A modified equation for calculating low density lipoprotein cholesterol in Pakistani population

Abstract

OBJECTIVE: To derive an equation for accurate estimation of low-density lipoprotein cholesterol (LDL-C) in the Pakistani population. METHODS: A modified equation was derived on the dataset (n = 59,148) from the Pakistani population, comprising directly measured LDL-C (dLDL-C) and other lipids using a regression model. The equation was validated on an internal (n = 29,633) and external dataset (n = 385,434), and the results were compared with the standard equations being used in the Pakistani population: Friedewald and Teerakanchana equation. The concordance between the dLDL-C and calculated LDL-C (cLDL-C) was determined by median difference (MD) and the agreement between dLDL-C and cLDL-C was analyzed by Bland Altman graphics. RESULTS: The modified equation (M.Eq) displayed best correlation (r = 0.974) and MD of -0.07 mmol/L on the derivation dataset. Similarly, the equation provided the best correlation and least MD on the internal (r = 0.970, MD = -0.13) and external validation datasets (r = 0.953, MD = -0.02). The Bland-Altman plot for the modified equation displayed the least bias in the derivation (-0.0012 mmol/L), internal validation (-0.13 mmol/L), and external validation (-0.02 mmol/L). CONCLUSION: The modified equation can be utilized for clinical settings in Pakistan that do not facilitate direct measurements of LDL-C.

Keywords

• cardiovascular diseases
• low density lipoprotein
• analysis
• lipoproteins, ldl
• cholesterol
• triglycerides
• analysis
• modified equation
• friedewald
• teerakanchana
• bland altman