Changes in postprandial gut hormones after metabolic surgery: a comparison of gastric bypass and sleeve gastrectomy

Abstract

Background Laparoscopic gastric bypass (GB) is reportedly more effective than laparoscopic sleeve gastrectomy (SG) in the treatment of patients with a low body mass index and type 2 diabetes mellitus. However, the mechanism remains speculative. We compared the postprandial gut hormone patterns between patients undergoing laparoscopic GB and laparoscopic SG at 2 years after surgery in a hospital-based, prospective study. Methods A total of 16 laparoscopic GB and 16 laparoscopic SG patients were followed up and appraised for glucose homeostasis. Two years after surgery, the mixed meal test and gut hormones were evaluated in 13 laparoscopic GB and 13 laparoscopic SG patients who had been included in the previous randomized trial. Results The preoperative characteristics, such as body mass index, body weight, waist circumference, and duration of T2DM were comparable between the 2 groups. T2DM remission was achieved in 13 (81%) laparoscopic GB and 3 (19%) laparoscopic SG patients ( P < .05) 2 years after surgery. The laparoscopic GB patients had lost more weight and had a smaller waist circumference and lower levels of glucose and hemoglobin A1c, and lower insulin resistance than the SG patients. Significant differences were found in acyl ghrelin, des-acyl ghrelin, cholecystokinin, and resistin between the 2 groups, but none in obestatin, gastric inhibitory peptide, glucagon-like peptide-1, and leptin. Conclusions Both laparoscopic GB and laparoscopic SG have strong hindgut effects after surgery, but GB has a significant duodenal exclusion effect on cholecystokinin. The laparoscopic SG group had lower acyl ghrelin and des-acyl ghrelin levels but greater concentrations of resistin than the laparoscopic GB group.