Incidence and risk factors for subtypes of cerebral infarction in a general population - The Hisayama study

Background and Purpose-We estimated the incidence of first-ever cerebral in farction in regard to its subtypes and analyzed their risk factors separate ly in a community-based prospective cohort study in Japan. Methods-Stroke-free subjects (n = 1621) aged greater than or equal to 40 ye ars were followed up for 32 years from 1961. During this period, 298 cerebr al infarctions occurred and were divided into 167 lacunar, 62 atherothrombo tic, 56 cardioembolic, and 13 undetermined subtypes of infarction on the ba sis of clinical information including brain imaging and autopsy findings. Results-The age-adjusted incidence of lacunar infarction (3.8 per 1000 pers on-years for men and 2.0 for women) was higher than, that of atherothrombot ic infarction (1.2, 0.7) and cardioembolic infarction (1.3, 0.5) in both se xes. Time-dependent Cox's proportional hazard analysis revealed systolic bl ood pressure as well as age to be independent risk factors for all subtypes of cerebral infarction except for cardioembolic infarction in men. Additio nally, ST depression on EGG, glucose intolerance, and smoking in men and le ft ventricular hypertrophy on ECG and body mass index in women remained sig nificant risk factors for lacunar infarction. ST depression was also signif icantly related to events of atherothrombotic infarction in women. The risk of atrial fibrillation for cardioembolic infarction was outstandingly high in both sexes, and left ventricular hypertrophy and lower total cholestero l were additional risk factors for cardioembolic infarction in women. Conclusions-In this Japanese population, lacunar infarction was the most co mmon subtype of cerebral infarction and had a greater variety of risk facto rs, including not only hypertension but also ECG abnormalities, diabetes, o besity, and smoking, than did atherothrombotic infarction or cardioembolic infarction.