Objective: Obesity is known to be associated with diverse disease outcomes; however, the effect of body weight on the occurrence of stroke remains controversial and has not been studied sufficiently, particularly among Asian populations and among women. The purpose of this study was to investigate the effect of BMI on the risk of stroke among Korean women.
Methods and procedures: The overall risk of stroke and the risk of different subtypes of stroke were evaluated in relation to BMI using Cox's proportional hazard models among 439,582 Korean women, aged 30-95 years, in a 13-year prospective cohort study with enrollment from 1992-1995. Stratified analyses were performed for age groups and cigarette smoking status.
Results: The average BMI was 23.2 kg/m(2) at baseline. The overall risk of stroke was the lowest in the group with a BMI <20.0 and increased with BMI in a dose-dependent manner. However, the direction and strength of association varied according to the type of stroke and age groups. The risk of ischemic stroke (IS) showed a strong and progressive linear relationship with an increase in the BMI, while the relationship was less linear for hemorrhagic stroke (HS). The association between the risk of stroke and BMI was modified by age, with a weaker association at higher ages.
Discussion: In Korean women, the BMI showed a progressive and linear relationship with the occurrence of stroke. The association of BMI with the risk of stroke was modified by age.