A Leap above Friedewald Formula for Calculation of Low-Density Lipoprotein-Cholesterol

PURPOSE: The purpose was to compare the different calculated methods of low-density lipoprotein cholesterol (LDL-C) estimation and to determine which of them correlate best with the direct method. MATERIALS AND METHODS: The records of 480 samples for lipid profile were analyzed. Apart from the direct method, LDL-C was calculated by Friedewald low-density lipoprotein cholesterol method (F-LDL-C), modified Friedewald low-density lipoprotein cholesterol method (MF-LDL-C), and Anandaraja low-density lipoprotein cholesterol method (A-LDL-C). Paired t-test and Pearson correlation were evaluated between the different methods. Degree of agreement between the calculated methods and direct method was detected by Bland–Altman graphical plots. RESULTS: A strong correlation was found between all calculated LDL-C methods and direct low-density lipoprotein cholesterol method (D-LDL-C) assay, that is, F-LDL-C versus D-LDL-C = 0.94; A-LDL-C versus D-LDL-C = 0.93 and MF-LDL-C versus D-LDL-C = 0.95. No statistically significant difference was found between D-LDL-C and MF-LDL-C. Bland–Altman plot for MF-LDL-C showed minimal negative bias. CONCLUSIONS: The study pointed out that MF-LDL-C correlated maximally with D-LDL-C estimation at all levels of triglycerides and MF-LDL-C can be used in place of D-LDL-C when the direct method cannot be afforded.