Blood Cadmium and Lead and Chronic Kidney Disease in US Adults: A Joint Analysis

TLDR

Environmental exposure to cadmium and lead is common and known to be nephrotoxic at high levels, yet few studies have examined low‑level associations with kidney disease, especially for joint exposure. The study used NHANES 1999–2006 data from 14,778 adults (≥20 yr) and measured geometric mean blood cadmium of 0.41 µg/L and lead of 1.58 µg/dL. After adjusting for covariates, the highest cadmium quartile was associated with 1.92‑fold higher odds of albuminuria, 1.32‑fold higher odds of reduced eGFR, and 2.91‑fold higher odds of both, while combined high cadmium and lead exposure increased odds to 2.34, 1.98, and 4.10 respectively, supporting both metals as CKD risk factors.

Abstract

Environmental cadmium and lead exposures are widespread, and both metals are nephrotoxic at high exposure levels. Few studies have evaluated the associations between low-level cadmium and clinical renal outcomes, particularly with respect to joint cadmium and lead exposure. The geometric mean levels of blood cadmium and lead were 0.41 μg/L (3.65 nmol/L) and 1.58 μg/dL (0.076 μmol/L), respectively, in 14,778 adults aged ≥20 years who participated in the National Health and Nutrition Examination Survey (1999–2006). After adjustment for survey year, sociodemographic factors, chronic kidney disease risk factors, and blood lead, the odds ratios for albuminuria (≥30 mg/g creatinine), reduced estimated glomerular filtration rate (eGFR) (<60 mL/minute/1.73 m2), and both albuminuria and reduced eGFR were 1.92 (95% confidence interval (CI): 1.53, 2.43), 1.32 (95% CI: 1.04, 1.68), and 2.91 (95% CI: 1.76, 4.81), respectively, comparing the highest with the lowest blood cadmium quartiles. The odds ratios comparing participants in the highest with the lowest quartiles of both cadmium and lead were 2.34 (95% CI: 1.72, 3.18) for albuminuria, 1.98 (95% CI: 1.27, 3.10) for reduced eGFR, and 4.10 (95% CI: 1.58, 10.65) for both outcomes. These findings support consideration of cadmium and lead as chronic kidney disease risk factors in the general population and provide novel evidence of risk with environmental exposure to both metals.