Association between residual cholesterol inflammation index and cardiovascular disease in a Chinese population

NIU Yu-fei; LI Jin-jiang; JIN Chun-rong

doi:10.3969/j.issn.1672-5301.2026.02.013

Abstract：Objective To investigate the association between the residual cholesterol inflammation index(RCII)and the risk of cardiovascular disease(CVD)in a Chinese population.Methods This cross-sectional study analyzed data from 10,815 participants aged≥45 years form the 2011 China Health and Retirement Longitudinal Study(CHARLS).The RCII was calculated as follows:RCII=RC×hs-CRP/10,where Residual Cholesterol(RC)=Total Cholesterol(TC)-(High-Density Lipoprotein Cholesterol(HDL-C)+Low-Density Lipoprotein Cholesterol(LDL-C)).Multivariable Logistic regression models were constructed to evaluate the associations of RC and RCII with CVD.The exposure-response relationships were characterized using restricted cubic splines(RCS)to test for non-linearity.Analyses were stratified by median high-sensitivity C-reactive protein(hs-CRP)levels(1.04 mg/L)to assess the modifying effect of inflammation.Subgroup analyses were also conducted.Additionally,receiver operating characteristic(ROC)curves were used to assess the discriminatory ability of RCII for CVD.Results The participants were categorized into RCII quartiles:Q1:0.011(0.006,0.015),Q2:0.034(0.027,0.042),Q3:0.081(0.065,0.105)and Q4:0.278(0.189,0.504).The prevalence of CVD increased progressively across these quartiles(11.2%,12.9%,15.8%and 18.0%).After adjusting for age,sex,urban/rural residence,smoking and alcohol consumption,and comorbidities(e.g.,hypertension and diabetes),multivariable Logistic regression revealed that higher RCII quartiles(Q3 and Q4)were independently associated with increased CVD risk(Q3:OR=1.185,95%CI 1.003-1.402;Q4:OR=1.24,95%CI 1.052-1.463).In contrast,RC quartiles did not show statistically significant association.RCS analysis indicated a linear relationship between RC and CVD(Pnonlinearity=0.981)and a significant non-linear relationship for RCII(Pnonlinearity<0.001).Stratified analysis revealed that RC was significantly associated with CVD only in the high-inflammation group(hs-CRP>1.04 mg/L;Poverall=0.006).ROC analysis demonstrated that RCII exhibited superior discriminatory ability for CVD compared to RC.Conclusions Elevated RCII levels are significantly associated with a higher risk of CVD in individuals aged 45 and older,suggesting that RCII may serve as a risk factor for CVD.Further research is needed to validate these findings.