Does the Antitumor Necrosis Factor-α Therapy Decrease the Vertebral Fractures Occurrence in Inflammatory Bowel Disease?

BACKGROUND/

OBJECTIVE

Osteoporosis and osteoporotic fracture risk are extraintestinal manifestations of the inflammatory bowel disease, whose etiopathogenic mechanisms have not been determined yet. Anti-tumor necrosis factor (TNF)-α are used in treatment of inflammatory bowel disease (IBD), but it is unknown if they play a role in osteoporotic fracture prevention. The objective of this study was to know if anti-TNF decreases fracture risk or modifies bone mineral density. To determine the possible risk factors associated with fractures, and assess the incidence of vertebral fractures in IBD patients.

METHODS

Longitudinal prospective cohort study (7 yr of follow-up); which included 71 IBD patients, 23 received anti-TNF-α; the remaining 48 received conventional treatment, constituted the control group. Patients participated in a questionnaire which gathered risk factors associated with the development of osteoporosis and fractures. Radiographs of the dorsolumbar-spine were performed and also a bone density measurement. Their biochemical and bone remodeling parameters were determined.

RESULTS

Although patients who did not receive anti-TNF-α, suffered more fractures but biologic therapy did not reduce the risk of new vertebral fractures. The increase of bone mass was significantly higher the group treated with anti-TNF-α. The increase in the lumbar spine was of 8% and in the femoral neck was of 6.7%. The only determinant factor for the incidence of vertebral fractures was a history of previous fractures (odds ratio of 12.8; confidence interval 95% 2.37-69.9; p = 0.003). The incidence of vertebral fractures in IBD patients was considerably high: 26.7/700 patient-yr.

CONCLUSIONS

Anti-TNF-α, although increased bone mass in these patients, did not reduce the risk of new vertebral fractures. In this study, patients with IBD have a considerably high incidence of fractures. Only the existence of previous vertebral fractures was a predictive factor for consistent fractures.