Incretin therapy for type 2 diabetes: GLP-1 receptor agonists and DPP-4 inhibitors

Abstract

Incretin therapy is a glucose-lowering therapy which has attracted great interest during recent years. It is based on the antidiabetic action of the incretin hormone glucagon-like peptide-1 (GLP-1), which involves both stimulation of insulin secretion and inhibition of glucagon secretion. This results in lowering of both fasting and postprandial glycaemia. Incretin therapy is either with GLP-1 receptor agonists or with inhibitors of dipeptidyl peptidase-4 (DPP-4), which is the enzyme which inactivates endogenous GLP-1. The GLP-1 receptor agonists are injected subcutaneously once or twice daily or once weekly. The DPP-4 inhibitors are oral tablets taken once or twice daily. Both therapies reduce HbA_1c without weight gain, and for GLP-1 receptor agonists with a weight reduction. Incretin therapy is safe with very few adverse events and an additional value of the therapy is a very low risk for hypoglycaemia. Incretin therapy is efficient both in monotherapy and in combination with metformin, sulphonylureas, thiazolidinediones and insulin. Its main indication is as add-on to metformin in patients who are insufficiently controlled on metformin alone, and an important indication is also in combination with insulin therapy. The experienced value of incretin therapy for patient care will most likely result in increased use of this therapy during the coming years.

Keywords:

• incretin hormones
• GLP-1
• DPP-4
• treatment
• type 2 diabetes