Effects of dietary oxidative balance score on diabetic nephropathy and renal function: insights from retrospective and cross-sectional studies.

Background: The relationship between dietary oxidative balance score (DOBS) and diabetes-related renal events remains unclear.

Methods: In this study, the associations between serum micronutrients and diabetic nephropathy (DN) in participants matched by propensity score (PSM) were retrospectively analyzed. And next, a cross-sectional analysis was performed with the National Health and Nutritional Examination Survey (NHANES) database. Weighted multivariate adjusted logistic regression models, dose-response curves, subgroup analysis, and mediation analysis were the main methods of this study. Finally, sensitivity analyses were performed by PSM and multiple imputation (MI).

Results: Retrospective findings suggest that single antioxidants may not be representative of an individual's overall antioxidant levels. The results of the cross-sectional study indicated that the higher the DOBS, the greater the beneficial effects on DN [Q4 vs. Q1: OR (95% CI): 0.78 (0.63, 0.96), p for trend = 0.008] and renal function in DN [Q4 vs. Q1: β (95% CI): 5.395 (1.590, 9.199), p for trend = 0.004]. The above correlations were linear negative correlation (p for nonlinear = 0.989) and linear positive correlation (p for nonlinear = 0.593) respectively. Chronic inflammation mediated the above associations to some extent. The results of sensitivity analysis were consistent with the original analysis.

Conclusion: Higher dietary antioxidant exposure has a positive effect on DN and renal function in DN, mediated partially by chronic inflammation.