A 70-year-old woman with a history of myocardial infarction 2 years ago presents for follow-up. She has been adherent to atorvastatin 80 mg daily for the past 18 months. Current vital signs: BP 136/80 mmHg, HR 68 bpm. Recent lipid panel shows LDL cholesterol 102 mg/dL, HDL cholesterol 38 mg/dL, and triglycerides 180 mg/dL. Liver function tests and creatine kinase are normal. Her cardiologist is considering the addition of a PCSK9 inhibitor to reduce her residual cardiovascular risk. Which of the following best describes the mechanism by which PCSK9 inhibitors reduce plasma LDL cholesterol concentration?
- A)Inhibition of HMG-CoA reductase in hepatic mitochondria
- B)Decreased hepatic synthesis of apolipoprotein B-100
- C)Inhibition of PCSK9-mediated degradation of LDL receptors, increasing their surface expression on hepatocytesGABARITO
- D)Increased activity of lipoprotein lipase in adipose tissue
- E)Reduced intestinal absorption of dietary cholesterol via inhibition of NPC1L1
Explicação
PCSK9 inhibitors (evolocumab, alirocumab) work by binding to PCSK9 protein and preventing it from binding to LDL receptors on hepatocytes. PCSK9 normally promotes endocytosis and lysosomal degradation of LDL receptors. By blocking this interaction, PCSK9 inhib... Ver explicação completa e trilha adaptativa →