Hypercholesterolemia, Stroke And Statins

Abstract

The link between serum cholesterol levels and the incidence of stroke still remain to be established. There are conflicting reports from a series of observational cohort studies. However, clinical trials with HMG CoA reductase inhibitors (also called statins) have shown that cholesterol lowering therapy used in the primary and secondary prevention of myocardial infarction significantly reduced cardiovascular events including strokes. Meta analysis of trials with statins have shown a relative risk reduction in stroke of 12 to 48% in patients with coronary heart disease after MI. It has been postulated that the clinical action of statins is the result of pleiotropic / antiatherogenic effects rather than simply a reduction in cholesterol. The putative beneficial effect of statins in stroke involve blocking of macrophage and platelet activation, improvement of endothelial cell vasomotor function, enhancement of endothelial fibrinolytic function, immunosuppressive and anti-inflammatory action, inhibition of smooth muscle cell proliferation and particularly enhancement of endothelial nitric oxide synthase (eNOS).