The apolipoprotein E gene and its age-specific effects on cognitive function.

The E4 allele of the apolipoprotein E gene (APOE) is a well-established determinant of Alzheimer's disease but its relation to cognitive function is much less understood. We studied the age-specific effects of the APOEE4 allele on cognitive function and cardiovascular risk factors in 2208 related individuals. APOEE4 allele was significantly associated with reduced test scores for Adult Verbal Learning Test, particularly on the memory and learning sub domains, in persons older than 50 years of age. The effect of APOEE4 was independent of the effect of APOEE4 on vascular risk factors and most pronounced on learning ability. Our findings suggest that APOE*E4 has an effect on cognitive function predominantly in the elderly, independent of vascular risk factors.