MEASUREMENT OF LOW-DENSITY-LIPOPROTEIN PARTICLE-SIZE BY HIGH-PERFORMANCE GEL-FILTRATION CHROMATOGRAPHY

We describe a new technique for measuring LDL size by high-performance gel-filtration chromatography (HPGC). LDL was subjected to chromatogr aphy, and the column effluent was monitored at 280 nm. The retention t ime of the LDL peak was used to calculate the LDL diameter. We compare d the HPGC method with gradient gel electrophoresis (GGE) on 2-10% non denaturing polyacrylamide gels. In a group of 60 non-insulin-dependent diabetes mellitus patients, LDL size as measured by HPGC and GGE was highly correlated (r = 0.88, P < 0.001). Good reproducibility, high pr ecision, and the possibility of analyzing large series of samples are the main advantages of the automated HPGC method. Within-run and betwe en-run CV for LDL size measured by HPGC were <0.1% and 0.2%, respectiv ely. There was a significant inverse association between LDL size meas ured by HPGC and the logarithm of plasma triglycerides (r = -0.84, P < 0.001), and a significant positive association with the LDL free chol esterol/protein ratio (r = 0.89, P < 0.001).