Cholesterol

Question 1

What is the first step in atherogenesis?

Answer 1

Endothelial injury caused by high LDL, smoking, hypertension, or diabetes.

Question 2

What happens after lipid entry during atherogenesis?

Answer 2

LDL oxidizes within the vessel wall.

Question 3

How do monocytes contribute to atherogenesis?

Answer 3

They migrate, become macrophages, and engulf oxidized LDL to form foam cells.

Question 4

What is a fatty streak in atherogenesis?

Answer 4

Foam cell accumulation creating early lesions.

Question 5

What is the role of smooth muscle cells in atherogenesis?

Answer 5

They migrate, proliferate, and form a fibrous cap.

Question 6

What happens when a plaque ruptures in atherogenesis?

Answer 6

Exposes the lipid core, leading to thrombus formation and potential blockage.

Question 7

What are triglycerides, and what is their function?

Answer 7

Energy storage molecules made of glycerol and three fatty acids.

Question 8

How are triglycerides used during fasting?

Answer 8

Broken into free fatty acids and glycerol for energy.

Question 9

What is cholesterol, and what are its functions?

Answer 9

A sterol used for cell membranes, hormones, bile acids, and vitamin D.

Question 10

What is free cholesterol?

Answer 10

Active cholesterol in cell membranes and plasma, maintaining membrane fluidity.

Question 11

What is esterified cholesterol?

Answer 11

Cholesterol combined with fatty acids for storage and transport.

Question 12

What are the two sources of cholesterol?

Answer 12

Dietary (e.g., eggs, dairy) and liver synthesis (de novo).

Question 13

What is the starting point of the mevalonate pathway?

Answer 13

Acetyl-CoA formation.

Question 14

What enzyme converts HMG-CoA into mevalonate?

Answer 14

HMG-CoA reductase.

Question 15

What is the target of statins in cholesterol synthesis?

Answer 15

HMG-CoA reductase.

Question 16

What is squalene, and what is its role in cholesterol synthesis?

Answer 16

An intermediate processed into lanosterol and then cholesterol.

Question 17

What are chylomicrons?

Answer 17

Large lipoproteins that transport dietary triglycerides and cholesterol to tissues.

Question 18

What is the role of VLDL?

Answer 18

Transports triglycerides from the liver to tissues.

Question 19

What is IDL, and how is it formed?

Answer 19

Intermediate lipoprotein formed after triglyceride delivery by VLDL.

Question 20

What is LDL, and why is it considered ‘bad cholesterol’?

Answer 20

Derived from IDL, it delivers cholesterol to tissues and promotes plaque formation.

Question 21

What is HDL, and why is it considered ‘good cholesterol’?

Answer 21

A protein-rich lipoprotein that removes cholesterol to the liver for excretion.

Question 22

How is coronary artery disease (CAD) risk calculated?

Answer 22

Divide LDL by HDL.

Question 23

What LDL/HDL ratio indicates low CAD risk for males?

Answer 23

1.0.

Question 24

What LDL/HDL ratio indicates very high CAD risk for males?

Answer 24

7.99.

Question 25

What is the target total cholesterol level?

Answer 25

Less than 200 mg/dL.

Question 26

What are the HDL targets for men and women?

Answer 26

Men >40 mg/dL; women >50 mg/dL.

Question 27

What is the target LDL level?

Answer 27

Less than 130 mg/dL.

Question 28

What is the target triglyceride level?

Answer 28

Less than 120 mg/dL.

Question 29

What are primary causes of hypercholesterolemia?

Answer 29

Genetic mutations, such as familial LDL receptor mutations.

Question 30

What are secondary causes of hypercholesterolemia?

Answer 30

Obesity, Type II diabetes, hypothyroidism, CKD, or medications.

Question 31

Why is dietary cholesterol control often insufficient?

Answer 31

The liver compensates by increasing endogenous cholesterol synthesis.

Question 32

How does soluble fiber affect cholesterol?

Answer 32

Reduces absorption of dietary cholesterol.

Question 33

What are dietary sources of omega-3 fatty acids?

Answer 33

Fish and flaxseed.

Question 34

How do plant sterols and stanols reduce cholesterol?

Answer 34

Compete with cholesterol for absorption in the intestine.

Question 35

What is the MOA of statins?

Answer 35

Inhibit HMG-CoA reductase to decrease cholesterol synthesis.

Question 36

What are the side effects of statins?

Answer 36

Muscle pain and elevated liver enzymes.

Question 37

What is the MOA of niacin?

Answer 37

Reduces VLDL and LDL synthesis; increases HDL.

Question 38

What is the MOA of fibrates?

Answer 38

Activate PPAR-alpha to enhance triglyceride metabolism.

Question 39

What is the MOA of bile acid resins?

Answer 39

Bind bile acids, forcing the liver to use cholesterol to produce more bile acids.

Question 40

What is the MOA of cholesterol absorption inhibitors?

Answer 40

Block the NPC1L1 transporter to reduce dietary cholesterol absorption.

Question 41

What is the novel MOA of PCSK9 inhibitors?

Answer 41

Prevent LDL receptor degradation, enhancing LDL clearance.

Question 42

What are the risks of hypocholesterolemia?

Answer 42

Increased cancer risk, hemorrhagic stroke, anxiety, impaired healing, and preterm birth.