With regard to monotherapy with OHAs, incidence of hypoglycemia was high in the patients using drugs to promote insulin secretion as 4% for SU agents and 3.8% for glinide agents, followed by 3.5% for pioglitazone, whereas ≤ 2% in patients using metformin, DPP-4 inhibitors, or α-GIs. This evidence concerns the gene DPP4 and Hypoglycemia.