Association between blood metals mixture and chronic kidney disease in adults: NHANES 2013-2016

The association between single metal exposure and chronic kidney disease (CKD) has been established. However, there is limited research on the effects of multi-metal mixtures and their potential age-specific associations with kidney injury. This study aimed to examine the relationship between metal mixtures and kidney function in adults, while also exploring the modifying effects of age. We included a subset (n = 4250) of a nationally representative adult population in the National Health and Nutrition Examination Survey (NHANES) 2013–2016. Kidney function was assessed using the glomerular filtration rate (eGFR) and creatinine albumin ratio (ACR). Regression, additive interaction, and quantile-g calculation (qgcomp) model were employed to estimate the individual and combined effects of lead, cadmium, mercury, and manganese on kidney injury and the risk of CKD. Modification effects of age, sex, and BMI were further explored by stratified analysis. Pb and Cd were found to be positively associated with decreased kidney function. For a one Ln-unit increase in lead and cadmium, the adjusted ORs of CKD were 1.59 (95% CI: 1.36, 1.86) and 1.33 (95% CI:1.11, 1.60), respectively. We also observed an interaction between lead and cadmium for ACR. We also observed the joint effect between Pb and Cd on eGFR, ACR and CKD. Stratified analysis found a higher risk of decreased kidney function among older individuals. The qgcomp model further showed that metal mixture was associated with decreased kidney function and the risk of CKD (OR = 1.48, 95% CI: 1.20, 1.84). And lead and cadmium were the main contributors. And Pb and Cd were the major components that increased the risk of CKD. Co-exposure to metal mixture were associated with reduced kidney function in adults, especially in older. Our findings support co-exposure to lead and cadmium as risk factors of CKD in adults.