P371. Prospective study of prevalence and incidence of vertebral fractures in long-term anti-TNF alpha maintenance therapy treatment for inflammatory bowel disease
B. Maldonado Pérez1, M.Á. Vázquez Gámez2, L. Castro Laria1, M.J. Montoya García2, R. Pérez Cano2, J.M. Herrerías Gutiérrez1, 1Hospital Universitario Virgen Macarena, Gastroenterology, Seville, Spain, 2University of Seville, Medicine Department, Seville, Spain
Osteoporosis is an extraintestinal complication of inflammatory bowel disease (IBD). A decrease in bone mineral density (BMD) is a common finding in this disease, as well as an increase in the risk of fracture, whose physiopathogenic mechanisms are not yet fully clarified. The evidence suggests that the TNF-alpha and TNF superfamily are fundamental in the bone remodelling.
We evaluated long term therapy effect with anti-TNF alpha on the prevalence an incidence of morphometric vertebral fractures, BMD and parameters of bone remodelling in patients with IBD after 8 years of follow up. We try to identify posible risk factors related to the occurrence of vertebral fractures and associated with changes in BMD.
Observational, longitudinal, prospective 8 years follow-up study. We included 71 patients (38 with Crohn's disease, 32 with ulcerative colitis and 1 with indeterminate colitis); median age: 37.2±11.9 years; range: 13–67 years, 27 women and 44 men, recruited from the IBD Unit of our Hospital. 23 of them were treated with anti-TNF, 48 patients who did not received treatment, were the reference group.
All patients were performed a questionnaire data collection (affiliation, anthropometric, toxic habits and related disease). At the beginning and end of the study were made: A posteroanterior and lateral X-rays of the dorsal and lumbar spine (D7 to L5) to calculate the rate of vertebral deformity. We measured BMD by DEXA (QDR-1000 Hologic densitometer) of the lumbar spine (L2–L4) and proximal right femur. We also determinate biochemical parameters and bone remodeling.
The incidence of vertebral fractures in our study population was 7% (from a 14.1% initial prevalence to 21% in 8 years follow up). The greatest number of fractures was observed in patients treated with anti-TNF (17.4%), although without statistical significance. Patients with biologic treatment significantly increased BMD in both lumbar spine (p = 0.01) and femoral neck (p = 0.02). Anti-TNF in fractured patients, did not modify the behavior of BMD and parameters of bone remodeling. We found a statistically significant increase in alkaline phosphatase (p = 0.002), OC (p = 0.001) and PTH (p = 0.02) in the treated group compared to the reference group. We found a positive correlation between biological therapy and BMD in the fractured group of our patients (p = 0.01). No relationship between steroids treatment and new vertebral fractures was observed. In multivariate analysis, none of the measured parameters was predictor of fracture.
Anti-TNF-alpha therapy leads to a significant increase in BMD. Although this treatment did not decrease the risk of a new vertebral fracture, perhaps studies with more patients and longer term could modify these results.