The Influence Of Postprandial Hypertriglyceride Rich Lipoprotein On The Vascular Endothelial Function In Elderly Diabetic Patients And The Role Of Lipid-regulating Drug

[Objective]The aim of this study is to investigate the dynamic change of Postprandial hypertriglyceride rich lipoprotein in elderly diabetic patients and provide lipid-regulating drugs for them,so as to explore the effects on the endothelial function and the mechanism of diabetes inducing AS,and to present objective evidence for early treating hypertriglyceridemia and preventing AS.[Methods]Subjects were assigned to two groups:the observed group of 30 fasting normotriglyceridemic elderly type 2 diabetic patients who were divided into two subgroups:PNTG[4 hour postprandial blood triglyceride level(TG4h≤2.0mmol/l)]and PHTG(TG4h＞2.0mmol/l)according to the level of TG4h±2s in control group;the normal control group of 12 healthy subjects(NC).Total triglyceride(TG),NO,ET-1,PAI-1,t-PA were measured before and 2,4 and 6 hours after a fatty meal(600kcal,60%fat, 14%protein,26%carbohydrate).Carotid IMT,fasting FMD and 4h after the meal were measured by ultrasonography.Bezafibrate were given to the PHTG group at a dose of 200mg three times daily.All of the above indexes were tested again after three-month treatment.[Results]1.The comparison of TG:Compared with fasting state,the levels of TG2h-6h were obviously increased(P＜0.01).Compared with the control group,the levels of TG was obviously higher,especially the level of TG_4h(P＜0.01).The levels of TG were obviously lower after bezafibrate therapy.2.The changes of NO,ET-1:Compared with the control group,the levels of NO were obviously lower and the levels of ET-1 were obviously higher. Compared with PNTG group,the levels of NO were obviously lower;But no significant difference in ET-1 was observed before and after oral fat-tolerance test(OFT).The levels of NO were obviously higher and the levels of ET-1 were obviously lower after bezafibrate therapy.Relation analysis:NO was negatively correlated with TG(r=-0.355,P=0.031),ET-1 was positively correlated with TG(r=0.432,P=0.008).3.The comparison of PAI-1 and t-PA:The level of PAI-1 at 4h was significantly higher than at 0h(P＜0.01)and the level of t-PA was significantly lower at 4h than at 0h(P＜0.01).Compared with control group, the level of PAI-1 was significantly increased and the level of t-PA was significantly decreased in the diabetic group.Compared with PNTG,the level of PAI-1 was significantly increased(P＜0.05)and the level of t-PA was significantly decreased in the PHTG(P＜0.05).The level of PAI-1 was significantly decreased(P＜0.01)and the level of t-PA was significantly increased(P＜0.01)after bezafibrate therapy.Relation analysis:In the diabetic group,PAI-1 was positively correlated with TG(r=0.516, P=0.001),t-PA was negatively correlated with TG(r=-0.652,P＜0.001).4.The comparison of IMTc and FMD and relation analysis:Compared with control group,IMTc and△FMD was higher in the diabetic group;Compared with the PNTG,the PHTG had higher IMTc and△FMD.FMD_4hwas lower than FMD_0hin every group.IMTc and△FMD were significantly lower after bezafibrate therapy.Relation analysis:IMTc was negatively with△FMD (r=0.625,P＜0.01).[Conclusion]1.Most normotriglyceridemic diabetic patients are accompanied with the abnormal postprandial TG metabolism.Bezafibrate can significantly decrease the level of TG and improve the abnormality of postprandial lipid metabolism.2.In most elderly diabetic patients,NO concentration shows descending tendency,ET-1 shows ascending tendency.Bezafibrate can significantly increase the level of NO and decreased the level of ET-1, so as to improve vascular endothelial cell(VEC)dysfunction induced by dyslipidemia.3.The abnormal change of PAI-1 and t-PA can reflect the activity of fibrinolytic system,destroy the balance of cruor-fibrinolysis system. Bezafibrate can significantly increase the level of t-PA and decreased the level of PAI-1.4.Elderly diabetic patients have endothelial dysfunction and higher IMTc. Bezafibrate can improve VEC dysfunction and lower IMTc through decreasing the TG level.