Lifestyle is Not the Only Cause of Stroke Risk Factors Recently Attracting Attention

摘要

Cerebrovascular disease (stroke) remains the most common disease in Japan and other Asian countries despite the decrease in stroke mortality. It was expected that the incidence of stroke would decrease in line with the mortality rate, but it has not. The major causes of stroke include hypertension, diabetes, and hyperlipidemia, while alcohol, smoking, obesity, hyperuricemia, and polycythemia are other risk factors. All of these factors are closely related to lifestyle. In some cases, however, factors unrelated to lifestyle or generally ignored to date are involved in the etiology of stroke, particularly in young adults. Lipoprotein(a), C-reactive protein, infection with Chlamydia pneumoniae, anti-phospholipid antibodies, and genetic factors are typical risk factors for stroke that are not related to lifestyle. Homocysteine and hyperinsulinemia are also risk factors for stroke, although they are related to lifestyle to some extent. In this article, risk factors for stroke other than the conventional lifestyle-related factors are discussed briefly, mainly based on data obtained from patients whom we have examined. Our findings have emphasized that when risk factors unrelated to lifestyle are combined with lifestyle-related factors, there is a syngeristic effect on the development of stroke.