Background: Epidemiologic studies suggest a protective effect of regular intake of vitamin C and vitamin E as antioxidant in the manifestation of coronary heart disease. Cigarette smoke contains a large amount of radicals and reactive oxygen-derived substances enhancing aggregation of platelets. We investigated the effect of vitamin C as an important antioxidant in human plasma on the aggregation of human platelets in smokers and nonsmokers. Test Persons and Method: Overall 40 persons (mean age: 28 ± 9 years) were randomized. The groups of chronic smokers (21 ± 9 "packyears") and non-smokers consisted of 20 persons, respectively. In each group ten persons were treated with intravenous infusion of 3 g vitamin C or 100 ml 0.9% saline solution (placebo). The maximal aggregation was measured with an aggregometer after 0, 3, 6, and 24 hours with collagen concentrations of 0.5 μg/ml and 1.0 μg/ml, respectively. Results: In smokers with vitamin C application the group comparison by Wilcoxon's rank test demonstrated a significant decrease of platelet aggregation after 6 hours for both collagen concentrations (0.5 μg/ml and 1.0 μg/ml) compared to the placebo group (p ≤ 0.05), whereas nonsmokers with vitamin C application revealed a significant decrease of platelet aggregation after 3 and 6 hours for both collagen concentrations (0.5 μg/ml and 1.0 μg/ml) compared to the placebo group (p ≤ 0.03). The comparison between smokers and non-smokers regarding the effect of vitamin C on platelet aggregation for both collagen concentrations demonstrated no significant difference (3 hours: p= 0.84 and p = 0.97; 6 hours: p = 0.81 and p = 0.59; and 24 hours p = 0.57 and p = 0.06, not significant, respectively). Conclusion: These findings suggest that vitamin C exerts an unknown inhibitory effect on collagen-induced platelets aggregation. These observations may represent a further protective effect of vitamin C in the development of coronary heart disease.
- Coronary disease
- Platelet aggregation inhibitors