LDL Cholesterol

Measure LDL-C to estimate baseline ASCVD risk and guide statin initiation/intensity, especially in adults ≥20 years for primary or secondary prevention. Its clinical utility is predicting ASCVD events and quantifying percentage LDL-C reduction to monitor therapy effectiveness 1 [Level I evidence]. Absolute LDL-C reduction correlates with proportional ASCVD risk reduction (~20% per 38.7‑mg/dL decrease) 2 [Level I evidence].

LDL-C drives ASCVD risk; lower is better with no clear harmful lower limit 1 [Level I evidence]. Any 38.7‑mg/dL drop yields ~20% event reduction 2 [Level I evidence].
Cautions: calculated LDL-C is unreliable with TG >400 mg/dL; use direct or alternative methods 3 [Level I evidence]. Elevated apoB or Lp(a) adds independent risk even when LDL-C is low 4 [Level I evidence].