Abstract
BACKGROUND: Low muscle mass is a critical indicator of frailty and adverse health outcomes. However, the potential link between systemic oxidative stress and low muscle mass remains underexplored. This study aims to investigate the association between the Oxidative Balance Score (OBS) and low muscle mass in U.S. adults. METHODS: In this cross-sectional study, data from 4096 adults aged 20 to 59 years from National Health and Nutritional Examination Survey (NHANES) 2011 to 2018 were analyzed. Low muscle mass, the primary outcome, was evaluated utilizing the Foundation for the National Institutes of Health (FNIH) definition. Analysis involved the application of restricted cubic splines and weighted multivariate regression techniques. RESULTS: A nonlinear association was observed between OBS and low muscle mass (p for nonlinearity < 0.0049). Compared to the lowest OBS quartile, individuals in the highest quartile had an adjusted OR of 0.26 (95% CI: 0.14-0.48) for low muscle mass (P for trend < 0.001). Additionally, the adjusted β value for ALM/BMI was 0.067 (95% CI: 0.053-0.082), P for trend < 0.001. Both dietary and lifestyle OBS also showed negative associations with low muscle mass, with fully adjusted ORs of 0.38 (95% CI: 0.19-0.76) and 0.17 (95% CI: 0.05-0.62), respectively (both P for trends < 0.01). Furthermore, in stratified analyses, this relationship was particularly prominent in the 40-59 years age group (P for interaction = 0.048). CONCLUSION: Higher OBS, indicative of greater antioxidant exposure, was robustly associated with a lower risk of low muscle mass, particularly in 40-59 old adults. These findings underscore the potential role of oxidative balance in preserving muscle health and highlight the need for targeted interventions in this demographic. Further longitudinal studies are warranted to confirm these associations and evaluate potential clinical applications.