Bile acid profiles over 5 years after gastric bypass and duodenal switch: results from a randomized clinical trial

BACKGROUND: Bile acids have been proposed as key mediators of the metabolic effects after bariatric surgery. Currently no reports on bile acid profiles after duodenal switch exist, and long-term data after gastric bypass are lacking. OBJECTIVE: To investigate bile acid profiles up to 5 years after Roux-en-Y gastric bypass and biliopancreatic diversion with duodenal switch and to explore the relationship among bile acids and weight loss, lipid profile, and glucose metabolism. SETTINGS: Two Scandinavian University Hospitals. METHODS: We present data from a randomized clinical trial of 60 patients with body mass index 50-60 kg/m(2) operated with gastric bypass or duodenal switch. Repeated measurements of total and individual bile acids from fasting serum during 5 years after surgery were performed. RESULTS: Mean concentrations of total bile acids increased from 2.3 µmol/L (95% confidence interval [CI], -.1 to 4.7) at baseline to 5.9 µmol/L (3.5-8.3) 5 years after gastric bypass and from 1.0 µmol/L (95% CI, -1.4 to 3.5) to 9.5 µmol/L (95% CI, 7.1-11.9) after duodenal switch; mean between-group difference was -4.8 µmol/L (95% CI, -9.3 to -.3), P = .036. Mean concentrations of primary bile acids increased more after duodenal switch, whereas secondary bile acids increased proportionally across the groups. Higher levels of total bile acids at 5 years were associated with lower body mass index, greater weight loss, and lower total cholesterol. CONCLUSIONS: Total bile acid concentrations increased substantially over 5 years after both gastric bypass and duodenal switch, with greater increases in total and primary bile acids after duodenal switch. (Surg Obes Relat Dis 2017;0:000-000.) © 2017 American Society for Metabolic and Bariatric Surgery. All rights reserved.