Ten-year evaluation of homogeneous low-density lipoprotein cholesterol methods developed by Japanese manufacturers. Application of the Centers for Disease Control and Prevention/Cholesterol Reference Method Laboratory Network lipid standardization protocol

J Atheroscler Thromb. 2010 Dec 26;17(12):1275-81. doi: 10.5551/jat.5470. Epub 2010 Sep 25.

Abstract

Aim: The risk index for atherosclerotic cardiovascular diseases in the Japanese metabolic syndrome-focused health checkup program was changed from total cholesterol (TC) to low-density lipoprotein cholesterol (LDL-C). We discuss the validity of this change with respect to standardization.

Methods: The beta-quantification procedure of the Centers for Disease Control and Prevention (CDC) uses the LDL-C reference value as a target. Clinical laboratories and commercial manufacturers use homogeneous LDL-C methods for standardization. (A) For clinical laboratories, LDL-C in 648 samples requested from 108 hospitals was analyzed. (B) Manufacturers participated in the CDC/Cholesterol Reference Method Laboratory Network LDL-C standardization protocol. The standardization was conducted with a performance follow-up for the 10-year period from 1998 to 2008 at 2-year intervals, 6 times.

Results: (A) In clinical laboratories, acceptable LDL-C levels within ±4% of the CDC's criteria remained 70.4%, 456 of 648 subjects. Negative maximum bias deviating from the LDL-C target value was -35.8%, -52.5 mg/dL, and positive maximum bias was +24.5%, +32.3 mg/dL. (B) For manufacturers, the standardization achievement rate of the analytical reagent/instrument/calibrator system in the last four standardizations from 2002 to 2008 remained on average 66.6%, far lower than the level required.

Conclusions: The standardization achievement rate of homogeneous LDL-C methods was much low-er than that of TC. TC should still be used as a risk index for atherosclerotic cardiovascular diseases. The standardization achievement rate of homogeneous LDL-C should be maintained at 100%, at least using samples with normal lipoprotein profiles. The accuracy and specificity of LDL-C should be further improved before practical and clinical use.

MeSH terms

  • Atherosclerosis / etiology*
  • Bias
  • Cardiovascular Diseases / etiology
  • Centers for Disease Control and Prevention, U.S.
  • Cholesterol / blood*
  • Cholesterol, LDL / blood*
  • Cholesterol, LDL / standards
  • Follow-Up Studies
  • Humans
  • Japan
  • Metabolic Syndrome / complications
  • Predictive Value of Tests*
  • Reference Standards
  • Reproducibility of Results
  • United States

Substances

  • Cholesterol, LDL
  • Cholesterol