Mechanisms of Diabetes Relapse After Bariatric Surgery

The mechanisms of type 2 diabetes (T2DM) remission after gastric bypass surgery (GBP) are unclear. The levels of the gut hormones incretins and their effect on insulin secretion, which is impaired in T2DM, markedly increase after GBP. The anatomical changes of GBP, rather than weight loss, seem to be responsible for the changes of incretins. The objective of this proposal is to investigate the different mechanisms by which GBP, laparoscopic adjustable gastric banding (LAGB) and vertical sleeve gastrectomy (VSG) affect glucose control. We wish to understand the role of weight loss versus changes in gut peptides in the short and long term in morbidly patients with T2DM after GBP, LAGB or VSG. AIM 1: Will study the short term changes of incretins levels and effect in obese individuals with T2DM after GBP, LAGB or VSG, before and 1 month after GBP or before and after equivalent weight loss after LAGB or VSG. AIM 2: Will study the long-term (12 and 24 months after surgery) changes in the incretin effect on insulin secretion, in patients with T2DM after GBP, LAGB or VSG. AIM 3: Will study the changes of insulin secretion to IV glucose (AIRg) and insulin sensitivity (Si), measured by the minimal model, in patients with T2DM after GBP, VSG or LAGB, before and at 24 months after the surgery, at weight stability under condition of controlled diet.