Is secretion of glucagon-like peptide-1 reduced in type 2 diabetes mellitus

摘要

Postprandial augmentation of insulin secretion by gastrointestinal peptide hormones-the so-called 'incretin effect'-is reduced in patients with type 2 diabetes mellitus, an observation that has led to investigation of potential mechanisms for this defect. The incretin effect is mediated by the secretion and insulinotropic action of gastric inhibitory polypeptide and glucagon-like peptide-1 (GLP-1). Secretion of gastric inhibitory polypeptide is normal or slightly elevated in patients with type 2 diabetes mellitus, whereas the insulinotropic action of this hormone is almost completely lost. The situation is somewhat different for GLP-1, as the insulinotropic action of this hormone is relatively well-preserved. By contrast, postprandial GLP-1 secretion has been found to be reduced in some studies. In light of this finding, treatment with GLP-1 receptor agonists, such as exenatide, has been suggested to serve as a true replacement therapy that substitutes for a pathophysiological defect in type 2 diabetesmellitus.