Direct Measurement of High-Density Lipoprotein Cholesterol Evaluated

Kim, Young Ah; Lim, Hwan Sub; Lee, Jung Woon; Kim, Jeong Ho; Kwon, Oh Hun

Abstract

BACKGROUND: Serum high density lipoprotein (HDL)-cholesterol level is used as an assessment of the risk of coronary heart disease. In this study, we evaluated direct measurement of HDL- cholesterol in serum with polyethylene-modified enzymes and sulfated alpha-cyclodextrin.
METHODS
We evaluated the precision, the lower limit of detection, the recovery rate, the linearity, the interference for hemoglobin and the comparision with the result of HDL-cholesterol measured by selective precipitation method. We also studied the specificity of this direct method for very low density lipoprotein (VLDL) and low density lipoprotein (LDL).
RESULTS
The total imprecision was 3.8% (low), 3.5% (middle), 3.2% (high). The lower limit of detection was 0 mg/L. The recovery rate was satisfactory. The linearity was also (r2=0.99). This method showed a good correlation (r2=0.97) with the selective precipitation method in HDL- cholesterol measurement. VLDL-cholesterol (up to 300 mg/L) increased HDL-cholesterol only less than 3% but increased VLDL-cholesterol to 400 mg/L, more than 750 mg/L caused 5% and 15% of overestimation of HDL-cholesterol, respectively. LDL-cholesterol (142-1,073 mg/L) increased or decreased HDL-cholesterol by some degree (about 15%). Hemoglobin (up to 3,000 mg/L) did not influence this assay.
CONCLUSIONS
The direct measurement of HDL-cholesterol is satisfactory method in HDL- cholesterol measurement in good analytical performance and may be anticipated to reduce workload of laboratory because the sample pretreatment is not necessary.