APOE alleles in Alzheimer's disease and vascular dementia in a population aged 85+.

Apolipoprotein E genotyping was carried out in a stratified random sample of 52 patients with Alzheimer's disease, 48 patients with vascular or mixed dementia, and 49 nondemented controls in a population-based study of people aged 85 and older (the Vantaa 85+ Study). Our results indicate that the apolipoprotein E epsilon 4 allele is associated with approximately a twofold increase in clinically diagnosed Alzheimer's disease in this very old general population aged 85+. When combined with previous studies, our data also suggest that the association is decreasing with age. In contrast, there appears to be no relation between apolipoprotein E alleles and clinically diagnosed vascular dementia.