The Cardiovascular
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Martin Equation for Low-Density Lipoprotein Cholesterol (LDL-C)

Estimates LDL-C using an adjustable TG:VLDL-C factor instead of the fixed Friedewald divisor of 5.

Martin Equation for Low-Density Lipoprotein Cholesterol (LDL-C)
Total cholesterol
HDL cholesterol
Triglycerides
Complete the fields above to see the result.

When to use

  • Estimating LDL-C from a standard lipid panel, particularly when triglycerides are elevated and the Friedewald equation (fixed factor of 5) is expected to be inaccurate.

Formula

LDL-C = Non-HDL-C - (TG / adjustable factor), where the factor is the strata-specific median TG:VLDL-C ratio from a 180-cell table indexed by triglyceride level (30 strata) and non-HDL-C level (6 strata).

Pearls and pitfalls

  • More concordant with directly measured LDL-C than the Friedewald equation, especially when LDL-C is <70 mg/dL and triglycerides are elevated.
  • Not validated for triglycerides >800-1000 mg/dL or for type III dysbetalipoproteinemia; use a direct LDL-C measurement in these settings.

References

  1. Martin SS, Blaha MJ, Elshazly MB, et al. JAMA. 2013;310(19):2061-8.