Association between oxidative balance score and metabolic dysfunction-associated steatotic liver disease in US adolescents: A cross-sectional NHANES analysis.

Metabolic dysfunction-associated steatotic liver disease (MASLD) has emerged as a growing public health concern among obese youth. Oxidative stress plays a central role in the pathogenesis of MASLD, and an aggregate oxidative balance score (OBS), reflecting the balance between antioxidant and pro-oxidant exposures, may serve as a predictor of disease risk. The present study examined the association between OBS and MASLD among adolescents in the United States (US). We conducted a cross-sectional analysis of 2203 adolescents aged 12 to 17 years using data from the National Health and Nutrition Examination Survey 2017 to 2023. A US Fatty Liver Index score ≥ 30 was used as the diagnostic benchmark for MASLD classification. Logistic regression models were applied to quantify the association between OBS and MASLD, restricted cubic spline analyses were used to assess nonlinearity, and stratified analyses were performed according to sex, survey cycle, ethnicity, poverty-income ratio, age, height, and weight. The median OBS was 12.0, with an interquartile range of 3 to 18. MASLD was identified in 298 participants, corresponding to an unweighted sample prevalence of 13.53%. The adjusted association between OBS and MASLD showed evidence of nonlinearity. In an exploratory piecewise model, the data-derived turning point was 19.8; above this value, each 1-point increase in OBS was associated with 8% lower odds of MASLD, while the association below this value was not statistically significant. Subgroup estimates were generally inverse but imprecise. Among adolescents in the analytical sample, higher OBS was associated with lower MASLD prevalence after adjustment for age, sex, and ethnicity. The nonlinear pattern and data-derived turning point are exploratory and should not be interpreted as a clinical cutoff. Given the cross-sectional design and surrogate US Fatty Liver Index definition, these findings are hypothesis-generating and require confirmation in longitudinal studies using direct liver assessment.