Cross-sectional assessment of renal function in the inhabitants of a cadmium-polluted area
Aoshima, K.; Kawanishi, Y.; Fan, J.J.; Cai, Y.Q.; Katoh, T.; Teranishi, H.; Kasuya, M.
Annals of Clinical and Laboratory Science 25(6): 493-503
1995
ISSN/ISBN: 0091-7370 PMID: 8572558 Document Number: 453632
To understand the development of cadmium (Cd)-induced renal tubular dysfunction, cross-sectional assessment of renal function in the inhabitants of the Cd-polluted Jinzu River basin in Toyama, Japan, was carried out. Sixty-seven men and 78 women, aged 56 to 71 years whose urinary beta-2-microglobulin (beta-2-m) exceeded 1,000 mu-g/g creatinine, were examined and divided into five groups according to their values of fractional excretion of beta-2-m (FE-beta-2-m). Comparisons were made between six groups including the inhabitants of a non-polluted area as a reference group. Significantly increased values of fractional excretion of urate (FE-UA), calcium (FE-Ca), sodium (FE-Na), and chloride (FE-Cl), serum creatinine and beta-2-m, and urinary protein were detected even in the subjects with FE-beta-2-m level below 1 percent compared with the reference group. Fractional phosphate reabsorption (percent TRP) was significantly decreased in the subjects with FE-beta-2-m level above 10 percent. Creatinine clearance (C-Cr) decreased with increase in FE-beta-2-m, and the subjects with FE-beta-2-m above 30 percent showed significantly decreased C-Cr values compared to those with FE-beta-2-m below 30 percent, In summary, FE-UA, FE-Ca, FE-Na, and FE-Cl, as well as low-molecular-weight proteins such as beta-2-m, are increased in the early stage of Cd-induced renal tubular dysfunction. Although percent TRP was maintained by the decreased C-Cr, there was a marked decrease in percent TRP in subjects with progressive stage showing FE-beta-2-m level above 10 percent. No sex difference in renal tubular dysfunction was found in this cross-sectional study.