DPP-4 inhibitors (DPP-4i) are becoming 1st line oral anti-diabetic drugs (OAD) in the management of type 2 diabetes in Japan; approximately 3-million patients, one third of those with diagnosis of diabetes, receive DPP-4i. The widespread use of DPP-4i in Japan is partly due to accumulating data from clinical trials demonstrating that DPP-4 inhibitors exert greater HbA1c-lowering effects in Japanese type 2 diabetes patients and also in non-obese Asian type 2 diabetes patients when compared to diabetes patients of other ethnicities (Ann Pharmacother 2012;46:1453-69; Diabetologia 2013;56:696-708).