Improvement of endothelial vasomotor dysfunction by treatment with alpha-tocopherol in patients with high remnant lipoproteins levels
OBJECTIVES This study sought to examine whether oral intake of alpha-tocopherol, an antioxidant, could improve endothelium-dependent vasorelaxation in patients with high remnant lipoproteins levels. BACKGROUND Remnant lipoproteins are known to be atherogenic and impair endothelium-dependent arterial...
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Published in | Journal of the American College of Cardiology Vol. 33; no. 6; pp. 1512 - 1518 |
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Main Authors | , , , , , , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
New York, NY
Elsevier Inc
01.05.1999
Elsevier Science |
Subjects | |
Online Access | Get full text |
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Summary: | OBJECTIVES
This study sought to examine whether oral intake of alpha-tocopherol, an antioxidant, could improve endothelium-dependent vasorelaxation in patients with high remnant lipoproteins levels.
BACKGROUND
Remnant lipoproteins are known to be atherogenic and impair endothelium-dependent arterial relaxation, but the underlying mechanisms remain unclear. Oxidative stress is a common feature of various risk factors for atherosclerosis.
METHODS
Flow-mediated vasodilation of the brachial artery during reactive hyperemia was examined by high resolution ultrasound technique before and at the end of 4 weeks treatment with oral administration of alpha-tocopherol acetate (300 IU/day) or placebo, which was randomly assigned, in 40 patients with high serum levels of remnants and in 30 patients with low remnants levels in the fasting state (>75th percentile and <25th percentile, respectively, of the distribution of remnants levels in 150 consecutive hospitalized patients).
RESULTS
Before treatment, flow-mediated vasodilation was lower in patients with high remnants levels than in those with low levels (4.1 ± 0.3% vs. 6.0 ± 0.5%, p < 0.01). Treatment with alpha-tocopherol but not with placebo significantly increased flow-mediated dilation in patients with high remnants levels (7.5 ± 0.4% after alpha-tocopherol vs. 4.2 ± 0.4% after placebo, p < 0.01). In patients with low remnants levels, alpha-tocopherol was not effective. The beneficial effect with alpha-tocopherol in high remnants patients was associated with decrease in plasma levels of thiobarbituric acid reactive substances, an indicator of lipid peroxidation (6.6 ± 0.3 nmol/ml before alpha-tocopherol vs. 4.6 ± 0.3 after alpha-tocopherol, p < 0.05).
CONCLUSIONS
Alpha-tocopherol improved impairment of endothelium-dependent vasodilation in patients with high remnants levels. The increase in oxidative stress may at least partly contribute to endothelial vasomotor dysfunction in patients with high remnants levels. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 ObjectType-News-3 content type line 23 |
ISSN: | 0735-1097 1558-3597 |
DOI: | 10.1016/S0735-1097(99)00057-1 |