Effect of sitagliptin on serum FABP4 level. A: Treatment with sitagliptin (50 mg/day; n = 24; M/F: 15/9) as a monotherapy (n = 14; M/F: 7/7) or a combination therapy with glimepiride, a sulfonylurea (n = 10; M/F: 8/2), for 12 weeks significantly decreased FABP4 levels in patients with type 2 diabetes mellitus. Open circle, male in the monotherapy group; closed circle, female in the monotherapy group; open square, male in the combination therapy group; closed square, female in the combination therapy group. B, C: Both monotherapy with sitagliptin (B) and combination therapy with sitagliptin and sulfonylurea (C) for 12 weeks significantly decreased FABP4 levels in patients with type 2 diabetes mellitus. * P < 0.01.