Lipids (1)

Question 1

What are lipids?

Answer 1

Fatty or oily compounds soluble in organic solvents, including lipoproteins, cholesterol, apolipoproteins, and phospholipids.

Question 2

What are lipoproteins?

Answer 2

Complex compounds with a central hydrophobic core containing cholesterol esters and triglycerides, surrounded by free cholesterol, phospholipids, and apolipoproteins.

Question 3

How are lipoproteins classified?

Answer 3

Based on size, lipid composition, and apolipoprotein type, including Chylomicrons, VLDL, IDL, LDL, HDL, and Lp(a).

Question 4

What is the function of apolipoproteins?

Answer 4

They facilitate the carriage of lipids and cholesterol in the blood, serve as ligands for receptors, guide lipoprotein formation, and activate or inhibit enzymes.

Question 5

What are the two major metabolic pathways of lipoproteins?

Answer 5

Endogenous (synthesis by the liver) and exogenous (from diet).

Question 6

What begins the endogenous lipoprotein pathway?

Answer 6

Formation of VLDL in the liver.

Question 7

What happens to triglycerides in the endogenous pathway?

Answer 7

Lipoprotein lipase metabolizes them to form free fatty acids and IDL.

Question 8

What is a key function of HDL in cholesterol transport?

Answer 8

It transports cholesterol directly to the liver or indirectly transfers it to VLDL or LDL.

Question 9

What initiates the exogenous lipoprotein pathway?

Answer 9

Incorporation of dietary lipids into chylomicrons in the intestine.

Question 10

What are the pro-atherogenic lipoproteins?

Answer 10

Chylomicron remnants, VLDL, IDL, LDL, and Lp(a).

Question 11

What is the primary risk factor for atherosclerosis?

Answer 11

High levels of LDL and apolipoprotein B (apoB100).

Question 12

What is atherogenesis?

Answer 12

The process of atherosclerotic plaque formation, a major cause of coronary artery heart disease.

Question 13

Which immune cells are involved in atherogenesis?

Answer 13

T and B cells, monocytes, and macrophages.

Question 14

What does chronic inflammation lead to in atherosclerosis?

Answer 14

Formation of a necrotic core made up of dead smooth muscle cells and macrophages.

Question 15

What is Lp(a)?

Answer 15

An independent risk factor for atherothrombotic events, consisting of an LDL particle linked to apo(a).

Question 16

What is dyslipidemia?

Answer 16

An imbalance of lipids such as cholesterol, LDL, triglycerides, and HDL.

Question 17

What is hyperlipidemia?

Answer 17

A condition with elevated lipid levels in the body, often associated with high cholesterol.

Question 18

What defines hyperlipidemia in terms of percentile levels?

Answer 18

LDL, total cholesterol, triglycerides above the 90th percentile or HDL below the 10th percentile.

Question 19

What role does HDL cholesterol play?

Answer 19

It helps regulate cholesterol levels to prevent atherogenic imbalances.

Question 20

What is the effect of oxidation on lipoproteins?

Answer 20

The outer shell of lipoproteins is highly susceptible to oxidation by free radical species.

Question 21

What do statins inhibit?

Answer 21

The enzyme HMG-CoA reductase, which catalyzes the conversion of HMG-CoA to mevalonate.

Question 22

What is the primary therapeutic use of statins?

Answer 22

To reduce triglyceride levels and treat dyslipidemia.

Question 23

What do bile acid sequestrants (BAS) do?

Answer 23

Reduce plasma LDL cholesterol by interrupting entero-hepatic circulation of bile acids.

Question 24

What is the multifaceted effect of nicotinic acid (niacin) on lipoproteins?

Answer 24

Increases HDL cholesterol, decreases LDL cholesterol and triglycerides.

Question 25

Fill in the blank: Elevated levels of LDL cholesterol increases the risk of developing _______.

Answer 25

atherosclerotic plaques.

Question 26

True or False: HDL cholesterol is known as 'bad' cholesterol.

Answer 26

False.

Question 27

What is HDL cholesterol known as?

Answer 27

The 'good' cholesterol ## Footnote HDL cholesterol absorbs cholesterol in the blood and carries it back to the liver for elimination.

Question 28

What is the effect of elevated HDL cholesterol levels?

Answer 28

Reduces the risk for heart disease and stroke.

Question 29

What effect does niacin have on lipoprotein(a)?

Answer 29

Reduces lipoprotein(a) by about 25%.

Question 30

What are fibric acid derivatives also known as?

Answer 30

Fibrates.

Question 31

How do fibrates affect blood triglyceride levels?

Answer 31

They attenuate levels by decreasing hepatic production of VLDL.

Question 32

What is one benefit of fibrates concerning HDL cholesterol?

Answer 32

They enhance the production of apoA-I, increasing levels of higher HDL cholesterol.

Question 33

What conditions are fibrates used to treat?

Answer 33

Primary hypercholesterolemia and mixed dyslipidemia.

Question 34

What are some collateral effects of fibrates?

Answer 34

Gastrointestinal tract problems, increased hepatic transaminase activity, and myopathy.

Question 35

Are fibrates recommended for use with statins?

Answer 35

No, they are not recommended for use together.

Question 36

What is the primary function of ezetimibe?

Answer 36

Inhibits intestinal cholesterol absorption.

Question 37

What is the most common use of ezetimibe?

Answer 37

To lower levels of LDL cholesterol.

Question 38

What conditions is ezetimibe used to treat?

Answer 38

Primary hyperlipidemia, mixed hyperlipidemia, familial hypercholesterolemia (HoFH), and homozygous sitosterolemia.

Question 39

What is LDL apheresis?

Answer 39

A technique that uses a machine to remove unwanted LDL cholesterol from the blood.

Question 40

How frequently is LDL apheresis performed?

Answer 40

Every two to three weeks.

Question 41

What is the effect of LDL apheresis on Lp(a)?

Answer 41

It is effective for lowering Lp(a) in individuals with elevated levels.

Question 42

What do PCSK9 monoclonal antibodies do?

Answer 42

Significantly reduce Lp(a) by around 30% and LDL cholesterol by 30-50%.

Question 43

What is mipomersen used to treat?

Answer 43

Homozygous familial hypercholesterolemia.

Question 44

What is the mechanism of action of mipomersen?

Answer 44

Inhibits apolipoprotein B (apoB) synthesis.

Question 45

What are some antioxidants that may reduce lipoprotein oxidative stress?

Answer 45

* Ascorbate (vitamin C) * Alpha-tocopherol (vitamin E) * Urate * Glutathione peroxidases * Peroxiredoxins * Catalase * Superoxide dismutase * Bilirubin.