Effect of gastric bypass surgery on the incretins

Aims Our studies were designed to understand the role of the gut hormones incretins GLP-1 and GIP on diabetes remission after gastric bypass surgery (GBP) Method Morbidly obese patients with type 2 diabetes (T2DM) were studied before and 1, 6, 12, 24 and 36 months after GBP A matched group of patients were Studied before and after a diet-induced 10 kg weight loss. equivalent to the weight loss 1 month after GBP All patients underwent an oral glucose tolerance test and in isoglycaemic glucose intravenous challenge to measure the incretin effect Results Post-prandial GLP-1 and GIP levels increase after GBP and the incretin effect on insulin secretion normalizes to the level of non diabetic controls In addition. the pattern of insulin secretion in response to oral glucose changes after GBP. with recovery of the early phase. and post-prandial glucose levels decrease significantly These changes were not seen after an equivalent weight loss by diet The changes in incretin levels and effect observed at 1 month are long lasting and persist up to 3 years after the surgery The improved insulin release and glucose tolerance after GBP were shown by others to be blocked by the administration of a GLP-1 antagonist in rodents, demonstrating, that these metabolic changes are. in part. GLP-1 dependent Conclusion Although sustained and significant weight loss is likely to be the key mediator of diabetes remission after GBP, the changes of incretins improve the early phase of insulin secretion and post-prandial glucose levels. and contribute to the better glucose tolerance (C) 2009 Published by Elsevier Masson SAS