[Effect of vitamin C on platelet aggregation in smokers and nonsmokers].
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 nonsmokers 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 microgram/ml and 1.0 microgram/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 microgram/ml and 1.0 microgram/ml) compared to the placebo group (p < or = 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 microgram/ml and 1.0 microgram/ml) compared to the placebo group (p < or = 0.03). The comparison between smokers and nonsmokers 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).


CONCLUSIONS
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.
Schindler
Thomas H
TH
Medizinische Klinik III, Klinik für Kardiologie und Angiologie, Universität Freiburg. schindler.th@t-online.de
Lewandowski
Eva
E
Olschewski
Manfred
M
Hasler
Karla
K
Solzbach
Ulrich
U
Just
Hanjörg
H
D000328:Adult; D001205:Ascorbic Acid / Q000494:pharmacology*; D003327:Coronary Disease / Q000097:blood; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D010974:Platelet Aggregation / Q000187:drug effects*; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects / Q000097:blood*
D001205:Ascorbic Acid