Abstract 4366664: Impact of the Lipid-Lowering Therapy on the Distribution Differences Between Lipid Fractions

Background: Diagnosis of hypercholesterolemia relies on laboratory assessment of lipid parameters. This study aimed to evaluate differences in the distribution of low-density lipoprotein cholesterol (LDL-C), non-high density lipoprotein cholesterol (non-HDL-C), and apolipoprotein B (apoB) concentrations according to the presence and type of lipid-lowering therapy (LLT). Material and Methods: This retrospective analysis included consecutive patients who had at least one measurement of LDL-C, apoB, and non-HDL-C between March and November 2024 in a high-volume tertiary hospital. All lipid fractions were expressed as percentages of measurements above and below cut-off values established by the recent ESC guidelines. Subgroup analysis based on the LLT type was performed, with patients divided into either single or combined LLT. Results: A total of 5 047 patients were included in the analysis. Among patients on LLT, most received statin monotherapy (77.3%), predominantly atorvastatin. Combined therapy, primarily statin plus ezetimibe, was used in 22.7% of treated patients. Discordance between on-target apoB levels and elevated LDL-C concentrations occurred in 26.6% of untreated patients, 13.6% of all LLT-treated patients, 15.1% of single LLT patients, and 8.6% of combined LLT patients. Similarly, discordance between on-target non-HDL-C and elevated LDL-C levels was observed in 13.5% of untreated patients, 7.5% of all LLT-treated patients, 8.4% of single LLT patients, and 4.8% of combined LLT patients. Conclusions: Classification of hyperlipidemia based on LDL-C, non-HDL-C, and apoB concentrations reveals significant discrepancies between these markers, especially between LDL-C and apoB. LLT significantly reduces these discrepancies, with combined LLT being particularly effective.