Lipid Biochemistry USMLE Step 1 Practice Question
A 41-year-old man presents with acute pancreatitis and severe hypertriglyceridemia. Vital signs: BP 128/82, HR 98, RR 20, Temp 37.8°C, SpO2 98%. Serum triglycerides are 2800 mg/dL with lactescent appearance; amylase is elevated at 420 U/L. He reports persistent epigastric pain despite NPO status and IV fluids for 48 hours. He denies recent alcohol use. Which of the following best describes the direct pathophysiologic mechanism by which severe hypertriglyceridemia precipitates pancreatic injury?
Answer choices
- AImpaired synthesis of pancreatic digestive enzymes
- BObstruction of the main pancreatic duct by triglyceride-rich particles
- CCompetitive inhibition of amylase secretion
- DHypervolemia leading to increased intra-acinar pressure
- EDirect toxic effects of free fatty acids on pancreatic acinar cellsCorrect answer
- FDecreased pancreatic blood flow due to increased serum viscosity and microvascular occlusion
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