High Blood Cholesterol and Other Lipids
No consistent association has been demonstrated between levels of total cholesterol, HDL-C (good) cholesterol, or LDL-C (bad) cholesterol with overall stroke risk (all types combined). Although you will often read that high total cholesterol is a major risk factor for ischemic stroke, the data are actually conflicting. In contrast, the data associating levels of total cholesterol and other serum lipids with atherosclerotic cardiovascular disease are far more robust.
Further research is needed on any associations with ischemic stroke, specific ischemic stroke subtypes, or hemorrhagic stroke.
Populations at special risk
Overall, total cholesterol levels and LDL levels are somewhat higher in Hispanic males than in the US overall male population. However, the differences in various lipid levels between major U.S. racial/ethnic populations groups are overall small.
Relationship to pathogenesis
Concerning cerebrovascular disease specifically, what is known is that elevated total cholesterol and LDL-C is associated with increased degree and progression of carotid atherosclerosis, while elevated HDL-C levels have the opposite effect.
A little about control/treatment
To reduce the risk of myocardial infarction (and possibly stroke), recommended levels for adults are total cholesterol <200 mg/dL and HDL-C ≥40 mg/dL. An individual’s LDL-C goal depends on how many additional risk factors they may have. The recommended levels may be achieved by diet, increased physical activity, and/or cholesterol-lowering agents (statins or other pharmacological agents).
Note that the statins (3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors) may have important effects on atherosclerotic disease in addition to their lipid-lowering properties, and recent studies show that they reduce stroke risk.