Interventions for preventing weight gain after smoking cessation

 

Abstract

Background

Most people who stop smoking gain weight. There are some interventions that have been designed to reduce weight gain when stopping smoking. Some smoking cessation interventions may also limit weight gain although their effect on weight has not been reviewed.

Objectives

To systematically review the effect of: (1) Interventions targeting post-cessation weight gain on weight change and smoking cessation.

(2) Interventions designed to aid smoking cessation that may also plausibly affect weight on post-cessation weight change.

Search methods

Part 1 - We searched the Cochrane Tobacco Addiction Group's Specialized Register and CENTRAL in September 2011.

Part 2 - In addition we searched the included studies in the following "parent" Cochrane reviews: nicotine replacement therapy (NRT), antidepressants, nicotine receptor partial agonists, cannabinoid type 1 receptor antagonists and exercise interventions for smoking cessation published in Issue 9, 2011 of the Cochrane Library.

Selection criteria

Part 1 - We included trials of interventions that were targeted at post-cessation weight gain and had measured weight at any follow up point and/or smoking cessation six or more months after quit day.

Part 2 - We included trials that had been included in the selected parent Cochrane reviews if they had reported weight gain at any time point.

Data collection and analysis

We extracted data on baseline characteristics of the study population, intervention, outcome and study quality. Change in weight was expressed as difference in weight change from baseline to follow up between trial arms and was reported in abstinent smokers only. Abstinence from smoking was expressed as a risk ratio (RR). We used the most rigorous definition of abstinence available in each trial. Where appropriate, we performed meta-analysis using the inverse variance method for weight and Mantel-Haenszel method for smoking using a fixed-effect model.

Main results

Part 1: Some pharmacological interventions tested for limiting post cessation weight gain (PCWG) resulted in a significant reduction in WG at the end of treatment (dexfenfluramine (Mean difference (MD) -2.50 kg, 95% confidence interval (CI) -2.98 to -2.02, 1 study), phenylpropanolamine (MD -0.50 kg, 95% CI -0.80 to -0.20, N=3), naltrexone (MD -0.78 kg, 95% CI -1.52 to -0.05, N=2). There was no evidence that treatment reduced weight at 6 or 12 months (m). No pharmacological intervention significantly affected smoking cessation rates.

Weight management education only was associated with no reduction in PCWG at end of treatment (6 or 12m). However these interventions significantly reduced abstinence at 12m (Risk ratio (RR) 0.66, 95% CI 0.48 to 0.90, N=2). Personalised weight management support reduced PCWG at 12m (MD -2.58 kg, 95% CI -5.11 to -0.05, N=2) and was not associated with a significant reduction of abstinence at 12m (RR 0.74, 95% CI 0.39 to 1.43, N=2). A very low calorie diet (VLCD) significantly reduced PCWG at end of treatment (MD -3.70 kg, 95% CI -4.82 to -2.58, N=1), but not significantly so at 12m (MD -1.30 kg, 95% CI -3.49 to 0.89, N=1). The VLCD increased chances of abstinence at 12m (RR 1.73, 95% CI 1.10 to 2.73, N=1). There was no evidence that cognitive behavioural therapy to allay concern about weight gain (CBT) reduced PCWG, but there was some evidence of increased PCWG at 6m (MD 0.74, 95% CI 0.24 to 1.24). It was associated with improved abstinence at 6m (RR 1.83, 95% CI 1.07 to 3.13, N=2) but not at 12m (RR 1.25, 95% CI 0.83 to 1.86, N=2). However, there was significant statistical heterogeneity.

Part 2: We found no evidence that exercise interventions significantly reduced PCWG at end of treatment (MD -0.25 kg, 95% CI -0.78 to 0.29, N=4) however a significant reduction was found at 12m (MD -2.07 kg, 95% CI -3.78 to -0.36, N=3).

Both bupropion and fluoxetine limited PCWG at the end of treatment (bupropion MD -1.12 kg, 95% CI -1.47 to -0.77, N=7) (fluoxetine MD -0.99 kg, 95% CI -1.36 to -0.61, N=2). There was no evidence that the effect persisted at 6m (bupropion MD -0.58 kg, 95% CI -2.16 to 1.00, N=4), (fluoxetine MD -0.01 kg, 95% CI -1.11 to 1.10, N=2) or 12m (bupropion MD -0.38 kg, 95% CI -2.00 to 1.24, N=4). There were no data on WG at 12m for fluoxetine.

Overall, treatment with NRT attenuated PCWG at the end of treatment (MD -0.69 kg, 95% CI -0.88 to -0.51, N=19), with no strong evidence that the effect differed for the different forms of NRT. There was evidence of significant statistical heterogeneity caused by one study which reported a 4.3 kg reduction in PCWG due to NRT. With this study removed, the difference in weight change at end of treatment was -0.45 kg (95% CI -0.66 to -0.27, N=18). There was no evidence of an effect on PCWG at 12m (MD -0.42 kg, 95% CI -0.92 to 0.08, N=15).

We found evidence that varenicline significantly reduced PCWG at end of treatment (MD -0.41 kg, 95% CI -0.63 to -0.19, N=11), but this effect was not maintained at 6 or 12m. Three studies compared the effect of bupropion to varenicline. Participants taking bupropion gained significantly less weight at the end of treatment (-0.51 kg (95% CI -0.93 to -0.09 kg), N=3). Direct comparison showed no significant difference in PCWG between varenicline and NRT.

Authors' conclusions

Although some pharmacotherapies tested to limit PCWG show evidence of short-term success, other problems with them and the lack of data on long-term efficacy limits their use. Weight management education only, is not effective and may reduce abstinence. Personalised weight management support may be effective and not reduce abstinence, but there are too few data to be sure. One study showed a VLCD increased abstinence but did not prevent WG in the longer term. CBT to accept WG did not limit PCWG and may not promote abstinence in the long term. Exercise interventions significantly reduced weight in the long term, but not the short term. More studies are needed to clarify whether this is an effect of treatment or a chance finding. Bupropion, fluoxetine, NRT and varenicline reduce PCWG while using the medication. Although this effect was not maintained one year after stopping smoking, the evidence is insufficient to exclude a modest long-term effect. The data are not sufficient to make strong clinical recommendations for effective programmes to prevent weight gain after cessation.

 

Plain language summary

Interventions for preventing weight gain after smoking cessation

When giving up smoking, most people put on weight. Many smokers are concerned about this and say it may put them off making an attempt quit. Some studies show that weight gain also leads to people resuming smoking after an initially successful quit attempt. On the other hand, there are good reasons to believe that trying to limit weight gain may reduce the chance of stopping smoking. Several drug and behavioural programmes to limit post cessation weight gain have been tested. Of the drug treatments, naltrexone showed the most promise, but there were no data on its effects on weight once drug treatment stopped and there was not enough evidence to judge its effects on long term quitting. Weight management education alone did not limit weight gain and may undermine cessation. Weight management education with personalised support giving feedback on personal goals and a personal energy prescription limited weight gain and there was no evidence that it undermined cessation. Intermittent use of a VLCD improved cessation success and weight gain in the short term but not in the longer term.

Some smoking cessation treatments also limited weight gain. Bupropion, fluoxetine, NRT and varenicline all limited weight gain during treatment, however the effects on weight gain reduction were smaller after the treatment had stopped and there was insufficient evidence to be sure that these effects persisted in the long-term. There was some evidence to suggest that exercise reduced post cessation weight gain but more studies are needed to clarify whether this was a chance finding. The effects of all interventions were modest in relation to the average weight gain that follows stopping smoking.

 

摘要

背景

避免戒菸後體重增加的處置

大部分戒菸的人都會變胖，長期來說平均增加體重7公斤。有一些戒菸特別處置也可以限制體重的增加。許多戒菸藥物和其他的處置也同樣能限制體重增加。

目標

此篇文獻分成兩個部份：(1)特別設計來協助戒菸及控制戒菸後體重增加的處置(2)主要是戒菸的處置，同樣的似乎對於體重也有影響。

搜尋策略

第一部份：我們搜尋Cochrane Tobacco Addiction Group's Specialized Register which includes trials indexed in MEDLINE, EMBASE, SciSearch and PsycINFO, 其他的回顧文獻，和研討會的摘要。第二部分：我們艘尋Cochrane 內有關戒菸的回顧文獻，包括尼古丁替代治療，抗鬱劑，nicotine receptor partial agonists, cannabinoid type 1 receptor antagonists (rimonabant), 和運動處置。這些發表在The Cochrane Library 2008的Issue 4。

選擇標準

第一部份：我們採用的研究是特別針對戒菸及戒菸後體重增加的處置，這些研究在任何追蹤的時間點都測量體重，以及(或)戒菸6個月或6個月以上後的吸菸狀況。第二部分：我們採用的研究是從Cochrane回顧文獻中所選的，是針對在戒菸試驗結束或之後體重增加，而能夠調節戒菸後體重增加的研究。

資料收集與分析

在第一部份我們摘錄有關吸菸和體重的資料。第二部分只摘錄體重的資料。戒菸的比率以risk ratio (RR)表示，使用研究中對於戒菸最嚴格定義以及有的使用生化方式加以證實的比率。結果 是以體重的變化來表示。如果資料適合，我們使用the MantelHaenszel method 做吸菸的後設分析(metaanalysis)已及使用fixedeffect model來計算體重的inverse variance 。

主要結論

有證據顯示藥物治療的確可以顯著在治療後期減少體重的增加(dexfenfluramine (−2.50kg [2.98kg to −2.02kg], fluoxetine (−0.80kg [1.27kg to −0.33kg], phenylpropanolamine (PPA) (−0.50kg [0.80kg to −0.20kg], naltrexone (−0.76kg [1.51kg to −0.01kg])). 但是沒有證據指出6或12個月後藥效還能維持。 在行為治療中，只有給予體重控制建議無法減重，而且可能還會減少戒菸比率。個別化的計畫在治療結束及在12個月時也可達到減重的效果(−2.58kg [5.11kg to −0.05kg]), 不過對戒菸沒有影響(RR 0.74 [0.39 to 1.43])。極低的卡路里飲食(−1.30kg (−3.49kg to 0.89kg] 在12個月時)以及認知行為治療(CBT)(−5.20kg (−9.28kg to −1.12kg] 在12個月時)都可以提高戒菸率以及減重(在治療結束以及長期追蹤上)bupropion (300mg/day)以及fluoxetine (合併30mg and 60mg/day combined)，都發現可以在治療結束後有減重效果，分別為(−0.76kg [1.17kg to −0.35kg] I2 = 48%) and −1.30kg [1.91kg to −0.69kg]) 沒有證據顯示bupropion的減重效果與劑量有關在1年的時候bupropion的效果變小且confidence intervals上呈現出沒效果的情況(−0.38kg [2.001kg to 1.24kg]) 沒有證據顯示運動治療在治療結束後可以顯著地減重，但在12個月時卻顯示有效(−2.07kg [3.78kg, −0.36kg] 使用NRT治療，在治療結束後可以減少體重(−0.45kg [0.70kg, −0.20kg])但不同型式的NRT間並沒有差異，在12個月時評估的減重效果差不多(−0.42kg [0.92kg, 0.08kg]) ，但是 confidence intervals 上卻是呈現出沒效果的情況。 沒有相關資料呈現rimonabant 的減重效果。 沒有證據顯示治療結束後，varenicline 可以顯著地減少體重，至於後續追蹤則目前尚無資料。有一個研究隨機分配成功戒菸者到治療組接受12個多星期的治療，結果顯示可減重 0.71kg (−1.04kg to −0.38kg). 有3個研究顯示在治療結束後，服用bupropion的受試者體重上升明顯地比服用varenicline要少。

作者結論

行為處置若只有一般性建議，則對體重減輕是無效的，而且會降低戒菸率。個別化的計畫、低卡路里攝取和CBT是有效的，但不會降低戒菸。運動處置在治療結束時體重沒有明顯降低，但是就長期來說體重是會降低的。Bupropion, fluoxetine, 尼古丁替代療法和varenicline(可能)都會達到減重效果。 bupropion, fluoxetine, 尼古丁替代療法在戒菸後的一年間無法繼續維持效果，不過目前的證據不足以排除中度的長期效果。目前資料不足以強烈建議哪一個是有效的計畫。

翻譯人

本摘要由彰化基督教醫院胡淑惠翻譯。

此翻譯計畫由臺灣國家衛生研究院(National Health Research Institutes, Taiwan)統籌。

總結

避免戒菸後體重增加的處置 大部分的人在戒菸後體重都會增加。由於這個原因，通常使得許多吸菸者放棄戒菸或者戒菸後再次吸菸。檢驗不同的藥物和行為處置來看看在增加戒藥的同時是否也能達到減重的效果。在藥物治療上，naltrexone是最顯著的，但是並有證據支持在停藥後或者長期使用上有減輕體重的效果。針對個人設計的，行為治療較會成功，而低卡路里飲食和認知行為治療在減輕體重上是較為顯著的，兩種治療可以增加長期戒菸率，但是長期下來可以有減輕體重效果的只有認知行為治療。沒有足夠的證據來判斷是否極低卡路里飲食能長期維持減重效果。幫助戒菸的處置也可能會有減重的效果，其中Bupropion, fluoxetine 以及 尼古丁替代療法都能在治療過程減輕體重，但是在治療停止後減重效果變小，而且也沒有足夠的證據顯示這些效果能長期持續。Varenicline在治療期間也許能降低體重，但沒有足夠的證據證實這點以及它的長期效果。有一些證據顯示在戒菸後，運動能有長期減重的效果，但是需要更多的研究來證實。