UPDATED: New Equation for Low-Density Lipoprotein Cholesterol Calculation at Stanford Health Care

ORDER CODE: LCDPC, LPDC

SUMMARY

Effective February 1, 2021, the National Institutes of Health (NIH) equation (below) will replace the Friedewald equation for all lipid panels that report calculated low-density lipoprotein cholesterol (LDL-C) (1,2). The NIH calculation provides a more accurate LDL-C result than the Friedewald equation, particularly in patients with low LDL-C concentrations (< 70 mg/dL) (1,2). The NIH equation gives valid LDL-C results with triglyceride (TG) concentrations up to 800 mg/dL (1,2). When the triglyceride concentration is >800 mg/dL, the LDL-C will not be calculated, and a direct LDL-C should be ordered.

The NIH equation performs equally well in both fasting and non-fasting states.

NIH equation:

LDL-C = TC/0.948 – HDL-C/0.971 – (TG/8.56 + [TG x NonHDL-C]/2140 – TG²/16100) – 9.44

The following algorithm is implemented for the reporting of calculated LDL-C values:

A TG value up to 800 mg/dL; the LDL-C will be reported using the NIH equation.
When the TG value is >800 mg/dL, the LDL-C will NOT be reported.

References

Sampson M, Ling C, Sun Q, Harb R, Ashmaig M, Warnick R, Sethi A, Fleming JK, Otvos JD, Meeusen JW, Delaney SR, Jaffe AS, Shamburek R, Amar M, Remaley AT. A New Equation for Calculation of Low-Density Lipoprotein Cholesterol in Patients With Normolipidemia and/or Hypertriglyceridemia. JAMA Cardiol. 2020 Feb 26;5(5):1-9.
Sathiyakumar V, Blumenthal RS, Elshazly MB. New information on accuracy of LDL-C estimation. American College of Cardiology. March 20, 2020. Accessed August 14, 2020. https://www.acc.org/latest-in-cardiology/articles/2020/03/19/16/00/new-information-on-accuracy-of-ldl-c-estimation