title: Hepatitis C viral infection and the risk of dementia.
abstract: OBJECTIVE
  Hepatitis C virus (HCV) infection may cause cognitive impairment, but no studies have focused specifically on cognitive impairment stemming from HCV. The purpose of this study was to investigate the potential increased risk for dementia in HCV-infected patients.
  
  
  METHODS
  A population-based cohort study based on the Taiwan National Health Insurance Research Database was conducted. From all potential participants aged 50 years or more, a total of 58,570 matched (1:1) pairs of HCV-infected patients and non-HCV-infected patients were included. Each subject was individually tracked from 1997 to 2009 to identify incident cases of dementia (onset in 1999 or later). Cox proportional hazards regressions were employed to calculate the hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between HCV infection and dementia.
  
  
  RESULTS
  There were 2989 dementia cases from the HCV-infected cohort during the follow-up period of 533,861.1 person-years; the overall incidence rates of dementia differed from the non-HCV cohort (56.0 vs. 47.7 cases per 10,000 person-years, P < 0.05). The adjusted HR for dementia was 1.36 (95% CI 1.27-1.42) for HCV-infected patients after adjusting for alcohol-related disease, liver cirrhosis, hepatic encephalopathy and hepatocellular carcinoma.
  
  
  CONCLUSIONS
  HCV infection may increase the risk for dementia. Further mechanistic research is needed.
authors: Institute of Occupational Medicine and Industrial Hygiene, National Taiwan University College of Public Health, Taipei, Taiwan.|Department of Psychiatry, Cathay General Hospital, Taipei, Taiwan.|School of Medicine, Fu Jen Catholic University, Taipei, Taiwan.
authors: W-C
authors: WC
authors: Chiu
authors: Institute of Occupational Medicine and Industrial Hygiene, National Taiwan University College of Public Health, Taipei, Taiwan.|Division of Toxicology, Department of Emergency Medicine, Taichung Veterans General Hospital, Taichung, Taiwan.|School of Medicine, Chung Shan Medical University, Taichung, Taiwan.
authors: Y-T
authors: YT
authors: Tsan
authors: Institute of Occupational Medicine and Industrial Hygiene, National Taiwan University College of Public Health, Taipei, Taiwan.|Department of Medical Education, National Taiwan University Hospital, Taipei, Taiwan.
authors: S-L
authors: SL
authors: Tsai
authors: Department of Psychiatry, Cathay General Hospital, Taipei, Taiwan.|School of Medicine, Fu Jen Catholic University, Taipei, Taiwan.
authors: C-J
authors: CJ
authors: Chang
authors: Institute of Occupational Medicine and Industrial Hygiene, National Taiwan University College of Public Health, Taipei, Taiwan.|Department of Public Health, National Cheng Kung University College of Medicine, Tainan, Taiwan.
authors: J-D
authors: JD
authors: Wang
authors: Institute of Occupational Medicine and Industrial Hygiene, National Taiwan University College of Public Health, Taipei, Taiwan.|Department of Environmental and Occupational Medicine, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan.|Department of Public Health, National Taiwan University College of Public Health, Taipei, Taiwan.
authors: P-C
authors: PC
authors: Chen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D003704:Dementia / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D006526:Hepatitis C / Q000150:complications* / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012306:Risk; D013624:Taiwan / Q000453:epidemiology
keywords: Alzheimer's disease; chronic hepatitis; dementia; hepatitis C