Lipid Biochemistry USMLE Step 1 Practice Question
A 52-year-old woman with familial hypercholesterolemia presents with BP 138/86, HR 82, and fasting labs showing LDL 95 mg/dL (40% reduction on atorvastatin) but triglycerides persistently elevated at 500 mg/dL. HDL cholesterol is low at 32 mg/dL. She denies alcohol use and diabetes screening is negative. Analysis reveals decreased cholesteryl ester transfer protein (CETP) activity. Which mechanism best explains her persistent hypertriglyceridemia despite LDL improvement?
Answer choices
- AAccumulation of free cholesterol in macrophages
- BReduced LDL receptor expression on hepatocytes
- CImpaired transfer of cholesteryl esters from HDL to VLDL and LDLCorrect answer
- DEnhanced lipoprotein lipase activity in adipose tissue
- EIncreased hepatic production of VLDL particles
- FDecreased apolipoprotein B-100 catabolism leading to prolonged VLDL particle circulation
See the full explanation
Get the correct-answer rationale, why each distractor is wrong, the underlying mechanism, and high-yield associations — plus adaptive practice that targets your weak areas — with a free MedBoardPRO account.