ASSOCIATION BETWEEN RENAL TUBULAR DYSFUNCTION AND MORTALITY AMONG RESIDENTS IN A CADMIUM-POLLUTED AREA, NAGASAKI, JAPAN

A retrospective cohort study was carried out to clarify the effect of exposure to environmental cadmium (Cd) on mortality. A total of 256 residents aged 50 years or older, living in Sasu, a Cd-polluted area in Tsushima Island in Nagasaki Prefecture, Japan, were followed from July 1979 to February 1989. The expected number of deaths calculated was based on the sex- and age- specific mortality rate in Tsushima Island in 1985. In Sasu residents of both sexes with urinary beta-2-microglobulin (beta-2-m) concentration greater than 1,000-mu-g/g creatinine in 1979, observed deaths were greater than expected. However, the p value of the difference was less than 0.05 only in men. The relationships of age, mean blood pressure, urinary beta-2-m and urinary Cd concentration to mortality were examined using Cox's proportional hazards model. Urinary beta-2-m was independently and significantly related to mortality in men but not in women. The results suggest an association between Cd-induced renal tubular dysfunction and mortality.