Clinical Investigation About Artery Vasodilation Function In The Early Stage Of Type 2 Diabetes Mellitus

OBJECTIVE To study the alteration of artery endo- thelium-dependentvasodilation in the early stage of type 2 diabetes mellitus (T2DM).METHODS 44 patients with T2DM but without vascular complications and 40normal subjects were recruited. Fasting glucose, fasting-insulin, HbA₁c, TC, TG,HDL-C, LDL-C, Uric acid, NO and ET-1 were measured after 8h overnight fast. Oral75g glucose tolerance test was performed. The inner diameter of brachial artery,arteria carotis and the thickness of intima middle (IMT) fascia of carotid artery wasassessed by a high-resolution ultrasound system before and after reactive hyperemia.Vasodilation function was calculated as changed percent in brachial artery diameter 1min before and after reactive hyperemia. The variations in inner diameter of brachialartery after reactive hyperemia with increased flow (at rest, endothelium-dependentdilation) and after sublingual glyceryl-trinitrate (GNT- an endothelium-independentdilation) were measured.RESULTS Fasting glucose (FPG), fasting-insulin (FINS), 2h plasma glucose(2hPG), HbA₁c, TC, TG, HDL-C, LDL-C, HOMA-IR, NO and ET-1 weresignificantly different between the two groups (p＜0.05 or p＜0.01). There were nosignificant differences between the two groups in age, sex, BMI, SBP, DBP and UA(p＞0.05). Flow-mediated dilation and GNT-induced dilation in the early stage ofT2DM patients were significantly lower than that in the control group (p＜0.05 orp＜0.01).There were no significant differences between the two groups in baselineflow. The baseline vessel inner diameter were significantly wider than that in thecontrol group (p＜0.001 or p＜0.032). The correlation relationships were differentbetween different groups at different IMT regions (Pearson analysis).CONCLUSION The endothelium-dependent arterial dilation and theendothelium-independent dilation were decreased in the early stage of T2DM patients.