Dyslipidemia Assessed in Pediatric Patients: Validation of LDL-C Assessed by Friedewald Formula, Direct Assessment,...

Background: The epidemic increase in obesity, metabolic syndrome, cardiac disease, or hypertension is associated with lipid deregulation. Studies suggest a strong link between elevated levels of plasma cholesterol and the premature formation of atherosclerotic plaques. Primary prevention of early clinical manifestations of atherosclerosis allows slowing or preventing the development of several health problems later in adult life. Objectives: The purpose of this study was the validation of LDL-C measured by the Friedewald formula, direct method, and Sampson-NIH Formula. The results of the three methods used to assess LDL-C were compared to check whether the three measurements of LDL-C yielded different results. Methods: The study was conducted in a large cohort of in-patients aged 8 months to 18 years. Lipid profile parameters were determined. Indirect methods for dyslipidemia diagnosis were compared against direct LDL measurement. Incorrect and missed diagnoses were analyzed. To measure the central tendency, a statistical analysis of distributions of numerical variables was used. Differences between categorical variables were assessed. The agreement between pairs of competing methods in estimating LDL concentration was assessed via Bland-Altman analysis. Results: In total, 1982 pediatric patients underwent lipid profile assessment. Significant differences in lipid parameters between boys and girls were observed. TG, TC, and HDL levels were higher in boys. LDL-C as measured by the Friedewald formula and direct methods showed significant differences. Comparison of the direct methods with the Sampson-NIH indicated that the Sampson-NIH formula underestimates LDL values. Conclusions: The analysis revealed differences between the methods used to assess dyslipidemia. A systematic underestimation of LDL concentrations determined by the indirect methods was found. Small differences between the Friedewald and Sampson-NIH methods were observed. Although both indirect methods underestimate LDL levels compared to the direct method, the differences between them are small, though still detectable.