Background: While the nephrotoxicity of lead and cadmium is well-established, the impact of low-level exposure on risk of chronic kidney disease (CKD) and long-term health outcomes, especially in CKD patients, remains unclear. This study examines the association between low-level lead and cadmium exposure with risks of CKD and long-term mortality.
Method: We analyzed data from adult participants of 2003-2012 National Health and Nutrition Examination Survey in the United States. CKD was defined as estimated glomerular filtration rate < 60 ml/min/1.73 m2. Elevated blood lead (≥ 1.5 μg/dL) and cadmium (≥ 0.4 μg/L) levels were assessed for their associations with CKD and all-cause mortality, with survival tracked until December 31, 2019.
Results: Among the 24,810 participants (mean age 44.4 years, 48.9% male), 1,309 (3.9%) had CKD. Lead and cadmium levels were significantly higher in participants with CKD compared to those without. Elevated lead (OR: 1.41, 95% CI: 1.15-1.74) and cadmium (OR: 1.23, 95% CI: 1.03-1.46) levels were both associated with increased CKD risk, with the highest risk in those with both lead ≥ 1.5 μg/dL and cadmium ≥ 0.4 μg/L (OR: 1.65, 95% CI 1.27-2.14). During a median follow-up of 141 months, 2,255 participants died (7.0 per 10,000 person-months). Elevated cadmium was associated with higher mortality risk in CKD (HR: 1.42, 95% CI: 1.07-1.88) and non-CKD populations (HR: 1.40, 95% CI: 1.24-1.58), while lead levels were not significantly associated with mortality in either group. Participants with both elevated lead and cadmium had a significantly higher mortality risk (HR: 1.32, 95% CI: 1.13-1.54).
Conclusion: Low-level cadmium and lead exposure are linked to increased CKD risk, with cadmium also associated with higher long-term mortality in both CKD and non-CKD populations. These findings highlight the need for public health efforts to reduce exposure and further research on long-term impacts.
Copyright: © 2024 Kuo et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.