Relation between nicotine intake and Alzheimer's disease.
OBJECTIVE
To study the association between Alzheimer's disease and nicotine intake through smoking.


METHODS
Population based case-control study.


METHODS
City of Rotterdam and four northern provinces of The Netherlands.


METHODS
198 patients with early onset Alzheimer's disease, 198 controls matched for age and sex, and families of 17 patients in whom Alzheimer's disease was apparently inherited as an autosomal dominant disorder.


METHODS
Age of onset of dementia, relative risk of Alzheimer's disease.


RESULTS
89 of 193 patients with Alzheimer's disease had a history of smoking compared with 102 of 195 controls. Among the patients and controls with a family history of dementia, smoking was significantly less common in those with dementia (40/95 with dementia v 55/96 controls; relative risk 0.35; 95% confidence interval 0.16 to 0.78). The risk of Alzheimer's disease decreased with increasing daily number of cigarettes smoked before onset of disease (relative risk 0.3 in those smoking greater than 21/day v 1 in non-smokers). In six families in which the disease was apparently inherited as an autosomal dominant disorder, the mean age of onset was 4.17 years later in smoking patients than in non-smoking patients from the same family (p = 0.03).


CONCLUSIONS
These findings suggest an inverse association between smoking and Alzheimer's disease, although smoking cannot be advocated for other health reasons. We speculate that nicotine may have a role in the aetiology of both Alzheimer's disease and Parkinson's disease.
van Duijn
C M
CM
Department of Epidemiology and Biostatistics, Erasmus University Medical School, Rotterdam, The Netherlands.
Hofman
A
A
D000328:Adult; D000544:Alzheimer Disease / Q000453:epidemiology* / Q000209:etiology / Q000235:genetics; D016022:Case-Control Studies; D003704:Dementia / Q000235:genetics; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009538:Nicotine / Q000008:administration & dosage*; D010300:Parkinson Disease / Q000209:etiology / Q000235:genetics; D012907:Smoking / Q000453:epidemiology*
D009538:Nicotine