Lipoproteins and the endothelium: insights from clinical research.

Elevated plasma levels of atherogenic lipoproteins such as low-density lipoprotein (LDL) and remnant lipoproteins and low levels of HDL cholesterol constitute major risk factors for the development of atherothrombotic disease. In addition to their role in the initiation and propagation of atherosclerosis, hyperlipidemia also causes endothelial dysfunction. In addition, hyperlipidemia has an influence on thrombosis by modulating levels of prothrombotic and fibrinolytic factors, thus promoting the final step in the atherosclerotic process, vascular occlusion. In the last 5 years, randomized, prospective, placebo-controlled studies aimed at reducing plasma levels of atherogenic lipoproteins have demonstrated a significant effect on cardiovascular morbidity and all-cause mortality in both primary and secondary prevention. Although the mechanisms underlying the clinical benefit of lipid-lowering therapy remain uncertain, the lowering of lipids has been associated with improved endothelial function and a less thrombotic state, two factors that could play a role in the benefit of lipid lowering. This review focuses on recent clinical research related to the impact of lipoproteins and lipid-lowering therapy on endothelial function and plasma levels of prothrombotic and fibrinolytic factors.