백혈구 수치와 뇌졸중 발생에 관한 전향적 cohort 연구

Abstract

Background: Stroke is one of the most common causes of death in Korea. This study was done to evaluate the association of white blood cell (WBC) count with risk of hemorrhagic and ischemic stroke in a large cohort drawn from a sample of Korean population.

Methods: 350,366 participants (85,225 men, 265,141 women) were enrolled in this prospective cohort study from 1993 to 2001. We used Cox proportional hazards models to analysis, adjusting for age, cigarette smoking, blood pressure, physical activity, total cholesterol levels, fasting blood sugar, family history of cardiovascular disease, and body mass index.

Results: During 8 years of follow up, 3,097 hemorrhagic stroke and 5,370 ischemic stroke occurred. Compared with lowest quartile of WBC count (<5500 sells/mm3), men in the highest quartile of WBC count (>7600 cells/mm3) had 1.3 times higher risk of morbidity and mortality from ischemic stroke (95% CI 1.1~1.5, p<.0001). In women with WBC count 6500~7500 cells/mm3 had 1.2 times higher risk from ischemic stroke (95% CI 1.1~1.3, p=0.001). Multivariate adjusted relative risk from ischemic stroke in women when WBC count of >7600 cells/ mm3 was 1.3 times (95% CI 1.2~1.4, p<.0001). No significant associations of WBC count with hemorrhagic stroke mortality and morbidity were seen in men and women. Results from subsequent analyses stratified by smoking status were consistent with this finding.

Conclusions: Elevated WBC count is associated with mortality and morbidity in ischemic but not hemorrhagic stroke among men and women independent of smoking and most traditional stroke risk factors in this Korean cohort.