当前位置： SCI文献检索 > JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY期刊下所有文献 > Effects of vitamin E on chronic and acute endothelial dysfunction in smokers.

Effects of vitamin E on chronic and acute endothelial dysfunction in smokers.

Abstract：

OBJECTIVES:The aims of this study were to determine whether chronic or acute impairment of flow mediated vasodilation (FMD) in the brachial artery of smokers can be restored or preserved by the antioxidant vitamin E. BACKGROUND:Transient impairment of endothelial function after heavy cigarette smoking and chronic endothelial dysfunction in smokers result at least in part from increased oxidative stress. METHODS:We studied 22 healthy male smokers (mean +/- SD, 23 +/- 9 cigarettes per day) randomly assigned to receive either 600 IU vitamin E per day (n = 11, age 28 +/- 6 years) or placebo (n = 11, age 27 +/- 6 years) for four weeks and 11 age-matched healthy male nonsmokers. Flow mediated vasodilation and endothelium-independent, nitroglycerin-induced dilation were assessed in the brachial artery using high resolution ultrasound (7.5 MHz) at baseline and after therapy. Subjects stopped smoking 2 h before the ultrasound examinations. At the end of the treatment period, a third scan was obtained 20 min after smoking a cigarette (0.6 mg nicotine, 7 mg tar) to estimate transient impairment of FMD. RESULTS:Flow mediated vasodilation at baseline was abnormal in the vitamin E (5.3 +/- 3.8, p < 0.01) and in the placebo group (6.4 +/- 3.5, p < 0.05) compared with nonsmoking controls (11.6 +/- 4.7). Using a two-way repeated measures analysis of variance (ANOVA) to examine the effects of vitamin E on FMD, we found no effect for the grouping factor (p = 0.5834) in the ANOVA over time but a highly significant difference with respect to time (p = 0.0065). The interaction of the time factor and the grouping factor also proved to be significant (p = 0.0318). Flow mediated vasodilation values remained similar after treatment for four weeks in both groups but declined faster after smoking a cigarette in subjects taking placebo compared with those receiving vitamin E (p values from successive differences for the time/group factor: 0.0001/0.0017). The transient attenuation of FMD (calculated as the percent change in FMD) was related to the improvement of the antioxidant status, estimated as percent changes in thiobarbituric acid-reactive substances (r = -0.67, p = 0.0024). Nitroglycerin-induced dilation did not differ between study groups at baseline or after therapy. CONCLUSIONS:These results demonstrate that oral supplementation of vitamin E can attenuate transient impairment of endothelial function after heavy smoking due to an improvement of the oxidative status but cannot restore chronic endothelial dysfunction within four weeks in healthy male smokers.

journal_name

J Am Coll Cardiol

journal_title

Journal of the American College of Cardiology

authors

Neunteufl T,Priglinger U,Heher S,Zehetgruber M,Söregi G,Lehr S,Huber K,Maurer G,Weidinger F,Kostner K

doi

10.1016/s0735-1097(99)00542-2

subject

Has Abstract

pub_date

2000-02-01 00:00:00

pages

277-83

issue

eissn

0735-1097

issn

1558-3597

pii

S0735-1097(99)00542-2

journal_volume

pub_type

临床试验,杂志文章,随机对照试验

在线工具

Effects of vitamin E on chronic and acute endothelial dysfunction in smokers.