Homocysteine and cognitive function in a population-based study of older adults.
OBJECTIVE
To assess the relations between homocysteine levels and neurobehavioral test scores representing a broad range of cognitive domains in a population-based study of older adults.


METHODS
Cross-sectional analysis of first-visit data of subjects in the Baltimore Memory Study, a longitudinal study.


METHODS
Specific neighborhoods in Baltimore.


METHODS
Participants were 1,140 randomly selected residents aged 50 to 70 with a mean age+/-standard deviation of 59.3+/-5.9; 65.9% were female, and 54.2% were white and 41.1% African-American.


METHODS
Twenty neurobehavioral test scores in eight cognitive domains.


RESULTS
Linear regression models revealed that homocysteine was consistently and strongly associated with worse neurobehavioral test performance, in crude analysis and after control for a large set of important covariates. Associations were observed in all eight cognitive domains assessed but were strongest and most consistent in the domains of simple motor and psychomotor speed, eye-hand coordination/manual dexterity, and verbal memory and learning. On average, an increase in homocysteine levels from the 25th to the 75th percentile, all in the generally accepted normal range, was equivalent in its association with neurobehavioral test scores to an increase of 4.2 years of age. Logistic regression models revealed that, on average, for the neurobehavioral tests associated with homocysteine, subjects in the highest quartile of homocysteine levels were more than two times as likely to be in the lowest quartile of neurobehavioral test scores as those in the lowest quartile.


CONCLUSIONS
Higher homocysteine levels were associated with worse function across a broad range of cognitive domains, and the magnitude of the associations was large. The data suggest that homocysteine may be a potentially important modifiable cause of cognitive dysfunction.
Schafer
Jyme H
JH
Department of Environmental Health Sciences, Division of Occupational and Environmental Health, Johns Hopkins University, Baltimore, Maryland, USA.
Glass
Thomas A
TA
Bolla
Karen I
KI
Mintz
Margaret
M
Jedlicka
Anne E
AE
Schwartz
Brian S
BS
D000368:Aged; D015142:Baltimore; D003071:Cognition; D003430:Cross-Sectional Studies; D005260:Female; D005853:Geriatrics; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D008568:Memory; D008875:Middle Aged; D011597:Psychomotor Performance
D006710:Homocysteine