title: 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.
authors.affiliation: National Cerebral and Cardiovascular Center, Department of Preventive Cardiology, Lipid Reference Laboratory, Japan. Electronic address: nakamura.masakazu.hp@ncvc.go.jp.
authors.forename: Masakazu
authors.initials: M
authors.lastname: Nakamura
authors.affiliation: Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, Japan.
authors.forename: Yuzo
authors.initials: Y
authors.lastname: Kayamori
authors.affiliation: Public Health, Department of Social and Environmental Medicine, Graduate School of Medicine, Osaka University, Japan.
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Iso
authors.affiliation: Osaka Center for Cancer and Cardiovascular Disease Prevention, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kitamura
authors.affiliation: Osaka Center for Cancer and Cardiovascular Disease Prevention, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Kiyama
authors.affiliation: National Cerebral and Cardiovascular Center, Department of Preventive Cardiology, Lipid Reference Laboratory, Japan.
authors.forename: Isao
authors.initials: I
authors.lastname: Koyama
authors.affiliation: National Cerebral and Cardiovascular Center, Department of Preventive Medicine and Epidemiologic Informatics, Office of Evidence-based Medicine and Risk Analysis, Japan.
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Nishimura
authors.affiliation: National Cerebral and Cardiovascular Center, Department of Preventive Medicine and Epidemiologic Informatics, Japan.
authors.forename: Michikazu
authors.initials: M
authors.lastname: Nakai
authors.affiliation: Public Health, Department of Social and Environmental Medicine, Graduate School of Medicine, Osaka University, Japan; Ministry of Health, Labour and Welfare, Health Service Bureau, Cancer Control and Health Promotion Division, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Noda
authors.affiliation: Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, USA.
authors.forename: Mahnaz
authors.initials: M
authors.lastname: Dasti
authors.affiliation: Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, USA.
authors.forename: Hubert W
authors.initials: HW
authors.lastname: Vesper
authors.affiliation: National Cerebral and Cardiovascular Center, Department of Preventive Cardiology, Department of Preventive Medicine and Epidemiologic Informatics, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Miyamoto
mesh_terms: D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood*; D006801:Humans; D012015:Reference Standards; D012044:Regression Analysis; D015203:Reproducibility of Results; D014461:Ultracentrifugation
chemical_list: D008076:Cholesterol, HDL; D008078:Cholesterol, LDL
keywords: Beta quantification; Bottom fraction cholesterol; HDL cholesterol; LDL cholesterol