INS and type 2 diabetes mellitus: Vildagliptin was also associated with improved β-cell function that is likely secondary to the improved metabolic state such as improved proinsulin processing (a reduction in the proinsulin to insulin ratio) (24) and the acute insulin response to IV glucose after 6 weeks treatment with vildagliptin in subjects with IFG (16), and after 12 weeks treatment with vildagliptin in patients with T2DM (26).