Homocysteine and the risk of ischemic stroke in a triethnic cohort: the NOrthern MAnhattan Study.
OBJECTIVE
The level of total homocysteine (tHcy) that confers a risk of ischemic stroke is unsettled, and no prospective cohort studies have included sufficient elderly minority subjects. We investigated the association between mild to moderate fasting tHcy level and the incidence of ischemic stroke, myocardial infarction, and vascular death in a multiethnic prospective study.


METHODS
A population-based cohort was followed for vascular events (stroke, myocardial infarction, and vascular death). Baseline values of tHcy and methylmalonic acid were measured among 2939 subjects (mean age, 69+/-10; 61% women, 53% Hispanics, 24% blacks, and 20% whites). Cox proportional models were used to calculate hazard ratios (HRs) and 95% CIs in tHcy categories after adjusting for age, race, education, renal insufficiency, B12 deficiency, and other risk factors.


RESULTS
The adjusted HR for a tHcy level > or =15 micromol/L compared with <10 micromol/L was greatest for vascular death (HR=6.04; 95% CI, 3.44 to 10.60), followed by combined vascular events (HR=2.27; 95% CI, 1.51 to 3.43), ischemic stroke (HR=2.01; 95% CI, 1.00 to 4.05), and nonvascular death (HR=2.02; 95% CI, 1.31 to 3.14). Mild to moderate elevations of tHcy of 10 to 15 micromol/L were not significantly predictive of ischemic stroke, but increased the risk of vascular death (2.27; 95% CI, 1.44 to 3.60) and combined vascular events (1.42; 95% CI, 1.06 to 1.88). The effect of tHcy was stronger among whites and Hispanics, but not a significant risk factor for blacks.


CONCLUSIONS
Total Hcy elevations above 15 micromol/L are an independent risk factor for ischemic stroke, whereas mild elevations of tHcy of 10 to 15 micromol/L are less predictive. The vascular effects of tHcy are greatest among whites and Hispanics, and less among blacks.
Sacco
Ralph L
RL
Department of Neurology, Columbia University College of Physicians and Surgeons and the Mailman School of Public Health, New York, NY, USA. rls1@columbia.edu
Anand
Kishlay
K
Lee
Hye-Seung
HS
Boden-Albala
Bernadette
B
Stabler
Sally
S
Allen
Robert
R
Paik
Myunghee C
MC
D000368:Aged; D044383:Black People; D015331:Cohort Studies; D005260:Female; D006630:Hispanic or Latino; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D008297:Male; D008764:Methylmalonic Acid / Q000097:blood; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000453:epidemiology / Q000208:ethnology; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D020521:Stroke / Q000097:blood* / Q000453:epidemiology / Q000208:ethnology*; D014652:Vascular Diseases / Q000097:blood / Q000453:epidemiology / Q000208:ethnology; D044465:White People
D006710:Homocysteine; D008764:Methylmalonic Acid