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/m2 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.