A 65-year-old woman is brought to the emergency room by her husband because she is experiencing chest pain radiating to her left arm. The attending physician diagnoses her as suffering from a mild myocardial infarction and prescribes appropriate intervention. Blood work reveals her total cholesterol to be 280 mg/dL, so a statin is prescribed. Statin drugs inhibit the activity of HMG-CoA reductase. Which of the following best describes how taking statin drugs leads to reduced serum cholesterol and LDL levels?
A) it decreases the serum level of LDL by promoting catabolism
B) it increases the serum level of HDL, thereby promoting increased reverse cholesterol transport
C) it inhibits synthesis of LDL receptors
D) it inhibits the formation of LDL from IDL
E) it inhibits the rate-limiting step in cholesterol biosynthesis

Question

Quizplus · Accepted Answer

Statins inhibit HMG-CoA reductase, the rate-limiting enzyme in cholesterol biosynthesis, leading to decreased cholesterol production and increased LDL receptor expression, which lowers serum LDL levels.  The statin drugs inhibit HMG-CoA, which is the rate-limiting enzyme in de novo cholesterol biosynthesis. Thus, inhibition of cholesterol synthesis reduces the amount of free and LDL-associated cholesterol in the serum

A 65-Year-Old Woman Is Brought to the Emergency Room by Her