DOI: 10.36347/sjams.2018.v06i03.029

Pages: 951-959

Serum levels of low-density lipoprotein cholesterol (LDL-C) dictate not only diagnosis but also risk classification and treatment of cardiovascular diseases. Owing to the cost-effectiveness, Friedewald formula (FF) is primarily preferred and adopted method to assess serum LDL-C levels especially when triglycerides (TG) <400 mg/dL. FF employs a fixed factor of 5 for the ratio of TG to very low density lipoprotein cholesterol (TG:VLDL-C). Martin et. al., in their recent study proposed an adjustable factor using N-strata-specific median TG:VLDL-C ratios. They constructed 180-cell table based on non-High-density lipoprotein cholesterol (non-HDL-C) and TG levels. In the present cross-sectional study, the performance of LDL-C measurements based on FF (LDL-CF) and novel method (LDL-CN) in comparison to direct homogenous assay (LDL-CD) was evaluated. A total of 480 lipid profile data with serum TG <400 mg/dL were procured. The efficacy of both LDL-CF and LDL-CN measurements were evaluated under broader as well as in constricted ranges of TG. The entire lipid profile data was pooled under Group I comprising broader range of TG i.e., TG <400 mg/dL. The data of Group I were further stratified into subsequent three groups with constricted range of TG. Hence, Group II (TG<100 mg/dL), Group III (TG=100-199 mg/dL), Group IV (TG=200-399 mg/dL) comprised 153, 170 and 147 samples, respectively. Bland-Altman (B&A) and Lin’s concordance correlation coefficient (CCC, ρc) analysis were used as statistical tools. Difference plot of B&A analysis indicated narrow 95% limits of agreement (LOA) as bias±2 standard deviations with low percentage error for LDL-CN in contrast to LDL-CF at all ranges of TG. Although both formula based methods were in substantial strength-of-agreement with LDL-CD yet LDL-CN expressed marginally higher ρc (95%CI) with precision and accuracy in all Groups. Hence, in corroboration with earlier studies, our study also further supports the efficacy of LDL-CN in comparis