Body mass index and stroke mortality by smoking and age at menopause among Korean postmenopausal women.

Abstract

The association between body mass index and mortality caused by subtypes of stroke among postmenopausal women in terms of smoking status and age at menopause remains controversial. The data were derived from a cohort study of 3321 with 17.8 years of follow-up (1985 to 2002). Hazard ratios (HRs) and 95% CIs for strokes as related to body mass index were estimated by Cox proportional hazard models adjusted for age, hypertension, smoking, drinking, occupation, education, self-reported health, and age at menopause. A stratified analysis was conducted by age at menopause and smoking status. The obese group (body mass index >or=27.5 kg/m(2)) had higher risks of total stroke mortality (HR, 1.59; 95% CI, 1.05 to 2.42) and hemorrhagic stroke mortality (HR, 2.91; 95% CI, 1.37 to 6.19) than the normal weight group (18.5<or= body mass index <23.0). Among ever smokers, the obese group showed significantly increased risks of total stroke mortality (HR, 2.33; 95% CI, 1.00 to 5.43) and ischemic stroke mortality (HR, 7.21; 95% CI, 1.18 to 44.3). Obesity had more effect on stroke mortality among women who experienced menopause at age <50 than women with age >or=50. For the obese group of the former, the HR of total stroke was 2.04 (95% CI, 1.25 to 3.34) and that of hemorrhagic stroke 6.46 (95% CI, 2.42 to 17.25). In this prospective study, obesity raised the risks of total stroke mortality and hemorrhagic stroke mortality among Korean menopausal women. It was more evident with women who experienced menopause at age <50. The obese group of ever smokers was at an increased risk of ischemic stroke mortality.