Anti-atherosclerotic effects of sitagliptin in patients with type 2 diabetes mellitus

BACKGROUND Advanced glycation end products, selectins, and adiponectin play important roles in the development of atherosclerosis in individuals with diabetes. Sitagliptin has been shown to reduce the concentration of glycated hemoglobin in diabetic patients. However, its effects on soluble receptor for advanced glycation end products (sRAGEs), selectins, and adiponectin in these patients are poorly understood. This study was conducted to assess the effects of sitagliptin on the circulating levels of sRAGEs, monocyte chemoattractant protein-1 (MCP-1), selectins, and adiponectin in patients with type 2 diabetes. METHODS Diabetic patients eligible for sitagliptin monotherapy or combination therapy (eg, sitagliptin plus a sulfonylurea) were administered sitagliptin (50 mg/day) for 6 months. Levels of soluble P-selectin (sP-selectin), soluble E-selectin (sE-selectin), soluble vascular cell adhesion molecule-1 (sVCAM-1), MCP-1, sRAGEs, and adiponectin were measured by ELISA at baseline and after 3 and 6 months of treatment. RESULTS At baseline, the levels of MCP-1, sP-selectin, sE-selectin, and sVCAM-1 were higher and the level of adiponectin was lower in diabetic patients than in nondiabetic patients. Sitagliptin therapy for 3 and 6 months significantly reduced plasma levels of sP-selectin, sE-selectin, sVCAM-1, and MCP-1 relative to baseline, while significantly increasing adiponectin levels. sRAGEs did not exhibit a statistical significance, although there was an increasing tendency. Furthermore, the reductions in sP-selectin, sE-selectin, sVCAM-1, and MCP-1 during sitagliptin therapy were significantly greater in responders, defined as patients with a significant increase in adiponectin levels, than in nonresponders. In contrast, responders showed a significant increase in the plasma concentration of sRAGEs. CONCLUSION Sitagliptin shows an adiponectin-dependent anti-atherothrombotic effect, which may be beneficial for primary prevention of atherothrombosis, in patients with type 2 diabetes.