Race, APOE ϵ4, and Long-Term Cognitive Trajectories in a Biracial Population Sample

Kumar B. Rajan, Elizabeth A. McAninch, Robert S. Wilson, Jennifer Weuve, Lisa L. Barnes, Denis A. Evans

Research output: Contribution to journalArticle

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Abstract

Background: The association of the APOE ϵ4 allele with incident Alzheimer's dementia is higher among European Americans (EAs) than African Americans (AAs), but similar for the rate of cognitive decline. Objective: To examine the racial differences in the association of the APOE ϵ4 allele with incident Alzheimer's dementia and cognitive decline. Methods: Using a population-based sample of 5,117 older adults (66% AAs and 63% females), we identified cognitive trajectory groups from a latent class mixed model and examined the association of the APOE ϵ4 allele with these groups. Results: The frequency of the APOE ϵ4 allele was higher among AAs than EAs (37% versus 26%). Four cognitive trajectories were identified: slow, mild, moderate, and rapid. Overall, AAs had a lower baseline global cognition than EAs, and a higher proportion had rapid (7% versus 5%) and moderate (20% versus 15%) decline, but similar mild (44% versus 46%), and lesser slow (29% versus 34%) decline compared to EAs. Additionally, 25% of AAs (13% of EAs) with mild and 5% (<1% of EAs) with slow decline were diagnosed with incident Alzheimer's dementia. The APOE ϵ4 allele was associated with higher odds of rapid and moderate decline compared to slow decline among AAs and EAs, but not with mild decline. Conclusions: AAs had lower cognitive levels and were more likely to meet the cognitive threshold for Alzheimer's dementia among mild and slow decliners, explaining the attenuated association of the ϵ4 allele with incident Alzheimer's dementia among AAs.

Original languageEnglish (US)
Pages (from-to)45-53
Number of pages9
JournalJournal of Alzheimer's Disease
Volume72
Issue number1
DOIs
StatePublished - Jan 1 2019

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Keywords

  • Alzheimer's disease
  • Apolipoproteins E
  • cognitive aging
  • race relations

ASJC Scopus subject areas

  • Neuroscience(all)
  • Clinical Psychology
  • Geriatrics and Gerontology
  • Psychiatry and Mental health

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