Abstract P2082: Discordance of Small Dense Low-Density Lipoprotein Cholesterol beyond Low-Density Lipoprotein Cholesterol or Non-High-Density Lipoprotein Cholesterol and Carotid Plaque Risk

Abstract

Introduction: We aimed to evaluate the associations of small dense low-density lipoprotein cholesterol (sdLDL-C), large buoyant LDL-C (lbLDL-C), and sdLDL-C/LDL-C ratio with carotid plaque (CP) risk in the general Chinese population, and to conduct discordance analyses to determine which of these lipid biomarkers can more effectively reflect CP risk beyond traditional lipid markers, such as total LDL-C and non-high-density lipoprotein cholesterol (non-HDL-C). Hypothesis: We inferred that sdLDL-C and sdLDL-C/LDL-C ratio would provide additional CP risk information beyond LDL-C and non-HDL-C. Methods: This study enrolled 20,369 participants from the Beijing Healthy Management Cohort. Discordances between sdLDL-C, lbLDL-C, or sdLDL-C/LDL-C with LDL-C or non-HDL-C, as well as discordance between sdLDL-C/LDL-C and sdLDL-C, were defined based on residual differences and medians. CP was diagnosed using Color Doppler ultrasound of the carotid artery. Logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Results: In our study, 10,445 (51.28%) participants were men, and the median age was 43.00 [34.00, 54.00] years. Higher sdLDL-C and sdLDL-C/LDL-C ratio, but not lbLDL-C, were associated with increased CP risk. Additionally, discordantly high sdLDL-C (OR, 1.403; 95% CI, 1.283–1.534 for LDL-C; OR, 1.356; 95% CI, 1.240–1.483 for non-HDL-C) and discordantly low lbLDL-C (OR, 1.406; 95% CI, 1.286–1.537 for LDL-C; OR, 1.178; 95% CI, 1.077–1.288 for non-HDL-C), relative to LDL-C or non-HDL-C, were significantly associated with an elevated risk of CP compared to the concordance groups. Conversely, discordantly low sdLDL-C (OR, 0.823; 95% CI, 0.743–0.911 for LDL-C; OR, 0.863; 95% CI, 0.781–0.953 for non-HDL-C) and discordantly high lbLDL-C (OR, 0.825; 95% CI, 0.745–0.913 for LDL-C; OR, 0.930; 95% CI, 0.845–1.023 for non-HDL-C) were associated with a reduced risk. Finally, the discordantly high sdLDL-C/LDL-C ratio versus LDL-C (OR, 1.310; 95% CI, 1.199–1.431), non-HDL-C (OR, 1.228; 95% CI, 1.124–1.343) and sdLDL-C (OR, 1.464; 95% CI, 1.323–1.620) was linked with increased CP risks. Conclusions: The sdLDL-C and sdLDL-C/LDL-C ratio, not lbLDL-C, are superior to LDL-C and non-HDL-C in identifying CP risk, and sdLDL-C/LDL-C further captures additional risk information beyond sdLDL-C alone. These findings underscore the importance of monitoring sdLDL-C and sdLDL-C/LDL-C to enhance residual risk assessment for atherosclerosis in clinical practice.