Effect of vildagliptin, a dipeptidyl peptidase-4 inhibitor, on parameters of glucose metabolism and cardio-ankle vascular index (CAVI) in individuals with type 2 diabetes

Background Dipeptidyl peptidase-4 (DPP-4) inhibitors are the most frequently used first-line agents for the treatment of type 2 diabetes in Japan. This study aimed to examine the effects of vildagliptin, a DPP-4 inhibitor, on glucose metabolism and arterial stiffness. Methods Twenty treatment-naïve patients with type 2 diabetes (8 males and 12 females) received vildagliptin 50 mg twice daily for 6 months. Self-monitored blood glucose measurements and a 75-g oral glucose tolerance test (OGTT) were performed during the study. Systemic arterial stiffness was assessed using the cardio-ankle vascular index (CAVI). Results After 6 months of vildagliptin treatment, a significant decrease in median HbA1c (from 8.3 to 6.4%, p < 0.001) and γ-GTP (from 25 to 19 IU/L, p < 0.001), an increase in fasting HOMA-β (from 26.1 to 34.5%, p = 0.013), and a marginally significant decrease in CAVI (from 8.9 to 8.4, p = 0.087) were observed. The glycemic variability parameters also improved, whereas insulin sensitivity and oxidative stress remained unchanged. Participants with lower glycemic variability in the 75-g OGTT after 6 months of vildagliptin treatment showed a significant decrease in CAVI. The baseline BMI was significantly higher in participants with decreased CAVI than in those with no change in CAVI (24.5 vs. 20.8 kg/m 2 , p = 0.047). Conclusions After 6 months of vildagliptin treatment, glucose metabolism parameters including insulin secretion improved. A decrease in the CAVI was also observed, especially in individuals with improved glycemic variability in the 75-g OGTT. Vildagliptin may be suitable for vascular protection in individuals with high glycemic variability and/or an elevated BMI.