Nutritional-inflammatory indices and gallstone risk: complementary insights from hospital-based and community-based cohorts in China

Gallstone is a common digestive disorder closely associated with inflammatory responses and nutritional metabolic disturbances. However, evidence regarding the association between composite nutritional-inflammatory indices and gallstone risk remains limited. This study aims to investigate the association of albumin/neutrophil to lymphocyte ratio (ANLR) and neutrophil percentage to albumin ratio (NPAR) with gallstone prevalence using two independent cohorts from China. This cross-sectional study analyzed two cohorts: a hospital-based cohort (Zibo Central Hospital, 2014–2024, n =27,594) and a community-based cohort (Fuzhou Xiadu Community Health Service Center, 2021–2024, n =6,702). This two cohorts were analyzed independently. ANLR and NPAR were derived from routine blood tests and serum albumin levels. Gallstones were diagnosed via abdominal ultrasonography. Multivariable logistic regression models were used to evaluate the associations of ANLR and NPAR with gallstones. Restricted cubic spline (RCS) regression was employed to examine dose-response relationships. Subgroup analyses and multiple imputation were performed as sensitivity analyses. In the hospital cohort, each doubling of ANLR was associated with a 8% reduction in gallstone risk (OR=0.92, 95% CI: 0.89–0.96), while NPAR was positively associated (OR=1.15, 95% CI: 1.05–1.25). These associations were validated in the community cohort (ANLR: OR=0.84, 95% CI: 0.73–0.96; NPAR: OR=1.54, 95% CI: 1.11–2.14). RCS analysis revealed a nonlinear threshold effect for ANLR in the hospital cohort (inflection point=1.481), with a significant inverse association below the threshold (OR=0.751, 95% CI: 0.616–0.915) and no association above it. Subgroup and sensitivity analyses confirmed the robustness of these findings. ANLR and NPAR are independently associated with gallstone prevalence in Chinese populations, with ANLR serving as a protective factor and NPAR as a risk factor. These simple and accessible indices may facilitate early identification of high-risk individuals for gallstones in both clinical and community settings. Future studies employing a prospective design are required to validate this association and clarify the underlying biological mechanisms.