atherosclerosis/arteriosclerosis

Atherosclerosis/arteriosclerosis

A complex pathological condition in which the body reshapes and also damages the surface of the blood vessels as a direct consequence of various interactive metabolic processes that involve lipids (fats), white blood cells, antibodies, platelets, and other hormones and proteins. The current theory about what causes atherosclerosis is that most atherosclerosis is a product of an inflammation of the endothelium (the lining of blood vessels that comes into direct contact with circulating blood). This inflammatory process is ongoing and may progress and regress, depending upon the local conditions to which the endothelium is exposed. If the damaging process to the vessel continues, the blood vessel may become occluded (blocked).


However, more frequently, plaque accumulates from within the endothelium and finally ruptures into the lumen of the blood vessel, exposing lipids and other proteins directly into the bloodstream. This sets off a massive cascade of events that perpetuates the problem locally. The body harnesses the white blood cells, proteins, hormones, interleukins (hormones made by the white blood cells),
and the platelets, ultimately creating an occlusive blood clot (thrombus).
This clot results in even more blocking of blood flow and also prevents sufficient oxygen from reaching the affected organ. Depending on the severity of the blood flow blockage, atherosclerosis may lead to a heart attack, stroke, or other serious
medical problems. Experts now know that most myocardial infarctions
(heart attacks) occur in blood vessels that are only initially less than 50 percent blocked but, because of less stable caps on the vessel’s lining, are much more likely to rupture. In contrast, vessels that have not yet ruptured but have progressed to 80–99 percent occlusion have thick, fibrous coverings which, although they limit blood flow, are much less likely to rupture and lead to a complete occlusion. In addition, as the condition has typically progressed slowly, the tissue that is endangered has often had sufficient time to develop collateral
blood vessels upon which to rely. These are vessels that have bypassed the diseased area and, thus, help the organ—and the patient—to survive.


Risk Factors

Risk factors for atherosclerosis, include the following:
• High levels of “bad” cholesterol (low-density
lipoproteins)
• Low levels of “good” cholesterol (high-density
lipoproteins)
• Obesity
• DIABETES MELLITUS
• Hypertension
• An age of 65 and older (the risk for atherosclerosis
increases with age)
• Lack of exercise
• Insulin resistance syndrome
• A family history of atherosclerosis