Effect of Tumor Necrosis Factor Alpha Inhibition on Bone Density and Turnover Markers in Patients with Rheumatoid Arthritis and Spondyloarthropathy

ObjectivesAnti-tumor necrosis factor-α (TNFα) therapy has proven efficacious in improving both disease activity and focal bone erosions in patients with rheumatoid arthritis (RA) and spondyloarthopathies. We review the current literature reporting on the effect of anti-TNFα on bone density as measured by dual energy radiograph absorptiometry at the lumbar spine and hip, as well as markers of bone turnover and resorption, in patients using anti-TNFα for rheumatic disease indications.MethodsA PubMed search, as well as manual search of related articles and references of articles retrieved, was performed to identify all studies pertaining to the effect of anti-TNFα therapy on bone mineral density (BMD) and bone turnover markers.ResultsIn RA, 4 studies (238 patients) showed a stabilization or increase of BMD at the spine (up to 2.8%) or hip (up to 13.1%), with only 1 negative study in 48 patients (decline of 3.2% at the spine and 2.7% at the hip). In spondyloarthopathies, 3 studies (75 patients) all demonstrated an increase in BMD at the lumbar spine (3.2-3.6%) and at the hip (1.8-2.2%). Changes in markers of bone formation and bone resorption were heterogeneous but in general represented a modest increase in formation and decline in resorption.ConclusionsIn general, anti-TNFα therapy has a beneficial effect on bone density and bone turnover markers. Retrieved studies were heterogeneous with regards to patients studied, underlying risks for osteoporosis, and supplemental therapy, which may limit the findings of the true effect of anti-TNFα therapy on bone.