Glucagon like peptide-1 may not be related with type 2 diabetes resolution after Gastric Bypass

Glucagon like peptide-1 (GLP-1) is a gut hormone related to insulin sensitivity. It has been suggested as a major factor for the improved glucose tolerance ensuing after Roux-en-Y Gastric Bypass (RYGBP) surgery. In this procedure, a stomach pouch is connected directly to the small intestine just beyond the duodenum. The remaining small intestine, with the rest of the stomach attached, is connected into a lower part of the intestine creating the "Y" shape that gives the technique its name. A work published in Diabetes Care suggests that the resolution of type 2 diabetes after RYGBP may be explained by mechanisms beyond enhancement of GLP-1 action. The first author of the paper is Dr. Amanda Jiménez, and Dr. Josep Vidal is the latter, both from the IDIBAPS team Diabetes: metabolic and molecular networks and the Endocrinology Service of the Hospital Clínic of Barcelona directed by Dr. Vidal.

In this study a set of indicators were measured after a meal challenge with either a GLP-1r antagonist or saline infusion in subjects with sustained remission of type 2 diabetes after RYGBP and healthy controls. The presence of the GLP-1r antagonist, which should have altered the glucose metabolism in case GLP-1 action was directly related with type 2 diabetes remission, resulted in marginal deterioration of the 2-h plasma glucose after meal intake in RYGBP subjects. Furthermore, glucose response to meal intake was similarly enlarged in the two study groups. The limited deterioration of glucose tolerance on blockade of GLP-1 action suggests the beneficial effects of RYGBP over type 2 diabetes may not be significantly related with GLP-1 as previously thought.

Reference: Jiménez A, Casamitjana R, Viaplana-Masclans J, Lacy A, Vidal J. GLP-1 Action and Glucose Tolerance in Subjects With Remission of Type 2 Diabetes Mellitus After Gastric Bypass Surgery. Diabetes Care. 2013 Jan 28. [Epub ahead of print]. doi: 10.2337/dc12-1535