Association between remnant cholesterol and atherosclerosis plaques in single and multiple vascular territories.

In recent years, the role of remnant cholesterol (RC) in the development and progression of cardiovascular diseases has gained increasing attention. However, evidence on the association between RC and subclinical atherosclerosis is limited. This study aims to examine the relationship between RC and atherosclerotic plaques in single and multiple vascular territories. This retrospective cross-sectional study used baseline data from participants enrolled between October 2022 and May 2024 in the National Key Research Program "Study on the Prevention and Control System of Risk Factors for Panvascular Diseases". Color Doppler ultrasonography was performed to detect plaques in 4 vascular territories: Bilateral carotid arteries, bilateral subclavian arteries, abdominal aorta, and iliac-femoral arteries. RC was calculated as total cholesterol minus the sum of low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C). Participants were categorized into quartiles (Q1-Q4) according to RC levels. The proportions of participants with ≥2 plaques in a single vascular territory and with plaques in ≥2 vascular territories were compared across RC quartiles. Multivariate ordinal Logistic regression was used to assess the association between RC and the number of plaques in a single vascular territory, as well as the risk of multiple vascular territory involvement. Additionally, the effects of LDL-C/RC concordance on plaque distribution were analyzed. A total of 3 539 participants were included, of whom 2 169 (61.29%) were male, with a age of (51.94±9.22) years. From Q1 to Q4, the proportion of participants with ≥2 plaques in a single vascular territory (bilateral carotid, subclavian, abdominal aorta, and iliac-femoral arteries), as well as those with plaques in ≥2 vascular territories, increased progressively. Compared with Q1, both Q3 and Q4 were significantly associated with higher plaque numbers in a single vascular territory (both P<0.05). When treated as a continuous variable, higher RC levels were associated with an increased risk of greater plaque numbers within a single vascular territory (all P<0.05). RC levels were also significantly associated with multiple vascular territory involvement: Compared with Q1, Q4 had a 1.015-fold higher risk odds ratio (OR)=2.015, 95% confidence interval (CI) 1.669 to 2.433, and each 1 mmol/L increase in RC corresponded to a 0.160-fold increased risk (OR=1.160, 95% CI 1.073 to 1.271). In LDL-C/RC coordination analysis, compared with the low LDL-C/low RC group, the low LDL-C/high RC group was significantly associated with multiple vascular territory involvement (OR=1.576, 95% CI 1.220 to 2.036). Elevated RC levels are closely associated with atherosclerotic plaques in both single and multiple vascular territories, even among individuals with normal LDL-C, suggesting that RC should be considered in clinical risk assessment and management of atherosclerosis.