Hip fracture risk and cadmium in erythrocytes: a nested case-control study with prospectively collected samples

Calcif Tissue Int. 2014 Feb;94(2):183-90. doi: 10.1007/s00223-013-9796-5. Epub 2013 Oct 8.

Abstract

Several studies have investigated the relation between bone mass density and cadmium exposure, but only few studies have been performed on fractures and biomarkers of cadmium. This study analyzed the association between hip fracture risk and cadmium in erythrocytes (Ery-Cd). Prospective samples from the Northern Sweden Health and Disease Study's biobank were used for 109 individuals who later in life had sustained a low-trauma hip fracture, matched with two controls of the same age and gender. The mean concentration of Ery-Cd (±SD) in case samples was 1.3 ± 1.4 versus 0.9 ± 1.0 μg/L in controls. The odds ratio (OR) was 1.63 [95% confidence interval (CI) 1.10-2.42] for suffering a hip fracture for each microgram per liter increase in Ery-Cd. However, when taking smoking into consideration (never, former, or current), neither Ery-Cd nor smoking showed a statistically significant increase in fracture risk. Using multiple conditional logistic regression with BMI, height, and smoking, the estimated OR for a 1-μg/L increase in Ery-Cd was 1.52 (95% CI 0.77-2.97). Subgroup analysis showed an increased fracture risk among women (OR = 1.94, 95% CI 1.18-3.20, for a 1 μg/L increase), which also remained in the multiple analysis (OR = 3.33, 95% CI 1.29-8.56). This study shows that fracture risk is associated with Ery-Cd. It is, however, not possible to draw firm conclusions on whether cadmium is the causal factor or whether other smoking-related factors cause this association. Subgroup analysis shows that cadmium is a risk factor for hip fracture among women.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Cadmium / analysis
  • Cadmium / blood*
  • Case-Control Studies
  • Environmental Pollutants / analysis
  • Environmental Pollutants / blood
  • Erythrocytes / chemistry*
  • Erythrocytes / metabolism
  • Female
  • Hip Fractures / blood*
  • Hip Fractures / epidemiology
  • Hip Fractures / etiology*
  • Humans
  • Male
  • Middle Aged
  • Osteoporosis / blood
  • Osteoporosis / complications
  • Osteoporosis / epidemiology
  • Osteoporotic Fractures / blood*
  • Osteoporotic Fractures / epidemiology
  • Risk Factors
  • Sweden / epidemiology

Substances

  • Environmental Pollutants
  • Cadmium