Lifestyle factors and risk of cerebrovascular disease in women. The Copenhagen City Heart Study

Abstract

Background and purpose: The purpose of the present analysis was to determine how lifestyle influences the risk of cerebrovascular disease in women participating in the Copenhagen City Heart Study.

Methods: A random sample of a white, lower and middle-class, urban population selected in 1976 was invited to two cardiovascular examinations at 5-year intervals. The present analysis was based on 7060 women invited to an initial examination from 1976 through 1978, aged 35 years or more, and without previous stroke or transient ischemic attack. At the initial examination, potential risk factors were recorded. The 265 first cases of stroke and transient ischemic attack were ascertained at a second examination 5 years later and through hospital records and death certificates through 1988. The Cox regression model was used to estimate the influence of the factors recorded on the risk of cerebrovascular disease.

Results: The relative risks of cigarette smoking and lack of physical activity were 1.4 and 1.45; 95% confidence limits, 1.02 to 1.94 and 1.01 to 2.08, respectively). The relative risk of daily consumption of tranquilizers was 1.25 (95% confidence limits, 0.96 to 1.62). No significant influence was found for number of cigarettes, body mass index, or alcohol intake. In postmenopausal women, there was a statistically significant interaction (P < .041) between smoking and hormone replacement therapy. Smokers receiving this therapy had a 28% lower risk of cerebrovascular disease than smokers not receiving it.

Conclusions: The statistically significant and equally potent effects on the risk of cerebrovascular disease were found for cigarette smoking and lack of physical activity. The risk associated with smoking seemed to be influenced by hormonal replacement therapy.