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Cell-free Biochemical Fluorometric Enzymatic Assay for High-throughput Measurement of Lipid Peroxidation in High Density Lipoprotein
Published on: October 12, 2017
Evaluation of four different equations for calculating LDL-C with eight different direct HDL-C assays
Marcelo Jose Andrade Oliveira1, Hendrick E van Deventer, Lorin M Bachmann
1Department of Laboratory Medicine, Clinical Center, National Institutes of Health, 10 Center Drive, Bethesda, MD 20892, United States.
Background:
Low-density lipoprotein cholesterol (LDL-C) is often calculated (cLDL-C) by the Friedewald equation, which requires high-density lipoprotein cholesterol (HDL-C) and triglycerides (TG). Because there have been considerable changes in the measurement of HDL-C with the introduction of direct assays, several alternative equations have recently been proposed.
Methods:
We compared 4 equations (Friedewald, Vujovic, Chen, and Anandaraja) for cLDL-C, using 8 different direct HDL-C (dHDL-C) methods. LDL-C values were calculated by the 4 equations and determined by the β quantification reference method procedure in 164 subjects.
Results:
For normotriglyceridemic samples (TG<200mg/dl), between 6.2% and 24.8% of all results exceeded the total error goal of 12% for LDL-C, depending on the dHDL-C assay and cLDL-C equation used. Friedewald equation was found to be the optimum equation for most but not all dHDL-C assays, typically leading to less than 10% misclassification of cardiovascular risk based on LDL-C. Hypertriglyceridemic samples (>200mg/dl) showed a large cardiovascular risk misclassification rate (30%-50%) for all combinations of dHDL-C assays and cLDL-C equations.
Conclusion:
The Friedewald equation showed the best performance for estimating LDL-C, but its accuracy varied considerably depending on the specific dHDL-C assay used. None of the cLDL-C equations performed adequately for hypertriglyceridemic samples.
