Abstract Bariatric surgery is a metabolic surgery known to be an efficient treatment for weight loss, with adequate long-term maintenance. Interestingly, some studies have reported a reduction in branched chained amino acids (BCAAs) after bariatric surgery, which putatively contributes to post-surgical metabolic improvement. The current systematic review and meta-analysis investigated the effect of bariatric surgery on the level of BCAAs. PubMed, SCOPUS, EMBASE, and Web of Science databases were searched from their inception to July 2019. All clinical trials which investigated the effect of bariatric surgery on the levels of valine, leucine, and isoleucine, for more than one week, were included. Nine studies (11 effect sizes) were analyzed via meta-analytical techniques using random-effects models. The pooled data suggested that bariatric surgery significantly reduced the valine (standardized mean difference [SMD]: - 1.89, 95% CI: -2.79, -0.99, I2 = 90.9%), leucine (SMD: -0.96, 95% CI: -1.48, -0.44, I2 = 72.4%), and isoleucine (SMD: -0.58, 95% CI: -0.84, -0.31, I2 = 66.3%) levels after surgery compared with before the surgery. Overall, bariatric surgery significantly reduced the levels of valine, leucine, and isoleucine compared with before the surgery. Further large-scale and homogenous trials are needed to better discern the generalizability of our findings.

中文翻译：

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减肥手术降低支链氨基酸水平：系统评价和荟萃分析

摘要 减肥手术是一种代谢手术，被认为是一种有效的减肥方法，并具有足够的长期维护。有趣的是，一些研究报告了减肥手术后支链氨基酸 (BCAA) 的减少，这可能有助于术后代谢改善。目前的系统评价和荟萃分析调查了减肥手术对支链氨基酸水平的影响。从 PubMed、SCOPUS、EMBASE 和 Web of Science 数据库开始搜索到 2019 年 7 月。所有研究减肥手术对缬氨酸、亮氨酸和异亮氨酸水平影响的临床试验都包括在内。九项研究（11 个效应量）通过元分析技术使用随机效应模型进行了分析。汇总数据表明，减肥手术显着降低了缬氨酸（标准化平均差 [S​​MD]：- 1.89，95% CI：-2.79，-0.99，I2 = 90.9%）、亮氨酸（SMD：-0.96，95% CI：- 1.48, -0.44, I2 = 72.4%) 和异亮氨酸 (SMD: -0.58, 95% CI: -0.84, -0.31, I2 = 66.3%) 水平与手术前相比。总体而言，与手术前相比，减肥手术显着降低了缬氨酸、亮氨酸和异亮氨酸的水平。需要进一步的大规模和同质试验来更好地辨别我们发现的普遍性。总体而言，与手术前相比，减肥手术显着降低了缬氨酸、亮氨酸和异亮氨酸的水平。需要进一步的大规模和同质试验来更好地辨别我们发现的普遍性。总体而言，与手术前相比，减肥手术显着降低了缬氨酸、亮氨酸和异亮氨酸的水平。需要进一步的大规模和同质试验来更好地辨别我们发现的普遍性。