Relationships between blood concentrations of cadmium, lead, mercury, selenium, and manganese and the risk of chronic kidney disease: a cross-sectional study based on NHANES 2011-2018.

Introduction: Currently, knowledge on relationships between blood concentrations of cadmium, lead, mercury, selenium, and manganese and the risk of chronic kidney disease (CKD) is lacking. The aim of the study was to ex-plore the relationships between blood concentrations of heavy metals and the occurrence of CKD.

Material and methods: Data from the National Health and Nutrition Examination Survey (NHANES) 2011-2018 were used to investigate the relationships between blood concentrations of mercury, lead, cadmium, selenium, and manganese and the occurrence of CKD using a weighted logistic recession analysis. Restrictive cubic spline analysis was applied to assess the dose-response relationship. The sample population was divided into four groups based on the quartiles of heavy metal concentrations (Q1: < 25^th percentile, Q2: 25^th-50^th percentile, Q3: 50^th-75^th percentile, Q4: ≥ 75^th percentile).

Results: A total of 15,450 participants were included. With regard to blood lead concentrations, the odds ratio (OR) for CKD in Q4 relative to Q1 was 1.36 (95% confidence interval [CI]: 1.20-1.61), indicating an increased oc-currence of CKD in Q4. With regard to blood cadmium concentrations, the ORs for CKD in Q2, Q3, and Q4 were 1.06 (95% CI: 0.92-1.22), 1.21 (95% CI: 1.05-1.39), and 1.52 (95% CI: 1.31-1.76), respectively. Non-linear dose-response relationships were identified between blood cadmium and lead concentrations and the occurrence of CKD. Further, blood lead and cadmium concentrations showed statistically significant interaction effects with age, hypertension, and obesity on CKD.

Conclusions: Higher cadmium and lead concentrations in blood are asso-ciated with increased occurrence of CKD, especially in older adults, people with hypertension, and people with obesity.