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

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/MnCl2, phosphotungstate/MgCl2 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 health 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.