Osteoporosis in rheumatoid arthritis

Abstract

Introduction. Osteoporosis is a disease where bones lose their bone mineral density (BMD) which causes bone fragility and leads to fractures, Rheumatoid arthritis (RA) is an autoimmune inflammatory disease that affects the joints symmetrically and is known to cause secondary osteoporosis Aim of the study. To study literatures that focus on the risk factors of osteoporosis and the correlation between it and rheumatoid arthritis. Materials and methods. A literature search using, PubMed, Medscape and the national scientific information archive was performed. among the most relevant articles we selected 70, the data were analyzed by content structure and summarized,as well as statistical analysis where possible. Results. In patients with RA four biomarkers are found to predict fracture sites, Tartrateresistant acid phosphate 5b (TRACP-5b), undercarboxynated osteocalcin (Uc-OC) and bone specific alkaline phosphate (BAP) are able to realize both BMD and bone quality while homocysteine is able to realize only bone quality, In RA patients annual bone mineral density changes are 0.14 + 2.70 in lumbar spine, 0.46 + in proximal hip and 1.14 + 1.85 in forearm. Some studies show that in lumbar spine Homocysteine is the significant predictor for fractures, while in the proximal hip and forearm homocysteine does not have any significance. The most potent predictors for hip and forearm fractures are DAS28-ESR, blood pressure and Vitamin D levels other authors consider a better predictor to be ACPA and Methotrexate dosage use. Another hypothesis suggests that mycobacterium Avium Paratuberculosis (MAP) infection associated with TNF polymorphisms in patients with rheumatoid arthritis might cause secondary osteoporosis and it was found that the association between MAP infection in patients with rheumatoid arthritis and a risk for development of osteoporosis. Conclusions. Osteoporosis is a common condition diagnosed in patients with RA. Secondary osteoporosis due to RA depends on the disease activity, ACPA level, MTX dosage. Some biochemical markers, as homocysteine, TRACP-5b, Uc-OC and bone specific alkaline phosphate can serve as predictors for osteoporotic fractures at different sites.