Lipids and stroke: a paradox resolved

V. Hachinski, C. Graffagnino, M. Beaudry, G. Bernier, C. Buck, A. Donner, J. D. Spence, G. Doig and B. M. Wolfe
Department of Clinical Neurological Sciences, London Health Sciences Centre-University Campus, Ontario, Canada.

BACKGROUND: Although dyslipidemia is a well established risk factor for coronary artery disease, its relationship to ischemic cerebrovascular disease has remained unclear, perhaps because of the heterogeneous nature of strokes. METHODS: In a case-control study, we measured the serum concentrations of total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, serum triglycerides, and lipoprotein(a) levels and determined the apolipoprotein E phenotype and serum ferritin level in 90 consecutive systematically investigated patients with stroke or transient ischemic attack of atherothrombotic origin. Ninety age-, sex-, and community-matched subjects served as controls. RESULTS: Plasma total cholesterol (5.99 vs 5.45 mmol/L [232 vs 211 mg/dL], P=.003), low-density lipoprotein cholesterol (3.96 vs 3.45 mmol/L [153 vs 133 mg/dL], P=.004), and serum triglyceride (2.09 vs 1.82 mmol/L [8] vs 70 mg/dL], P=.03) levels were significantly higher among the patients with atherothrombotic strokes and transient ischemic attacks than among the control subjects. The inverse was true for high-density lipoprotein cholesterol (1.07 vs 1.18 mmol/L [41 vs 46 mg/dL], P=.02) levels. No significant differences were found in lipoprotein(a) levels or in the distribution of apolipoprotein E phenotypes or allele frequency. Serum ferritin levels did not differ significantly between patients and control subjects. CONCLUSIONS: Elevated low-density lipoprotein cholesterol and triglyceride levels are significant independent risk factors in patients with proven atherothrombotic cerebrovascular disease manifesting as stroke or transient ischemic attack. The level of stored serum iron, as reflected by serum ferritin levels, does not correlate with the presence of atherothrombotic cerebrovascular or coronary disease.