Effect of bariatric surgery on circulating FGF-19: A systematic review and meta-analysis

Fibroblast growth factor-19 (FGF-19) is a gut hormone which interacts with metabolism and is depleted in obesity. There is some indication that the hormone undergoes a resurgence following bariatric surgery (BS), an effect which may contribute to the beneficial outcomes of such procedures. This systematic review and meta-analysis aims to synthesize the available literature on FGF-19 levels before and after BS. MEDLINE, Scopus and Web of Science databases were searched, and the effect of different surgical procedures and degrees of body mass index (BMI) reduction on FGF-19 levels was assessed by DerSimonian and Laird random-effects model in meta-analysis and dose-response analyses. This meta-analysis, which included 474 patients from 25 arms undergoing one of five BS procedures, revealed a significant increase in the levels of circulating FGF-19 following all-type BS. Vertical sleeve gastrectomy, duodenal-jejunal bypass liner and Roux-en-Y gastric bypass all significantly increased circulating FGF-19 levels from baseline. However, gastric banding failed to achieve the same, and in fact, biliopancreatic diversion was associated with decreased circulating FGF-19. Finally, an inverse association between FGF-19 and the degree of BMI-reduction post-operatively was noted. FGF-19 is increased by BS and may represent a pharmaceutical target in efforts to reproduce the beneficial effects of BS in a medical setting.