Total homocysteine and cognition in a tri-ethnic cohort: the Northern Manhattan Study.
OBJECTIVE
Several studies implicate elevated homocysteine as a risk factor for dementia and cognitive decline, but most studies have involved subjects older than 55 years from homogeneous populations. The authors examined homocysteine and cognition in a tri-ethnic community sample 40 years and older.


METHODS
The Northern Manhattan Study includes 3,298 stroke-free subjects. Of these 2,871 had baseline fasting total homocysteine (tHcy) levels and Mini-Mental State Examination (MMSE) scores available. The authors used multiple linear regression to examine the cross-sectional association between baseline tHcy levels and mean MMSE scores adjusting for sociodemographic and vascular risk factors.


RESULTS
Homocysteine levels were related to age, renal function, and B12 deficiency. Those with B12 deficiency had tHcy levels five points higher (9.4 vs 14.4 nmol/L). Mean MMSE scores differed by age, sex, and race-ethnic group. Those with hypertension, diabetes, cardiac disease, and B12 deficiency had lower MMSE scores. In multivariate analyses, elevated tHcy was associated with lower mean MMSE scores for those older than 65 but not for those 40 to 64. Adjusting for B12 deficiency and sociodemographic factors the mean MMSE was 2.2 points lower for each unit increase in the log tHcy level (95% CI -3.6, -0.9). Adding vascular risk factors to the model did not attenuate this effect (mean MMSE -2.2 points; 95% CI -3.5, -0.9).


CONCLUSIONS
Elevated homocysteine was independently associated with decreased cognition in subjects older than 65 in this tri-ethnic cohort, adjusting for sociodemographic and vascular risk factors.
Division of Stroke and Critical Care, Department of Neurology, College of Physicians and Surgeons of Columbia University, NI-Room 640, 710 W168th Street, New York, NY 10032, USA. cbw7@columbia.edu
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Wright
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Lee
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Paik
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Stabler
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Allen
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D000328:Adult; D001741:Black or African American; D000367:Age Factors; D000368:Aged; D053327:Apolipoprotein E4; D001057:Apolipoproteins E / Q000235:genetics; D003071:Cognition; D003072:Cognition Disorders / Q000097:blood / Q000208:ethnology; D015331:Cohort Studies; D005006:Ethnicity; D005215:Fasting / Q000097:blood; D005260:Female; D006630:Hispanic or Latino; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D020138:Hyperhomocysteinemia / Q000097:blood / Q000208:ethnology; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009519:New York City; D011581:Psychological Tests; D012307:Risk Factors; D012959:Socioeconomic Factors; D014806:Vitamin B 12 Deficiency / Q000097:blood / Q000208:ethnology; D044465:White People
D053327:Apolipoprotein E4; D001057:Apolipoproteins E; D006710:Homocysteine