Association of Oxidative Balance Score with Diabetic Kidney Disease: NHANES, 1999-2018

Background: Oxidative stress is implicated in diabetic kidney disease (DKD) pathogenesis. The Oxidative Balance Score (OBS), which integrates dietary and lifestyle factors, offers a comprehensive measure of oxidative/antioxidant status and may predict the risk of chronic diseases. However, its association with DKD prevalence and mortality remains uncertain. Methods: This cross-sectional study analyzed data from the National Health and Nutrition Examination Survey (NHANES, 1999–2018) for adults with DKD. Logistic regression evaluated associations between OBS and DKD prevalence, while Cox proportional hazards models assessed relationships between OBS and all-cause and cardiovascular mortality in DKD patients. Analyses included Kaplan-Meier survival, restricted cubic splines, two-piecewise logistic regression, and subgroup evaluations. Results: Among 8,686 adults with diabetes (mean age 60.8 years; 51.7% male), DKD prevalence was 42.1%. Both continuous and categorical analyses showed inverse associations of total, dietary, lifestyle OBS with lower DKD prevalence. Furthermore, continuous measures of total, dietary, and lifestyle OBS exhibited negative significant correlations with all-cause mortality, while only the lifestyle OBS tertile (Q2) was linked to reduced cardiovascular mortality. Kaplan-Meier analysis aligned with Cox results. RCS analyses identified significant nonlinear inverse associations between OBS and DKD incidence (inflection point: OBS=9) and all-cause mortality (inflection point: OBS=21). Age modified the inverse associations between OBS and DKD, while family income influenced OBS associations with cardiovascular mortality. Conclusion: OBS, encompassing both dietary and lifestyle components, are inversely associated with DKD prevalence and all-cause mortality in DKD patients. OBS may serve as a marker for identifying DKD risk, with antioxidant-rich diets and healthy lifestyle interventions potentially offering protective effects against DKD and reducing mortality risk. Funding: Government Support – Non-U.S.