title: Hepatitis C virus infection as a risk factor for Parkinson disease: A nationwide cohort study.
abstract: OBJECTIVE
  To determine whether hepatitis C virus (HCV) infection is a risk factor for developing Parkinson disease (PD).
  
  
  METHODS
  This nationwide population-based cohort study was based on data obtained from a dataset of the Taiwan National Health Insurance Research Database for the period 2000 to 2010. A total of 49,967 patients with viral hepatitis were included for analysis. Furthermore, 199,868 people without viral hepatitis were included for comparisons. Patients with viral hepatitis were further grouped into 3 cohorts: hepatitis B virus (HBV) infection, HCV infection, and HBV-HCV coinfection. In each cohort, we calculated the incidence of developing PD. A Cox proportional hazards model was applied to estimate the risk of developing PD in terms of hazard ratios (HRs) and 95% confidence intervals (CIs).
  
  
  RESULTS
  The crude HRs for developing PD was 0.66 (95% CI = 0.55-0.80) for HBV infection, 2.50 (95% CI = 2.07-3.02) for HCV infection, and 1.28 (95% CI = 0.88-1.85) for HBV-HCV coinfection. The association between HCV and PD remained statistically significant after adjustments for age, sex, and comorbidities (adjusted HR = 1.29, 95% CI = 1.06-1.56).
  
  
  CONCLUSIONS
  We conducted a large nationwide population-based study and found that patients with HCV exhibit a significantly increased risk of developing PD.
authors.affiliation: From the Departments of Neurology (H.-H.T.), Neurology and Pharmacology (H.-H.L.), Internal Medicine (C.-Z.L.), and Nuclear Medicine (R.-F.Y.), National Taiwan University Hospital, Taipei; College of Medicine, National Taiwan University (H.-H.L., C.-Z.L.), Taipei; Management Office for Health Data (C.-H.M.) and Department of Nuclear Medicine and PET Center (C.-H.K.), China Medical University Hospital, Taichung; College of Medicine (C.-H.M.), China Medical University, Taichung; Department of Radiology (R.-F.Y.), National Taiwan University College of Medicine, Taipei; Graduate Institute of Clinical Medical Science and School of Medicine (C.-H.K.), College of Medicine, China Medical University, Taichung, Taiwan.
authors.forename: Hsin-Hsi
authors.initials: HH
authors.lastname: Tsai
authors.affiliation: From the Departments of Neurology (H.-H.T.), Neurology and Pharmacology (H.-H.L.), Internal Medicine (C.-Z.L.), and Nuclear Medicine (R.-F.Y.), National Taiwan University Hospital, Taipei; College of Medicine, National Taiwan University (H.-H.L., C.-Z.L.), Taipei; Management Office for Health Data (C.-H.M.) and Department of Nuclear Medicine and PET Center (C.-H.K.), China Medical University Hospital, Taichung; College of Medicine (C.-H.M.), China Medical University, Taichung; Department of Radiology (R.-F.Y.), National Taiwan University College of Medicine, Taipei; Graduate Institute of Clinical Medical Science and School of Medicine (C.-H.K.), College of Medicine, China Medical University, Taichung, Taiwan.
authors.forename: Horng-Huei
authors.initials: HH
authors.lastname: Liou
authors.affiliation: From the Departments of Neurology (H.-H.T.), Neurology and Pharmacology (H.-H.L.), Internal Medicine (C.-Z.L.), and Nuclear Medicine (R.-F.Y.), National Taiwan University Hospital, Taipei; College of Medicine, National Taiwan University (H.-H.L., C.-Z.L.), Taipei; Management Office for Health Data (C.-H.M.) and Department of Nuclear Medicine and PET Center (C.-H.K.), China Medical University Hospital, Taichung; College of Medicine (C.-H.M.), China Medical University, Taichung; Department of Radiology (R.-F.Y.), National Taiwan University College of Medicine, Taipei; Graduate Institute of Clinical Medical Science and School of Medicine (C.-H.K.), College of Medicine, China Medical University, Taichung, Taiwan.
authors.forename: Chih-Hsin
authors.initials: CH
authors.lastname: Muo
authors.affiliation: From the Departments of Neurology (H.-H.T.), Neurology and Pharmacology (H.-H.L.), Internal Medicine (C.-Z.L.), and Nuclear Medicine (R.-F.Y.), National Taiwan University Hospital, Taipei; College of Medicine, National Taiwan University (H.-H.L., C.-Z.L.), Taipei; Management Office for Health Data (C.-H.M.) and Department of Nuclear Medicine and PET Center (C.-H.K.), China Medical University Hospital, Taichung; College of Medicine (C.-H.M.), China Medical University, Taichung; Department of Radiology (R.-F.Y.), National Taiwan University College of Medicine, Taipei; Graduate Institute of Clinical Medical Science and School of Medicine (C.-H.K.), College of Medicine, China Medical University, Taichung, Taiwan.
authors.forename: Cha-Ze
authors.initials: CZ
authors.lastname: Lee
authors.affiliation: From the Departments of Neurology (H.-H.T.), Neurology and Pharmacology (H.-H.L.), Internal Medicine (C.-Z.L.), and Nuclear Medicine (R.-F.Y.), National Taiwan University Hospital, Taipei; College of Medicine, National Taiwan University (H.-H.L., C.-Z.L.), Taipei; Management Office for Health Data (C.-H.M.) and Department of Nuclear Medicine and PET Center (C.-H.K.), China Medical University Hospital, Taichung; College of Medicine (C.-H.M.), China Medical University, Taichung; Department of Radiology (R.-F.Y.), National Taiwan University College of Medicine, Taipei; Graduate Institute of Clinical Medical Science and School of Medicine (C.-H.K.), College of Medicine, China Medical University, Taichung, Taiwan.
authors.forename: Ruoh-Fang
authors.initials: RF
authors.lastname: Yen
authors.affiliation: From the Departments of Neurology (H.-H.T.), Neurology and Pharmacology (H.-H.L.), Internal Medicine (C.-Z.L.), and Nuclear Medicine (R.-F.Y.), National Taiwan University Hospital, Taipei; College of Medicine, National Taiwan University (H.-H.L., C.-Z.L.), Taipei; Management Office for Health Data (C.-H.M.) and Department of Nuclear Medicine and PET Center (C.-H.K.), China Medical University Hospital, Taichung; College of Medicine (C.-H.M.), China Medical University, Taichung; Department of Radiology (R.-F.Y.), National Taiwan University College of Medicine, Taipei; Graduate Institute of Clinical Medical Science and School of Medicine (C.-H.K.), College of Medicine, China Medical University, Taichung, Taiwan. d10040@mail.cmuh.org.tw.
authors.forename: Chia-Hung
authors.initials: CH
authors.lastname: Kao
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D015984:Causality; D015331:Cohort Studies; D015897:Comorbidity; D005260:Female; D006526:Hepatitis C / Q000175:diagnosis* / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000175:diagnosis* / Q000453:epidemiology*; D015203:Reproducibility of Results; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D017678:Sex Distribution; D013624:Taiwan / Q000453:epidemiology