Sitagliptin improves vascular endothelial function in Japanese type 2 diabetes patients without cardiovascular disease

We evaluated the effect of sitagliptin on vascular endothelial function in Japanese type 2 diabetes patients without cardiovascular disease. Subjects included 24 Japanese type 2 diabetes patients without cardiovascular disease. This study was a prospective, open-label, randomized clinical trial. We divided the study subjects into 2 groups: subjects who received sitagliptin 50 mg daily (sitagliptin group, n = 12) and subjects who did not receive sitagliptin (control group, n = 12). Brachial artery flow-mediated dilation (FMD) was measured after overnight fasting. Sitagliptin administration was initiated at 1 month after enrollment in study (baseline). FMD and level of biochemical variables in the sitagliptin and control groups were measured at baseline and 3 months from baseline (3 months). We evaluated the effect of sitagliptin on vascular endothelial function by measuring FMD. FMD at 3 months was significantly higher in the sitagliptin group than in the control group (5.36% ± 2.18% vs 3.41% ± 2.29%, P = 0.040), while FMD at baseline was not significantly different between the 2 groups. In addition, FMD of the sitagliptin group at 3 months was significantly higher than that at baseline (5.36% ± 2.18% vs 3.67% ± 2.30%, P = 0.004), while no significant differences were observed in the FMD of the control group during the study period. The change in the adiponectin from baseline to 3 months was significantly higher in the sitagliptin group than that in the control group (0.82 ± 2.18 μg/mL vs 0.01 ± 0.55 μg/mL, P = 0.039). Sitagliptin improves vascular endothelial function of the brachial artery in Japanese type 2 diabetes patients without cardiovascular disease. Furthermore, elevation of adiponectin may induce reduction of endothelial dysfunction in type 2 diabetes patients treated with sitagliptin.