title: Cigarette smoking and risk of disabling dementia in a Japanese rural community: a nested case-control study.
abstract: BACKGROUND
  Previous prospective cohort studies have examined the association between smoking and the risk of dementia, but the results were inconsistent.
  
  
  METHODS
  A prospective, nested, case-control study was conducted to examine the association between cigarette smoking and risk of disabling dementia within the cohort of 6,343 men and women aged 35-85 years. Incident dementia was documented in 208 men and women (95 cases with and 113 cases without a history of stroke). Two control subjects per case were selected by matching for sex, age and year of examination.
  
  
  RESULTS
  The multivariable odds ratios (95% CI) for current versus never smokers were 2.3 (1.1-4.7) for total dementia, 2.6 (0.8-8.2) for dementia with a history of stroke and 2.2 (0.8-5.7) for dementia without it, yielding no effect of stroke history on the smoking-dementia association. A dose-response relationship was noted between the years of cigarette smoking and the risk of total dementia, and a significant excess risk was found for smoking duration of >or=45 years.
  
  
  CONCLUSIONS
  The present prospective study suggests that long-term cigarette smoking may raise the risk of disabling dementia.
authors.affiliation: Public Health, Department of Social and Environmental Medicine, Graduate School of Medicine, Osaka University, Osaka, Japan.
authors.forename: Ai
authors.initials: A
authors.lastname: Ikeda
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Yamagishi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Tanigawa
authors.forename: Renzhe
authors.initials: R
authors.lastname: Cui
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yao
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Noda
authors.forename: Mitsumasa
authors.initials: M
authors.lastname: Umesawa
authors.forename: Choylye
authors.initials: C
authors.lastname: Chei
authors.forename: Kimiko
authors.initials: K
authors.lastname: Yokota
authors.forename: Yumi
authors.initials: Y
authors.lastname: Shiina
authors.forename: Mitiko
authors.initials: M
authors.lastname: Harada
authors.forename: Keiko
authors.initials: K
authors.lastname: Murata
authors.forename: Takashi
authors.initials: T
authors.lastname: Asada
authors.forename: Takashi
authors.initials: T
authors.lastname: Shimamoto
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Iso
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D015331:Cohort Studies; D003704:Dementia / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011446:Prospective Studies; D012307:Risk Factors; D012424:Rural Population; D012907:Smoking / Q000009:adverse effects*; D013997:Time Factors