老年糖尿病患者脂肪餐后血管内皮活性因子的变化

Study on changes of vascular endothelium secreted factors after oral fatty meal test in elderly diabetic patients

目的观察老年糖尿病患者脂肪餐后血管内皮活性因子的动态变化及其与血脂的关系。方法选择老年糖尿病患者（糖尿病组）36例和健康老年人（对照组）20例进行6h脂肪餐负荷试验。糖尿病组根据空腹和脂肪餐后4h三酰甘油（TG）水平分为空腹TG增高组、餐后TG增高组和餐后TG正常组3个亚组。各组均测定脂肪餐前后血清一氧化氮（NO）、内皮素-1（ET1）、纤溶酶原激活物抑制物-1（PAI-1）、组织型纤溶酶原激活物（t-PA）的浓度，并分析与TG的相关性。结果（1）NO、ET-1及NO／ET-1的变化：对照组脂肪餐后2hNO浓度显著升高、ET-1水平显著降低，6h均恢复至餐前水平；而糖尿病各亚组脂肪餐后NO逐渐降低、ET-1逐渐升高，餐后6h变化最为明显。与对照组比较，糖尿病各亚组脂肪餐后各点NO／ET-1均显著降低（P〈0．01），而餐后TG增高组和空腹TG增高组与餐后TG正常组比较差异有统计学意义（P〈0．05或P％0．01）。（2）t-PA、PAI-1及PAI-1／t-PA的变化：各组脂肪餐后4h PAI-1水平轻度升高、t—PA水平轻度降低；与对照组比较，糖尿病组PAI-1／t—PA显著升高，糖尿病各亚组比较，餐后TG增高组和空腹TG增高组显著高于餐后TG正常组（P〈0．05或P〈0．01）。（3）与TG的相关性分析：直线相关分析显示，糖尿病组TG与NO、t-PA显著负相关（r=-0．360，P〈0．05；r=-0．649，P〈0．01），与ET-1、PAI-1显著正相关（r=0．421，P〈0．01；r=0．520，P〈0．01）。结论老年糖尿病患者存在血管内皮活性因子平衡失调，血脂异常可加重这一改变和血管内皮功能的损伤。

Objective To investigate the dynamic changes of vascular endothelium secreted factors after oral fatty meal test and the correlation of the factors with blood lipid in elderly diabetic patients. Methods Thirty-six elderly diabetic patients （diabetic group） and twenty healthy elderly subjects（control group） were selected into the study and received oral fatty meal test for 6 hours. Diabetic group was divided into three subgroups, including fasting hypertriglyceridemia subgroup, postprandial hypertriglyceridemia subgroup and postprandial normotriglyceridemia subgroup. Serum nitric oxide （ NO）, endothelin-1 （ ET-1 ）, plasminogen activator inhibitor-1 （ PAI-1 ） and tissue plasminogen activator （t-PA） were measured before and after oral fatty meal test. Results （1） The level of serum NO was significantly increased and ET-1 was significantly reduced in control group 2 hours after oral fatty meal test and were returned to basal state 6 hours after the test. But in diabetic group, postprandial serum NO level were decreased and ET-1 were increased gradually and reached to the peak 6 hours after oral fatty meal test. The ratio of NO/ET-1 was lower in diabetic group than that in control group （P〈 0.01）. There were important differences among fasting hypertriglyceridemia subgroup, postprandial hypertriglyceridemia subgroup and postprandial normotriglyceridemia subgroup（P〈0.05 or〈0.01）. （2） The level of PAI-1 was increased and t-PA was decreased slightly 4 hours after oral fatty meal test in control and diabetic groups. Compared with control group, PAI-1/t-PA obviously increased in diabetic group. Meanwhile, PAI-1/t PA in fasting hypertriglyceridemia and postprandial hypertriglyceridemia subgroups were significantly higher than that in postprandial normotriglyceridemia subgroup（P〈0. 05 or〈0. 01）. （3） In the diabetic group, TG was negatively correlated with NO and t-PA（r=-0. 360 P〈0.05;r= -0. 649,P〈0.01） and positively correlated with ET 1 and PAI-1（r=0. 421 ,P〈0.01 ;r=0. 520,P〈0.01）. Conclusions The elderly diabetic patients suffer from the imbalance of vascular endothelium secreted factors. The postprandial abnormal TG metabolism may aggravate the change and further damage the vascular endothelial function.