The Association between Red Blood Cell Distribution Width to Albumin Ratio and Gallstones: A Cross-Sectional Study with Propensity Score Matching

Abstract

Background: The ratio of red blood cell distribution width to albumin (RAR) is an emerging and cost-effective composite inflammatory indicator that can reflect the systemic inflammatory status of the body. However, the potential relationship between RAR and gallstones has not been systematically evaluated.

Methods: This study is based on data from the National Health and Nutrition Examination Survey (NHANES) in the United States, conducted from 2017 to 2020, involving 7,679 adults. Use propensity score matching (PSM) to control for selection bias and construct a multivariate logistic regression model to evaluate the association between RAR and gallstones. A restrictive cubic spline (RCS) is employed to investigate potential nonlinear relationships, while subgroup analysis is used to assess interactions and heterogeneity.

Results: The elevated level of RAR is significantly positively correlated with the risk of gallstones (OR=1.358, 95% CI: 1.194-1.545), and this correlation remains robust after PSM (OR=1.357, 95% CI: 1.156-1.593). RCS analysis suggests a linear relationship between RAR and the incidence of gallstones. The subgroup analysis results showed that this association remained consistent in most populations, and alcohol consumption and physical activity had significant moderating effects on this association (p for interaction < 0.05).

Conclusions: RAR is significantly positively correlated with the risk of gallstones, suggesting that it can be used as a convenient and easily accessible potential inflammatory biomarker to assist in early risk identification and population screening of gallstones. This discovery provides a new research perspective and intervention basis for the stratified management and precise prevention and treatment of gallstones.