Evaluation of the positive effects on insulin-resistance and β-cell measurements of vildagliptin in addition to metformin in type 2 diabetic patients.

We evaluated the positive effects of vildagliptin in addition to metformin on glycemic control and β-cell function in type 2 diabetic patients. One hundred and seventy-one type 2 diabetic patients were instructed to add vildaglipin 50mg twice a day or placebo to metformin for 12 months. Body mass index (BMI), glycemic control, fasting plasma insulin (FPI), HOMA-IR, HOMA-β, fasting plasma proinsulin (FPPr), proinsulin/fasting plasma insulin ratio (Pr/FPI ratio), C-peptide, glucagon, vaspin, visfatin, and omentin-1 were evaluated. Before, and after 12 months since the addition of vildagliptin, patients underwent a combined euglycemic hyperinsulinemic and hyperglycemic clamp, with subsequent arginine stimulation. Vildagliptin+metformin were more effective than placebo+metformin in reducing body weight and BMI, glycemic control, HOMA-IR, glucagon and insulin resistance measurements. Vildagliptin+metformin gave also a better increase of HOMA-β, and of all β-cell parameters after the clamp. We also recorded a significant correlation between M value increase and the decrease of vaspin, visfatin, and omentin-1 obtained with vildagliptin+metformin. Vildagliptin, in addition to metformin, proved to be effective in improving β-cell function and in reducing insulin resistance measurements.