A comparative analysis of direct LDL measurement and calculated LDL: Assessing accuracy and clinical implications

Background: Accurate assessment of low-density lipoprotein cholesterol (LDL-C) is crucial for managing atherosclerotic cardiovascular disease (ASCVD) risk. Traditional methods like the Friedewald equation have limitations, especially in hypertriglyceridemic or non-fasting conditions. Direct LDL-C measurement offers potential for greater accuracy. Methodology: This prospective observational study, conducted from 2023 to 2024 at Pacific Medical College and Hospital, involved 110 patients aged 18-65 years. Ethical approval was obtained. Participants, not on lipid-lowering medications, provided blood samples after a 12-hour fast. Trained phlebotomists collected blood samples following standardized procedures. LDL-C levels were calculated using the Friedewald equation and directly measured using specialized assays. Participants were categorized based on triglyceride levels for comparative analysis. Results: Significant differences in LDL-C levels were observed between calculated and direct measurement methods, especially in patients with high triglyceride levels. Group 3, with triglyceride levels exceeding 400 mg/dL, showed substantial disparities. The Bland-Altman analysis demonstrated acceptable agreement between methods, albeit with slight bias. Conclusion: Meticulous selection of LDL-C measurement methods is crucial, particularly in patients with metabolic abnormalities. Triglyceride levels significantly influence LDL-C estimation accuracy. Alternative methods like direct LDL-C measurement, especially in patients with elevated triglyceride levels, can enhance cardiovascular risk management.