Comparison of different analytical and precipitation methods for direct estimation of serum high-density lipoprotein cholesterol

Abstract

In this study two commercial enzymatic methods for the determination of serum cholesterol have been adapted for a continuous-flow analyser and a discrete multichannel analyser. The selective precipitation methods for lipoproteins using either dextran sulphate/MgCl₂, heparin/MnC1₂, phosphotungstate/ MgC1₂ or polyethylene glycol (mol.wt 6000) were compared with each other and with ultracentrifugal analysis as well as with agarose gel electrophoresis for lipoproteins. The results indicated that the dextran sulphate/MgCl₂ precipitation procedure was the method of choice for the determination of HDL-cholesterol from clear and hyperlipemic sera. HDL-cholesterol values for 391 apparently healthy women (x ± SD) were 1.58 ± 0.34 mmol/l and for 432 men 1.27 ± 0.29 mmol/l. The corresponding HDL-cholesterol/cholesterol ratios for women were 0.292 ± 0.068 and for men 0.229 ± 0.069. The HDL-cholesterol in serum was slightly age dependent in women, while the HDL-cholesterol/cholesterol ratio showed highly significant negative correlation with the age in both women and men.

Key Words:

• Cholesterol
• Hyperlipidemias
• Lipoproteins
• lipoprotein fractionation
• polymer precipitation of lipoproteins