title: Association of environmental tobacco smoke with dementia and Alzheimer's disease among never smokers.
abstract: BACKGROUND
  Environmental tobacco smoke (ETS) is known to be harmful; however, its association with dementia remains controversial and with Alzheimer's disease (AD) is unknown.
  
  
  METHODS
  Using a standard interview method, the author carried out a multicenter cross-sectional study of dementia in China by examining 2692 never-smoking people aged ≥60 years. Relative risks (RRs) of AD and all dementia, as diagnosed by psychiatrists, in relation to ETS were calculated in a multivariate regression model.
  
  
  RESULTS
  The adjusted RR for all dementia was 1.78 (95% confidence interval [CI]: 1.18-2.68). The increased risk was mainly from exposure to ETS at home (1.87, 95% CI: 1.19-2.93), and it was associated with exposure duration. The adjusted RR for AD was 2.28 (95% CI: 1.82-2.84); the matched figure for ETS exposure at home, at work, and at other places was 2.15 (95% CI: 1.69-2.74), 2.04 (95% CI: 1.72-2.42), and 1.80 (95% CI: 0.96-3.38), respectively. The association of the increased risk with a total cumulative exposure dose was at borderline significance.
  
  
  CONCLUSIONS
  The risk of dementia and AD increased with ETS exposure. Banning smoking in public areas may help reduce a dementia epidemic worldwide.
authors.affiliation: Division of Health and Social Care Research, King's College London, London, UK. ruoling.chen@kcl.ac.uk
authors.forename: Ruoling
authors.initials: R
authors.lastname: Chen
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000453:epidemiology* / Q000209:etiology*; D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D003704:Dementia / Q000453:epidemiology* / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*
chemical_list: D014028:Tobacco Smoke Pollution