Gut peptides before and following Roux‐En‐Y gastric bypass: A systematic review and meta‐analysis.

Summary: A systematic search was conducted in Medline Ovid, Embase, Scopus, and Cochrane Central Register of Controlled Trials up until March 2021 following PRISMA guidelines. Studies included evaluated ghrelin, GLP‐1, PYY or appetite sensation via visual analogue scales (VASs) before and after Roux‐en‐Y gastric bypass (RYGB) in adults. A multilevel model with random effects for study and follow‐up time points nested in study was fit to the data. The model included kcal consumption as a covariate and time points as moderators. Among the 2559 articles identified, k = 47 were included, among which k = 19 evaluated ghrelin, k = 40 GLP‐1, k = 22 PYY, and k = 8 appetite sensation. Our results indicate that fasting ghrelin levels are decreased 2 weeks post‐RYGB (p = 0.005) but do not differ from baseline from 6 weeks to 1‐year post‐RYGB. Postprandial ghrelin and fasting GLP‐1 levels were not different from pre‐surgical values. Postprandial levels of GLP‐1 increased significantly from 1 week (p < 0.001) to 2 years post‐RYGB (p < 0.01) compared with pre‐RYGB. Fasting PYY increased at 6 months (p = 0.034) and 1 year (p = 0.029) post‐surgery; also, postprandial levels increased up to 1 year (p < 0.01). Insufficient data on appetite sensation were available to be meta‐analyzed. [ABSTRACT FROM AUTHOR]