An enzymic and centrifugal method for estimating high-density lipoprotein cholesterol

Area of Science:

• Clinical Chemistry
• Biochemistry
• Lipid Metabolism

Background:

• Accurate measurement of high-density lipoprotein cholesterol (HDL-C) is crucial for cardiovascular risk assessment.
• Traditional precipitation methods for HDL-C determination often involve complex procedures and limitations.

Purpose of the Study:

• To describe a novel enzymic method for measuring HDL-C using a centrifugal analyzer.
• To evaluate the efficacy of polyethylene glycol (PEG) for precipitating interfering lipoproteins.

Main Methods:

• Utilized polyethylene glycol (Mr 6000) at a final concentration of 100 g/L to precipitate low-density and very-low-density lipoproteins.
• Employed ethylenediaminetetraacetate-stabilized plasma, overcoming challenges associated with heparin/Mn2+ precipitation.
• Verified complete precipitation of beta-lipoproteins and retention of alpha-lipoproteins in solution using rocket immunoelectrophoresis.

Main Results:

• Achieved excellent reproducibility with a between-run coefficient of variation (CV) of 3.6% and a within-run CV of 0.8%.
• Demonstrated cost-effectiveness with reagent costs at $US 0.13 per test and high sample throughput capability.
• Established normal ranges for HDL-C: 1.20 +/- 0.31 mmol/L for men and 1.52 +/- 0.38 mmol/L for women (n=539 men, n=444 women).

Conclusions:

• The described enzymic method using PEG precipitation offers a reliable, efficient, and economical approach for HDL-C measurement.
• This method simplifies the analysis of HDL-C, making it suitable for routine clinical laboratory use.
• Provides updated normal reference ranges for HDL-C in adult men and women.