Renal effects of low-level environmental cadmium exposure: 5-year follow-up of a subcohort from the Cadmibel study

Background The clinical relevance of renal effects of cadmium in people exp osed in the environment remains uncertain. This study examined the evolutio n of renal effects observed in a population exposed to cadmium in the envir onment. Methods 208 men and 385 women surveyed in 1985-89 (Cadmium in Belgium study [Cadmibel]; baseline) were reexamined on average 5 years later (Public hea lth and environmental exposure to cadmium study [PheeCad]; follow-up). Urin ary and blood cadmium and markers of renal tubular dysfunction and glomerul ar effects were measured. The association between cadmium body burden and r enal factors was examined by multivariate logistic and linear regression. Findings In men, mean urinary cadmium excretion and blood cadmium concentra tion measured at follow-up were 7.5 nmol/24 h (SD 1.9) and 6.1 nmol/L (2.2) , reductions of 16% and 35% from baseline, respectively. In women, the corr esponding values were 7.6 nmol/24 h (1.9) and 7.8 nmol/L (2.1), reductions of 14% and 28% from baseline. No indication of progressive renal damage was found and the overall results suggest that the effects of low environmenta l exposure to cadmium on the kidney are weak, stable, or reversible. Interpretation Subclinical renal effects that have been reported in Belgium in patients with increased cadmium body burden are not associated with pro gressive renal dysfunction and most likely represent non-adverse manifestat ions.