GLP1R and type 2 diabetes mellitus: The pathophysiology of type 2 diabetes is complex including β cell failure, muscle, and liver insulin resistance, increased renal glucose reabsorption, reduced incretin response, α cell insulin resistance, reduced secretion of and increased resistance to GLP-1 and glucose-dependent insulinotropic polypeptide (GIP) and appetite dysregulation (DeFronzo, 2009).