008

MethodsOp
CO
ParticipantsN 184 (M/F:87/97)(B/W/A.0/184/0)
Normotension
Age 50
InterventionsSR 81 (138-57)
Dur 7
OutcomesSBP, DBP
NotesLoFo:16; 184 of 200 completed the study. IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Low riskRandomisation by computer generated numbers
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1196 Paulsen 2009

MethodsDB
CO
ParticipantsN 22 (M/F:12/10)(B/W/A.0/22/0)
Normotension
Age 47
InterventionsSR 47 (357-310)
Dur 4
OutcomesSBP, DBP, renin, aldo
NotesLoFo: 5. 22 of 27 completed study. IT: No.
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1197 Dickinson 2009

MethodsOp
CO
ParticipantsN 29 (M/F: 7/22)
Normotension (116/73)
Mean age 63
InterventionsSR 92 (156-64)
Dur 14
OutcomesSBP
DBP
Notes

LoFo: 3

IT: No

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low riskcomputer generated
Blinding (performance bias and detection bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1198 SE He 2009

MethodsDB
CO
ParticipantsWhites: 77; Blacks: 75; Asians: 35
Hypertension (Baseline BP 147/91)
Mean Age 50
InterventionsSR 55 (165-110)
Dur 42
OutcomesSBP
DBP
Renin Aldosterone
NotesLoFO: W/B/A: 6/6/6
IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low riskcomputer generated, ethnic stratfication
Allocation concealment (selection bias)Low risktablets supplied by independent company
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1199 P Meland 2009

MethodsOp
P
ParticipantsN 46 (M/F:34/12)(B/W/A.0/46/0)
Hypertension
Age 56
InterventionsSR 43 (126-83)
Dur 56
OutcomesSBP, DBP,
Aldo, Chol, Trig
NotesLoFo: 0. 71 tested, 46 included.
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1200 SE Pimenta 2009

MethodsOp
CO
ParticipantsN 12 (M/F:4/8)(B/W/A.6/6)
Hypertension
Age 55.5
InterventionsSR 206 (252-46)
Dur 7
OutcomesSBP, DBP, renin, aldo
NotesLoFo: 1. 12 of 13 completed study. IT: No
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not described
Blinding (performance bias and detection bias)
All outcomes
High risk 
Incomplete outcome data (attrition bias)
All outcomes
Low risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1201 P Nowson 2009

MethodsOp
P
ParticipantsN 111 women
59 normotensives and 35 hypertensives completed
Mean age 59
InterventionsSR 42 (108-66)
Dur 98
OutcomesSBP
DBP
NotesLoFo: 16 IT: No. Two different diets were compared and there was other differences between the diets than sodium intake. These differences were assumed not to influence blood pressure.
Risk of bias
BiasAuthors' judgementSupport for judgement
Allocation concealment (selection bias)Unclear riskRandomisation procedure not desribed in detail. randomisation stratified by BMI.
Blinding (performance bias and detection bias)
All outcomes
High risk 
Selective reporting (reporting bias)Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
High risk 

1202 Weir 2010

MethodsCO, SB
Participants

N 132 (M/F: 73/59, W/B/A: 115/15/2)

Hypertension

Mean age: 51.5

Interventions

SR 123 (208-85)

28 days

Outcomes

SBP

DBP

Notes 
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding of participants and personnel (performance bias)
All outcomes
High risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

1203 Starmans-Kool 2011

  1. a

    Op: open; SB: single blind; DB: double blind; P: parallel; CO: cross-over; N: number of persons in trial; Hyp:Hypertensive; Norm: Normotensive; Age: mean age of persons in trial; SR: Sodium Reduction, mmol/24-h; Dur.: duration of intervention, days; SBP: net change of systolic blood pressure, mmHg; DBP: net change of diastolic blood pressure, mmHg; NA: Noradrenaline; A: Adrenaline; Chol: Cholesterol; HDL: High Density Lipoproteine; LDL: Low Density Lipoprotein.
    TG: triglyceride
    LoFo: Number lost to follow up
    IT: "intention to treat" of those lost to follow-up

Methods

CO

DB

Participants

10 males

Normotension

Mean age 32

Interventions

SR 97 (191-94)

14 days

Outcomes

SBP

DBP

Notes 
Risk of bias
BiasAuthors' judgementSupport for judgement
Blinding (performance bias and detection bias)
All outcomes
Low risk 
Blinding of participants and personnel (performance bias)
All outcomes
Low risk 
Blinding of outcome assessment (detection bias)
All outcomes
Low risk 

Characteristics of excluded studies [ordered by study ID]

StudyReason for exclusion
Anderson 1990No data on urine sodium excretion
Dodson 1989Includes only patients with diabetes mellitus
Imanishi M 2001Includes only patients with diabetes mellitus
Miller JA 1997Includes only patients with diabetes mellitus
Mühlhauser I 1996Includes only patients with diabetes mellitus
Palmer 1989No data on urine sodium excretion
Parfrey 1981Withdrawal of paper by the authors due to erroneous form
Ruppert 1991Sub study of Ruppert 1993
Ruppert 1994Sub study of Ruppert 1993
Steegers 1991Sub study of van Buul 1997