P425. Long term effects of anti-TNF-therapy on bone mass in IBD, a retrospective cohort study
R.L. Roscam Abbing1, N.M. Appelman-Dijkstra2, R.A. Veenendaal1, N.A. Hamdy2, A.E. van der Meulen-de Jong1, 1Leiden University Medical Center, Gastroenterology and Hepatology, Leiden, Netherlands, 2Leiden University Medical Center, Center for bone quality, Leiden, Netherlands
Osteoporosis is observed in 11–31% of patients with IBD and is of multifactorial origin, including disease activity, corticosteroid use and malabsorption. The increased use of anti-TNF-alpha agents has resulted in significantly improved control of disease activity, obviating long term corticosteroid use. Anti-TNF-alpha therapy has been shown to decrease bone turnover and increase BMD in the short term. The long term effects of these agents on BMD have so far not been studied in IBD.
In a retrospective study design 66 patients with IBD, selected on the basis of use anti-TNF-alpha therapy for more than 1 year and who had consecutive DXA measurements, were studied. A number of these patients had also received bisphosphonate therapy. We analysed the long term effects of anti-TNF-alpha, with or without concurrent bisphosphonate therapy, on BMD.
Of the 66 patients, 32 had also been treated with bisphosphonates. Average age was 35±11 years (42% male). A vast majority of patients had been treated with corticosteroids at some stage. Intestinal resection was prevalent in both groups at baseline (38%), although the number of resections per patient was higher in the bisphosphonate group (1.23 vs. 2.25). Average follow up was 123±37 months. Duration of therapy with anti-TNF-alpha was 4.4±2.6 and 4.1±1.8 years with additional bisphosphonate therapy. Vitamin D levels and disease activity were comparable at baseline and during follow up between groups. Compared to baseline lumbar spine BMD had increased significantly at the end of follow up in the TNF-alpha + bisphosphonate group and remained stable in the only TNF-alpha group. In contrast femoral neck BMD decreased significantly in both groups (−0.052 g/cm2 vs. −0.038 g/cm2) at the end of the follow up period.
Despite the known beneficial effects of anti-TNF-alpha and bisphosphonates on BMD in the short term, results from this study suggest that these beneficial effects are not sustained in the long term after discontinuation of therapy, particularly at the femoral neck. These data suggest that in patients with severe refractory disease, in whom anti-TNF-alpha therapy is indicated, the beneficial effect of this agent on bone is short-lived, despite additional bisphosphonate therapy. Based on these findings we recommend that in patients with IBD at high risk for bone loss, BMD should be monitored during and after cessation of anti-TNF-alpha therapy +/− bisphosphonates in order to enable timely reinstatement of bone protective treatment.