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Carnitine supplementation of parenterally fed neonates

  • Review
  • Intervention

Authors


Abstract

Background

Carnitine, a quaternary amino acid, plays an important role in the oxidation of long chain fatty acids. Both breast milk and infant formulas contain carnitine. However, it is not routinely provided in parenteral nutrition solutions. Non supplemented parenterally fed infants have very low tissue carnitine levels. The clinical significance of this is uncertain. Carnitine deficiency may be an etiological factor in the limited ability of premature babies to utilize parenteral lipid. In vitro studies have suggested that fatty acid oxidation is impaired when the tissue carnitine levels fall below 10% of normal. Therefore relative carnitine deficiency may impair fatty acid oxidation, thus reducing the available energy and impairing growth.

Objectives

The primary aim of this review is to determine whether carnitine supplementation of parenterally fed neonates will improve weight gain.
The secondary aims are to determine the effect on lipid tolerance and ketogenesis.

Search methods

Computerised searches were carried out by both reviewers. Searches were made of Medline, Embase, The National Research Register (UK), the Cochrane Controlled Trials Register and expert informants. The MeSH headings used were carnitine and parenteral nutrition.

Selection criteria

Only randomised trials were considered. Trials were included if they involved carnitine supplementation alone, parenterally fed newborn infants, and measured at least one outcome of interest (weight gain, plasma fatty acids, plasma triglycerides, quantity of lipid tolerated, respiratory quotient or beta hydroxybutyrate levels).

Data collection and analysis

The two reviewers searched the literature separately and reached a consensus for inclusion of trials. Data were extracted and evaluated by the two reviewers independently of each other. Authors were contacted if possible to clarify or provide missing data.

Main results

Fourteen studies were identified, six met the selection criteria. The results of the review are limited by the fact that the studies were generally short term and studied different outcomes. One study examined short term and long term weight gain, three reported only short term weight gain, three reported biochemical results in response to a short lipid challenge, and two reported results obtained during normal parenteral nutrition.

Among infants supplemented with carnitine, there was no evidence of effect on weight gain, lipid utilization or ketogenesis.

Authors' conclusions

We found no evidence to support the routine supplementation of parenterally fed neonates with carnitine.

摘要

背景

腸外營養新生兒的肉鹼(Carnitine)補充

肉鹼(Carnitine)由四個氨基酸組成,在長鏈脂肪酸氧化時有重要作用。乳汁與嬰兒配方食品均含有肉鹼。然而,在腸外營養配方中並未常規添加。食用未補充腸外營養的嬰兒組織中的肉鹼含量很低。其臨床意義尚不清楚。肉鹼缺乏限制早產兒利用腸外脂質的能力。體外研究顯示當組織肉鹼含量低於正常值10%時脂肪酸氧化作用減弱。因而肉鹼相對缺乏可能減少脂肪酸氧化,從而減少有效可用的能量進而影響生長。

目標

本回顧主要目的是確定對新生兒腸外補充肉鹼(Carnitine)是否促進體重增加。次要目的是確定對脂質耐受性和生酮作用的影響。

搜尋策略

由兩位作者員進行網路數位檢索。檢索的資料庫包括了MEDLINE,EMBASE,The National Research Register (UK), the Cochrane Controlled Trials Register和專家訊息。使用的MeSH題詞是肉鹼(cacrtine)和腸外營養(parenteral nutrition)。

選擇標準

只收納隨機試驗。納入涉及單純補充肉鹼(Carnitine),腸外營養新生兒,以及至少測量一項要關心的結果(體重增加,血漿脂肪酸,血漿三酸甘油酯,脂質耐受量,呼吸商或beta hydroxybutyrate量)的試驗。

資料收集與分析

兩位作者分別進行文獻檢索,並對納入試驗達成共識。兩位作者彼此獨立提取和評估資料。為澄清或提供遺漏的數據,如有可能則與原作者進行聯繫。

主要結論

找到14項試驗,6項符合選擇標準。因納入的研究普遍是短期研究且研究的目標結果也不同,所以影響到本回顧的結果。一項試驗檢視短期與長期體重增加,三項試驗僅報告短期體重增加,三項試驗報告短期脂質改變的生物化學反映,兩項試驗報告正常腸外營養獲得的結果。在有補充肉鹼的嬰兒,沒有影響體重增加,脂質應用或生酮作用的證據。

作者結論

沒有發現證據支持對新生兒予腸外常規補充肉鹼(carnitine)。

翻譯人

本摘要由臺中榮民總醫院葉惠英翻譯。

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

總結

沒有足夠證據支持對新生兒予腸外補充肉鹼促進體重增加。早產新生兒(胎齡37週前出生)經常需要除經口以外的體外額外營養補充。肉鹼(Carnitine)是在母乳哺育或嬰兒奶粉中有的胺基酸但不常在體外營養配方中。它輔助脂肪酸轉成能量促進生長。本試驗回顧沒有發現足夠證據支持體外肉鹼補充有助於早產兒體重增加或脂質耐受。需要進一步研究評量。

Plain language summary

Carnitine supplementation of parenterally fed neonates

Not enough evidence that carnitine supplements improve weight gain in parenterally fed newborns. Preterm newborns (born before 37 weeks) frequently need extra nutritional supplements parenterally (given other ways than by the mouth). Carnitine is an amino acid found in both breast milk and infant formulas but is not routinely given parenterally. It helps fatty acids to convert into energy and helps in growth. The review of trials found not enough evidence to show any benefit of parenteral carnitine supplements on weight gain or lipid tolerance in preterm newborns. More research is needed.

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