Tirzepatide is a recently approved treatment for type-2 diabetes. Treatment with tirzepatide decreases body weight while improving glucose metabolism in patients with obesity and type-2 diabetes. Although the drug is designed to activate receptors for glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), the contribution of activating the GIP receptor in the overall efficacy of tirzepatide is not fully understood. A team of researchers demonstrated for the first time that tirzepatide stimulates insulin secretion in the human pancreas via the GIP receptor. These results contrast with findings in mice, where tirzepatide primarily stimulated insulin secretion via the GLP-1 receptor. This study is now published in Nature Metabolism.
Globally, type-2 diabetes and obesity are on the rise, with prevalence rates having tripled since the 1980’s, according to the WHO. Both diseases are associated with an impaired insulin action and treatment options are explored extensively, including those that target relevant hormone receptors. Two clinically validated targets are the receptors for glucagon-like peptide-1 (GLP-1) and for glucose-dependent insulinotropic polypeptide (GIP). Both receptors increase insulin secretion upon activation. Tirzepatide is a once-weekly GIP receptor and GLP-1 receptor agonist. It is a single molecule that activates the body’s receptors for GIP and GLP-1, which are natural incretin hormones.
