Rheumatoid Arthritis is an inflammatory disease that causes the cartilage and connective tissue around the tendons in joints to degrade. It leads to bone destruction and erosion of bone mineral density. This process can happen quickly in some patients. A decline in bone density is a major cause of disability in patients with Rheumatoid Arthritis.
Normal adults lose about 12 percent of the strength in their backbone each decade. However, patients with Rheumatoid Arthritis who don't receive preventive treatment lose about 10 percent per year, the equivalent of an 8-fold acceleration of aging effects in loss of bone strength. Patients with Rheumatoid Arthritis are at high risk for fractures, especially when treated with corticosteroids.
How are they connected?
Patients with Rheumatoid Arthritis may take corticosteroids to control inflammation. Corticosteroids, such as prednisone, are the chemical cousins of important hormones our pituitary gland produces. These powerful medications have the unfortunate side effect of decreasing bone mineral density.
Bone loss in Rheumatoid Arthritis can be localized around joints or widespread throughout the body. The connective tissue that line tendons in freely moving joints (for example, hips or shoulders) produce proteins and growth factors that increase osteoclast formation and activity. Osteoclasts are cells that eat away at bones, causing erosions and resulting in bone loss. Rheumatoid Arthritis may directly cause bone density erosion or the erosions may be the result of steroid treatment. Either way, the goal in managing Rheumatoid Arthritis is to relieve inflammation and prevent collateral structural bone damage.
However, a study published in the Journal of Clinical Rheumatology (March 2009) found that only 40 percent of long-term corticosteroid users in one specific rheumatology practice were treated for bone loss or given baseline bone density scans.
There is good news, however. Certain drugs can help prevent bone loss in Rheumatoid Arthritis patients.
Zolendric acid (Reclast) and risedronate (Actonel) are both effective in reducing the risk of corticosteroid-induced osteoporosis. In fact, patients who take Reclast only need one infusion of the drug each year, while Actenol patients take a daily pill. Infliximab, another anti-inflammatory drug, is a type of anti-TNF-alpha therapy. TNF (tumor necrosis factor) increases bone loss and plays a central role in bone destruction in patients with Rheumatoid Arthritis.
If you have Rheumatoid Arthritis and take corticosteroids, you should be concerned about bone loss. Ask your doctor for a baseline bone scan and discuss whether you should take steps to prevent this accelerated and destructive bone loss.
Sources
http://www.medscape.com/viewarticle/559687
http://www.medscape.com/viewarticle/559686
http://www.medscape.com/viewarticle/584357
http://www.arthritistoday.org/news/corticosteroid-bone-loss.php?ht
http://www.medscape.com/viewarticle/559687_2
http://www.ncbi.nlm.nih.gov/pubmed/12379632
http://www.ncbi.nlm.nih.gov/pubmed/19707447?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DiscoveryPanel.Pubmed_Discovery_PMC&linkpos=1&log$=citedinpmcarticles&logdbfrom=pubmed
