LDL cholesterol performance of beta quantification reference measurement procedure

Abstract

Background: Accurate measurement of blood lipids is crucial in cardiovascular disease risk management. The Centers for Disease Control and Prevention (CDC) Cholesterol Reference Method Laboratory Network (CRMLN) has assured the accuracy of these measurements for over 20 years using beta quantification (BQ) method as reference measurement procedure (RMP) for high- and low-density lipoprotein cholesterol (HDL-C, LDL-C). Only limited data exist about the performance of the BQ RMP.

Methods: Bottom fraction cholesterol (BFC), HDL-C, and LDL-C results after ultracentrifugation from the CDC lipid reference laboratory and the Japanese CRMLN laboratory were compared using 280 serum samples measured over the past 15 years. Data were compared statistically using method comparison and bias estimation analysis.

Results: Regression analysis between CDC (x) and Osaka (y) for BFC, HDL-C, and LDL-C were y=0.988x+1.794 (R(2)=0.997), y=0.980x+1.118 (R(2)=0.994), and y=0.987x+1.200 (R(2)=0.997), respectively. The Osaka laboratory met performance goals for 90% to 95% of the CDC reference values.

Conclusions: The BQ method by the Osaka CRMLN laboratory is highly accurate and has been stable for over 15 years. Accurate measurement of BFC is critical for the determination of LDL-C.

Keywords: Beta quantification; Bottom fraction cholesterol; HDL cholesterol; LDL cholesterol.