Is APOE--epsilon4 a risk factor for cognitive impairment in normal aging?
OBJECTIVE
To examine the relationship between APOE genotype and cognitive functioning in normal aging, and to determine whether this relationship was moderated by age or the presence of a number of disease conditions, including cardiovascular disease and diabetes.


METHODS
The sample was drawn from the Charlotte County Healthy Aging Study, a community-based, cross-sectional study of randomly selected older adults in Charlotte County, FL. A total of 413 older adults (mean age = 72.90 years) were examined in the current study. Participants completed tasks that indexed a variety of dimensions of cognitive functioning, including episodic memory, implicit memory, psychomotor speed, and attention. In addition, participants provided self-reported and objective indices of health status and were genotyped for APOE.


RESULTS
Mean-level results indicated that groups with and without the APOE-epsilon4 allele performed similarly on all domains of cognitive functioning. Significant age group differences were observed in episodic memory, psychomotor speed, and attention but not implicit memory. Significant gender differences were present for episodic memory and the Stroop test. Analyses also indicated that participants' age did not exert an impact on the relationship between APOE-epsilon4 and cognitive functioning. Further, the presence of cardiovascular disease or diabetes did little to moderate the relationship between APOE-epsilon4 and cognition.


CONCLUSIONS
The authors found no evidence for a relationship between presence of the APOE-epsilon4 allele and cognitive functioning. Further, age or the presence of a number of chronic conditions did not significantly moderate the effect of APOE genotype on cognitive performance. These results indicate that the presence of the epsilon4 allele is not a risk factor for cognitive impairment in normal aging.
Small
B J
BJ
Department of Gerontology, University of South Florida, Tampa 33620, USA. bsmall@luna.cas.usf.edu
Graves
A B
AB
McEvoy
C L
CL
Crawford
F C
FC
Mullan
M
M
Mortimer
J A
JA
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D000704:Analysis of Variance; D053327:Apolipoprotein E4; D001057:Apolipoproteins E / Q000235:genetics*; D003071:Cognition / Q000502:physiology*; D003430:Cross-Sectional Studies; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology*; D008875:Middle Aged; D012044:Regression Analysis; D012307:Risk Factors
D053327:Apolipoprotein E4; D001057:Apolipoproteins E