Apolipoprotein E genotypes and cognitive functions in healthy elderly persons

Objectives - We investigated whether apoE genotypes correlate with cognitiv e functions in clinically healthy persons. Methods - In 1993 and 1995, we m easured information processing speed, delayed free recall and semantic aspe cts of long-term memory in 227 men and 105 women aged 65 and over, a random ly selected subsample of the prospective Basel Study. Cardiovascular risk f actors and education were assessed. Results E2 were more prevalent in old-o ld (>75 years, 23.5% vs 15%) compared to E4 than in young-old (<75 years, 1 9.3% vs 23.5%). Taking into account age and education, subjects with epsilo n(3)/epsilon(4) or epsilon 4/epsilon 4 alleles (E4) performed lowest in all 3 tests compared to those homozygous for epsilon 3 (E3) or carriers of one or two epsilon(2) alleles (E2) (reaction time P=0.009, free recall P=0.05, WAIS-R vocabulary P<0.05). In old-old there was a significant difference b etween E2 and E4 for reaction time (P=0.02) and free recall (P<0.02) but no t for vocabulary (P=0.086). In all 3 groups there were no significant chang es after 2 years. The subgroup with the genotype epsilon(2)/epsilon(4) perf ormed consistently best in the cognitive tests. Cholesterol was significant ly increased in the E4 and E3 group compared to the E2 group. Conclusion - ApoE genotype correlates with cognitive performance. The increased prevalen ce of E2 in the old-old and the significantly lower plasma cholesterol leve ls suggest differential morbidity and mortality as important factors influe ncing the prevalence of cognitive disorders in late life.