COMPARATIVE STUDY OF THE ESTIMATION OF LDL CHOLESTEROL BY THE DIRECT METHOD AND FRIEDEWALD EQUATION IN SECONDARY HYPERLIPIDEMIA

The objective of the study is to measure the difference between the levels of LDL by Direct method versus Friedewald equation. The study includes 30 patients and 30 controls in the age of 25 – 75 years of both sexes. Fasting blood samples were collected and estimated Total Cholesterol (TC), Triglycerides (TG), Low Density Lipoprotein (LDL-C) cholesterol and High density lipoprotein (HDL) cholesterol, LDL cholesterol by direct method and by Friedewald’s formula (FW). There is a significant difference between LDL Direct and LDL-FW at triglyceride range of 1 – 100, (p= 0.01), 201 – 300 (p= 0.01) and no significant difference (p= 0.9) at   101 – 200, (p= 0.3) at 301 – 400 and (p= 0.2) at >400. There is a significant difference between LDL Direct and LDL-FW (p= 0.01) at total cholesterol range of 200 – 249 and no significant difference (p= 1.0) at 100 – 149, (p= 1.0) at 150 – 199 and (p= 0.9) at >250. There is significant difference between LDL values by direct and FW method (p=0.0490). LDL by Direct method is lower due to non interference of cholesterol and triglyceride, and LDL by FW is higher due to interference by cholesterol and triglyceride. The study has concluded that LDL-C by Direct method is reliable than Friedewald equation.