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How does high LDL cholesterol increase the risk of atherosclerosis?
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cardiovascular disease
This micrograph shows a cross section of a coronary artery narrowed by an atherosclerotic plaque (purplish matter inside the artery). Most heart attacks are caused by the rupture of an atherosclerotic plaque, which triggers the formation of a clot that abruptly blocks blood flow to part of the heart muscle.
High levels of low-density lipoproteins (LDLs) increase the risk of atherosclerosis by promoting the accumulation of fatty materials within the innermost layer of the artery wall, known as the intima.12
The process occurs as follows:
- Infiltration: LDLs, which function as vehicles for transporting cholesterol through the body, infiltrate the arterial endothelium.2
- Immune Response: The presence of these lipids draws macrophages—a type of white blood cell—to the site to scavenge the deposited materials.12
- Foam Cell Formation: As macrophages ingest the lipids, they become "foam cells". These cells eventually die and accumulate within the arterial lining.132
- Plaque Development: The buildup of foam cells, along with other substances like calcium, smooth muscle cells, and cellular debris, causes the formation of atherosclerotic plaques.2
These plaques thicken and enlarge over time, narrowing the vessel channel and potentially obstructing blood flow, which serves as the primary mechanism for the development of cardiovascular disease.12