Biochemistry
Glucose-dependent Insulinotropic Polypeptide (GIP)
Definition
Glucose-dependent Insulinotropic Polypeptide (GIP) is a 42-amino acid incretin hormone secreted by K-cells in the duodenum and jejunum in response to dietary carbohydrates and fats. GIP stimulates insulin secretion in a glucose-dependent manner, promotes lipid metabolism in adipose tissue, and may have protective effects on pancreatic beta cells. Dual GIP/GLP-1 receptor agonists such as tirzepatide have demonstrated superior glycemic control and weight reduction compared to selective GLP-1 receptor agonists alone, suggesting synergistic metabolic benefits from targeting both incretin pathways.