title: Does hepatitis C virus infection increase risk for stroke? A population-based cohort study.
abstract: BACKGROUND
  The relationship between hepatitis C virus infection and risk of stroke remains inconsistent. This study evaluates the risk of stroke in association with chronic hepatitis C infection in a longitudinal population-based cohort.
  
  
  METHODS
  We identified 4,094 adults newly diagnosed with hepatitis C infection in 2002-2004 from the Taiwan National Health Insurance Research Database. Comparison group consisted of 16,376 adults without hepatitis C infection randomly selected from the same dataset, frequency matched by age and sex. Events of stroke from 2002-2008 were ascertained from medical claims (International Classification of Diseases, Ninth Revision, Clinical Modification, ICD-9-CM, codes 430-438). Multivariate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated for potential associated factors including HCV infection, age, sex, low-income status, urbanization, cessation of cigarette smoking, alcohol-related illness, obesity, history of chronic diseases and medication use.
  
  
  RESULTS
  During 96,752 person-years of follow-up, there were 1981 newly diagnosed stroke cases. The HRs of stroke associated with medical conditions such as hypertension, diabetes and heart disease were 1.48 (95% CI 1.33 to 1.65), 1.23 (95% CI 1.11 to 1.36) and 1.17 (95% CI 1.06 to 1.30), respectively, after adjustment for covariates. The cumulative risk of stroke for people with hepatitis C and without hepatitis C infections was 2.5% and 1.9%, respectively (p<0.0001). Compared with people without hepatitis C infection, the adjusted HR of stroke was 1.27 (95% CI 1.14 to 1.41) for people with hepatitis C infection.
  
  
  CONCLUSIONS
  Chronic hepatitis C infection increases stroke risk and should be considered an important and independent risk factor.
authors.affiliation: Health Policy Research Center, Taipei Medical University, Taipei, Taiwan.
authors.forename: Chien-Chang
authors.initials: CC
authors.lastname: Liao
authors.forename: Ta-Chen
authors.initials: TC
authors.lastname: Su
authors.forename: Fung-Chang
authors.initials: FC
authors.lastname: Sung
authors.forename: Wan-Hsin
authors.initials: WH
authors.lastname: Chou
authors.forename: Ta-Liang
authors.initials: TL
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D016001:Confidence Intervals; D003710:Demography; D005260:Female; D016174:Hepacivirus / Q000502:physiology*; D006526:Hepatitis C / Q000150:complications* / Q000821:virology*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016016:Proportional Hazards Models; D012307:Risk Factors; D020521:Stroke / Q000453:epidemiology* / Q000209:etiology* / Q000821:virology; D013624:Taiwan / Q000453:epidemiology; D055815:Young Adult