Lipid Biochemistry USMLE Step 1 Practice Question
A 45-year-old man presents with eruptive xanthomas, hepatosplenomegaly, and recurrent pancreatitis. Vital signs show BP 138/82 mmHg, HR 88/min, RR 16/min, temp 37.2°C. Serum triglycerides are 2,800 mg/dL with normal cholesterol levels. Abdominal ultrasound reveals pancreatic edema. He denies alcohol use. Family history is significant for similar lipid abnormalities. Genetic testing confirms a mutation in lipoprotein lipase. Which of the following best explains the accumulation of triglyceride-rich lipoproteins in this patient?
Answer choices
- AReduced clearance of HDL by hepatic lipase
- BImpaired hydrolysis of chylomicron and VLDL triglyceridesCorrect answer
- CIncreased enterocyte absorption of dietary cholesterol
- DDecreased hepatic synthesis of apolipoprotein B-100
- EEnhanced conversion of VLDL to LDL in circulation
- FApoC-II deficiency preventing LPL activation at the capillary endothelium
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