Lifestyle-Related Oxidative Balance Score and Depression in Diabetic Kidney Disease: A Multicohort Cross-Sectional Study

Background: To investigate the potential link between oxidative balance score (OBS) and the likelihood of depression in individuals diagnosed with diabetic kidney disease (DKD). Methods: Data were obtained from multiple representative sources, including the National Health and Nutrition Examination Survey (NHANES), the China Health and Retirement Longitudinal Study (CHARLS), and clinical records from the China-Japan Friendship Hospital (CJFH). Weighted multivariate logistic regression modeling and survival analyses were performed. Results: A significant difference in all-cause mortality was observed between patients with and without DKD ( P < 0.0001). Furthermore, among DKD patients, those with depression exhibited higher all-cause mortality compared with non-depressed patients at 31 weeks ( P < 0.05). In NHANES, a higher OBS was associated with a reduced risk of depression (Odds Ratio [OR]: 0.87, 95% Confidence Interval [CI]: 0.76-0.98, P < 0.05). A consistent negative correlation was observed between Oxidative Balance Score (OBS)-lifestyle and depression risk (OR: 0.66, 95% CI: 0.47-0.91, P = 0.015). However, the significance of such associations for OBS-dietary disappeared. In CHARLS, each unit increase in OBS-lifestyle was associated with a 12% reduction in depression risk (95% CI: 0.78-0.98, P = 0.025). The CJFH database revealed a correlation coefficient of 0.37 ( P < 0.0001) between body mass index (BMI) and depression score. Restricted cubic spline analysis revealed a U-shaped relationship between OBS-lifestyle and depression risk ( P = 0.001). Multiple machine learning methods identified BMI as the main variable predicting depression risk. Conclusion: A higher lifestyle-derived OBS was inversely correlated with depression risk in the DKD cohort, with BMI identified as a principal contributing factor within this composite score.