Dynamics of bile acid profiles, GLP-1, and FGF19 after laparoscopic gastric banding

Abstract

Context: An increase of bile acids (BAs), fibroblast growth factor 19 (FGF19), and glucagon-like peptide 1 (GLP-1) has been implicated in metabolic improvements after Roux-en-Y gastric bypass and vertical sleeve gastrectomy. However, data are still conflicting regarding their role after laparoscopic adjustable gastric banding (LAGB). Objective: To assess the fasting BA, FGF19, and GLP-1 concentrations in plasma before and after LAGB and to test for correlations with immunometabolic parameters. Furthermore, hepatic farnesoid X receptor (FXR) expression and regulation of FXR-dependent genes were analyzed. Design and Setting: Observational study at the University Hospital Innsbruck. Patients: Twenty obese patients. Interventions: Fasting plasma samples were taken before, 3, 6, and 12 months after LAGB. Liver biopsies were obtained at surgery and after 6 months postoperatively. Main Outcome Measures: BA profiles, GLP-1 and FGF19 levels, hepatic FXR expression and regulation of FXR target genes were determined. Results: Total, conjugated, and secondary BAs transiently increased 3 months after LAGB (P < 0.01). Only one BA, glycolithocholic acid sulfate, remained significantly elevated throughout the whole follow-up period (P < 0.05). GLP-1 had increased transiently 3 months after surgery (P < 0.01), whereas FGF19 levels increased continuously (P < 0.05). Insulin, homeostasis model assessment index, C-reactive protein, FGF19, and GLP-1 correlated positively with different BAs. No differences were seen in hepatic FXR expression and FXR-regulated genes. Conclusions: Our study results, not only identified LAGB-induced changes in BAs and BA-induced hormones, but also revealed associations between changes in BA profile with GLP-1 and FGF19.