Independent predictors of cognitive decline in healthy elderly persons.
BACKGROUND
Several studies have shown that individually memory, hippocampal volume, and motor measures presage the onset of dementia. It is unclear if these independently contribute to the prediction of mild cognitive impairment.


OBJECTIVE
To determine the ability of memory, hippocampal volume, and a gait speed to independently predict cognitive decline in healthy elderly persons.


METHODS
A prospective, longitudinal, observational cohort study with a mean follow-up of 6 years.


METHODS
One hundred eight optimally healthy elderly cognitively intact subjects.


METHODS
Any cognitive impairment noted on the Clinical Dementia Rating Scale (score = 0.5) or persistent or progressive cognitive impairment. Cox modeling determined if time to onset of cognitive impairment was associated with baseline logical memory II test score (a measure of delayed recall), hippocampal volume (magnetic resonance imaging), or gait speed (time to walk 30 ft [9 m]) independent of age, sex, depression, or the allele producing the epsilon4 type of apolipoprotein E (APOE epsilon4).


RESULTS
Questionable dementia occurred in 48 participants in a mean (SD) of 3.7 (2.4) years. This progressed to persistent cognitive impairment in 38 of these participants in a mean (SD) of 4.4 (2.4) years. Logical memory II test performance and hippocampal volume each predicted onset of questionable dementia, independent of age and sex. Time to walk 30 ft additionally contributed independently to the prediction of time to onset of persistent cognitive impairment. Possessing the APOE epsilon4 allele and depression did not enter either model significantly.


CONCLUSIONS
Models combining multiple risk factors should refine the prediction of questionable dementia and persistent cognitive impairment, harbingers of dementia. Individuals at risk for cognitive impairment may represent a high-risk group for intervention.
Marquis
Scott
S
Department of Medicine (Neurology), University of Alberta, 2E3.08, 8440 112th St, Edmonton, Alberta, Canada T6G 2B7. richard.camicioli@ualberta.ca
Moore
M Milar
MM
Howieson
Diane B
DB
Sexton
Gary
G
Payami
Haydeh
H
Kaye
Jeffrey A
JA
Camicioli
Richard
R
D000368:Aged; D000483:Alleles; D001057:Apolipoproteins E / Q000235:genetics; D003072:Cognition Disorders / Q000209:etiology*; D003863:Depression / Q000150:complications; D005260:Female; D005500:Follow-Up Studies; D005684:Gait; D006624:Hippocampus / Q000033:anatomy & histology / Q000473:pathology; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory; D016017:Odds Ratio; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D012737:Sex Factors; D016138:Walking
D001057:Apolipoproteins E