Development of cholesterol-rich fatty plaques in artery walls is an inflammatory disease involving cells of the immune system. The disease causes the artery walls to thicken, stiffen and lose normal elasticity, which restricts blood flow and raises blood pressure. Fatty plaques in major heart arteries can lead to a heart attack. Plaques in the carotid arteries in your neck that feed your brain can result in stroke. Controlling your blood level of low-density lipoprotein, or LDL, cholesterol represents an important step toward reducing your cardiovascular disease risk.
The formation of fatty plaques in artery walls is called atherosclerosis, a type of arteriosclerosis or hardening of the arteries. Atherosclerosis may begin in childhood and usually evolves over a period of many years through a series of stages. The most common initiating event is the sticking of LDL onto the artery walls. LDL then passes through the inner wall cell layer. Cells in the artery walls treat entrapped LDL as a foreign substance and an inflammatory response results. Over time, continued influx of LDL causes the arterial wall plaques to grow and become fibrous and calcified. Cigarette smoking, high blood pressure and high blood glucose promote atherosclerosis.
The inflammatory process in arteriosclerosis is complex. The presence of LDL in the artery stimulates the immune system and attracts circulating white blood cells. In the process of trying to remove LDL, the white blood cells are converted into "foam cells." Their presence is characteristic of the early stages of atherosclerosis. In response to the inflammatory process, muscle cells in your arteries increase in number and produce a fibrous protein called collagen to form a cap over the damaged area of the artery wall. These changes reduce blood flow through the artery. The surface of the artery becomes not only narrower, but less smooth, which can cause small particles called blood platelets to stick. Platelets are a key component in blood clots. Platelets adhering to a plaque may eventually form a potentially fatal blood clot that completely blocks blood flow.
The liver produces a protein called C-reactive protein, or CRP, in response to inflammation. CRP enters the blood and promotes inflammation and atherosclerosis in diseased arteries. In people with atherosclerosis, an elevated blood level of CRP may predict a future heart attack, according the researchers involved in the the Cardiovascular Health Study sponsored by the National Institutes of Health. However, because CRP is produced in response to most forms of inflammation, infection and tissue damage, doctors' ability to predict heart disease risk based on CRP alone is limited.
An LDL cholesterol level of 160 mg/dL or above is considered too high. If you have an elevated LDL level, regular exercise, weight loss and adhering to a diet low in saturated animal fats and simple sugars, and rich in soluble fiber from oats, beans, fruits and vegetables may help to bring it down. Alternatively, your doctor may prescribe a statin medication, such as rosuvastatin (Crestor), atorvastatin (Lipitor) and simvastatin (Zocor). Statin drugs decrease your body’s production of cholesterol. Consuming foods that contain antiinflammatory compounds may also help to inhibit the initiation and progression of atherosclerosis. For example, omega-3 polyunsaturated fatty acids present in fatty ocean fish and compounds called polyphenols, such as those found in red wine and soybeans, may help protect against the development of atherosclerosis.
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