Improved Pancreatic β-Cell Function in Type 2 Diabetic Patients After Lifestyle-Induced Weight Loss Is Related to Glucose-Dependent Insulinotropic Polypeptide

After lifestyle-induced weight loss, improvements in oral glucose-induced insulin secretion in older, obese, nondiabetic subjects seem to be largely dependent on improved insulin sensitivity. However, in older obese diabetic patients, improved insulin secretion is a consequence of elevated beta-cell function. We demonstrate for the first time that changes in insulin secretion after lifestyle intervention may be mediated via alterations in GIP secretion from intestinal K-cells.