Inhibition of DPP-4: a new therapeutic approach for the treatment of type 2 diabetes

Abstract
Background: Glucagon-like peptide-1 (GLP‑1) and glucose-dependent insulinotropic polypeptide (GIP) are hormones secreted by the enteroendocrine cells of the gut in response to the ingestion of nutrients. These incretin hormones, so called because they increase insulin secretion, are key modulators of pancreatic islet hormone secretion and, thus, glucose homeostasis. The glucoregulatory effects of incretins are the basis for new therapies currently being developed for the treatment of type 2 diabetes mellitus (T2DM). Drugs that inhibit dipeptidyl peptidase-4 (DPP‑4), a ubiquitous enzyme that rapidly inactivates both GLP-1 and GIP, increase active levels of these hormones and, in doing so, improve islet function and glycemic control in T2DM.Scope: In this review, we briefly describe (1) the role of pancreatic islet dysfunction in the onset and progression of T2DM, (2) the rationale for developing drugs that enhance incretin activity, (3) the evidence that inhibition of DPP‑4 is effective in ameliora...