Lipid and lipoprotein biomarkers and the risk of ischemic stroke in postmenopausal women.

BACKGROUND Few studies simultaneously investigated lipids and lipoprotein biomarkers as predictors of ischemic stroke. The value of these biomarkers as independent predictors of ischemic stroke remains controversial. METHODS We conducted a prospective nested case-control study among postmenopausal women from the Women's Health Initiative Observational Study to assess the relationship between fasting lipids (total cholesterol, low-density lipoprotein cholesterol [LDL-C], high-density lipoprotein cholesterol [HDL-C], and triglycerides), lipoproteins (LDL, HDL, and very low-density lipoprotein [VLDL] particle number and size, intermediate-density lipoprotein [IDL] particle number, and lipoprotein (a)), and risk of ischemic stroke. Among women free of stroke at baseline, 774 ischemic stroke patients were matched according to age and race to control subjects, using a 1:1 ratio. RESULTS In bivariate analysis, baseline triglycerides (P<0.001), IDL particles (P<0.01), LDL particles (P<0.01), VLDL triglyceride (P<0.001), VLDL particles (P<0.01), VLDL size (P<0.001), LDL size (P=0.03), and total/HDL cholesterol ratio (P<0.01) were significantly higher among women with incident ischemic stroke, whereas levels of HDL-C (P<0.01) and HDL size (P<0.01) were lower. No significant baseline difference for total cholesterol (P=0.15), LDL-C (P=0.47), and lipoprotein (a) (P=0.11) was observed. In multivariable analysis, triglycerides (odds ratio for the highest versus lowest quartile, 1.56; 95% confidence interval, 1.13-2.17; P for trend=0.02), VLDL size (odds ratio, 1.59; 95% confidence interval, 1.10-2.28; P for trend=0.03), and IDL particle number (odds ratio, 1.46; 95% confidence interval, 1.04-2.04; P for trend=0.02) were significantly associated with ischemic stroke. CONCLUSIONS Among a panel of lipid and lipoprotein biomarkers, baseline triglycerides, VLDL size, and IDL particle number were significantly associated with incident ischemic stroke in postmenopausal women.