Lipid Biochemistry USMLE Step 1 Practice Question
A 68-year-old man with metabolic syndrome presents with BP 148/92 mmHg, HR 88/min, and fasting glucose 118 mg/dL despite metformin 1000 mg daily. Labs show triglycerides 280 mg/dL, HDL 32 mg/dL, and HOMA-IR 3.2 indicating insulin resistance. LDL is 105 mg/dL. He denies chest pain or dyspnea. Which of the following best describes the pathophysiology of his dyslipidemia?
Answer choices
- AInsulin resistance increases hepatic VLDL production and decreases HDL synthesisCorrect answer
- BHigh blood glucose directly inhibits lipoprotein lipase in adipose tissue
- CHyperglycemia directly increases apolipoprotein C-III production
- DInsulin resistance increases LDL receptor expression on hepatocytes
- EMetformin impairs HMG-CoA reductase feedback inhibition
- FInsulin resistance impairs lipoprotein lipase activity and increases hepatic cholesterol esterase expression
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