Evaluating the impact of environmental metal mixtures on chronic kidney disease risk: Insights from the National Health and Nutrition Examination Survey 2011-2016.

BackgroundChronic kidney disease is a global health issue, with environmental metal mixtures potentially contributing to its risk, although interactions between metals remain unclear. The present study aims to systematically explore the association between exposure to environmental metal mixtures and the risk of chronic kidney disease as well as their potential interactive effects.MethodsData from 3514 adults (aged ≥20 years) who participated in the National Health and Nutrition Examination Survey 2011-2016 were analyzed. Blood concentrations of lead, cadmium, mercury, selenium, manganese, serum copper, and zinc were measured. Chronic kidney disease was defined by an estimated glomerular filtration rate of <60 mL/min/1.73 m² or urinary albumin-creatinine ratio of ≥30 mg/g. Logistic regression, restricted cubic splines, weighted quantile sum, Bayesian kernel machine regression, and machine learning were used for data analysis.ResultsHigher concentrations of lead, cadmium, and copper were linked to an increased risk of chronic kidney disease; zinc showed protective effects. Weighted quantile sum indicated that exposure to metal mixtures was positively associated with chronic kidney disease risk (odds ratio: 1.58, 95% confidence interval: 1.30-1.94), with lead and cadmium showing the highest contribution. Bayesian kernel machine regression confirmed the cumulative/interactive effects of metals. XGBoost (area under the curve: 0.801) showed good predictive performance.ConclusionsEnvironmental metal mixtures, especially lead and cadmium, increase the risk of chronic kidney disease. Metal interactions modulate renal effects, highlighting the need for exposure reduction strategies.