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

Abstract

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 <or=-2.5 SD and reduced BMD as Z score <or=-1 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.