1. Cigarette smoking is known to increase the risk of cardiovascular disease in both men and women. Experimental and epidemiological studies have demonstrated that cigarette smoking is associated with several indices of increased platelet activation and platelet/vessel wall interaction in men. The aim of the present study was to test the hypothesis that cigarette smoking is linked to an increased platelet activity in women also.
2. In 26 healthy smoking and non-smoking women (age 21–49 years) the urinary excretion of the thromboxane A2 metabolite 2,3-dinor-thromboxane B2 (an index of platelet activation) and of the prostacyclin metabolite 2,3-dinor-6-keto-prostaglandin F1α (an index of platelet/vessel wall interaction) were analysed by g.c.-m.s. in samples collected on days 3, 10 and 20 of their respective menstrual cycles.
3. The urinary excretion of 2,3-dinor-thromboxane B2 did not vary significantly during the menstrual cycle, either in the smokers or in the non-smokers. It was consistently higher (P < 0.004) in the group of smokers (average of days 3, 10 and 20, 395 ± 61 pg/mg of creatinine; mean ± sem) than in the group of non-smokers (average 188 ± 22 pg/mg of creatinine).
4. The urinary excretion of 2,3-dinor-6-keto-prostaglandin F1α did not differ between the groups on any of the days studied (average on days 3, 10 and 20 in the smokers and non-smokers was 281 ± 50 and 227 ± 30 pg/mg of creatinine, respectively).
5. These data demonstrate that smoking fertile women excrete more of the thromboxane A2 metabolite than do non-smokers, thereby supporting the hypothesis that cigarette smoking elicits platelet activation in healthy women. In contrast, platelet/vessel wall interaction does not appear to be facilitated in smoking compared with non-smoking women. The data suggest that platelet activation is not a major haemostatic mechanism during menstruation.