OBJECTIVES: The aim of this study was to compare the Friedewald Formula with direct homogeneous low density lipoprotein cholesterol (LDL-C) assay for the detection of LDL-C levels. METHODS: Fasting serum samples were obtained for lipid analysis from 1001 patients. Total cholesterol (TC) and triglyceride (TG) levels were measured with enzymatic methods and the measurements of high density lipoprotein cholesterol (HDL-C) and LDL-C levels were detected using direct methods. RESULTS: The mean levels of serum TC, TG, HDL-C and LDL-C were detected with in the reference range. The LDL-C estimated by the Friedewald formula was significantly correlated (P<0.01) with the direct method but there was a negative bias among them. CONCLUSION: Laboratories cannot use direct method as a substitute for Friedewald formula because direct method has not been standardized in large populations and increase cholesterol assay costs. Copyright 2008 Elsevier Ireland Ltd. All rights reserved.
OBJECTIVES: The aim of this study was to compare the Friedewald Formula with direct homogeneous low density lipoprotein cholesterol (LDL-C) assay for the detection of LDL-C levels. METHODS: Fasting serum samples were obtained for lipid analysis from 1001 patients. Total cholesterol (TC) and triglyceride (TG) levels were measured with enzymatic methods and the measurements of high density lipoprotein cholesterol (HDL-C) and LDL-C levels were detected using direct methods. RESULTS: The mean levels of serum TC, TG, HDL-C and LDL-C were detected with in the reference range. The LDL-C estimated by the Friedewald formula was significantly correlated (P<0.01) with the direct method but there was a negative bias among them. CONCLUSION: Laboratories cannot use direct method as a substitute for Friedewald formula because direct method has not been standardized in large populations and increase cholesterol assay costs. Copyright 2008 Elsevier Ireland Ltd. All rights reserved.