Dose-response relations between urinary cadmium and tubular proteinuria in cadmium-exposed workers

Am J Ind Med. 1994 Dec;26(6):759-69. doi: 10.1002/ajim.4700260605.

Abstract

Cadmium in urine reflects the body burden in cadmium-exposed individuals. Urinary beta 2-microglobulin is frequently used as a marker of tubular proteinuria with an arbitrarily chosen value (34 micrograms/mmole creatinine) as the cut-off limit. Both this cut-off level and a lower limit (25 micrograms/mmole creatinine) were used in a study of the relationship between urinary cadmium and beta 2-microglobulin in 561 cadmium-exposed battery workers. There was a clear dose-response relation between the urinary cadmium level and the prevalence of tubular proteinuria ranging from 0.8% in the lowest exposure group, excreting less than 1 nmole cadmium/mmole creatinine, to 46.4% (50.0 for the lower cut-off level) in the highest exposure group with a mean urinary cadmium of 15 nmole/mmole creatinine. The relation between urinary cadmium and tubular proteinuria was also assessed using probit analysis. There was a 10% response at a urinary cadmium of 3 nmole/mmole creatinine. The impact of age on the dose-response relation was explored in two age groups with the cut-off point at 60 years of age, showing a 10% prevalence of tubular proteinuria at urinary cadmium levels of 1.5 nmole/mmole creatinine in this older age group and 5.0 nmole/mmole creatinine in the category under 60 years of age. The study thus indicates that the present health-based limit (10 nmole/mmole creatinine) proposed by the World Health Organization (WHO) is too high and it is suggested that a new limit should be set to 3 nmole/mmole creatinine.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Cadmium / adverse effects
  • Cadmium / metabolism*
  • Cadmium / urine
  • Cohort Studies
  • Confidence Intervals
  • Female
  • Humans
  • Kidney Function Tests
  • Kidney Tubules / metabolism*
  • Male
  • Metallurgy*
  • Middle Aged
  • Occupational Exposure / adverse effects*
  • Proteinuria / chemically induced*
  • Proteinuria / urine

Substances

  • Cadmium