The Effects of One-Anastomosis Gastric Bypass on Glucose Metabolism in Goto-Kakizaki Rats.

BACKGROUND: The improvement in glucose metabolism after bariatric surgery is well established. The aim of this study was to investigate the hormones and glycemic control in diabetes after a one-anastomosis gastric bypass (OAGB) variant in an animal model of non-obese type 2 diabetes mellitus.

METHODS: Thirty-six Goto-Kakizaki rats were randomly assigned to undergo one of the following procedures: OAGB (18 rats) or sham intervention (18 rats). Each group was subdivided into three additional groups according to the time of surgery (early-12 weeks; intermediate-16 weeks; and late-20 weeks). Weight, fasting glycemia, glucose tolerance test (OGTT), and hormone levels (glucagon, insulin, glucagon-like peptide-1 [GLP-1], and glucose-dependent insulinotropic peptide [GIP]) were measured.

RESULTS: All rats maintained their weight. The OGTT showed a significant improvement in glycemic levels in rats with OAGB in all time groups (p < 0.002, for all groups at 60 min). Insulin levels decreased significantly in all animals with OAGB, but glucagon levels increased (glucagon paradoxical response). GLP-1 and GIP increased in rats with OAGB at all times, but was only statistically significant in the early surgery group of GLP-1 (p < 0.005).

CONCLUSION: OAGB in a non-obese diabetic rat model improves glycemic control, with a significant decrease in glucose and insulin levels. This reduction without weight loss suggests a surgically induced enhancement of pancreatic function. It appears that this improvement occurs, although the GLP-1 levels were significantly increased only in the early stages. The paradoxical response of glucagon should be further evaluated.