TY - JOUR
T1 - Smoking and risk of dementia and Alzheimer's disease in a population-based cohort study
T2 - The Rotterdam Study
AU - Ott, A.
AU - Slooter, A. J.C.
AU - Hofman, A.
AU - Van Harskamp, F.
AU - Witteman, J. C.M.
AU - Van Broeckhoven, C.
AU - Van Duijn, C. M.
AU - Breteler, M. M.B.
PY - 1998/6/20
Y1 - 1998/6/20
N2 - Background. Previous studies suggested a protective effect of smoking on Alzheimer's disease, but most were case-control studies based on prevalent cases. The findings of prospective studies on the association between smoking and the risk of dementia are inconclusive. Methods. We did a population-based follow-up study of elderly people who were initially free of dementia. 6870 people aged 55 years and older agreed to take part. Smoking history was taken at baseline and participants were classified as never smokers, former smokers, and current smokers. During follow-up, we recorded all incident cases of dementia. We used never smokers as the reference category to calculate relative risks of dementia and Alzheimer's disease by Cox proportional hazards regression, after adjustment for age, sex, education, and alcohol intake. We also examined modification of risk by age, sex, and the apolipoprotein E (APOE) genotype. Findings. During mean follow-up of 2.1 (range 1.5-3.4) years, 146 incident cases of dementia were detected, of which 105 were Alzheimer's disease. Compared with never smokers, smokers had an increased risk of dementia (relative risk 2.2 [95% CI 1.3-3.6]) and Alzheimer's disease (2.3 [1.3-4.1]). Smoking was a strong risk factor for Alzheimer's disease in individuals without the APOEε4 allele (4.6 [1.5-14.2]), but had no effect in participants with this allele (0.6 [0.1-4.8]). Interpretation. Smoking was associated with a doubling of the risk of dementia and Alzheimer's disease. Our finding that carriers of the APOEε4 had no increased risk of dementia suggests an interaction between smoking and the APOEε4 genotype in the aetiology of Alzheimer's disease.
AB - Background. Previous studies suggested a protective effect of smoking on Alzheimer's disease, but most were case-control studies based on prevalent cases. The findings of prospective studies on the association between smoking and the risk of dementia are inconclusive. Methods. We did a population-based follow-up study of elderly people who were initially free of dementia. 6870 people aged 55 years and older agreed to take part. Smoking history was taken at baseline and participants were classified as never smokers, former smokers, and current smokers. During follow-up, we recorded all incident cases of dementia. We used never smokers as the reference category to calculate relative risks of dementia and Alzheimer's disease by Cox proportional hazards regression, after adjustment for age, sex, education, and alcohol intake. We also examined modification of risk by age, sex, and the apolipoprotein E (APOE) genotype. Findings. During mean follow-up of 2.1 (range 1.5-3.4) years, 146 incident cases of dementia were detected, of which 105 were Alzheimer's disease. Compared with never smokers, smokers had an increased risk of dementia (relative risk 2.2 [95% CI 1.3-3.6]) and Alzheimer's disease (2.3 [1.3-4.1]). Smoking was a strong risk factor for Alzheimer's disease in individuals without the APOEε4 allele (4.6 [1.5-14.2]), but had no effect in participants with this allele (0.6 [0.1-4.8]). Interpretation. Smoking was associated with a doubling of the risk of dementia and Alzheimer's disease. Our finding that carriers of the APOEε4 had no increased risk of dementia suggests an interaction between smoking and the APOEε4 genotype in the aetiology of Alzheimer's disease.
UR - https://www.scopus.com/pages/publications/0032551222
U2 - 10.1016/S0140-6736(97)07541-7
DO - 10.1016/S0140-6736(97)07541-7
M3 - Article
C2 - 9652667
AN - SCOPUS:0032551222
SN - 0140-6736
VL - 351
SP - 1840
EP - 1843
JO - Lancet
JF - Lancet
IS - 9119
ER -