Related Experiment Videos
The relationship between cholesterol and stroke: implications for antihyperlipidaemic therapy in older patients
C Sarti1, M Kaarisalo, J Tuomilehto
1Department of Epidemiology and Health Promotion, National Public Health Institute, Helsinki, Finland. cinzia.sarti@ktl.fi
Insights
High cholesterol increases ischemic stroke risk, especially in the elderly. Hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors may offer additional stroke protection beyond cholesterol reduction alone.
Area of Science:
- Cardiovascular Epidemiology
- Neurology
- Pharmacology
Background:
- Existing research on serum cholesterol and stroke risk is reviewed, often extrapolated from myocardial infarction (MI) trials.
- Focus is placed on the elderly, a high-risk group for stroke, and the role of cholesterol in stroke prevention.
Purpose of the Study:
- To review epidemiological data on serum cholesterol levels and stroke risk.
- To evaluate the potential reduction in stroke risk through hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitor treatment, particularly in the elderly.
Main Methods:
- Review of epidemiological studies on serum cholesterol and stroke.
- Analysis of evidence for HMG-CoA reductase inhibitors in stroke risk reduction.
Main Results:
- Serum cholesterol levels are determinants of stroke, though associations are relatively weak.
- Elevated total cholesterol and low high-density lipoprotein-cholesterol predispose to ischemic stroke in the elderly.
- HMG-CoA reductase inhibitors may reduce stroke risk more than expected from cholesterol reduction alone, possibly due to antioxidant and endothelium-stabilizing effects.
Conclusions:
- High serum cholesterol is a risk factor for ischemic stroke, with a significant population attributable risk in the growing elderly population.
- Prospective trials are needed to evaluate cholesterol reduction with HMG-CoA reductase inhibitors for ischemic stroke prevention in the elderly.
- Tolerability and cost-effectiveness of lipid-lowering drugs for primary stroke prevention in the elderly require assessment.
Abstract:
Various studies on the relationship between serum cholesterol level and the risk of stroke have been published recently. Subsequent reviews have extrapolated information on stroke from the clinical trials originally aimed at lowering cholesterol for the primary and secondary prevention of myocardial infarction (MI) in middle-aged patients. We have reviewed the epidemiological knowledge on the relationship between serum cholesterol levels and stroke, and also focused on possible reduction of the risk of stroke with hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitor treatment. Possible benefits from such therapy are particularly relevant for the elderly population which is at particularly high risk for stroke. The effects of serum cholesterol levels on the risk for haemorrhagic and ischaemic stroke have been evaluated. Indirect epidemiological evidence indicates that serum levels of total cholesterol and its subfractions are determinants of stroke, but their associations are relatively weak. When exploring the possible association of serum cholesterol levels with the increased risk of stroke with aging, we concluded that, as in younger adults, elevated total cholesterol and decreased high density lipoprotein-cholesterol levels predispose to ischaemic stroke in the elderly. The mechanism through which serum cholesterol levels increase stroke risk is based on its actions on the artery walls. Indirect evidence suggests that the reduction in the stroke risk with HMG-CoA reductase inhibitors is larger than would be expected with reduction of elevated serum cholesterol level alone. Therefore, antioxidant and endothelium-stabilising properties of HMG-CoA reductase inhibitors may contribute in reducing the risk of stroke in recipients. Lowering high serum cholesterol with HMG-CoA reductase inhibitors has been beneficial in the primary and secondary prevention of MI. No trials have specifically tested the effect of cholesterol lowering with HMG-CoA reductase inhibitors on stroke occurrence. High serum cholesterol levels are a risk factor for ischaemic stroke, although the risk imparted is lower than that for MI. Although the relative risk of stroke associated with elevated serum cholesterol levels is only moderate, its population attributable risk is high given the increase in the elderly population worldwide. The effect of cholesterol reduction with HMG-CoA reductase inhibitors on prevention of ischaemic stroke should be evaluated in prospective, randomised, placebo-controlled trials in the elderly. The tolerability of lipid-lowering drugs in the elderly and the cost effectiveness of primary prevention of stroke using lipid-lowering drugs also needs to be assessed in the elderly.