Lipid Biochemistry USMLE Step 1 Practice Question
A 50-year-old man with a family history of premature coronary artery disease presents for screening. Vital signs are BP 138/88 mmHg, HR 78/min, RR 16/min, temp 37°C, SpO2 98%. Laboratory values reveal total cholesterol 240 mg/dL, LDL 160 mg/dL, and HDL 35 mg/dL. Fasting triglycerides are 150 mg/dL. He denies chest pain and takes no medications. Which lipoprotein particle property most directly determines his atherogenicity?
Answer choices
- ATotal LDL cholesterol concentration, which correlates linearly with cardiovascular risk
- BTriglyceride to cholesterol ratio in VLDL remnants
- CSize and density of LDL particles, with smaller dense particles being more atherogenicCorrect answer
- DHDL particle number relative to total HDL cholesterol mass
- EApolipoprotein A-I content, which determines reverse cholesterol transport capacity
- FApolipoprotein B-100 oxidation state, with maximally oxidized particles conferring the highest atherogenic potential
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