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

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.