Abstract
The exact determination of LDL cholesterol by ultracentrifugation is time-consuming and expensive procedure, whereas the Friedewald formula which can be determined LDL cholesterol using the concentration of serum triglyceride gives an imprecise value for LDL cholesterol in case of hypertriglyceridemia.
Precipitation method by heparin-citrate solution for the determination of LDL cholesterol was tested and compared to the data of ultracentrifugation and Friedewald's methods in the present study.
1) Precipitation of LDL except other serum lipoproteins was determined by the methods of immunodiffusion, electrophoresis and additional recovery examination of VLDL and LDL.
2) For the determination of LDL cholesterol, there was a good correlation between ultracentrifugation and the present methods (r=0.9695, y=1.0349x+5.4411) as well as that between ultracentrifugation and Friedewald's methods (r=0.9707, y=1.0316x-2.5561) in normolipidemia.
3) In hypertriglyceridemia exceeding 400mg/dl, a slight deteriolation was observed between ultracentrifugation and the present methods (r=0.7971, y=0.8926x-4.4083, r=0.7582, y=0.9911x-25.4388, respectively).
4) In hypertriglyceridemia above 600mg/dl below 1, 000mg/dl, the present method was superior to that of Friedewald, although there was no significant difference between two methods in hypertriglyceridemia above 400mg/dl below 600mg/dl.
5) Determination of LDL cholesterol in supernatant after addition of heparin-citrate solution was superior to that of LDL cholesterol in pellet.
From these results we conclude that the present method may be suitable for the determination of LDL cholesterol.
