A 41-year-old woman presents for routine lipid screening. Vital signs are normal (BP 118/76, HR 72, RR 14). Fasting labs show HDL 65 mg/dL, triglycerides 95 mg/dL, and LDL calculated at 85 mg/dL using the Friedewald equation. Repeat measurement by direct immunoassay yields LDL 110 mg/dL. She denies statin use and has no history of recent illness or dietary changes. Which factor best explains this discrepancy between the two calculation methods?
- A)The patient's triglycerides are too low to use the Friedewald equation accurately
- B)The patient has a VLDL remnant abnormality causing equation overestimation
- C)The patient's HDL includes lipoprotein X, inflating the estimate
- D)The patient has elevated Lp(a) particles that are counted as LDL in the direct methodGABARITO
- E)Laboratory calibration error occurred between the two measurements
Explicação
Lipoprotein(a) [Lp(a)] particles resemble LDL particles (they contain apoB-100 and cholesterol) and are counted as LDL in direct LDL measurement methods, but the Friedewald equation (LDL = TC - HDL - TG/5) does not account for Lp(a). Elevated Lp(a) causes the ... Ver explicação completa e trilha adaptativa →