维生素C和维生素E对急性糖负荷致原发性高血压血管内皮功能损害的保护作用

为探讨急性糖负荷对高血压病患者内皮依赖性血管舒张功能的影响及急性期维生素C和维生素E对血管内皮功能的保护作用。选取 39例高血压病患者和 2 1例正常血压的对照者随机各分为 3组 (共 6组 ) ,禁食 12h后分别口服 75g葡萄糖 (糖负荷组 )、口服 75g葡萄糖同时服维生素C(维生素C组 )和口服 75g葡萄糖同时服维生素C和维生素E(维生素C和E组 )。在服糖前及服糖后 1、2、3h采用高分辨率血管外彩超检测相同时间点的肱动脉血流介导的内皮依赖性血管舒张功能 ,并分别测定血清抗氧化产物。在三组受试者中 ,高血压病组的基础内皮功能均较正常组下降 ,但未达到统计学意义 ;急性糖负荷明显损伤血管内皮功能 (9.4 8%± 3.33%比 13.0 9%±6 .78% ,P <0 .0 5 ) ,且高血压病患者较正常对照者更为显著 (9.4 8%± 3.33%比 14 .2 0 %± 6 .4 8% ,P <0 .0 5 )。抗氧化维生素对糖负荷所致的血管内皮功能的损害呈剂量依赖性的保护作用。由此可见 ,急性高血糖能造成血管内皮功能的损害 ,这种损害在原发性高血压患者中尤为明显 ,并能由高浓度的维生素C和维生素E逆转。

Endothelium Dependent Vasodilation Attenuated by Acute Glucose Loading in the Patients with Essential Hypertension:the Effect of Vitamin C and Vitamin E

Aim To explore the influence of acute glucose loading on endothelium-dependent vasodilation in essential hypertension and the protective effect of vitamin C and vitamin E. Methods 39 patients with essential hypertension (EH) and 21 normaltensive controls were randomly divided into three groups. We evaluated the acute effects of oral glucose loading(75 g) alone, with Vitamin C (2 g) and E (0.8 g) or Vitamin C (0.9 g) on endothelium-dependent flow-mediated dilation (EDF) of the brachial artery assessed by high-resolution ultrasound technique on 0,1,2,3 hour after glucose loading respectively. At the same time, we measured the concentrations of plasma superoxide dismutase (SOD), total antioxidative capacity (T-AOC) and superoxide anion (O 2 -). Results The basic EDF were diminished in EH. After 75 g glucose loading, EDF were decreased significantly in both patients (9.48%±3.33% vs 13.09%±6.78%, p<0.05) and controls (14.20%±6.48% vs 17.91%±6.87%, p<0.05). The severity of postprandial EDF was more serious in EH than in controls groups (9.48%±3.33% vs 14.20%±6.48%, p<0.05). The impairment was most significant in the first hour and returned to the basic level in the second hour. Different dose of vitamins can improve the impairment in a dose-dependent manner. Conclusions EDF impairment was induced by acute hyperglycemia in EH patients which can be reversed by high concentration of vitamin C and vitamin E.