Association of Remnant Cholesterol Inflammation Index with Cardiovascular Risks and All-Cause Mortality in Individuals with Diabetes or Prediabetes

Qi-Lin Ma; Lei-Lei Du; Jia Peng

doi:10.4093/dmj.2025.0305

Association of Remnant Cholesterol Inflammation Index with Cardiovascular Risks and All-Cause Mortality in Individuals with Diabetes or Prediabetes

Diabetes Metab J. 2025 Oct 2. doi: 10.4093/dmj.2025.0305. Online ahead of print.

Authors

Qi-Lin Ma^#¹, Lei-Lei Du^#², Jia Peng¹

Affiliations

¹ Department of Cardiovascular Medicine, National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.
² Laboratory of Cardiovascular Science, Beijing Clinical Research Institute, Beijing Friendship Hospital, Capital Medical University, Beijing, China.

^# Contributed equally.

PMID: 41035340
DOI: 10.4093/dmj.2025.0305

Abstract

Background: Remnant cholesterol (RC) and low-grade inflammation are established contributors to cardiovascular disease (CVD) risks in diabetes. However, their combined prognostic impact remains unclear in dysglycemia. We evaluated the remnant cholesterol inflammation index (RCII), integrating RC and high-sensitivity C-reactive protein (hsCRP), for predicting mortality and CVD risks in diabetes/prediabetes.

Methods: This study included 2206 United States adults with diabetes/prediabetes from National Health and Nutrition Examination Survey 2015-2018. RCII was calculated as [RC (mg/dL)×hsCRP (mg/L)]/10. All-cause mortality was tracked via National Death Index until 2019; CVD risk was assessed cross-sectionally. Cox proportional hazard regression determined the hazard ratio (HR) and 95% confidence intervals (CIs) of RCII for all-cause mortality. Logistic regression models estimated the odds ratio (OR) and 95% CIs of RCII for CVD risks.

Results: For CVD risks, Q4 vs. Q1 demonstrated increased odds (OR, 2.32; 95% CI, 1.23 to 4.37), though per-standard deviation (SD) increments were non-significant (OR, 1.15; 95% CI, 0.98 to 1.35; P=0.083). During a median of 38 months follow-up, higher RCII quartiles showed graded associations with all-cause mortality (Q4 vs. Q1: HR, 2.45; 95% CI, 1.08 to 5.58; per 1-SD increase: HR, 1.21; 95% CI, 1.08 to 1.35). Restricted cubic splines confirmed dose-dependent relationships for CVD risks and all-cause mortality (all P=0.005 for overall). Subgroup analyses revealed consistent mortality associations but sex-specific CVD interactions (P=0.047 for interaction).

Conclusion: Our study found the RCII as a biomarker for predicting all-cause mortality and CVD risks in individuals with prediabetes or diabetes, highlighting the synergistic effects of RC and low-grade inflammation on adverse outcomes in this population and may facilitate early identification of individuals at heightened risk for CVD.

Keywords: Cholesterol; Diabetes mellitus; Heart disease risk factors; Inflammation; Mortality; Prediabetic state.