Abstract
HDL-cholesterol (HDL-C) levels of human sera (n=70) from normolipidemic and hyperlipidemic subjects have been measured by the improved HPLC method using a gel filtration column (TSKgel Lipopropak, 7.5 mm×600 mm/TOSOH Co. Tokyo) and an eluent (TSKeluent LP1). HDL-C levels by the HPLC method were compared with three methods: (1) one-step ultracentrifugation using a Beckman Lp-42+Ti Rotor,(2+) the precipitation method with heparin/Ca2++, Ni2++, and (3) the direct measurement method with polethylene glycolmodified enzymes and sulfated α-cyclodextrin. Although correlations between the HPLC method and the other three methods were high (r=0.972+-0.995, n=70), HDL-C levels by the ultracentrifugation were significantly higher than those by the HPLC method in subjects with low HDL-C levels, and were lower in subjects with high HDL-C levels, Peaks of lipoproteins larger than HDL were observed in the HPLC patterns of HDL fraction separated by the ultracentrifugation for many subjects with low HDL-C levels. HDL-C levels obtained by the precipitation method and the direct method were slightly lower than these obtained by the HPLC method. The HDL-C levels obtained by the precipitation method were markedly lower in subjects with high HDL-C levels.
