Lipoproteins and the endothelium: Insights from clinical research

Elevated plasma levels of atherogenic lipoproteins such as low-density lipo protein (LDL) and remnant lipoproteins and low levels of HDL cholesterol co nstitute major risk factors for the development of atherothrombotic disease . In addition to their role in the initiation and propagation of atheroscle rosis, hyperlipidemia also causes endothelial dysfunction. In addition, hyp erlipidemia has an influence on thrombosis by modulating levels of prothrom botic and fibrinolytic factors, thus promoting the final step in the athero sclerotic process, vascular occlusion. In the last 5 years, randomized, pro spective, placebo-controlled studies aimed at reducing plasma levels of ath erogenic lipoproteins have demonstrated a significant effect on cardiovascu lar morbidity and all-cause mortality in both primary and secondary prevent ion. Although the mechanisms underlying the clinical benefit of lipid-lower ing therapy remain uncertain, the lowering of lipids has been associated wi th improved endothelial function and a less thrombotic state, two factors t hat could play a role in the benefit of lipid lowering. This review focuses on recent clinical research related to the impact of lipoproteins and lipi d-lowering therapy on endothelial function and plasma levels of prothrombot ic and fibrinolytic factors.