Incretin based therapies for type 2 diabetes mellitus.

ABSTRACT

The incretin effect denominates the phenomenon that oral glucose elicits a higher insulin response than intravenous glucose. Glucagon like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide are the principal hormones responsible for incretin effect. In patients with type 2 diabetes the incretin effect of these hormones is impaired. Therapeutic approaches for enhancing the incretin action include degradation resistant GLP-1 receptor agonists (incretin mimetics) and inhibitors of dipeptidyl peptidase-IV (DLP-IV) activity (incretin enhancers- gliptins). These groups of medications have similar efficacy with regards to glycaemic improvement (reduction of HbA1c between 0.5 to 1.1%) and have side-effects like nausea. The incretin mimetics are injectable agents and are more likely to reduce weight or be weight neutral when compared to the oral gliptins. Long-term studies are essential to determine the real potential and role of these newer agents in the management of type 2 diabetes.