Associations Between Serum Copper, Zinc and Copper/Zinc Ratio and Risk of Chronic Kidney Disease: A cross-sectional analysis of the NHANES 2011-2016

Abstract

Abstract Several studies have indicated an association between serum copper and zinc and chronic kidney disease, while there was antagonism between serum copper and zinc, and the serum copper/zinc ratio was more accurate than detecting the two elements alone. This study aims to evaluate the associations of serum copper, zinc and copper/zinc rate with the risk of CKD using the 2011–2016 National Health and Nutritional Examination Surveys (NHANES). A total of 7764 participants were included in the analyses. Weighted multivariable logistic regression was applied to investigate the association between serum zinc and copper level and CKD after adjusting for potential confounders. A restricted cubic spline (RCS) to explore the relationships and trend between copper/zinc ratio and the risk of developing CKD. Machine learning of the XGBoost algorithm model was used to assess each variable’s contribution to the risk of having CKD. In this study, when the serum copper/zinc level decreased to less than 1.2, the risk of having CKD was reduced to 0.57 (95%CI, 0.39–0.84, p = 0.006). The RCS model showed a negative liner correlation between serum copper/zinc ratio and CKD risk (p < 0.001 and the value of nonlinear equal to 0.06), and when the ratio was lower than 1.49, the OR of having CKD begins to be lower than 1 and shows a rapidly increasing trend. In the XGBoost model, besides the glomerular filtration rate, the Copper/Zinc ratio was the most relative variable in our study. Therefore, the copper/zinc ratio would be a relatively important risk factor for predicting having CKD, and further researches are needed to explore the potential mechanism between copper/zinc and CKD.