GLP-1 as a Therapeutic Agent in Patients with Type 2 Diabetes Mellitus

The gastrointestinal tract has a crucial role in the control of energy homeostasis through the action of multiple peptides known as incretins that act on distant target sites to promote the efficient uptake and storage of energy. In particular, GLP-1, an incretin hormone secreted from the intestinal mucosa in response to meal ingestion, is shown to augment the magnitude of meal-stimulated insulin secretion from islet β cells in a glucose-dependent manner and thus proved to be a novel candidate for treatment in patients with diabetes mellitus. This article reviews the biological actions of GLP-1 regulating glucose homeostasis, with an emphasis on mechanisms of action and the emerging therapeutic roles of GLP-1 analogues, and DPP-4 inhibitors for the treatment of diabetes mellitus.