Fig. 2.

DPP-4 biology and pharmacology of DPP-4i. Incretin hormones, GLP-1, and gastric inhibitory peptide (GIP) regulate insulin secretion in a glucose-dependent manner. DPP-4i inhibit degradation of GLP-1 and GIP, thereby contributing to glycemic control. However, DPP-4i will have multiple effects beyond glycemic control that occur by GLP-1-independent mechanisms because of wide substrate specificity and direct effects of DPP-4 with other proteins. GLP-1R, GLP-1 receptor; I/R, ischemia-reperfusion; MI, myocardial infarction; NPY-1, neuropeptide Y-1; VSMC, vascular smooth muscle cell.