Oral administration of ascorbic acid attenuates endothelial dysfunction after short-term cigarette smoking.

Short-term cigarette smoking is associated with persistent endothelial dysfunction. Data on the reversibility of this effect with per os antioxidants after short-term smoking are lacking. This study examines the effect of orally administered ascorbic acid on cigarette smoking-induced endothelial dysfunction. In the present double-blind, randomized, crossover study, 19 healthy subjects (28.7 +/- 6.8 years, mean +/- SD) were examined by high-resolution ultrasonography of the brachial artery before and 0, 30, 60, 90, and 120 minutes after smoking a cigarette. Flow-mediated dilatation (FMD) was used as a method to examine endothelial function. Measurements were performed on two different days, 2 hours after oral administration of 2 g of ascorbic acid or placebo. FMD was similar for each subject between the two visits at baseline. FMD was significantly decreased after smoking with both placebo and ascorbic acid. However, there was a significant beneficial effect of ascorbic acid on the FMD change over time after smoking. After smoking, the FMD dropped to less than half of the baseline value. Thereafter in the placebo group, FMD increased to 70% of baseline value in 90 minutes, but in the ascorbic acid group the FMD increased to 70% of baseline value in 46 minutes. Oral administration of ascorbic acid attenuates endothelial dysfunction after short-term cigarette smoking by shortening its duration.