CLS Secondary Causes of Dyslipidemia 2 — Questions and Answers
Question 1: Which thyroid condition is most commonly associated with elevated LDL-C due to decreased LDL receptor expression?
- Hyperthyroidism
- Hypothyroidism (Correct answer)
- Subclinical hyperthyroidism
- Thyroiditis
Correct answer: Hypothyroidism
Hypothyroidism reduces LDL receptor activity, leading to impaired LDL clearance and elevated LDL-C levels.
Question 2: A patient with nephrotic syndrome develops hyperlipidemia primarily due to which mechanism?
- Increased dietary cholesterol absorption
- Decreased hepatic lipoprotein lipase activity
- Compensatory hepatic lipoprotein overproduction due to low oncotic pressure (Correct answer)
- Increased LDL receptor expression
Correct answer: Compensatory hepatic lipoprotein overproduction due to low oncotic pressure
Nephrotic syndrome causes hepatic overproduction of VLDL and LDL in response to the low oncotic pressure from protein loss.
Question 3: Which medication class used for HIV treatment is most strongly linked to hypertriglyceridemia and insulin resistance?
- Integrase inhibitors
- CCR5 antagonists
- Older protease inhibitors (Correct answer)
- NNRTIs
Correct answer: Older protease inhibitors
Older HIV protease inhibitors (e.g., ritonavir, lopinavir) significantly inhibit lipid metabolism, causing hypertriglyceridemia and insulin resistance.
Question 4: Cushing's syndrome causes dyslipidemia primarily through which mechanism?
- Direct inhibition of HMG-CoA reductase
- Cortisol-driven insulin resistance and central adiposity (Correct answer)
- Decreased absorption of dietary fat
- Upregulation of LDL receptors
Correct answer: Cortisol-driven insulin resistance and central adiposity
Excess cortisol promotes insulin resistance and central obesity, leading to elevated triglycerides, low HDL-C, and often elevated LDL-C.
Question 5: A patient on chronic hemodialysis is most likely to exhibit which lipid abnormality pattern?
- Elevated LDL-C with normal triglycerides
- Hypertriglyceridemia with low HDL-C (Correct answer)
- Isolated low HDL-C with normal other fractions
- Elevated Lp(a) only
Correct answer: Hypertriglyceridemia with low HDL-C
End-stage renal disease is associated with impaired lipoprotein lipase activity, leading to hypertriglyceridemia and low HDL-C.
Question 6: Which class of antihypertensive agents is most associated with raising triglycerides and lowering HDL-C?
- ACE inhibitors
- Calcium channel blockers
- Non-selective beta-blockers (Correct answer)
- ARBs
Correct answer: Non-selective beta-blockers
Non-selective beta-blockers can raise triglycerides by 20–50% and lower HDL-C through reduced lipoprotein lipase activity.
Question 7: Obstructive liver disease such as primary biliary cholangitis most characteristically causes elevation of which lipoprotein?
- VLDL
- IDL
- Lipoprotein X (Correct answer)
- Chylomicrons
Correct answer: Lipoprotein X
Obstructive liver disease leads to accumulation of Lipoprotein X, an abnormal LP particle rich in unesterified cholesterol and phospholipids.
CLS Secondary Causes of Dyslipidemia 2
Which thyroid condition is most commonly associated with elevated LDL-C due to decreased LDL receptor expression?