High-density lipoprotein cholesterol and ischemic stroke in the elderly - The northern Manhattan stroke study

Context Elevated high-density lipoprotein cholesterol (HDL-C) levels have b een shown to be protective against cardiovascular disease. However, the ass ociation of specific lipoprotein classes and ischemic stroke has not been w ell defined, particularly in higher risk minority populations. Objective To evaluate the association between HDL-C and ischemic stroke in an elderly, racially or ethnically diverse population. Design Population-based, incident case-control study conducted July 1993 th rough June 1997. Setting A multiethnic community in northern Manhattan, New York, NY. Participants Cases (n = 539) of first ischemic stroke (67% aged greater tha n or equal to 65 years; 55% women; 53% Hispanic, 28% black, and 19% white) were enrolled and matched by age, sex, and race or ethnicity to stroke-free community residents (controls; n=905). Main Outcome Measure Independent association of fasting HDL-C levels, deter mined at enrollment, with ischemic stroke, including atherosclerotic and no natherosclerotic ischemic stroke subtypes. Results After risk factor adjustment, a protective effect was observed for HDL-C levels of at least 35 mg/dL (0.91 mmol/L) (odds ratio [OR], 0.53; 95% confidence interval [CI], 0.39-0.72). A dose-response relationship was obs erved (OR, 0.65; 95% CI, 0.47-0.90 and OR, 0.31; 95% CI,0.21-0.46) for HDL- C levels of 35 to 49 mg/dL (0.91-1.28 mmol/L) and at least 50 mg/dL (1.29 m mol/L), respectively. The protective effect of a higher HDL-C level was sig nificant among participants aged 75 years or older (OR, 0.51;95% CI,0.27-0. 94), was more potent for the atherosclerotic stroke subtype (OR, 0.20; 95% CI, 0.08-0.50), and was present in all 3 racial or ethnic groups studied. Conclusions Increased HDL-C levels are associated with reduced risk of isch emic stroke in the elderly and among different racial or ethnic groups. The se data add to the evidence relating lipids to stroke and support HDL-C as an important modifiable stroke risk factor.