ABSTRACT
The risk of coronary heart disease [CHD] is proportional to the LDL-C lipoprotein. Due to frequent use of Friedwald formula in estimation of LDL-C in most laboratories, this study was done to compare the Friedwald formula and direct measurement to determine the serum levels of LDL-C. This descriptive study was conducted on of 598 patients 226 male and 372 female whome referred to Imam Ali hospital Andimeshk cityin Khozestan province of Iran for health check up during 2009. 5 ml of the venous blood was drown. Total cholesterol [TC] [mg/dl], Triglyceride [TG] [mg/dl], HDL-C [mg/dl] and LDL-C [mg/dl] of serum are measured with Pars azmun company kits. The Friedwald formula was used for estimation of LDL-C. The K=3, 3.5 and 5 were used to stimate the lipid by Friedwald formula. Data were analyzed using SPSS-18, Pearson correlation coefficient and ANOVA tests. A total of 598 serum samples collected; 37.8% were men and 62.2% women. The mean age of participants was 38.8 +/- 10.77 years. Minimum age 21 years and maximum age was 77 years. Mean deviation for TG