Lipids and Cerebrovascular Disease

The relationship between lipids and stroke is complex. In most epidemiological cohorts, there is a direct relationship between cholesterol levels and ischemic stroke. The relationship of lipids to ischemic stroke, however, varies by stroke subtype, with associations strongest for atherosclerotic subtypes. Conversely, there is an increased risk of intracerebral hemorrhage (ICH) at low cholesterol levels, and there is evidence that small vessel disease may share a similar profile of inverse association with lipid levels. The associations also depend on the specific lipid component considered, with the data strongest for total cholesterol (TC) and low-density lipoprotein-cholesterol (LDL-C). Given the availability of increasingly potent lipid-lowering agents, understanding the relationship between dyslipidemia and stroke may improve primary and secondary stroke prevention strategies.Here, we review the literature on the relationship between dyslipidemia and stroke, with a focus on lipid screening recommendations and evidence-based approaches to management. Total and LDL-CIn most, but not all, observational studies, there is an association between higher total and LDL-C levels and increased ischemic stroke risk (Table 1).1–12View this table:Table 1. Lipid Profile Component and Ischemic Stroke RiskIn addition, most observational studies also found an association between lower TC and LDL-C levels and increased risk of hemorrhagic stroke (Table 2).2,13–17 A recent meta-analysis of 23 studies showed an inverse dose–response association between TC and hemorrhagic stroke (odds ratio [OR], 0.85 per 1 mmol/L increment; 95% confidence interval [95% CI], 0.80–0.91).18 The mechanism of this association remains unclear. Some studies, however, have shown low serum LDL-C levels in patients with liver disease19 and hematologic malignancies20 who are at a higher risk of ICH. This hypothesis can be tested in large population-based cohorts.View this table:Table 2. Lipid Profile Component and Hemorrhagic Stroke RiskOverall, epidemiological studies suggest competing stroke risk related to TC levels in …