LDL cholesterol performance of beta quantification reference measurement procedure

•Beta quantification is the reference method of low-density lipoprotein cholesterol.•We participated in the CDC LDL-C standardization program for over 15 years.•We aimed to clarify the precision and accuracy based on obtained results.•Bottom fraction cholesterol procedure is the key technique.

BackgroundAccurate 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.MethodsBottom 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.ResultsRegression analysis between CDC (x) and Osaka (y) for BFC, HDL-C, and LDL-C were y = 0.988x + 1.794 (R2 = 0.997), y = 0.980x + 1.118 (R2 = 0.994), and y = 0.987x + 1.200 (R2 = 0.997), respectively. The Osaka laboratory met performance goals for 90% to 95% of the CDC reference values.ConclusionsThe 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.