Plasma homocysteine levels and risk of Alzheimer disease.
OBJECTIVE
To explore the association between high homocysteine levels and risk of Alzheimer disease (AD) in the Washington Heights-Inwood Columbia Aging Project (WHICAP).


METHODS
The authors obtained fasting plasma samples in 909 elderly subjects chosen at random from a cohort of Medicare recipients; there was longitudinal data in 679 subjects without dementia at baseline who were followed for 3,206 person-years. Prevalent and incident dementia and its subtypes were diagnosed using standard methods.


RESULTS
There were 128 persons with prevalent AD and 109 with incident AD in 3,206 person-years of follow-up. The adjusted OR of prevalent AD for the highest quartile of homocysteine compared to the lowest was 1.3 (95% CI = 0.7, 2.3; p for trend = 0.25). In longitudinal analyses, the authors found that the adjusted hazard ratio of AD for the highest quartile of homocysteine was 1.4 (95% CI = 0.8, 2.4; p for trend = 0.31). The authors also found that high homocysteine levels were not related to a decline in memory scores over time. Age was a significant confounder in all the analyses. The study had 80% power to detect a hazard ratio of 1.3 in the longitudinal analyses.


CONCLUSIONS
High homocysteine levels were not associated with AD and were not related to a decrease in memory scores over time.
Luchsinger
J A
JA
Taub Institute for Research of Alzheimer's Disease and the Aging Brain, Columbia University, New York, USA.
Tang
M-X
MX
Shea
S
S
Miller
J
J
Green
R
R
Mayeux
R
R
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000097:blood / Q000453:epidemiology*; D001057:Apolipoproteins E / Q000235:genetics; D015331:Cohort Studies; D015897:Comorbidity; D015986:Confounding Factors, Epidemiologic; D003430:Cross-Sectional Studies; D003545:Cysteine / Q000097:blood; D003704:Dementia / Q000453:epidemiology; D003920:Diabetes Mellitus / Q000453:epidemiology; D005006:Ethnicity; D005260:Female; D005492:Folic Acid / Q000097:blood; D005500:Follow-Up Studies; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D020138:Hyperhomocysteinemia / Q000097:blood / Q000453:epidemiology*; D008297:Male; D008568:Memory; D009483:Neuropsychological Tests; D009519:New York City / Q000453:epidemiology; D015995:Prevalence; D012307:Risk Factors; D012494:Sampling Studies; D020521:Stroke / Q000453:epidemiology; D014805:Vitamin B 12 / Q000097:blood; D025101:Vitamin B 6 / Q000097:blood
D001057:Apolipoproteins E; D006710:Homocysteine; D025101:Vitamin B 6; D005492:Folic Acid; D003545:Cysteine; D014805:Vitamin B 12