Do Incretins play a role in the remission of type 2 diabetes after gastric bypass surgery: What are the evidence?

Abstract

Gastric bypass surgery (GBP), in addition to weight loss, results in dramatic remission of type 2 diabetes (T2DM). The mechanisms by which this remission occurs are unclear. Besides weight loss and caloric restriction, the changes in gut hormones that occur after GBP are increasingly gaining recognition as key players in glucose control. Incretins are gut peptides that stimulate insulin secretion postprandially; the levels of these hormones, particularly glucagon-like peptide-1, increase after GBP in response to nutrient stimulation. Whether these changes are causal to changes in glucose homeostasis remain to be determined. The purpose of this review is to assess the evidence on incretin changes and T2DM remission after GBP, and the possible mechanisms by which these changes occur. Our goals are to provide a thorough update on this field of research so that recommendations for future research and criteria for bariatric surgery can be evaluated.

Figures

Fig. 1

Schematic representation of gastric banding (a) and gastric bypass (b). Graphics courtesy of Packard Children's Hospital, Palo Alto, CA, USA

Fig. 2

Proposed model for mechanisms of T2DM remission after GBP based on available studies. Dashed lines indicate hypothetical links