Sitagliptin ameliorates vascular endothelial function in newly diagnosed type 2 diabetes patients / 中国医师杂志

ABSTRACT

Objective To investigate sitagliptin and repaglinide could ameliorate endothelial function in newly diagnosed type 2 diabetes patients and to explore its mechanism.Methods A total of 92 newly diagnosed type 2 diabetes patients with glycated hemoglobin A1c (HbA1c) from 6.5％ to 8.5％ was randomly assigned to sitagliptin group(n =46) receiving sitagliptin,and repaglinide group (n =46) receiving repaglinide for 12 weeks.The effect of sitagliptin on vascular endothelial function was measured with endothelium-dependent flow-mediated vasodilation (FMD).FMD,level of serum nitric oxide (NO),plasminogen activator inhibitor-1 (PAI-1) and biochemical variables in the two groups were measured at baseline and 12 weeks after treatment.Results Fasting blood glucose (FBG),postprandial blood glucose (PBG),and HbA1c decreased significantly both in sitagliptin and repaglinide groups after treatment,but the descent more significantly in the repaglinide group than those in the sitagliptin group (P ＜ 0.05).FMD,NO,and homeostasis model assessmentβ (HOMA-[β) were increased,and PAI-1 and homeostasis model assessment-insulin resistance (HOMR-IR) decreased in both two groups of patients (P ＜ 0.05).FMD,NO,and PAI-1 improved more significantly in sitagliptin groups (P ＜ 0.05).With FMD as dependent variables,multiple linear regression analysis showed that NO was a major protection factors of endothelial function,and PAI-1 and mean artery pressure (MAP) were major injury factors of endothelial function.Furthermore,with /FMD as the dependent variable,FMD as the dependent variable,and body mass index (BMI),MAP,HbA1c,HOMA-IR,triglycerides (TG),NO,and PAI-1 as a covariate-linear analysis of covariance showed that improved FMD with NO and PAI-1 were still relevant after treatment with sitagliptin.Conclusions Sitagliptin could improve vascular endothelial function evaluated by FMD better than repaglinide in newly diagnosed type 2 diabetes,the partial mechanism was related to the increase of NO level and the decrease of PAI-1 level,and the effect may be independent of the hypoglycemic effect.