Abstract
Gallstone disease is a common gastrointestinal disorder influenced by lipid metabolism and systemic inflammation. The remnant cholesterol inflammatory index (RCII), derived from remnant cholesterol (RC) and high-sensitivity C-reactive protein, integrates both components, yet its relationship with gallstones remains unclear. This study aimed to investigate the association between the RCII and gallstone disease in a nationally representative US population. We conducted a cross-sectional analysis using data from 2120 adults in the 2017 to 2020 cycle of the National Health and Nutrition Examination Survey. Gallstone status was based on self-reported physician diagnosis. RC (mg/dL) was estimated using the following formula: RC = TC - (LDL-C + HDL-C). RCII was calculated as RC × hs-CRP/10. Multivariable logistic regression and receiver operating characteristic curve analyses were performed using a complex survey design. Among the participants, 240 reported a history of gallstone disease. In adjusted logistic regression models, each unit increase in log-transformed RCII was associated with a 95% higher odds of gallstone disease (odds ratio: 1.95; 95% confidence interval: 1.62-2.35; P < .0001). Compared with the lowest quartile of RCII, the highest quartile had a significantly increased risk (odds ratio: 4.48; 95% confidence interval: 2.67-7.52; P < .001), with a clear dose-response trend (P for trend < .001). Receiver operating characteristic analysis revealed that RCII had the highest area under the curve (0.696), with a sensitivity of 52.7% and specificity of 75.8% at the optimal cutoff point. Higher RCII levels are independently associated with gallstone disease. As an integrated marker of lipid-related inflammation, RCII may serve as a potential risk indicator for gallstone formation.