Cadmium exposure and end-stage renal disease

Environmental exposure to cadmium may cause kidney damage and tubular proteinuria. We investigated the relationship between low-level cadmium exposure and end-stage renal disease (ESRD), indicated by renal replacement therapy (RRT), in a Swedish population environmentally or occupationally exposed to cadmium. Based on records of all persons in the population previously or presently employed in cadmium-battery production or residing in cadmium-polluted areas near the battery plants, we defined exposure as high (occupational), moderate (domicile < 2 km from a plant), low (domicile 2 to 10 km from a plant), or no exposure (domicile > 10 km from a plant). Comprehensive data were available for all individuals undergoing RRT since 1978. The annual incidence of RRT increased from 41 per million in the age group 20 to 29 years to 243 per million in the age group 70 to 79 years and was greater in a priori-defined populations with cadmium exposure. Adjusting for age and sex gave an increased Mantel-Haenszel rate ratio (MH-RR) of 1.8 (95% confidence interval [CI], 1.3 to 2.3) for RRT in the cadmium-exposed population compared with the unexposed group; the MH-RR was even higher for women (MH-RR, 2.3; 95% CI, 1.5 to 3.5). Directly age-standardized rate ratios for RRT and cadmium exposure increased from 1.4 (95% CI, 0.8 to 2.0) in the low-exposure group to 1.9 (95% CI, 1.3 to 2.5) and 2.3 (95% CI, 0.6 to 6.0) in the moderate- and high-exposure groups, respectively. We conclude that exposure to occupational or relatively low environmental levels of cadmium appears to be a determinant for the development of ESRD.