The Association Between Oxidative Balance Score and Liver Fibrosis: Evidence from NHANES 2007-2020

Background Oxidative stress is a key factor in the pathogenesis and progression of liver fibrosis. However, the extent to which individual antioxidant capacity modulates liver fibrosis risk has not been fully established. This study investigates the association between the Oxidative Balance Score (OBS) and liver fibrosis risk. Methods Using data from the National Health and Nutrition Examination Survey (NHANES, 2007–2020), this cross-sectional analysis evaluated 20 dietary and lifestyle factors to calculate OBS. Survey-weighted regression models assessed the OBS–fibrosis relationship, supported by restricted cubic spline (RCS) curves, mediation analysis, and stratified and sensitivity analyses to explore potential mechanistic pathways. Results Among 6,258 eligible adults (17.1% with liver fibrosis), fully adjusted models revealed a sex-specific association. Females in the highest OBS quartile exhibited a 44% lower fibrosis risk compared to the reference group, whereas no significant correlation was observed in males. A linear OBS–fibrosis relationship was identified in females, while males showed a nonlinear trend, with a notable risk reduction at OBS inflection points (scores 19–20). Mediation analysis suggested that OBS indirectly mitigates fibrosis risk through pathways involving inflammation, oxidative stress, and glucose-lipid metabolism. Stratified and sensitivity analyses confirmed result robustness. Conclusion Higher OBS scores are inversely associated with liver fibrosis risk in females, partially mediated by metabolic and inflammatory pathways. These findings highlight sex-specific differences in oxidative balance effects, emphasizing the need for tailored preventive strategies.