Scaling of visuospatial attention undergoes differential longitudinal change as a function of APOE genotype prior to old age: results from the NIMH BIOCARD study.
The effect of apolipoprotein E (APOE) genotype on longitudinal cognitive decline in midlife was investigated with attentional scaling. Healthy individuals (mean age 59.6 years) genotyped for APOE were tested at 3 12-month intervals on a cued visual search task. A random effects model revealed significant interaction in effect of precue size on search speed between APOE-epsilon4 gene dose and assessment, with longitudinal increases in noncarriers and heterozygotes but longitudinal decreases in homozygotes. Association of APOE-epsilon4 with cognitive decline in midlife is consistent with an Alzheimer's disease (AD) prodrome, albeit a decade or more before average age of AD diagnosis. However, cognitive decline in midlife associated with a gene modulating neuronal response to insult argues that the concept of an AD prodrome includes factors that allow as well as cause AD.
Greenwood
P M
PM
Cognitive Science Laboratory, Catholic University of America, Washington, DC, and Geriatric Psychiatry Branch, National Institute of Mental Health, USA. pgreenw1@gmu.edu
Sunderland
Trey
T
Putnam
Karen
K
Levy
James
J
Parasuraman
Raja
R
D000367:Age Factors; D000368:Aged; D000483:Alleles; D000704:Analysis of Variance; D001057:Apolipoproteins E / Q000235:genetics / Q000502:physiology*; D001288:Attention / Q000502:physiology*; D015415:Biomarkers; D003710:Demography; D004311:Double-Blind Method; D005260:Female; D005838:Genotype; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009315:National Institute of Mental Health (U.S.); D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D017063:Outcome Assessment, Health Care; D010775:Photic Stimulation / Q000379:methods; D011237:Predictive Value of Tests; D012306:Risk; D013028:Space Perception / Q000502:physiology*; D014481:United States
D001057:Apolipoproteins E; D015415:Biomarkers