Briefly explain the roles of low-density lipoprotein (LDL) cholesterol and high-density lipoprotein (HDL) cholesterol in the body.

Question

What will be an ideal response?

Answer 1

Cholesterol is used in the body to synthesize important hormones, manufacture vitamin D, and maintain healthy functioning of nervous system cells. Cholesterol receives much attention because of its direct relationship to heart disease. An increased risk for coronary heart disease (CHD) has been established in individuals with high total cholesterol, high LDL cholesterol, and low HDL cholesterol. The general recommendation is to keep the total cholesterol levels at less than 200 mg/dL. Cholesterol is transported primarily in the form of LDL and HDL. LDL ("bad") cholesterol tends to release cholesterol, which may then penetrate the lining of arteries and speed the process of atherosclerosis (the buildup of fatty tissue in the walls of arteries). LDL cholesterol particles are of two types: large, or pattern A, and small, or pattern B. Small particles are thought to pass through the inner lining of the coronary arteries more readily, thereby increasing the risk for a heart attack. A genetic variation of LDL cholesterol, known as lipoprotein-a, or Lp(a), is known to promote blood clots and earlier development of atherosclerosis. Not all cholesterol is bad. In a process known as reverse cholesterol transport, HDLs act as "scavengers," removing cholesterol from the body and preventing plaque formation in the arteries. The strength of HDL is in the protein molecules found in its coating. When HDL comes in contact with cholesterol-filled cells, these protein molecules attach to the cells and take their cholesterol. The belief is that the more HDL ("good") cholesterol, the better. HDL cholesterol is thought to offer some protection against heart disease.