SAT-141 Effect of Vildagliptin versus Glibenclamide on Glycemic Variability and Endothelial Function in Individuals with Type 2 Diabetes and Hypertension: A Randomized Controlled Trial

Abstract

Introduction: Glycemic variability has been considered as an important factor in the development of cardiovascular disease (CVD) in type 2 diabetes mellitus (T2DM). High glycemic variability causes endothelial dysfunction and increased oxidative stress. Among the drugs for T2DM, dipeptidyl peptidase-4 (DPP-4) inhibitors improve endothelial function and decrease glycemic variability. Objectives: To investigate the effects of vildagliptin, a DPP-4 inhibitor, compared with glibenclamide on the glycemic variability and endothelial function of patients with T2DM and hypertension (HT). Methods: Prospective, randomized, open, drug-controlled study. Fifty patients older than 35 years with T2DM and HT without CVD were randomized to receive vildagliptin (n=25) or glibenclamide (n=25), in addition to metformin in both groups. Laboratory tests and analysis of endothelial function were performed before and 12 weeks after treatment. Endothelial function, defined by the reactive hyperemia index (RHI), was analyzed by peripheral artery tonometry (endo-PAT2000). The glycemic variability was evaluated by capillary glycemia with intermittent monitoring device, 6 measures/day, for 3 days, before and after 12 weeks of treatment. The calculation of the standard deviation (SD) of the means of glycemia was used to evaluate the glycemic variability. Results: Glycemic variability decreased in the vildagliptin group, defined by median of SD: before 35.2 mg/dL (13.9 - 59.7) vs 30.7 mg/dL (16.1 - 64.3) after treatment (p=0.037) and did not change with glibenclamide, 37.6 (16.0 - 54.9) vs 37.5 mg/dL (16.5 - 80.03) (p=NS). Glycated hemoglobin was similar in both groups at baseline and decreased after 12 weeks, not significantly (8.3% ± 1.0 vs 8.0% ± 1.34, p=0.18 for vildagliptin, 7.9% ± 0.9 vs 7.5% ± 1.4, p=0.17 for glibenclamide). The fasting glycemia decreased in the vildagliptin (166 ± 38.7 mg/dL vs 147.5 ± 42.6 mg/dL, p=0.01) and glibenclamide groups (164 ± 43.5 mg/dL vs. 139 ± 54 mg/dL, p=0.01), with no difference between them. There were no changes in the RHI before and after treatment in both groups (2.34 ± 0.58 vs 2.24 ± 0.60, for vildagliptin, p=NS; 2.36 ± 0.51 vs 2.33 ± 0.49, p=NS for glibenclamide) and there was no difference between groups. There was no correlation between glycemic variability and RHI. Conclusions: Vildagliptin reduces glycemic variability, but has no action on endothelial function, evaluated by endo-PAT2000.