Abstract
We measured urinary cross-linked C-telopeptide of type I collagen (CTX) in 72 patients who were receiving bisphosphonate (BPs) treatment to investigate the risk of BPs-related osteonecrosis of the jaw (ONJ) . Thirty-six of the 72 patients had developed ONJ, and the other 36 had not. Urine was collected after an overnight fast, and the CTX level was measured by enzyme-linked immunosorbent assay as creatinine-converted values (Crconverted values) . The mean Cr-converted value in the BPs-treated patients tended to be lower than the standard value. The CTX level in the group with ONJ was significantly lower than that in the group without ONJ (p < 0.001) . The cut-off value of CTX as measured by the ROC curve was 98 Cr-converted values for the risk assessment of ONJ. The Cr-converted value was 98 or lower in 29 of/36 patients (81 %) in the group with ONJ. In contrast, the Cr-converted value was higher than 98 in 28 of/36 patients (78 %) in the group without ONJ.Therefore, the risk of developing ONJ is high when the Cr-converted value of the CTX level is 98 or lower. The CTX value in the injection prescription group was lower than that in the oral prescription group (P = 0.020) .
The CTX level was also lower in the A group concurrently receiving steroids (P < 0.001) and the group concurrently receiving steroids and anticancer drugs (P = 0.023) as compared with patients not receiving these drugs.
These findings suggest that urinary CTX measurement is useful for assessing the risk of developing BPs-related ONJ.
