| [Objective] To explore whether the elderly diabetic patients are accompanied with postprandial abnormal metabolism of serum lipids and vessel endothelial dysfunction and to investigate the assiociation of the abnormal postprandial triglyceride metabolism with flow mediated vasodilation(FMD), vessel active substances and intima-media thickness of carotide(IMTc).[Methods] In 36 elderly diabetic patients and 10 healthy controls, triglyceride, high-density lipoprotein, low-density lipoprotein, total cholesterol, apoliprotein Al, apoliprotein B, glucose, NO and ET-1 were measured before and 2, 4, 6h after Oral Fatty Test(OFT), PAI-1 and t-PA were measured before and 4h after OFT, Triglyceride peak response (TGPR) and the area under triglyceride curve (TG-AUC) over 6 hours were calculated and regarded as the index to show the response level of the subjects to OFT, the ratio of NO/ET-1 was calculated. At the same time, flow-mediated vasodilation(FMD) in the brachial artery was examined as an marker of endothelial function at the different time points with 7. 0 MHz ultrasound as percent arterial diameter change of upper-arm artery occlusion, IMTc was detected through two dimensional ultrasound in fasting state.[Results]1. Postprandial changes in lipids:①The comparation 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 TG4h[(2.98±0.80) vs(1.54±0.25)mmol/L,P <0.01]. Compared with the postprandial normotriglyceridemic group (PNTG), the levels of TG were higher in postprandial hypertriglyceridemic group(PHTG) and the fasting hypertriglyceridemic group(FHTG). According to the order of healthy controls,PNTG,PHTG and FHTG, we found that the TGPR and TG-AUC were high and the TGPT delayed gradually. The TG-AUC was positively correlated with theΔTG4h(r4=0.809, P<0.01).②The changes of other lipis:No significant difference in HDL-C,LDL-C,TC and LPa were observed in groups before and after OFT;compared with the controls, the level of HDL-C was lower and the level of Lpa was higher in diabetic group(P<0.05). The level of LPa in FHTG was higher than in the FNTG. The levels of AP0A1 and APOB began to ascent at 2 hours and reached the peak at 4 hours after OFT in each group. Compared with the fasting state, the level of APOB at 4th hour was obviously increased(P<0.05).2. The changes of NO,ET-1:①The changes of NO: In controls, the level of NO was higher at 2h than at 0h[(99.01±12.10) vs (75.52±11.72)μmmol/L, P<0.01], with the descendent of TG, NO concentration came back to the basic level at 6 hours. In diabetic group, NO concentration became low gradually, but only the level of NO at 6h was decreased obviously [(76.02±11.63) vs (99.01±12. 10)μmmol/L, P<0.05].②The changes of ET-1: In controls, the level of ET-1 was lower at 2h than at 0h [(58.54±11.02) vs (74.22±12.37)pg/ml,P<0.01], with the descendent of TG, ET-1 concentration came back to the basic level at 6 hours. In diabetic group, ET-1 concentration became high gradually after OFT, but only the level of ET-1 at 6h were decreased obviously[(121.92±18.41) vs (103.12±18.27)pg/ml, P<0.05]. Compared with the PNTG, the concentration of ET-1 were higher at 0h and at 4h in the PHTG and the FHTG(P<0.01).③The changes of N0/ET-1:In controls, there was a peak of NO/ET-1 ratio at the 2 hours. In diabetic group, NO/ET-1 ratio became low gradually, only NO/ET-1 at 6h was decreased obviously [(0.32±0.10) vs (0.51±0.15), P <0.05]. Compared with the PNTG, the ratio of NO/ET-1 was lower at 6h in the PHTG[(0.32±0.09) vs (0.41±0.09), P<0.05].④Relation analysis: NO was negtively correlated with TG(r=-0.360, P=0.031), ET-1 was positively correlated with TG(r=0.421, P=0.008).3. The comparation of PAI-1 and t-PA:①The change of PAI-1:The level of PAI-1 at 4h was significantly higher than at 0h(P<0.01). Compared with control group, the level of PAI-1 was significantly increased in the diabetic group[(41.28±12.45) vs (30.23±8.72), P<0.01]. Compared with PNTG, the level of PAI-1 was significantly increased in the PHTG and FHTG.②The change of t-PA: The level of t-PA was significantly lower at 4h than at 0h(P<0.01). Compared with control group, the level of t-PA was significantly decreased in the diabetic group. Compared with PNTG, the level of PAI-1 was significantly decreased in the PHTG and FHTG.③Relation analysis:In the diabetic group, PAI-1 was positively correlated with TG (r=0.520, P=0.001), t-PA was negatively correlated with TG(r=-0.649, P <0.001).4.The comparation of IMTc and FMD and relation analysis:Compared with control group, IMTc andΔFMD was higher in the diabetic group; Compared with the PNTG, the PHTG had higher IMTc andΔFMD. FMD4h was lower than FMD0h in every group. On regression analysis, IMTc andΔFMD was positively correlated with TG-AUC,ΔTG4,HOMA-IR,ET-1 and PAI-1 (P<0. 01), IMTc andΔFMD negatively with HDL-C,NO and t-PA, IMTc negatively withΔFMD (r=0.623, P<0.01).5. The comparation of HOMA-IR and the relation analysis: Compared with control group, the HOMA-IR was higher in diabetic group, HOMA-IR was positively related with TG2h,TG4h,TG6h,TG-AUC,TGPR(r=0.522, 0.533,0.487, 0.524, 0.617), Stepwise multiple regression analysis showed that HOMA-IR= 3.263TG4h-2. 66TG0h-0. 162. [Conclusion]1.Most normotriglyceridemic diabetic patients are accompanied with the abnormality of postprandial TG metabolism and IR, which IR is one of pathogenesis of elderly diabetic abnormal blood lipids after meal.2. In most diabetic patients, NO concentration shows descending tendency, ET-1 shows ascending tendency. Diabetic mellitus may result in the vessel endothelial dysfunction.3. The abnormal change of PAI-1 and t-PA can reflect the activity of fibrinolytic system directly,destroy the balance of cruor-fibrinolysis system.4. Diabetic patients have endothelial dysfunction and postprandial abnormal TG metabolism may aggravated endothelial dysfunction.5. Diabetic patients have higher IMTc and the abnormality of TG metabolism could increase the IMTc.
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