Long-term effect of combined vitamins E and C on coronary and peripheral endothelial function.

Abstract

OBJECTIVES:

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).

BACKGROUND:

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.

METHODS:

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.

RESULTS:

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.

CONCLUSIONS:

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.

• Authors: Scott Kinlay, Dominik Behrendt, James C Fang, Danielle Delagrange, Jason Morrow, Joseph L Witztum, Nader Rifai, Andrew P Selwyn, Mark A Creager, Peter Ganz
• Journal: Journal of the American College of Cardiology (J Am Coll Cardiol) Vol. 43 Issue 4 Pg. 629-34 (Feb 18 2004) ISSN: 0735-1097 [Print] United States
• PMID: 14975474 (Publication Type: Clinical Trial, Journal Article, Randomized Controlled Trial, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Antioxidants
• Vitamin E
• Ascorbic Acid

Topics

• Antioxidants (administration & dosage, therapeutic use)
• Ascorbic Acid (administration & dosage, therapeutic use)
• Brachial Artery (drug effects)
• Coronary Disease (drug therapy, physiopathology)
• Coronary Vessels (drug effects)
• Double-Blind Method
• Drug Therapy, Combination
• Endothelium, Vascular (drug effects, physiology)
• Female
• Humans
• Male
• Middle Aged
• Oxidative Stress (drug effects)
• Time Factors
• Vasodilation (physiology)
• Vitamin E (administration & dosage, therapeutic use)