Effects of miglitol, sitagliptin, and initial combination therapy with both on plasma incretin responses to a mixed meal and visceral fat in over-weight Japanese patients with type 2 diabetes. 'The MASTER randomized, controlled trial'

Absrtact Aim To assess changes in circulating incretin levels and body fat compositions with initial combination therapy with α-glucosidase inhibitor and dipeptidyl peptidase-4 inhibitor in patients with type 2 diabetes (T2D). Methods In this multicenter open-label 24-week trial, Japanese over-weight (BMI≥25kg/m 2 ) patients with T2D not taking medication or taking metformin and/or sulfonylurea were randomly assigned to receive either 50mg of miglitol three times a day (M, n =14), 50mg of sitagliptin once a day (S, n =14), or a combination of both (M+S, n =13). Changes in plasma incretin levels during a meal tolerance test (MTT) and body fat composition with impedance method were evaluated. Results During MTT, postprandial plasma glucose levels decreased more after M+S than after M or S, and postprandial serum insulin levels decreased significantly after M and M+S whereas they increased after S. After M, active gastric inhibitory polypeptide (aGIP) decreased significantly at 30min despite a significant increase at 120min. After S, aGIP levels increased significantly throughout the MTT. After M+S, aGIP increased significantly at 0 and 120min despite of significant decrease at 30min. M+S further enhanced postprandial active glucagon-like peptide-1 levels during MTT than S did. Total body fat mass decreased significantly after M and M+S. Visceral fat mass decreased significantly only after M+S. Serum adiponectin increased significantly only after M+S. Conclusions In over-weight patients with T2D, M+S may have a beneficial effect on adiposity with relation to these different effects on two incretins.