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 been shown to be protective against cardiovascular disease. However, the association of specific lipoprotein classes and ischemic stroke has not been well 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 through June 1997. Setting A multiethnic community in northern Manhattan, New York, NY. Participants Cases (n = 539) of first ischemic stroke (67% aged greater than 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, determined at enrollment, with ischemic stroke, including atherosclerotic and nonatherosclerotic 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 observed (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 mmol/L), respectively. The protective effect of a higher HDL-C level was significant 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 ischemic stroke in the elderly and among different racial or ethnic groups. These data add to the evidence relating lipids to stroke and support HDL-C as an important modifiable stroke risk factor.