Low Serum Bilirubin Level as an Independent Predictor of Stroke Incidence: A Prospective Study in Korean Men and Women

• Published in: Stroke (1970) Vol. 40; no. 11; pp. 3422 - 3427
• Main Authors: Kimm, Heejin, Yun, Ji Eun, Jo, Jaeseong, Jee, Sun Ha
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD American Heart Association, Inc 01.11.2009; Lippincott Williams & Wilkins
• Subjects: Adult; Aged; Aged, 80 and over; Asian Continental Ancestry Group; Bilirubin - blood; Biological and medical sciences; Biomarkers - blood; Cohort Studies; Female; Headache. Facial pains. Syncopes. Epilepsia. Intracranial hypertension. Brain oedema. Cerebral palsy; Humans; Incidence; Korea - epidemiology; Male; Medical sciences; Middle Aged; Nervous system (semeiology, syndromes); Neurology; Predictive Value of Tests; Prospective Studies; Risk Factors; Sex Characteristics; Stroke - blood; Stroke - diagnosis; Stroke - epidemiology; Vascular diseases and vascular malformations of the nervous system; Korea; Human; Cerebral infarction; Stroke; Nervous system diseases; Cardiovascular disease; hemorrhagic stroke; Hemorrhage; Cerebral disorder; Incidence; Vascular disease; stroke incidence; Central nervous system disease; Brain ischemia; bilirubin; Cerebrovascular disease; ischemic stroke
• ISSN: 0039-2499; 1524-4628; 1524-4628
• DOI: 10.1161/STROKEAHA.109.560649

BACKGROUND AND PURPOSE—Bilirubin is not only a waste end-product but also an antioxidant. Bilirubin is known to be associated with decrease in cardiovascular risk in men, but its relationship to stroke was not clearly understood. METHODS—Serum bilirubin concentrations were measured in 78 724 health examinees (41 054 men, aged 30–89 years) from 1994 to 2001. The subjects with potential hepatobiliary diseases or Gilbert syndrome were excluded from analysis. Stroke incidence outcome was collected from hospital records of admission attributable to stroke from 1994 to 2007. RESULTS—Serum bilirubin measurements were divided into 4 levels0 to 10.2, 10.3 to 15.3, 15.4 to 22.1, and 22.2 to 34.2 μmol/L. The number of stroke cases was 1137 in men and 827 in women. In Cox proportional hazard models, participants with a higher level of bilirubin showed lower hazard ratios in men with ischemic stroke after adjustment for multiple confounding factors compared to the lowest level of bilirubin (hazard ratio [HR], 0.72; 95% CI, 0.58–0.90 in level 3; HR, 0.66; 95% CI, 0.49–0.89 in level 4; P for trend=0.016). The risk of all stroke types also decreased as bilirubin levels increased (HR, 0.81; 95% CI, 0.68–0.97 in level 3; HR, 0.74; 95% CI, 0.58–0.94 in level 4; P for trend=0.0071). However, these associations were not seen in hemorrhagic stroke or in women. CONCLUSIONS—These findings suggest that serum bilirubin might have some protective function against stroke risk in men.