Variability of remnant cholesterol inflammation index exhibits a dose-response relationship with stroke risk: Evidence from the Chinese Kailuan cohort

To investigate the association between the variability of remnant cholesterol inflammatory index (RCII), a novel composite biomarker, and the risk of stroke, in order to provide a theoretical basis for stroke prevention.

A prospective cohort study was conducted on 38659 Kailuan individuals who took annual physical examinations in 2006, 2008, and 2010. These subjects were grouped based on the quartiles of RCII variability, which was represented by standard deviation (SD) and average real variability (ARV), and were followed up every 2 years, with the occurrence of stroke (including ischemic and hemorrhagic strokes), death, or the end of follow-up on December 31, 2022 as the endpoints. Kaplan-Meier method was used to calculate the cumulative incidence rate of endpoint events across different groups, and log-rank test was used to compare the difference of cumulative incidence of endpoint events in each group. Multivariate Cox proportional hazards regression model was adopted to analyze the association between RCII variability and risk of stroke.

Among the 38659 participants, a total of 2539 strokes occurred during a mean follow-up period of 11.22±2.26 years. After adjusting confounding factors, when the participants were grouped by the quartiles of RCII-SD, the hazard ratio (HR) for stroke was 1.034 (95%CI: 0.917~1.167, P=0.584), 1.146 (95%CI: 1.018~1.290, P=0.025), and 1.209 (95%CI: 1.066~1.370, P=0.003), respectively in the Q2, Q3, and Q4 groups, when compared with the Q1 group (P_trend <0.05). When they were grouped by the quartiles of RCII-ARV, the HR for stroke was 1.008(95%CI: 0.894~1.136, P=0.901), 1.109 (95%CI: 0.986~1.248, P=0.085), and 1.152(95%CI: 1.018~1.303, P=0.025), respectively, in the Q2, Q3, and Q4 groups, when compared with the Q1 group. Furthermore, both sensitivity and stratified analyses yielded similar results.

RCII variability is significantly associated with stroke, and the risk of stroke is gradually increasing with increment of the variability.

Relevant authorities can focus on reducing RCII variability as a central Objective by establishing regular monitoring mechanism, strengthening lifestyle interventions, and standardizing dietary, exercise, and weight management in order to suppress the index fluctuations. The principle of stable lipid-lowering in medication and optimization of therapeutic regimens with stable efficacy should be emphasized to prevent the risk of additional vascular damage.