LIPID AND LIPOPROTEIN DISORDERS MCQs | MCQ Quiz | OmpathStudy Kenya

Question 1

Which lipoprotein is responsible for transporting dietary triglycerides from the intestines to tissues?

Accepted Answer

Chylomicrons — Chylomicrons are the largest lipoproteins and transport dietary triglycerides from the intestines to other tissues. They are primarily involved in the transport of dietary fats.

Question 2

What is the primary function of HDL cholesterol?

Accepted Answer

Transport cholesterol from cells back to the liver for excretion — HDL (High-Density Lipoprotein) transports cholesterol from cells and tissues back to the liver for excretion, earning it the name "good cholesterol." High HDL levels are associated with lower cardiovascular risk.

Question 3

Which enzyme is responsible for breaking down triglycerides in adipose tissue during lipolysis?

Accepted Answer

Hormone-sensitive lipase — Hormone-sensitive lipase breaks down triglycerides into glycerol and free fatty acids, primarily in adipose tissue during lipolysis in response to hormonal signals.

Question 4

What happens to VLDL as it loses triglycerides?

Accepted Answer

It transforms into LDL — VLDL (Very-Low-Density Lipoprotein) carries triglycerides from the liver to tissues. As VLDL loses triglycerides through lipoprotein lipase action, it transforms into LDL.

Question 5

Which hormone promotes lipogenesis and inhibits lipolysis?

Accepted Answer

Insulin — Insulin promotes lipogenesis (fat synthesis) and inhibits lipolysis (fat breakdown), while glucagon and epinephrine have opposite effects, stimulating lipolysis.

Question 6

What is the genetic defect in familial hypercholesterolemia?

Accepted Answer

Mutation in LDL receptor genes — Familial hypercholesterolemia results from mutations affecting LDL receptors, leading to elevated LDL cholesterol. Heterozygous form has one mutated allele; homozygous has both alleles mutated.

Question 7

Which clinical sign consists of yellowish nodules commonly found on the Achilles tendon in hypercholesterolemia?

Accepted Answer

Tendon xanthomas — Tendon xanthomas are yellowish nodules on tendons, commonly around the Achilles tendon or hands, characteristic of severe hypercholesterolemia, particularly familial hypercholesterolemia.

Question 8

What condition can severe hypertriglyceridemia lead to?

Accepted Answer

Acute pancreatitis — Severe hypertriglyceridemia can lead to acute pancreatitis, presenting with abdominal pain, nausea, and vomiting. This is a serious complication of markedly elevated triglyceride levels.

Question 9

What is lipemia retinalis?

Accepted Answer

Milky appearance of retina due to extremely elevated triglycerides — Lipemia retinalis is a rare condition where triglycerides are extremely elevated (usually 2000-4000 mg/dL), leading to a milky appearance of the retinal vessels during eye examination.

Question 10

Which statin is commonly used to lower LDL cholesterol?

Accepted Answer

Atorvastatin — Atorvastatin is a statin (HMG-CoA reductase inhibitor) that is the primary treatment for lowering LDL cholesterol. Other statins include simvastatin and rosuvastatin.

Question 11

What is the primary metabolic pathway for fatty acid breakdown in mitochondria?

Accepted Answer

Beta-oxidation — Beta-oxidation is the process where free fatty acids are transported to mitochondria and converted into acetyl-CoA, which enters the Krebs cycle for energy production.

Question 12

Which apolipoprotein defect is responsible for familial dysbetalipoproteinemia?

Accepted Answer

Apolipoprotein E — Familial dysbetalipoproteinemia results from genetic defects in apolipoprotein E, leading to elevated IDL (Intermediate-Density Lipoprotein) cholesterol and premature atherosclerosis.

Question 13

What is the characteristic clinical finding of palmar xanthomas?

Accepted Answer

Associated with familial dysbetalipoproteinemia — Palmar xanthomas (yellowish deposits on the palms) along with tuberous xanthomas on elbows and knees are characteristic of familial dysbetalipoproteinemia.

Question 14

Which medication class primarily lowers triglycerides and sometimes raises HDL?

Accepted Answer

Fibrates — Fibrates (such as fenofibrate and gemfibrozil) are primarily used to lower triglycerides and can sometimes raise HDL cholesterol levels.

Question 15

What is Type I hyperlipoproteinemia characterized by?

Accepted Answer

Elevated chylomicrons due to lipoprotein lipase deficiency — Type I hyperlipoproteinemia is characterized by elevated chylomicrons due to lipoprotein lipase deficiency, leading to severe hypertriglyceridemia.

Question 16

When do heart attacks typically occur in heterozygous familial hypercholesterolemia?

Accepted Answer

Before age 50 years — In heterozygous familial hypercholesterolemia, early-onset cardiovascular disease with heart attacks or strokes often occurs at a younger age, typically before 50 years.

Question 17

What is the mechanism of action of ezetimibe?

Accepted Answer

Reduces cholesterol absorption in the intestine — Ezetimibe is a cholesterol absorption inhibitor that lowers LDL cholesterol by reducing cholesterol absorption in the intestine.

Question 18

Which secondary condition is associated with elevated triglycerides and low HDL cholesterol?

Accepted Answer

Diabetes mellitus (diabetic dyslipidemia) — Diabetic dyslipidemia is characterized by elevated triglycerides and low HDL cholesterol due to insulin resistance and diabetes mellitus.

Question 19

What laboratory test measures Total Cholesterol, LDL, HDL, and Triglycerides?

Accepted Answer

Lipid profile — A lipid profile (or lipid panel) is the standard test that measures total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides to assess lipid status.

Question 20

In homozygous familial hypercholesterolemia, when do heart attacks typically occur?

Accepted Answer

In childhood or adolescence — Homozygous familial hypercholesterolemia presents with extremely high LDL cholesterol and severe atherosclerosis, with heart attacks occurring in childhood or adolescence.

Question 21

What is xanthelasma?

Accepted Answer

Yellowish patches on eyelids or around the eyes — Xanthelasma refers to yellowish patches on the eyelids or around the eyes, which are cholesterol deposits commonly seen in hypercholesterolemia.

Question 22

Which class of drugs works by binding bile acids in the intestine to lower LDL cholesterol?

Accepted Answer

Bile acid sequestrants — Bile acid sequestrants (like cholestyramine and colesevelam) lower LDL cholesterol by binding bile acids in the intestine, forcing the liver to use cholesterol to make more bile acids.

Question 23

What is the recommended duration of moderate-intensity exercise per week for lipid management?

Accepted Answer

150 minutes — Regular physical activity of at least 150 minutes of moderate-intensity exercise per week (such as brisk walking or cycling) is recommended for improving lipid profiles.

Question 24

Which lipoprotein is a transitional form between VLDL and LDL?

Accepted Answer

IDL (Intermediate-Density Lipoprotein) — IDL (Intermediate-Density Lipoprotein) is a transitional form between VLDL and LDL, involved in lipid metabolism as VLDL loses triglycerides.

Question 25

What enzyme is key in lipogenesis (fatty acid synthesis)?

Accepted Answer

Acetyl-CoA carboxylase — Acetyl-CoA carboxylase is a key enzyme in lipogenesis, catalyzing the first committed step in fatty acid synthesis by converting acetyl-CoA to malonyl-CoA.

Question 26

Which condition is characterized by edema and elevated cholesterol/triglycerides due to protein loss in urine?

Accepted Answer

Nephrotic syndrome — Nephrotic syndrome presents with edema (swelling of legs, ankles, face) due to protein loss in urine, accompanied by elevated cholesterol and triglycerides.

Question 27

What are PCSK9 inhibitors particularly useful for?

Accepted Answer

Significantly lowering LDL cholesterol in familial hypercholesterolemia — PCSK9 inhibitors (like alirocumab and evolocumab) significantly lower LDL cholesterol and are especially useful for patients with familial hypercholesterolemia or those not achieving target levels with statins alone.

Question 28

What is Type IIa hyperlipoproteinemia characterized by?

Accepted Answer

Elevated LDL cholesterol — Type IIa hyperlipoproteinemia is characterized by elevated LDL cholesterol due to various genetic or environmental factors, increasing cardiovascular risk.

Question 29

Which prescription omega-3 fatty acid is used to lower triglyceride levels?

Accepted Answer

Icosapent ethyl — Icosapent ethyl is a prescription form of omega-3 fatty acid used specifically to lower triglyceride levels in patients with hypertriglyceridemia.

Question 30

What lipid abnormality is associated with hypothyroidism?

Accepted Answer

Elevated total cholesterol and LDL cholesterol — Hypothyroid dyslipidemia is characterized by elevated total cholesterol and LDL cholesterol due to decreased LDL receptor activity caused by thyroid hormone deficiency.

Question 31

Where does de novo lipogenesis primarily occur?

Accepted Answer

Liver and adipose tissue — De novo lipogenesis, the conversion of excess carbohydrates and proteins into fatty acids, primarily occurs in the liver and adipose tissue.

Question 32

What is Type V hyperlipoproteinemia characterized by?

Accepted Answer

Elevated chylomicrons and VLDL — Type V hyperlipoproteinemia is characterized by elevated chylomicrons and VLDL, often due to lipoprotein lipase deficiency or genetic conditions, leading to severe hypertriglyceridemia.

Question 33

Which dietary modification is recommended to lower LDL cholesterol?

Accepted Answer

Reduce saturated and trans fats — Reducing intake of saturated and trans fats (found in red meat, processed foods, and high-fat dairy products) is recommended to lower LDL cholesterol levels.

Question 34

What is familial combined hyperlipidemia associated with?

Accepted Answer

Elevated LDL cholesterol and triglycerides — Familial combined hyperlipidemia is characterized by elevated levels of both LDL cholesterol and triglycerides, often associated with premature cardiovascular disease.

Question 35

What is the main form of stored energy in the body?

Accepted Answer

Triglycerides — Triglycerides are the main form of stored energy in the body, stored primarily in adipose tissue and released during lipolysis when energy is needed.

Question 36

Which medications can induce secondary dyslipidemia?

Accepted Answer

Corticosteroids and antiretrovirals — Certain drugs such as corticosteroids and antiretrovirals can induce dyslipidemia as a side effect, requiring monitoring and potential lipid management.

Question 37

What is the role of fatty acid synthase?

Accepted Answer

Multi-enzyme complex that synthesizes fatty acids from acetyl-CoA — Fatty acid synthase is a multi-enzyme complex that synthesizes fatty acids from acetyl-CoA during lipogenesis, building long-chain fatty acids through repeated cycles.

Question 38

What clinical sign is arcus senilis?

Accepted Answer

Ring around the cornea — Arcus senilis is a ring around the cornea that can be a sign of hyperlipidemia, particularly in younger individuals, though it may also occur normally with aging.

Question 39

What percentage of sporadic colon cancers might be affected by lipid metabolism through APC gene mutations?

Accepted Answer

This question is incorrectly placed - APC relates to cancer, not lipid disorders — This appears to be a question error. APC gene mutations relate to colorectal cancer pathogenesis (from the oncology material), not lipid disorders. The documents should not be mixed in question formation.

Question 40

Which lipoprotein primarily carries cholesterol from the liver to peripheral cells?

Accepted Answer

LDL — LDL (Low-Density Lipoprotein) primarily carries cholesterol from the liver to cells throughout the body. High levels of LDL can lead to plaque buildup in arteries, earning it the name "bad cholesterol."

LIPID AND LIPOPROTEIN DISORDERS MCQs | MCQ Quiz | OmpathStudy Kenya

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