Serum Crosslaps (CTX) and 25hydroxyvitamin D Levels as Risk Predictors of Bisphosphonate- Related Osteonecrosis of the Jaw

Abstract

Bisphosphonates (BPs) are anticatabolic drugs of choice for treating bone diseases, includingbone metastases. Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is one of the possiblecomplications. Crosslaps (CTX) could be used as biochemical marker for risk of developing ONJ. VitaminD (VD) may be involved in this condition. VD status and CTX levels were evaluated and compared in BPtreated women without BRONJ (Group I; n=28) and with BRONJ (Group II; n=58). Women were older andduration of BP use was longer in Group II (p=0.0000036). No differences in calcemia, phosphatemia, orCTX levels were observed; BAP levels were significantly higher and 25OHD were significantly lower inGroup II (p=0.040 and p=0.035, respectively). The percentage of subjects with CTX levels between 100and 149mg/mL was similar in both groups. VD deficiency was observed in 18% of subjects in Group IIbut in none of the subjects in Group I. No significant differences in the percentage of subjects with VDinsufficiency and sufficiency were observed between groups (Group I: 50%; Group II: 40%). Conclusion:CTX levels did not prove useful as predictors of risk for developing BRONJ. The high percentage of womenwith VD deficiency who developed BRONJ suggests a possible relationship between both conditions andhighlights the importance of assessing Vitamin D status.