Risk of dementia in patients with leptospirosis: A nationwide cohort analysis

Chun Hsiang Chiu, Po Chung Chen, Ying Chuan Wang, Cheng Li Lin, Feng You Lee, Chia Chang Wu, Kuang Hsi Chang

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


Background: Studies have linked some bacterial infections with an increased likelihood for development of dementia. However, there is a paucity of data on the relationship between dementia and leptospirosis. In view of this, we conducted a retrospective cohort study to determine whether leptospirosis is a risk factor for dementia. Methods: Data were collected from the Taiwan National Health Insurance Research Databases (2000–2010) to investigate the incidence of and risk factors for dementia in patients with leptospirosis. Patients with leptospirosis who did not have a history of dementia were enrolled in the study. For each leptospirosis patient, four controls were randomly selected after frequency matching of age, sex, and index date. Cox proportional hazard regression models were used for the analyses of dementia risk. Results: A greater risk of dementia was observed in the leptospirosis cohort than in the non-leptospirosis cohort both in patients without any comorbidity (adjusted HR (aHR) = 1.23, 95% CI = 1.06–1.43) and with a comorbidity (aHR = 2.06, 95% CI = 1.7–2.5). Compared with the non-leptospirosis cohort without these comorbidities, the leptospirosis cohort with ≥2 comorbidities exhibited a significantly increased risk of dementia (aHR = 6.11, 95% CI = 3.15–11.9), followed by those with any one comorbidity (adjusted HR = 3.62, 95% CI = 1.76–7.46). Conclusions: Patients with leptospirosis were at a 1.89-fold greater risk of subsequent dementia, but potential genetic susceptibility bias in the study group is a major confound.

Original languageEnglish
Article number3168
JournalInternational Journal of Environmental Research and Public Health
Issue number17
Publication statusPublished - Sept 1 2019


  • Dementia
  • Leptospirosis
  • Risk factor
  • Vascular hypothesis

ASJC Scopus subject areas

  • Public Health, Environmental and Occupational Health
  • Health, Toxicology and Mutagenesis


Dive into the research topics of 'Risk of dementia in patients with leptospirosis: A nationwide cohort analysis'. Together they form a unique fingerprint.

Cite this