Risk of spontaneous vertebral fracture during bisphosphonates drug holiday

Abstract

Abstract Background Bisphosphonates are the most common treatment for osteoporosis with confirmed efficacy. However, less information is available on prolonged use. This study was performed to examine the risk of osteoporotic vertebral fractures during bisphosphonates holiday and estimate its predictors. Results Forty-two patients completed 2-year fracture-free holiday; 7 had spontaneous vertebral fracture. Among baseline characteristics, age was significantly higher in fracture group (69.99 ± 3.62 vs. 75.37 ± 3.81; P value 0.007); other factors were comparable. Longitudinal changes analysis showed that only alkaline phosphatase (ALP) increment had significant group over time interaction (P value 0.002). The difference between baseline and clinical end-point serum collagen type 1 cross-linked C-telopeptid (CTX) was significant in both fracture and non-fracture groups, whereas femoral neck and total hip BMD decline was significant in fracture group only. Multivariate analysis showed that only age (OR, 1.43; p, 0.011) and history of previous fractures (OR, 13.59; p, 0.044) are significant predictors of vertebral fractures. Conclusions These results suggest that older age and history of previous fracture should be considered as risk factors for vertebral fractures during bisphosphonates holiday. Furthermore, femoral neck and total hip BMD decline could be related to vertebral fractures. By the same token, overt increase of ALP and CTX could be an indicator of fracture occurrence.