Glucagon-like Peptide-1 (GLP-1) is a multifunctional incretin hormone that plays a crucial role in glucose homeostasis and metabolism. It is produced and secreted by the L cells of the intestine in response to food intake. GLP-1 exhibits several actions that contribute to its role in regulating blood sugar levels, particularly after meals.
- Enhancement of Glucose-Dependent Insulin Secretion: One of the primary actions of GLP-1 is to stimulate the pancreas to release insulin in response to elevated blood glucose levels. This effect is glucose-dependent, meaning that it occurs only when blood glucose levels are high, thereby reducing the risk of hypoglycemia (low blood sugar levels).
- Inhibition of Glucagon Secretion: GLP-1 helps lower blood glucose levels by inhibiting the secretion of glucagon, a hormone that increases blood glucose levels by stimulating glucose production in the liver.
- Delay in Gastric Emptying: GLP-1 slows down the rate at which the stomach empties its contents into the small intestine, leading to a slower absorption of glucose into the bloodstream. This action helps moderate the rise in blood glucose levels following a meal.
- Appetite Regulation and Satiety: GLP-1 has been shown to decrease appetite and increase feelings of fullness, which can contribute to reduced food intake and potentially aid in weight management.
The therapeutic potential of GLP-1 has been harnessed in the development of GLP-1 receptor agonists (GLP-1 RAs), a class of medications used in the treatment of type 2 diabetes mellitus. These medications mimic the actions of endogenous GLP-1, offering benefits such as improved glycemic control, potential weight loss, and a low risk of hypoglycemia when used as monotherapy. Additionally, research has indicated cardiovascular benefits associated with GLP-1 RAs, making them an attractive option for managing type 2 diabetes, especially in patients with or at risk for cardiovascular disease.