Effects of glucocorticoid treatment on focal and systemic bone loss in rheumatoid arthritis

Rheumatoid arthritis (RA) is characterized by an extensive dysregulation in skeletal homeostasis recognized as 1) focal articular bone erosions, 2) iuxta-articular osteopenia, 3) systemic osteoporosis (OP) and fractures, as is well documented in both cross-sectional and prospective studies. The disease activity, as a consequence of new insights into the complex interaction between bone cells and a variety of cells of the immune system, has emerged as the main responsible for both focal and systemic bone loss. Given this background, the therapeutic approach to RA has become more aggressive, and a more widespread use of low-dose glucocorticoids (GC), recently categorized as disease modifying antirheumatic drugs (DMARD) because of their additional joint sparing effect on the long-term, has also been recommended from the early stages. Addressing the effects of GC on systemic bone loss in RA, GC are considered, in addition to inflammation and inactivity, the major risk factors for OP and fractures. As a consequence, among the most recent recommendations (i.e. dosing, timing, and tapering strategies) for patients receiving GC for more than 3 months, prevention and treatment of GC-induced OP (i.e. calcium, vitamin D, and bisphosphonates) are included. However, innovative GC, characterized by a more favorable risk/benefit profile such as selective GC receptor agonists (SEGRA), are currently in the pipeline. This article reviews the major points of evidence so far available, regarding the effects of GC on focal and systemic bone loss.