School of Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, SO16 6YD, United Kingdom.
Department of General Surgery, University Hospital Southampton NHS Foundation Trust, Southampton, SO16 6YD, United Kingdom.
Clin Nutr ESPEN. 2022 Apr;48:121-140. doi: 10.1016/j.clnesp.2022.02.001. Epub 2022 Feb 10.
Bariatric, also termed metabolic, surgery is an increasingly common treatment for severe and complex obesity. It decreases macronutrient intake, influences nutrient absorption and modifies gastrointestinal physiology with the aim of reducing adiposity, improving metabolism and reducing disease risk. Bariatric surgery has been shown to result in micronutrient deficiencies. Whether it results in deficiencies of essential fatty acids (EFAs) and their bioactive polyunsaturated fatty acid (PUFA) derivatives is not clear. The aim of this systematic review is to identify whether there are effects of bariatric surgery on the blood levels of EFAs and other PUFAs.
A database search was conducted up to November 2020 using Medline, Embase and Cinahl databases, using relevant search terms identified by a PICO protocol. Only human studies reporting on PUFAs in a blood pool, published in the English language and available in full text were included. The Cochrane tool for assessing risk of bias was used and data were extracted.
Fifteen papers from fourteen studies with relevant data were identified for inclusion. Studies differed according to surgical intervention, duration, measured timepoints, sample size and PUFAs reported. Both increases and decreases in selected PUFAs were reported in different studies. For the EFAs linoleic acid and α-linolenic acid and for the longer-chain omega-3 PUFA eicosapentaenoic acid, bariatric surgery is associated with a transient decline in status (to about 6 months post-surgery) with a later return to pre-surgery levels. All studies had some risk of bias and most studies were of small size.
There is a decrease in blood levels of both EFAs and of eicosapentaenoic acid in the months following bariatric surgery. This may partly counter the desired effects of the surgery on blood lipids, insulin sensitivity and inflammation. Nutritional strategies (e.g. use of modified formulas or of supplements) may be able to correct the decrease in those PUFAs. Nevertheless, the observed decrease in PUFAs is transient.
减重（代谢）手术是治疗严重和复杂肥胖的一种越来越常见的方法。它减少了宏量营养素的摄入，影响了营养物质的吸收，并改变了胃肠道的生理功能，以减少肥胖、改善代谢并降低疾病风险。减重手术已被证明会导致微量营养素缺乏。但它是否会导致必需脂肪酸（EFAs）及其生物活性多不饱和脂肪酸（PUFA）衍生物的缺乏尚不清楚。本系统评价的目的是确定减重手术是否会影响 EFA 和其他多不饱和脂肪酸在血液中的水平。
我们使用 Medline、Embase 和 Cinahl 数据库，按照 PICO 方案确定的相关检索词，对截至 2020 年 11 月的数据库进行了检索。仅纳入报告血液多不饱和脂肪酸、以英语发表且可提供全文的人类研究。我们使用 Cochrane 偏倚风险评估工具进行评估并提取数据。
我们确定了 14 项研究的 15 篇相关论文，纳入了本研究。研究根据手术干预、持续时间、测量时间点、样本量和报告的多不饱和脂肪酸而有所不同。不同研究报告了选定多不饱和脂肪酸的增加和减少。对于 EFA 亚油酸和 α-亚麻酸，以及更长链的 ω-3 多不饱和脂肪酸二十碳五烯酸，减重手术后其状态会出现短暂下降（术后约 6 个月），之后恢复到术前水平。所有研究均存在一定的偏倚风险，且大多数研究的样本量较小。
减重手术后数月内，血液中 EFA 和二十碳五烯酸的水平会下降。这可能部分抵消了手术对血脂、胰岛素敏感性和炎症的预期影响。营养策略（例如使用改良配方或补充剂）可能能够纠正这些多不饱和脂肪酸的减少。然而，观察到的多不饱和脂肪酸减少是短暂的。
