Smoking and the occurrence of Alzheimer's disease: cross-sectional and longitudinal data in a population-based study.
The authors tested the hypothesis that smoking exerts a protective effect on Alzheimer's disease or dementia in a population-based cohort of 668 people aged 75-101 years (Sweden). Smoking was negatively associated with prevalent Alzheimer's disease (adjusted odds ratio = 0.6, 95% confidence interval 0.4-1.1) and dementia (adjusted odds ratio = 0.6, 95% confidence interval 0.4-1.0). Over 3-year follow-up (1989-1992), the hazard ratios of incident Alzheimer's disease and dementia due to smoking were 1.1 (95% confidence interval 0.5-2.4) and 1.4 (95% confidence interval 0.8-2.7). Mortality over 5-year follow-up was greater among smokers in demented (hazard ratio = 3.4) than nondemented (hazard ratio = 0.8) subjects. Smoking does not seem protective against Alzheimer's disease or dementia, and the cross-sectional association might be due to differential mortality.
Wang
H X
HX
Stockholm Gerontology Research Center, Department of Clinical Neuroscience and Family Medicine, Karolinska Institute, Sweden.
Fratiglioni
L
L
Frisoni
G B
GB
Viitanen
M
M
Winblad
B
B
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000453:epidemiology* / Q000209:etiology; D003430:Cross-Sectional Studies; D003704:Dementia / Q000453:epidemiology / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D016017:Odds Ratio; D011159:Population Surveillance; D015995:Prevalence; D012189:Retrospective Studies; D012907:Smoking / Q000009:adverse effects*; D015996:Survival Rate; D013548:Sweden / Q000453:epidemiology