Monday, June 27, 2011

Systemic effects of metal debris (7h of 7); excerpts from the Committee on Mutagenicity

Excerpts and commentary based on the 6/4 post-Metal on Metal Bearings, The Evidence So Far http://www.mydepuyhiprecall.com/2011/06/metal-on-metal-bearings-evidence-so-far.html

Genotoxic issues surrounding systemic effects of metal debris (continued from prior posts)

The committee on mutagenicity has reported that internal exposure to orthopedic metals is associated with increased genotoxicity.

This is a series of commentary from the committee on mutangenicity evidence based on the the key journal articles examined by that committee. I think you will find the results really interesting if you are concerned about the systemic effects of the metal.

5th piece of evidence reviewed by the committee:

J Toxicol Environ Health A. 2002 May 10;65(9):655-64.

Urinary 8-hydroxydeoxyguanosine and sister chromatid exchanges in patients with total hip replacements.

Source

Department of Occupational Medicine, University of Vienna, Austria. alex.pilger@akh-wien.ac.at

Abstract

Ion release from metal implants has been suspected to increase the risk of genotoxic effects in patients wearing orthopedic metal devices. In this study we used urinary 8-hydroxydeoxyguanosine (8-OHdG) as marker of oxidative DNA damage and the frequency of sister chromatid exchanges in lymphocytes to test a possible relationship between the concentrations of chromium or cobalt and the induction of cytogenetic modifications in 46 patients with total hip replacements. A broad range of individual levels of metals has been observed in these patients: chromium in blood, 1.59-14.11 microg/L; chromium in urine, 0.79-93.80 microg/24 h; cobalt in blood, 0.77-37.80 microg/L; cobalt in urine, 2.59-166.94 microg/24 h. By linear regression analysis, no significant correlation between urinary 8OHdG or sister chromatid exchange (SCE) and the concentrations of metals was found. However, cobalt in blood as well as 8-OHdG in urine were higher in patients with implants 3-4 yr old as compared to patients with implants 1-2 yr old. Smoking significantly increased the frequency of SCE. Our data do not indicate a dependence of 8-OHdG in urine or SCE on the levels of chromium or cobalt in patients with total hip replacements.

What did the committee say about these results?
  • While the test was adequately conducted, there was insufficient information on the interpretatoion of the assay data.
  • no conclusion could be drawn with respect to metal specifica mtuagenic effects from these data.

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