Đánh giá giá trị sử dụng của công thức tính nồng độ LDL-C huyết tương

Low-density lipoprotein cholesterol (LDL-C) plays a crucial role in cardiovascular health, acting as a primary contributor to atherosclerosis and a key indicator in the diagnosis and management of heart disease. Accurate determination of LDL-C concentration is therefore vital for clinical practice. While direct measurement offers the highest precision, its high cost and technical complexity limit widespread availability. Consequently, indirect calculation formulas, such as the widely used Friedewald formula, are often employed. However, the Friedewald formula exhibits limitations, particularly in patients with elevated triglyceride levels. The more recent Sampson formula was developed to address these shortcomings, offering an improved approach for calculating LDL-C. This study aims to evaluate the practical value of the Sampson formula by comparing its performance against the Friedewald formula and direct LDL-C measurement across different triglyceride concentrations, thereby informing its potential clinical utility in Vietnam.

Clinical laboratory professionals, biochemists, cardiologists, and researchers in lipid metabolism interested in accurate LDL-C assessment and the comparison of calculation formulas.

This cross-sectional study evaluated the practical utility of the Sampson formula for calculating plasma low-density lipoprotein cholesterol (LDL-C) by comparing it with the traditional Friedewald formula and direct LDL-C measurement. The research involved 323 patient samples from a military hospital, categorized into two groups based on triglyceride (TG) levels: < 4.5mmol/L (n=98) and ≥ 4.5mmol/L (n=225). Samples underwent direct LDL-C measurement, and LDL-C values were also calculated using both the Friedewald and Sampson formulas. Results indicated a strong positive correlation between the LDL-C values derived from both calculated formulas and direct measurements across both triglyceride groups. For samples with triglyceride levels below 4.5mmol/L, both the Sampson and Friedewald formulas demonstrated suitability as alternatives to direct LDL-C measurement, with Sampson showing a lower percentage difference (1.36% vs 4.61%). In contrast, for samples with elevated triglycerides (≥ 4.5mmol/L), the Sampson formula proved more accurate (D% of 12.2%) compared to the Friedewald formula (D% of 24.3%). Bland-Altman plots further supported the better agreement of the Sampson formula with direct measurement, especially in the high triglyceride group. However, neither formula, particularly at high triglyceride concentrations, fully met the stringent requirements for replacing direct LDL-C quantification as stipulated by the NCEP ATPIII guidelines. These findings suggest that while the Sampson formula offers improved accuracy over Friedewald, especially for patients with higher triglyceride levels, its clinical application as a complete replacement for direct measurement remains constrained by specific thresholds. The study highlights the need for continued research with larger, stratified sample sizes to further validate the utility of the Sampson formula.