Differential 5-Year Brain Atrophy Rates in Cognitively Declining and Stable APOE-Ε4 Elders

Authors

Dana A. Kelly, Rosalind Franklin UniversityFollow
Michael Seidenberg, Rosalind Franklin University of Medicine and ScienceFollow
Katherine Reiter, Marquette UniversityFollow
Kristy A. Nielson, Marquette UniversityFollow
John L. Woodard, Wayne State University
J. Carson Smith, University of Maryland at College Park
Sally Durgerian, BrainDataDriven LLCFollow
Stephen M. Rao, Schey Center for Cognitive NeuroimagingFollow

Document Type

Article

Language

eng

Publication Date

9-2018

Publisher

American Psychological Association

Source Publication

Neuropsychology

Source ISSN

0894-4105

Abstract

Objective: The apolipoprotein E (APOE) ε4 allele is the most important genetic risk factor for late-onset Alzheimer’s disease. Many ε4 carriers, however, never develop Alzheimer’s disease. The purpose of this study is to characterize the variability in phenotypic expression of the ε4 allele, as measured by the longitudinal trajectory of cognitive test scores and MRI brain volumes, in cognitively intact elders. Method: Healthy older adults, ages 65–85, participated in a 5-year longitudinal study that included structural MRI and cognitive testing administered at baseline and at 1.5 and 5 years postenrollment. Participants included 22 ε4 noncarriers, 15 ε4 carriers who experienced a decline in cognition over the 5-year interval, and 11 ε4 carriers who remained cognitively stable. Results: No baseline cognitive or volumetric group differences were observed. Compared to noncarriers, declining ε4 carriers had significantly greater rates of atrophy in left (p = .001, Cohen’s d = .691) and right (p = .003, d = .622) cortical gray matter, left (p = .003, d = .625) and right (p = .020, d = .492) hippocampi, and greater expansion of the right inferior lateral ventricle (p < .001, d = .751) over 5 years. Conclusions: This study illustrates the variability in phenotypic expression of the ε4 allele related to neurodegeneration. Specifically, only those individuals who exhibited longitudinal declines in cognitive function experienced concomitant changes in brain volume. Future research is needed to better understand the biological and lifestyle factors that may influence the expression of the ε4 allele. (PsycINFO Database Record (c) 2018 APA, all rights reserved)

Comments

Accepted version. Neuropsychology, Vol. 32, No. 6 (2018): 647-653. DOI. © 2018 American Psychological Association. Used with permission.

Recommended Citation

Kelly, Dana A.; Seidenberg, Michael; Reiter, Katherine; Nielson, Kristy A.; Woodard, John L.; Smith, J. Carson; Durgerian, Sally; and Rao, Stephen M., "Differential 5-Year Brain Atrophy Rates in Cognitively Declining and Stable APOE-Ε4 Elders" (2018). Psychology Faculty Research and Publications. 432.
https://epublications.marquette.edu/psych_fac/432