[Bone mineral density of the radius in patients with rheumatoid arthritis measured by dual energy X-ray absorptiometry].

Bone mineral density (BMD) of the radius was measured in 181 female patients with rheumatoid arthritis (RA) and 255 control subjects using dual energy X-ray absorptiometry (DXA). The BMD of RA patients was assessed according to patients' age and menopause and was compared with age-matched controls for various activity factors of RA and duration of the disease that might correlate with BMD. At stages I and II of premenopausal RA, generalised osteoporosis was not observed. At stages III and IV, the BMD decreased considerably in premenopausal RA patients at age of 45 years or older. There were significant correlations between the BMD of postmenopausal RA and all factors examined, many of which did not affect premenopausal RA. These results suggest that osteoporosis of female patients with RA is influenced only slightly by the disease itself, but it is secondary osteoporosis induced by decreased activities of daily living due to RA.