The APOE ε4 allele is associated with decline on delayed recall performance in community-dwelling older adults

OBJECTIVE: This study investigated whether the Apolipoprotein (APOE) epsilon 4 allele was associated with cognitive decline in community-dwelling older adults. DESIGN: Longitudinal cognitive performance of older adults with the epsilon 3/epsilon 4 genotype was compared with that of older adults with the epsilon 3/epsilon 3 genotype. SETTING: Aging Clinical Research Center, Stanford University. PARTICIPANTS: One hundred community-dwelling older adults were recruited from a pool of 531 individuals who had participated in a memory training study 4 to 5 years earlier. These individuals were concerned about their memory functioning and were recruited through newspaper advertisements and contacts with local senior centers. The 100 individuals who agreed to participate in the follow-up investigation were between 59 and 95 years of age. MEASUREMENTS: At both baseline and follow-up, subjects were administered a battery of seven cognitive tests that examined verbal and spatial memory, attention, speed-of-processing and language abilities. APOE genotype was determined at follow-up. RESULTS: Individuals with the epsilon 3/epsilon 4 APOE genotype were significantly younger than individuals with the APOE epsilon 3/epsilon 3 genotype. No significant differences were observed between the two groups on measures of attention, speed-of-processing, vocabulary, immediate verbal memory, and immediate spatial memory. However, those older adults with the epsilon 3/epsilon 4 genotype exhibited significantly greater decline in performance on delayed recall of verbal material than did those with the epsilon 3/epsilon 3 APOE genotype. CONCLUSION These findings are consistent with previous studies, which suggest that the APOE epsilon 4 allele predicts decline on measures of delayed recall.