The Incretin Effect And Its Significance – Basic To Applied Physiology

The gastrointestinal tract releases several hormones in response to oral food intake and absorption. The increased secretion of insulin in response to oral glucose administration when compared to intravenous glucose administration is called the Incretin effect. This is due to release of certain gut hormones which in turn cause an increased glucose stimulated insulin secretion. The incretin effect is due to two main hormones: Glucose-dependent Insulinotropic Polypetide (GIP) and Glucagon-like Peptide – 1 (GLP-1). The insulinotropic effect of GLP-1 is preserved in type 2 diabetic patients. Since GLP-1 is rapidly degraded by the plasma enzyme Dipeptidyl Peptidase IV (DPP-IV), GLP-1 receptor agonists and DPP-IV inhibitors are now being used to treat type 2 diabetes.