摘要
目的探讨维生素C对急性高血糖所致内皮功能损伤的保护作用。方法选择正常健康人10例、2型糖尿病(T2DM)患者20例。所有对象行75g葡萄糖耐量试验(OGTT)。其中,T2DM患者分为2组(各10例):单纯OGTT组和OGTT+维生素C组。均分别于OGTT0、60、120min采用高分辩血管外超声法检测肱动脉血流介导的内皮依赖性血管舒张功能和硝酸甘油(GNT)介导的内皮非依赖性血管舒张功能。结果在OGTT试验中,单纯OGTT组和OGTT+维生素C组0、60、120min内皮依赖性血管舒张功能分别明显高于对照组(P<0.05)。与0min相比,单纯OG-TT组和OGTT+维生素C组60min内皮依赖性血管舒张功能明显降低,120min又明显回升(P<0.05)。与单纯OG-TT组比较,OGTT+维生素C组60、120min内皮依赖性血管舒张功能明显增高(P<0.01),而0min2组相似。单纯OGTT组和OGTT+维生素C组在基础状态下,LDL-C、Lp(a)、FBG、HbA1c与内皮依赖性血管舒张功能呈负相关(P<0.01)。在OGTT中,单纯OGTT组和OGTT+维生素C组血糖与内皮依赖性血管舒张功能负相关(P<0.05)。结论高血糖快速抑制内皮依赖性血管舒张功能。提示延长或反复的餐后高血糖在糖尿病血管并发症的发生与发展中起重要作用。维生素C对急性高血糖所致内皮功能损伤具有明显保护作用。可能是通过维生素C保护NO免遭超氧阴离子和其它氧自由基的灭活起作用。
Objective To investigate the effect of vitamin C on endothelial dysfuetion after acute hyperglycemia in patients with type 2 diabetes （T2DM）. Methods Ten healthy men and 20 male patients with T2DM were studied. All subjects performed oral glucose tolerant test （OGTT）. Patients with T2DM were divided into 2 groups. Ten patients only took OGTT were as OGTT group, and the other 10 patients also accepted 2 grams of vitamin C orally as OGTT ＋ Vitamin C group. Endotheliurn-dependent and independent arterial dilation were measured using high resolution ultrasound technique at the 0min, 60min, and 120min during the OGTT. Results During the OGTT, the endothelium-dependent arterial dilation at 0min, 60min, 120min in OGTT group and OGTT ＋ Vitamin C group were significantly lower than those in control group respectively （P〈0. 05）. The endothelium-dependent arterial dilation at 60min were signifieantly lower than those at 0min, and also significantly lower than those at 120min in OGTT group and OGTT ＋ Vitamin C group （P〈 0.05）. Compared with OGTT group, the endothelium-dependent arterial dilation at 60 min and 120min increased signifi- cantly in OGTT ＋ Vitamin C group （P〈0. 05）, and there was no difference between the two groups at 0min. For patients at baseline, LDL-C, Lp（a）, FBG and HbAlc were negatively related to endothelium-dependent arterial dilation （P〈 0. 01）. During OGTT, blood glucose were negatively related to endothelium-dependent arterial dilation in OGTT group and OGTT ＋ Vitamin C group （P〈0. 05）. Conclusion Hyperglycemia rapidly suppresses endothelium-dependent arterial dilation. Prolonged and repeated post-prandial hyperglycemia may play an important role in the development of diabetic angiopathy. Vitamin C improves endothelium-dependent arterial dilation during acute hyperglycemia, and this may be related to the role of vitamin C to scavenge oxygen-derived free radicals.
出处
《华南国防医学杂志》
CAS
2008年第2期38-41,共4页
Military Medical Journal of South China
