The relationship between cadmium in kidney and cadmium in urine and blood in an environmentally exposed population

Toxicol Appl Pharmacol. 2013 May 1;268(3):286-93. doi: 10.1016/j.taap.2013.02.009. Epub 2013 Feb 27.


Introduction: Cadmium (Cd) is toxic to the kidney and a major part of the body burden occurs here. Cd in urine (U-Cd) and blood (B-Cd) are widely-used biomarkers for assessing Cd exposure or body burden. However, empirical general population data on the relationship between Cd in kidney (K-Cd), urine, and blood are scarce. Our objectives were to determine the relationship between cadmium in kidney, urine, and blood, and calculate the elimination half-time of Cd from the kidney.

Methods: Kidney cortex biopsies, urine, and blood samples were collected from 109 living kidney donors. Cd concentrations were determined and the relationships between K-Cd, U-Cd, and B-Cd were investigated in regression models. The half-time of K-Cd was estimated from the elimination constant.

Results: There was a strong association between K-Cd and U-Cd adjusted for creatinine (rp=0.70, p<0.001), while the association with B-Cd was weaker (rp=0.44, p<0.001). The relationship between K-Cd and U-Cd was nonlinear, with slower elimination of Cd at high K-Cd. Estimates of the K-Cd half-time varied between 18 and 44years. A K-Cd of 25μg/g corresponds to U-Cd of 0.42μg/g creatinine in overnight urine (U-Cd/K-Cd ratio: about 1:60). Multivariate models showed Cd in blood and urinary albumin as determinants for U-Cd excretion.

Discussion: In healthy individuals with low-level Cd exposure, there was a strong correlation between Cd in kidney and urine, especially after adjustment for creatinine. Urinary Cd was also affected by Cd in blood and urinary albumin. Previous estimates of the U-Cd/K-Cd ratio may underestimate K-Cd at low U-Cd.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Biomarkers / blood
  • Biomarkers / metabolism
  • Biomarkers / urine
  • Cadmium / blood*
  • Cadmium / urine*
  • Environmental Exposure* / analysis
  • Female
  • Humans
  • Kidney / chemistry
  • Kidney / metabolism*
  • Kidney Cortex / chemistry
  • Kidney Cortex / metabolism
  • Male
  • Middle Aged
  • Tissue Donors*
  • Young Adult


  • Biomarkers
  • Cadmium