Comparison of direct LDLc method aganst calculated method and evaluation of the direct method

Abstract

          The objectives of this study were to compare the Low density lipoprotein cholesterol(LDLc) level determined by direct method against the calculate method and to evaluate the direct method. 130 samples of different Triglyceride levels from 68 males, 62 females, aged 14-82 were determined for Cholesterol, Triglyceride and High density lipoprotein (HDLc) at the Department of Clinical Pathology, Phrae Hospital LDc was determined by Friedwald formula and a direct method using reagent kit, The mean levels of calculated DLc for total samples and at Triglyceride <200 mg/dl, 200-400 mg/dl, >400 mg/dl,were 107.32 mg/dl, 108.56 mg/dl, 113.09 mg/dl, and 101.98 mg/dl, respectively. The mean levels of direct method for total samples and at Triglyceride <200 mg/dl,200-400 mg/dl,>400 mg/dl,were 139.17 mg/dl,127.48 mg/dl, 143.18 mg/dl, and 152.07 mg/dl, respectively. The mean leels of calculated and direct LDLc for total samples and all 3 levels of Triglyceride were significantly difference (p<0.001). Correlation coefficient ® of direct LDLc against calculate LDLc for total samples and all 3 levels of Triglyceride were 0.73.0.985,0.937 and 0.719, respectively .

          The evaluation showed that the direct LDLc method had a good accuracy and had a good precision with analytical error percentage below 3. Within-run parentage CV and between-run percentage CV of 0.85 and 2.87, respectively. Thus, this direct method is recommended to replace the Friedewald calculation for decrease the limitation of calculate method in case of Triglyceride>400 mg/dl.