Nonlinear association of remnant cholesterol inflammatory index with metabolic dysfunction-associated steatotic liver disease in US adults: A cross-sectional NHANES study

The remnant cholesterol inflammatory index (RCII) is a composite index whose relationship with metabolic dysfunction-associated steatotic liver disease (MASLD) is uncertain. This research was designed to assess this association. This study involved adults from the 2017–2020 National Health and Nutrition Examination Survey (NHANES) program. Various analytical approaches, including multivariable logistic regression models, restricted cubic splines (RCS), threshold effect analysis, stratified analysis and receiver operating characteristic (ROC) analysis were used to explore the potential link between the RCII and MASLD. The study cohort consisted of 3361 participants, with 1945 (57.87%) diagnosed with MASLD. Adjusted to covariates, a positive correlation between RCII and MASLD was demonstrated through logistic analysis. Both RCS and threshold effect analyses indicated a nonlinear relationship between the RCII and MASLD, with an inflection point of 3.84 for MASLD. ROC analysis revealed that RCII had an area under the curve (AUC) of 0.73 for diagnosing MASLD. The findings reveal a significant association between the RCII and MASLD, proposing its potential value as a clinical biomarker for disease diagnosis.