Cadmium exposure and end-stage renal disease

Environmental exposure to cadmium may cause kidney damage and tubular prote inuria. 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 t o cadmium. Based on records of all persons in the population previously or presently employed in cadmium-battery production or residing in cadmium-pol luted areas near the battery plants, we defined exposure as high (occupatio nal), moderate (domicile < 2 km from a plant), low (domicile 2 to 10 km fro m a plant), or no exposure (domicile > 10 km from a plant). Comprehensive d ata were available for all individuals undergoing RRT since 1978. The annua l 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% confid ence interval [CI], 1.3 to 2.3) for RRT in the cadmium-exposed population c ompared with the unexposed group; the MH-RR was even higher for women (MH-R R, 2.3; 95% Cl, 1.5 to 3.5). Directly age-standardized rate ratios for RRT and cadmium exposure increased from 1.4 (95% Cl, 0.8 to 2.0) in the low-exp osure group to 1.9 (95% Cl, 1.3 to 2.5) and 2.3 (95% Cl, 0.6 to 6.0) in the moderate- and high-exposure groups, respectively. We conclude that exposur e to occupational or relatively low environmental levels of cadmium appears to be a determinant for the development of ESRD. (C) 2001 by the National Kidney Foundation, Inc.