ApoE concentration in total plasma; in HDL; apoA1 concentration of HDL that contains apoE; and HDL apoE density (HR with 95% CI). ApoE density was defined as the ratio of apoE concentration divided by apoA1 concentration in HDL that contains apoE. Plasma total apoE and apoA1 concentration of HDL that contains apoE were studied in the same model that included the covariates. ApoE concentration in HDL and HDL apoE density were studied in separate models that included the covariates. The covariates were hypertension, diabetes, body mass index, physical activity, and use of medications for hyperlipidemia. The nested case-control designs were matched on age, smoking, and fasting status.