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

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.

Endemic Nephropathy Around the World

“…Cd-induced renal disease was found in 10% of an environmentally exposed Belgian population at urinary concentrations of only 2 to 3 μg Cd/g creatinine 14 . A study of 902 Swedish battery workers identified urinary β 2 microglobulin (a measure of tubular dysfunction) as an effective screening tool for early identification of Cd nephrotoxicity 15 . Prompt recognition and subsequent avoidance can prevent progression to ESRF 15, 16.…”

“…A study of 902 Swedish battery workers identified urinary β 2 microglobulin (a measure of tubular dysfunction) as an effective screening tool for early identification of Cd nephrotoxicity 15 . Prompt recognition and subsequent avoidance can prevent progression to ESRF 15, 16. No chelating agent has been identified, so renal replacement therapy remains the mainstay of treatment.…”

Low level exposure to cadmium and early kidney damage: the OSCAR study

“…Occupational exposure to cadmium was high during the 5 five decades of operation at the plant, but has gradually decreased since the 1960s 1011 Environmental cadmium pollution from these plants was substantial in the past, in particular in the vicinity of the Fliseryd plant. Here we present data on cadmium and early tubular effects whereas results from measurements of bone density are reported elsewhere 11…”

Cadmium and Lead in Blood in Relation to Low Bone Mineral Density and Tubular Proteinuria

“…One plant was closed in 1974, but the other is still operating. Occupational exposure to cadmium and lead was high during the first decades of plant operation, but has gradually decreased since the 1960s (16,17).…”