Association between oxidative balance score and metabolic syndrome: a systematic review and meta-analysis

Introduction: Most patients with metabolic syndrome (MetS) are at enhanced risk of oxidative stress. This systematic review and meta-analysis assesses the association between oxidative balance score (OBS) and MetS (MetS). Method: Cochrane, Web of Science, PubMed, ProQuest, Embase, and Google Scholar databases were searched until January 15, 2025. Data were analyzed using IBM SPSS Statistics 19.0 and STATA 14. The results with P<0.05 were considered to be statistically significant. Results: Elevated OBSs were associated with declined risks of MetS in males (OR:0.88, 95% CI: 0.83, 0.93) and females (OR: 0.81, 95% CI: 0.76, 0.86). Likewise, elevated OBSs declined the risk of MetS in South Korea (OR: 0.75, 95% CI: 0.67, 0.84) and the USA (OR: 0.63, 95% CI: 0.53, 0.74), in the cohort (OR: 0.73, 95% CI: 0.63, 0.85) and cross-sectional (OR: 0.67, 95% CI: 0.58, 0.76) studies, in 40 to 49 years old patients (OR: 0.63, 95% CI: 0.53, 0.74) and patients aged 50 to 59 (OR:0.84, 95% CI: 0.77, 0.91), in the second (OR: 0.75, 95% CI: 0.66, 0.84) and third (OR: 0.50, 95% CI: 0.34, 0.74) tertiles, in the second (OR: 0.84, 95% CI: 0.78, 0.92), third (OR: 0.68, 95% CI: 0.59, 0.79), and fourth (OR: 0.50, 95% CI: 0.41, 0.61) quartiles, and in the fifth quintile (OR: 0.78, 95% CI: 0.63, 0.97). As such, the risk of MetS declined at elevated dietary oxidative balance score (DOBS) (OR: 0.79, 95% CI: 0.62, 1) and lifestyle-based oxidative balance score (LOBS) (OR: 0.39, 95% CI: 0.21, 0.71). Conclusion: Elevated OBS, DOBS, and LOBS scores mitigate the risk of MetS. MetS risk is lower in the United States females and those in their fourth decade. Collectively, MetS is less probable to occur at elevated OBS levels. Registration: This study has been compiled based on the PRISMA checklist, and its protocol was registered on the PROSPERO (ID: CRD42025643042 and Research Registry (UIN: reviewregistry1951) websites.