Apolipoprotein E genotype and association between smoking and early onset Alzheimer's disease.

OBJECTIVE--To investigate the hypothesis that differential survival between smokers and non-smokers leading to a decrease in the frequency of the e4 allele of the apolipoprotein E gene may explain the inverse relation between smoking history and early onset Alzheimer's disease. DESIGN--A population based case-control study. SETTING--The four northern provinces of the Netherlands and metropolitan Rotterdam. SUBJECTS--175 patients with early ons