Exceeding which of the following serum cholesterol levels significantly increases the risk of coronary artery disease?
A. 100 mg/dl
B. 150 mg/dl
C. 175 mg/dl
D. 200 mg/dl
Correct Answer: D. 200 mg/dl
Cholesterol levels above 200 mg/dl are considered excessive. They require dietary restriction and perhaps medication. Exercise also helps reduce cholesterol levels. The other levels listed are all below the nationally accepted levels for cholesterol and carry a lesser risk for CAD. The normal level of serum cholesterol is within 125 to 200 mg/dl.
Option A: 100mg/dl is an acceptable level of serum cholesterol. An elevated low-density lipoprotein cholesterol (LDL-C) level is a major risk factor for CAD, and several large, randomized, primary prevention trials have shown that lowering LDL-C levels with statins reduces the risk of major coronary events and coronary death.
Option B: 150 mg/dl is within the normal level of serum cholesterol. LDL is the particle that is responsible for transporting cholesterol to tissues. Cholesterol transportation is achieved by binding of the LDL receptor and apoB.
Option C: 175 mg/dl is still an acceptable level of serum cholesterol. HDL is a molecule that is antioxidant, antiinflammatory, antiapoptotic, and increases macrophage cholesterol excretion and endothelial healing. The removal of cholesterol from the body by the liver via HDL is called reverse cholesterol transport.