Oxidative balance is associated with diabetic kidney disease and mortality in adults with diabetes mellitus: Insights from NHANES database and Mendelian randomization

Objective: To explore and validate the association between the oxidative balance and prevalence of diabetic kidney disease (DKD) and mortality in patients with diabetes.

Study design: A large and representative sample from the National Health and Nutrition Examination Survey (NHANES) from 2013 to 2016 was analyzed to study the potential association between Oxidative Balance Score (OBS) and prognosis of DKD in adult diabetic patients. Weighted multivariate logistic regression analysis was conducted to examine the relationship between OBS and DKD risk. Subgroup analysis, sensitivity analysis, and mediation effect analysis were conducted to explore the effect of the covariates and assess the robustness of the findings. Mendelian randomization (MR) was employed to evaluate the correlated relationship between mitochondrial reactive oxygen species (ROS) levels and DKD at the genetic level.

Result: The highest OBS quartile showed the most significant negative correlation with DKD compared to the lowest OBS quartile (OR = 0.62, 95% CI 0.41-0.92, P = 0.017). Higher OBS was associated with a reduced risk of DKD (OR = 0.96; 95% CI = 0.93, 0.98; P < 0.001) and mortality (P = 0.021 by log-rank) in diabetic patients. This association remained robust even after excluding individual OBS components. Subgroup analysis revealed the interaction of metabolic syndrome on OBS was significant. Mediation analyses revealed that OBS's effect on DKD was independent of blood uric acid and cholesterol. Restricted cubic spline (RCS) analysis indicated a typical L-shaped relationship between OBS and DKD risk. The physical activity was identified as the core variable predicting DKD risk by two machine learning algorithms. MR showed a potential correlated relationship between ROS and microalbuminuria in DKD.

Conclusions: The high level of oxidative balance score was negatively correlated with the risk of DKD and mortality in diabetic patients.