Indirect calculation of LDL using thirteen equations in Pakistani population

Area of Science:

• Clinical Chemistry
• Cardiovascular Disease Diagnostics
• Lipid Metabolism

Background:

• Low-density lipoprotein cholesterol (LDL-C) is crucial for cardiovascular disease (CVD) diagnosis and treatment.
• Accurate LDL-C measurement is vital, but direct assays are often replaced by the Friedewald equation in Pakistan due to cost.
• The Friedewald equation's accuracy is limited by various factors, necessitating alternative calculation methods.

Purpose of the Study:

• To evaluate the accuracy of thirteen different equations for calculating LDL-C compared to direct measurement.
• To determine the most suitable LDL-C calculation equation for the Pakistani population, considering cost-effectiveness and accuracy.

Main Methods:

• Direct LDL-C (dLDL) measurements from 39,385 individuals were compared with LDL-C calculated by thirteen equations (cLDL-C).
• Statistical analysis, including correlation and median difference, was performed.
• Equations were validated across various ranges of triglycerides (TG), total cholesterol (TC), and high-density lipoprotein (HDL).

Main Results:

• The Teerakanchana equation showed a strong positive correlation (ρ=0.967) and the least median difference (-8.81) with dLDL.
• The Martin equation also demonstrated a strong correlation (ρ=0.967).
• For high TG levels (>500 mg/dL), the Teerakanchana equation exhibited the least median difference (1.31) and a strong correlation (ρ=0.800).

Conclusions:

• The Teerakanchana equation is a potentially viable alternative to the Friedewald equation for LDL-C calculation in the Pakistani population.
• This finding could improve the accuracy of cardiovascular risk assessment and management in resource-constrained settings.