The Melbourne atherosclerosis vitamin E trial (MAVET): a study of high dose vitamin E in smokers

Objective Our aim was to evaluate whether vitamin E (500IU) slowed the progression of carotid atherosclerosis in a population of chronic smokers over 4 years as measured by ultrasound determination of carotid intima-media thickness (IMT) and systemic arterial compliance (SAC). Methods The Melbourne Atherosclerosis Vitamin E Trial (MAVET) was a randomized, double-blind, placebo-controlled trial in which 409 male and female smokers aged 55 years and over were randomized to receive 500 1 U per day of natural vitamin E or placebo. The primary endpoint was progression of carotid atherosclerosis determined by intima-media thickness of the right common carotid artery. Secondary outcomes were change in systemic arterial compliance and lowdensity lipoprotein (LDL) oxidative susceptibility over time. Results The mean increase in intima-media thickness over time in the vitamin E group was 0.0041 mm/year faster than placebo (95% confidence interval - 0.0021 to 0.0102 mm/year, P= 0.20). Similarly, a non-significant difference between vitamin E and placebo was found for rate of change in systemic arterial compliance (P= 0.11). Vitamin E supplementation did, however, significantly reduce LDL oxidative susceptibility (P < 0.001). Conclusion Vitamin E supplementation is ineffective in reducing the progression of carotid atherosclerosis as measured by intima-media thickness in chronic smokers. This finding extends our knowledge of lack of effectiveness of vitamin E supplementation in populations with high oxidant stress.