SMOKING AND RISK OF MYOCARDIAL-INFARCTION IN WOMEN AND MEN - LONGITUDINAL POPULATION STUDY

Objective: To compare risk of myocardial infarction associated with sm oking in men and women, taking into consideration differences in smoki ng behaviour and a number of potential confounding variables. Design: Prospective cohort study with follow up of myocardial infarction. Sett ing: Pooled data from three population studies conducted in Copenhagen . Subjects: 11 472 women and 13 191 men followed for a mean of 12.3 ye ars. Main outcome measures: First admission to hospital or death cause d by myocardial infarction. Results: 1251 men and 512 women had a myoc ardial infarction during follow up. Compared with non-smokers, female current smokers had a relative risk of myocardial infarction of 2.24 ( range 1.85-2.71) and male smokers 1.43 (1.26-1.62); ratio 1.57 (1.25-1 .97). Relative risk of myocardial infarction increased with tobacco co nsumption in both men and women and was higher in inhalers than in non -inhalers. The risks associated with smoking, measured by both current and accumulated tobacco exposure, were consistently higher in women t han in men and did not depend on age. This sex difference was not affe cted by adjustment for arterial blood pressure, total and high density lipoprotein cholesterol concentrations, triglyceride concentrations, diabetes, body mass index, height, alcohol intake, physical activity, and level of education. Conclusion: Women may be more sensitive than m en to some of the harmful effects of smoking. Interactions between com ponents of smoke and hormonal factors that may be involved in developm ent of ischaemic heart disease should be examined further.