Lipid Biochemistry USMLE Step 1 Practice Question
A 55-year-old woman with type 2 diabetes and hypertension presents with fatigue. Vital signs: BP 142/88 mmHg, HR 88/min, RR 16/min, temp 37°C, SpO2 98% on room air. Lipid panel shows total cholesterol 240 mg/dL, LDL 130 mg/dL, HDL 35 mg/dL, triglycerides 350 mg/dL. HbA1c is 7.8%. She denies chest pain or dyspnea. Atorvastatin is initiated. Which mechanism best explains this drug's therapeutic effect on her lipid abnormalities?
Answer choices
- AInhibition of cholesterol esterification in the endoplasmic reticulum
- BInhibition of hepatic HMG-CoA reductase increases LDL receptor expressionCorrect answer
- CInhibition of PCSK9 protease activity
- DActivation of lipoprotein lipase in peripheral tissues
- EDirect inhibition of apolipoprotein B-100 synthesis
- FInhibition of acetyl-CoA carboxylase reduces malonyl-CoA and increases fatty acid oxidation
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