Comparison of different equations for estimation of low-density lipoprotein (LDL) - cholesterol

Objectives: The aim of this study was to compare low-density lipoprotein cholesterol (LDL-C) estimations using various formulas with directly measured LDL-C (d-LDL-C) in the Turkish population. Material and methods: A total of 1,478 participants who were aged between 18 and 80 were classified into five groups according to serum triglyseride (TG) concentration as follows: <100, 100-199, 200-299, 300-399, and 400-1000mg/dL. Glucose (Glu), LDL-C, total cholesterol (TC), HDL-C, TG, and HbA1C were measured with Cobas 6000 c501. d-LDL-C concentrations were measured by a homogenous direct assay using reagents. We investigated the accuracy 10 equations that are Friedewald, De Cordova, Ahmadi, Anandaraja, Teerakanchana, Chen, Hattori, Vujovic, Puavillai, and Hatta for estimating LDL-C in this study. Results: In group 1, Anandaraja formula correlated best with d-LDL-C (r=0.367), but this correlation is weakly. In group 2; Teerakanchana formula (r=0.931), in group 3; Friedewald and Teerakanchana formulas (r=0.935, r=0.961), in group 4; Teerakanchana formula (r=0.950) and in group 5, Anandaraja formula (r=0.792) correlated best with d-LDL-C. Conclusions: In this study, although there was a strong correlation between d-LDL-C measurement and estimated LDL-C formulas, there was a negative bias between results of these formulas and the d-LDL-C.