How should low-density lipoprotein cholesterol be calculated in 2022?

Area of Science:

• Clinical Chemistry
• Cardiovascular Disease Biomarkers
• Epidemiology

Background:

• The gold standard for low-density lipoprotein-cholesterol (LDL-C) measurement, β-quantification, is impractical for routine clinical use.
• The widely used Friedewald equation for estimating LDL-C has significant limitations, particularly with triglyceride levels exceeding 4.5 mmol/l.
• Numerous alternative equations have been developed globally to address the inaccuracies of the Friedewald equation.

Purpose of the Study:

• To systematically review and compare various equations used for calculating LDL-C against measured values.
• To identify the most accurate and clinically applicable method for LDL-C estimation in routine practice.

Main Methods:

• A comprehensive literature search was conducted to identify studies comparing different LDL-C calculation equations.
• Forty-five relevant studies were included in the analysis, evaluating the performance of various formulae.

Main Results:

• The Martin/Hopkins equation, utilizing an adjustable factor for triglyceride (TG) ratios, shows improved accuracy, especially for low LDL-C and elevated TG levels.
• The Sampson equation, developed for TG up to 9 mmol/l, demonstrates good performance across various conditions, including high TG and postprandial states.
• Both Martin/Hopkins and Sampson equations offer advantages over the Friedewald equation, particularly when TG levels are elevated.

Conclusions:

• The selection of an appropriate LDL-C calculation equation should be guided by the patient's triglyceride levels.
• Further validation of these advanced LDL-C estimation equations across diverse populations is essential for widespread clinical adoption.