Adequate selenium nutrition attenuated the association between cadmium and renal health in U.S. adults: evidence from NHANES data (2011-2018).

Cadmium (Cd) exposure is well-known to be hazardous to renal function. Although animal experiments suggest that selenium (Se) supplementation has beneficial effects on Cd-induced organ damage, epidemiological evidence on the mitigation of Se on Cd-induced renal damage is still insufficient. We used data from the National Health and Nutrition Examination Survey (NHANES) cycles from 2011 to 2018, and performed survey-weighted linear regression, logistic regression, and restricted cubic spline analyses to evaluate the associations of urine Cd (UCd), blood Cd (BCd), daily Se intake (DSe), and blood Se (BSe) with estimated glomerular filtration rate (eGFR), urine albumin creatinine ratio (UACR), and CKD risk, including the effects of DSe and BSe on the associations of UCd and BCd with renal health. In our study, UCd and BSe were positively associated with eGFR, but negatively associated with CKD risk. UCd and BCd were positively associated with UACR, and BCd was positively associated with CKD risk. No independent associations of DSe with eGFR, UACR, and CKD risk were observed. Additionally, we observed that the associations of Cd exposure with renal injury indicators and CKD risk were attenuated in participants with adequate DSe levels and/or higher BSe levels. Our findings suggested that Cd exposure was associated with renal impairment and CKD risk, and maintaining adequate DSe and good Se status attenuated the associations of Cd exposure with renal health. Further research is needed to evaluate the health effects of interactions between Se and Cd.