Kinlay Scott, Behrendt Dominik, Fang James C, Delagrange Danielle, Morrow Jason, Witztum Joseph L, Rifai Nader, Selwyn Andrew P, Creager Mark A, Ganz Peter
Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA.
J Am Coll Cardiol. 2004 Feb 18;43(4):629-34. doi: 10.1016/j.jacc.2003.08.051.
We tested whether long-term administration of antioxidant vitamins C and E improves coronary and brachial artery endothelial function in patients with coronary artery disease (CAD).
Endothelial function is a sensitive indicator of vascular health. Oxidant stress and oxidized low-density lipoprotein (LDL) impair endothelial function by reducing nitric oxide bioavailability in the artery wall.
We randomly assigned 30 subjects with CAD to combined vitamin E (800 IU per day) and C (1000 mg per day) or to placebos in a double-blind trial. Coronary artery endothelial function was measured as the change in coronary artery diameter to acetylcholine infusions (n = 18 patients), and brachial artery endothelial function was assessed by flow-mediated dilation (n = 25 patients) at baseline and six months. Plasma markers of oxidant stress (oxidized LDL and autoantibodies) were also measured.
Plasma alpha-tocopherol (p < 0.001) and ascorbic acid (p < 0.02) increased with active therapy. Compared to placebo, there was no improvement in coronary and brachial endothelial vasomotor function over six months. Although vitamins C and E tended to reduce F2-isoprostanes (p = 0.065), they failed to alter oxidized LDL or autoantibodies to oxidized LDL.
Long-term oral vitamins C and E do not improve key mechanisms in the biology of atherosclerosis or endothelial dysfunction, or reduce LDL oxidation in vivo.
我们测试了长期服用抗氧化维生素C和E是否能改善冠心病（CAD）患者的冠状动脉和肱动脉内皮功能。
内皮功能是血管健康的敏感指标。氧化应激和氧化型低密度脂蛋白（LDL）通过降低动脉壁中一氧化氮的生物利用度来损害内皮功能。
在一项双盲试验中，我们将30名CAD患者随机分为联合服用维生素E（每天800 IU）和C（每天1000 mg）组或安慰剂组。在基线和六个月时，通过测量冠状动脉直径对乙酰胆碱输注的变化来评估冠状动脉内皮功能（n = 18例患者），并通过血流介导的血管舒张来评估肱动脉内皮功能（n = 25例患者）。还测量了氧化应激的血浆标志物（氧化型LDL和自身抗体）。
积极治疗后血浆α-生育酚（p < 0.001）和抗坏血酸（p < 0.02）增加。与安慰剂相比，六个月内冠状动脉和肱动脉内皮血管运动功能没有改善。尽管维生素C和E倾向于降低F2-异前列腺素（p = 0.065），但它们未能改变氧化型LDL或氧化型LDL自身抗体。
长期口服维生素C和E并不能改善动脉粥样硬化生物学或内皮功能障碍的关键机制，也不能在体内降低LDL氧化。
