BONE LOSS IN RHEUMATOID-ARTHRITIS - INFLUENCE OF DISEASE-ACTIVITY, DURATION OF THE DISEASE, FUNCTIONAL-CAPACITY, AND CORTICOSTEROID TREATMENT

Axial and appendicular bone mass were studied in 95 patients with rheu matoid arthritis. The aims were to quantify bone mineral density (BMD) and to evaluate the importance of disease activity, duration of disea se, functional capacity, and corticosteroid treatment for bone loss in patients with rheumatoid arthritis. The BMD in the lumbar spine (BMD( SPINE)) did not differ from age-matched healthy controls, but distal f orearm BMD (BMD(ARM)) and metacarpal BMD (BMD(MCB)) were significantly lower in the patients (p<0,01 and p<0,001, respectively). Neither BMD (SPINE) nor BMD(MCB) were related to the disease activity at the time of investigation. By contrast, BMD(ARM) was decreased in patients with active disease. BMD in any of the three measured locations was not di rectly correlated to duration of the disease. However, the bone mass i n the appendicular skeleton was already decreased within the first two years after the start of the disease. The overall functional capacity in terms of physical activity increased BMD in the axial skeleton. Th e local functional capacity in terms of gripstrength was positively re lated to BMD in the appendicular skeleton. Patients with severe functi onal impairment had the lowest BMD(ARM). The decreased BMD in patients with rheumatoid arthritis seems primarily to be caused by an impaired physical activity which may be related to disease activity. Corticost eroids did not decrease BMD in neither the axial nor the appendicular skeleton. The antiinflammatory effect of steroids lead to clinical imp rovement, which may counteract the expected negative effect of these d rugs on bone in rheumatoid arthritis.