Increased Stroke Risk and Lipoprotein(a) in a Multiethnic Community: The Northern Manhattan Stroke Study

CONTEXT: Elevated lipoprotein(a) Lp(a) is associated with ischemic stroke (IS) among Whites, but data is sparse for non-White populations. OBJECTIVE: Using a population-based case-control study design with subjects from the Northern Manhattan Stroke Study, we assessed whether Lp(a) levels were independently associated with IS risk among Whites, Blacks and Hispanics. DESIGN AND SETTING: Lp(a) levels were measured in 317 IS cases (mean age 69 +/- 13 years; 56% women; 16% Whites, 31% Blacks and 52% Hispanics) and 413 community-based controls, matched by age, race/ethnicity and gender. In-person assessments included demographics, socioeconomic status, presence of vascular risk factors and fasting lipid levels. Logistic regression was used to determine the independent association of Lp(a) and IS. Stratified analyses investigated gender and race/ethnic differences. RESULTS: Mean Lp(a) levels were greater among cases than controls (46.3 +/- 41.0 vs. 38.9 +/- 38.2 mg/dl; p or =30 mg/dl were independently associated with an increased stroke risk in the overall cohort (adjusted odds ratio, OR, 1.8, 95% confidence interval, CI, 1.20-2.6; p = 0.004). There was a significant linear dose-response relationship between Lp(a) levels and IS risk. The association between IS risk and Lp(a) > or =30 mg/dl was more pronounced among men (adjusted OR 2.0, 95% CI 1.1-3.5; p = 0.02) and among Blacks (adjusted OR 2.7, 95% CI 1.2-6.2; p = 0.02). CONCLUSION: Elevated Lp(a) levels were significantly and independently associated with increased stroke risk, suggesting that Lp(a) is a risk factor for IS across White, Black and Hispanic race/ethnic groups.