Stability of High-Density Lipoprotein Cholesterol During Serum Incubation / 现代检验医学杂志

ABSTRACT

Objective To examine the stability of high-density lipoprotein cholesterol (HDL-C)during serum incubation at different temperature and time periods.Methods Ten healthy volunteers (4 males and 6 females,aged 24 to 59 years)from Beijing Hospital were recruited in May 2015.Fasting venous blood samples were collected and centrifuged to separate the sera.Serum samples were incubated at 4℃ for 24 h,25℃for 0,1,8 and 24 h (with or without an LCAT inhibitor).Serum to-tal cholesterol (TC),total free cholesterol (TFC)HDL-C and HDL-FC were measured by the HPLC Method.Results HDL-FC and HDL-C changed -6.91% and -2.17% during serum incubation at 4℃for 24h.TFC,HDL-FC and HDL-C changed significantly (averaged -13.70%,-25.88% and -1.53% respectively)during serum incubation at 25℃ for 24 h,in which the decrease of TFC and HDL-FC were inhibited by the addition of the LCAT inhibitor.The decrease of HDL-C was even higher in the presence of the LCAT inhibitor.Conclusion Serum TFC,HDL-C and HDL-FC levels changed during serum incubations,which were caused by the LCAT and CETP activities and the transfer of cholesterol among lipoproteins. For accurate measurement of serum HDL-C,prolonged serum storage should be avoided in clinical laboratories.