HDL cholesterol and stroke risk: The Multi-Ethnic Study of Atherosclerosis.

BACKGROUND AND PURPOSE Accurate identification of risk factors for stroke is important for public health promotion and disease prevention. HDL cholesterol is a potential risk factor, yet its role in stroke risk is unclear, as is whether HDL cholesterol content or particle number might be a better indicator of stroke risk. Furthermore, the degree to which ethnicity moderates the risk is unknown. As such, the current study examines the associations between incident stroke and both HDL cholesterol concentration and particle number, and assesses the moderating role of race and ethnicity. METHODS The sample is a racially diverse cohort of US adults between the ages of 45-84 years enrolled in the Multi-Ethnic Study of Atherosclerosis between 2000 and 2002 and followed until December 2011. The associations among cholesterol content and stroke risk, particle number and stroke risk, and the interaction with race were explored. RESULTS The incidence of stroke was 2.6%. HDL cholesterol concentration (mmol/L) (Hazard Ratio (HR) = .56; 95% Confidence Interval (CI): .312-.988) and number of large HDL particles (μmol/L) (HR = .52, CI: .278-.956) were associated with lower stroke risk. When interactions with race were evaluated, the relationship between both HDL variables and stroke were significant in Blacks, but not other races. CONCLUSIONS Higher HDL cholesterol and a higher concentration of large particles are associated with lower risk of stroke in Blacks. Further research is needed to elucidate the mechanisms by which HDL subfractions may differentially affect stroke outcome in different races/ethnicities.