Bone mineral density in patients with recently diagnosed, active rheumatoid arthritis

Objectives: Osteoporosis is a well- known extra- articular phenomenon in patients with uncontrolled, long-standing rheumatoid arthritis ( RA). In the present study, the extent of osteoporosis and reduced bone mineral density ( BMD) and the disease- related and demographic factors that are associated with osteoporosis and reduced BMD were examined in patients with recently diagnosed, active RA. Methods: BMD of the total hip and the lumbar spine was measured using dual- energy x ray absorptiometry in 381 patients with recently diagnosed active RA, who had never been treated with DMARDs or corticosteroids. Osteoporosis was defined as a T score <= 22.5 SD and reduced BMD as Z score <= 21 SD. Multivariate logistic regression analyses were performed to detect associations of osteoporosis and reduced BMD with disease activity, functional disability, joint damage ( Sharp - van der Heijde score) and demographic factors. Results: Osteoporosis and reduced BMD were found in the spine and/ or the hip in 11% and 25%, respectively, of the patients. Longer symptom duration and presence of rheumatoid factor ( RF) were the only RA- specific markers for osteoporosis and reduced BMD. Further, postmenopausal status in women, a low body mass index, familial osteoporosis, and, remarkably, male gender, were independently associated with osteoporosis and reduced BMD. Conclusion: In patients with recently diagnosed active RA who had never been treated with DMARDs or corticosteroids, BMD seems to be well- preserved and predominantly related to demographic factors. Longer symptom duration and a positive RF, but not higher disease activity or more joint damage, were related to osteoporosis and reduced BMD.