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Cholesterol, cholesterol lowering, and endothelial function
R A Vogel1, M C Corretti, J Gellman
1University of Maryland Hospital, Baltimore 21201, USA.
Insights
High cholesterol (hypercholesterolemia) contributes to atherosclerosis by causing endothelial dysfunction, which precedes anatomical changes. Lowering cholesterol improves endothelial function, reducing cardiovascular events.
Area of Science:
- Cardiovascular Science
- Endothelial Biology
- Lipid Metabolism
Background:
- Hypercholesterolemia is strongly linked to atherosclerosis through established data.
- Traditional theories focus on cholesterol deposition and inflammatory responses.
- The endothelium plays a critical role in vascular health and disease.
Purpose of the Study:
- To explore the role of endothelial dysfunction in hypercholesterolemia-induced atherosclerosis.
- To understand how endothelial function is affected by risk factors like high cholesterol and diet.
- To investigate the impact of cholesterol-lowering and antioxidant therapies on endothelial function.
Main Methods:
- Review of epidemiological, experimental, and clinical trial data.
- Analysis of the endothelium's role in vascular tone, lipid metabolism, and inflammation.
- Examination of studies on cholesterol lowering and antioxidant therapy effects on endothelial function.
Main Results:
- Endothelial dysfunction, characterized by impaired nitric oxide availability, precedes anatomical atherosclerosis.
- Hypercholesterolemia and high-fat diets promote endothelial dysfunction, leading to vasoconstriction and inflammation.
- Cholesterol-lowering therapies and antioxidants can improve endothelial function and reduce adhesion molecules.
Conclusions:
- Endothelial dysfunction is a key early mechanism in atherosclerosis development, driven by hypercholesterolemia.
- Restoring endothelial function through cholesterol lowering contributes to reduced cardiovascular events.
- Targeting endothelial dysfunction offers a promising therapeutic strategy for atherosclerosis.
Abstract:
A strong relationship between hypercholesterolemia and atherosclerosis has been established through epidemiological, experimental, and clinical trial data. Traditional theories on the pathophysiology of this relationship involve the deposition, modification, and cellular uptake of cholesterol, and the release of inflammatory and growth factors resulting in smooth muscle cell proliferation and collagen matrix production. The vasculature has recently been found to be an active and complex organ, with the endothelium playing a controlling role in vascular tone, lipid breakdown, thrombogenesis, inflammation, and vessel growth. In the presence of risk factors such as hypercholesterolemia, the endothelium promotes vasoconstriction, monocyte and platelet adhesion, thrombogenesis, and growth factor release. A high-fat diet also directly impairs endothelial function and increases coagulation factors. Endothelial dysfunction is associated with decreased availability of the predominant vasodilator nitric oxide, possibly by increased destruction by oxygen free radicals. This dysfunctional state appears before the earliest anatomic evidence of atherosclerosis and may represent an important initial step in its development. Several studies have shown improvements in endothelial function with cholesterol lowering in both normal individuals and those with coronary heart disease. Short-term improvements in endothelial-dependent vasodilation and adhesion molecule expression have also been reported with antioxidant therapy. These observations suggest that atherosclerosis is at least in part caused by endothelial dysfunction that favors cellular proliferation. This new understanding helps to explain the early and substantial reductions in major cardiovascular events associated with cholesterol lowering.