Comparative Study Of The Effects Of Pioglitazone, Metformin, Glipizide On Vascular Endothelial Function In Type 2 Diabetes

ObjectivesTo observation the effects of Pioglitazone, Metformin and Glipizide on vascular endothelial function-related indicators in type 2 diabetes. Investigate the difference and its possible mechanism of the influence of different treatment on vascular endothelial function in Type 2 diabetes mellitus.Methods1. 82 newly diagnosed T2DM were divided into three groups, including Pioglitazone group 28 cases (group A), Metformin group 30 cases (group B) and Glipizide group 24 (group C); 32 healthy subjects were selected as normal controls( group D). Serum endothelin -1 (ET-1), nitric oxide (NO), nitric oxide synthase (NOS) and inducible nitric oxide synthase (iNOS) levels were measured in the four groups. Waist-to-hipratio (WHR), body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting plasma glucose (FPG), postprandial blood sugar(P2hPG) ,glycosylated hemoglobin(HbA1c) were determined. The indexes were compared and analyzed among the four groups .2.Group A, group B and group C were given corresponding drug intervention. 3 months after treatment, the above-mentioned target of vascular endothelial function , blood glucose and glycosylated hemoglobin were determined in each group to compare with those before treatment, simultaneously analyzed the differences in each group after treatment.Results1. Compared with normal control group, ET-1 level of diabetes group was significantly elevated, NO, T-NOS, iNOS levels were significantly lower,with statistical significance (P <0.05).2. correlation analysis of ET-1, NO and FPG, HbA1c levels in the diabetic group: serum ET-1 was significantly positively correlated with FPG and HbA1c before treatment in the diabetic group; serum NO was significantly negatively correlated with FPG and HbA1c. ET-1 was significantly negatively correlated with NO. NO was significantly positively correlated with T-NOS.3. The changes of vascular endothelial function index before and after treatment in the diabetic group : (1) compared with before treatment, ET-1 level decreased, and NO, T-NOS, iNOS levels significantly increased after treatment in A and B groups. There were significant differences (P <0.05). (2) compared with before treatment, ET-1 was a little lower, NO, T-NOS and iNOS levels were a little higher with no significantl differences after treatment in the C group (P> 0.05). (3) 3 months after treatment, ET-1, NO, T-NOS and iNOS levels were no significant difference between group A and B (P> 0.05),and ET-1 level was significantly higher in the group C than that of group A and B, but NO, T-NOS, iNOS levels were significantly lower, the difference was statistically significant (P <0.05).Conclusion:1 The level of ET-1 is higher in patients with T2DM,while NO and NOS levels are lower, suggesting that vascular endothelial function are injuried in T2DM.2. Pioglitazone and Metformin regulating the levels of ET-1 ,NO and NOS superior to Glipizide, Which shows Pioglitazone and Metformin has better protecting effect on vascular endothelial function.