Bonham LW, Geier EG, Fan CC, Leong JK, Besser L, Kukull WA, Kornak J, Andreassen OA, Schellenberg GD, Rosen HJ, Dillon WP, Hess CP, Miller BL, Dale AM, Desikan RS, Yokoyama JS. Age-dependent effects of APOE ε4 in preclinical Alzheimer's disease.
Ann Clin Transl Neurol 2016;
3:668-77. [PMID:
27648456 PMCID:
PMC5018579 DOI:
10.1002/acn3.333]
[Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 06/03/2016] [Accepted: 06/14/2016] [Indexed: 11/10/2022] Open
Abstract
OBJECTIVE
The ε4 allele of apolipoprotein E (APOE) is the strongest known common genetic risk factor for Alzheimer's disease (AD) and alters age of onset in retrospective studies. Here, we longitudinally test the effects of APOE ε4 genotype and age during progression from normal cognition to AD.
METHODS
Using data from 5381 cognitively normal older individuals and Cox proportional hazards models, we longitudinally tested the effects of APOE genotype on progression from normal cognition to mild cognitive impairment (MCI) or AD in four age strata (<60, 60-70, 70-80, 80 + ) and with a sliding window approach between ages 60 and 85.
RESULTS
We found that APOE ε4 carrier status and dosage significantly influenced progression to MCI or AD in all four age groups and that APOE ε4-associated progression risk peaked between ages 70 and 75. We confirmed APOE ε4-associated progression risk in a subset of the cohort with pathologically proven diagnoses.
INTERPRETATION
Our findings indicate that in clinically normal individuals, APOE ε4 status significantly predicts progression to MCI or AD across older adulthood and that this risk varies with age. This information will be useful as therapeutic interventions become available and clinical decisions can be individually tailored based on age and genetic data.
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