Faculty Collaboration Database

Differential 5-year brain atrophy rates in cognitively declining and stable APOE-ε4 elders. Neuropsychology 2018 Sep;32(6):647-653

Date

06/19/2018

Pubmed ID

29911873

Pubmed Central ID

PMC6126943

DOI

10.1037/neu0000444

Scopus ID

2-s2.0-85048726898 (requires institutional sign-in at Scopus site)   11 Citations

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

Author List

Kelly DA, Seidenberg M, Reiter K, Nielson KA, Woodard JL, Smith JC, Durgerian S, Rao SM

Author

Kristy Nielson PhD Professor in the Psychology department at Marquette University

MESH terms used to index this publication - Major topics in bold

Aged
Aged, 80 and over
Aging
Apolipoprotein E4
Atrophy
Brain
Cognitive Dysfunction
Female
Humans
Longitudinal Studies
Magnetic Resonance Imaging
Male