%0 Journal Article %1 citeulike:505196 %A Bairaktari, E. %A Elisaf, M. %A Tzallas, C. %A Karabina, S. A. %A Tselepis, A. D. %A Siamopoulos, K. C. %A Tsolas, O. %C Laboratory of Biochemistry, University of Ioannina, 450 00, Ioannina, Greece. ebairakt@cc.uoi.gr %D 2001 %J Clin Biochem %K cholesterol ldl trial apob %N 8 %P 593--602 %T Evaluation of five methods for determining low-density lipoprotein cholesterol (LDL-C) in hemodialysis patients(1). %U http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11849617 %V 34 %X OBJECTIVES: Current recommendations for the management of dyslipidemia are largely based on the concentration of LDL-C. Most clinical laboratories estimate the concentration of LDL-C by the recommended routine method, the equation of Friedewald, in specimens from fasting subjects and with TG concentrations < 4.52 mmol/L. Because of the limitations of the Friedewald calculation, direct methods for an accurate quantification of LDL-C are needed. DESIGN AND METHODS: In the present study we evaluated the accuracy of the following 5 different procedures for LDL-C in 98 patients on hemodialysis: the Friedewald equation, where LDL-C is calculated from HDL-C, measured either by the precipitation procedure with dextran sulfate-Mg(2+) (Method 1), or by a direct HDL-C assay (Method 2), the Direct LDL assay (Method 3), the homogeneous N-geneous LDL assay (Method 4) and the calculated LDL-C values deriving from the ApoB based equation: 0.41TC - 0.32TG + 1.70ApoB - 0.27, (Clin Chem 1997;43:808-815) (Method 5). RESULTS: All five LDL-C methods were found to be in good agreement with ultracentrifugation/dextran sulfate-Mg(2+) precipitation with the coefficients of correlation of the assays to ranging between 0.93-0.95. However, significant differences in the mean values and biases vs. the reference method were observed. The Friedewald equation and the Direct assay were less affected by high LDL-C levels, and they presented higher sensitivity and higher negative predictive value. The N-geneous assay and the ApoB derived calculation were less affected by high triglyceride levels, and they presented higher specificity and higher positive predictive value. At the diagnostic LDL-C level of 3.37 mmol/L, both Friedewald calculations correctly classified 82/92 patients; Direct assay 86/98; N-geneous assay 88/98; and ApoB derived calculation 88/98. At the diagnostic LDL-C level of 2.98 mmol/L, Friedewald calculations (Method 1 and Method 2) correctly classified 82/92 and 81/92 patients, respectively; Direct assay (LDL-3) 87/98; N-geneous assay (LDL-4) 91/98; and ApoB derived calculation (LDL-5) 91/98. CONCLUSIONS: Among hemodialysis patients, who commonly present äverage" LDL-C concentrations and high TG levels, the N-geneous assay and the apoB derived calculation seem to yield more acceptable results for the estimation of LDL-C.

@article{citeulike:505196, abstract = {OBJECTIVES: Current recommendations for the management of dyslipidemia are largely based on the concentration of LDL-C. Most clinical laboratories estimate the concentration of LDL-C by the recommended routine method, the equation of Friedewald, in specimens from fasting subjects and with TG concentrations < 4.52 mmol/L. Because of the limitations of the Friedewald calculation, direct methods for an accurate quantification of LDL-C are needed. DESIGN AND METHODS: In the present study we evaluated the accuracy of the following 5 different procedures for LDL-C in 98 patients on hemodialysis: the Friedewald equation, where LDL-C is calculated from HDL-C, measured either by the precipitation procedure with dextran sulfate-Mg(2+) (Method 1), or by a direct HDL-C assay (Method 2), the Direct LDL assay (Method 3), the homogeneous N-geneous LDL assay (Method 4) and the calculated LDL-C values deriving from the ApoB based equation: 0.41TC - 0.32TG + 1.70ApoB - 0.27, (Clin Chem 1997;43:808-815) (Method 5). RESULTS: All five LDL-C methods were found to be in good agreement with ultracentrifugation/dextran sulfate-Mg(2+) precipitation with the coefficients of correlation of the assays to ranging between 0.93-0.95. However, significant differences in the mean values and biases vs. the reference method were observed. The Friedewald equation and the Direct assay were less affected by high LDL-C levels, and they presented higher sensitivity and higher negative predictive value. The N-geneous assay and the ApoB derived calculation were less affected by high triglyceride levels, and they presented higher specificity and higher positive predictive value. At the diagnostic LDL-C level of 3.37 mmol/L, both Friedewald calculations correctly classified 82/92 patients; Direct assay 86/98; N-geneous assay 88/98; and ApoB derived calculation 88/98. At the diagnostic LDL-C level of 2.98 mmol/L, Friedewald calculations (Method 1 and Method 2) correctly classified 82/92 and 81/92 patients, respectively; Direct assay (LDL-3) 87/98; N-geneous assay (LDL-4) 91/98; and ApoB derived calculation (LDL-5) 91/98. CONCLUSIONS: Among hemodialysis patients, who commonly present "average" LDL-C concentrations and high TG levels, the N-geneous assay and the apoB derived calculation seem to yield more acceptable results for the estimation of LDL-C.}, added-at = {2006-07-07T01:10:50.000+0200}, address = {Laboratory of Biochemistry, University of Ioannina, 450 00, Ioannina, Greece. ebairakt@cc.uoi.gr}, author = {Bairaktari, E. and Elisaf, M. and Tzallas, C. and Karabina, S. A. and Tselepis, A. D. and Siamopoulos, K. C. and Tsolas, O.}, biburl = {https://www.bibsonomy.org/bibtex/2239d9a37b71f06f2786df58e544c9817/biblio24}, citeulike-article-id = {505196}, interhash = {207c18155d4913661be239a663bc4cdb}, intrahash = {239d9a37b71f06f2786df58e544c9817}, issn = {0009-9120}, journal = {Clin Biochem}, keywords = {cholesterol ldl trial apob}, month = {November}, number = 8, pages = {593--602}, priority = {2}, timestamp = {2006-07-07T01:10:50.000+0200}, title = {Evaluation of five methods for determining low-density lipoprotein cholesterol (LDL-C) in hemodialysis patients(1).}, url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve\&db=pubmed\&dopt=Abstract\&list_uids=11849617}, volume = 34, year = 2001 }