Inkretin

Inkretins are a group of gastrointestinal hormones that are released after eating. They play a crucial role in regulating blood glucose levels. The primary inkretins in humans are glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP).

When food is ingested, particularly carbohydrates and fats, these hormones are secreted by specialized cells in the intestinal lining. Inkretins act on the pancreas, stimulating the release of insulin in a glucose-dependent manner. This means that insulin is released when blood glucose levels are high, and its release is suppressed when blood glucose levels are low, thus preventing hypoglycemia. Inkretins also suppress the secretion of glucagon, a hormone that raises blood glucose levels.

Beyond their effects on insulin and glucagon, inkretins also slow down gastric emptying, which contributes to a feeling of fullness and can reduce food intake. They may also have beneficial effects on cardiovascular health.

The inkretin system is impaired in individuals with type 2 diabetes, leading to reduced inkretin effect and contributing to hyperglycemia. This understanding has led to the development of important therapeutic strategies for managing type 2 diabetes. These include inkretin mimetics, such as GLP-1 receptor agonists, which mimic the action of natural GLP-1, and dipeptidyl peptidase-4 (DPP-4) inhibitors, which prevent the breakdown of inkretins, thereby increasing their levels and prolonging their activity.