[Osteoporotic changes in rheumatoid arthritis--longitudinal bone mass study and effect of 1 alpha-hydroxyvitamin D3].

Serial measurements of bone mass were carried out by single photon absorptiometry and/or X-ray microdensitometry of the second metacarpus in 29 rheumatoid arthritis patients not treated by corticosteroids. The effect of 1 alpha-hydroxyvitamin D3 on rheumatoid arthritis was also investigated by longitudinal bone mass study. In premenopausal females and also males, the rate of radial diaphyseal bone loss was less than 1%/year and bone loss was seen only in the periarticular region of affected joints. On the other hand, bone loss was much more rapid in both the periarticular and diaphyseal regions in postmenopausal patients. 1 alpha-hydroxyvitamin D3 administration for more than 1 year produced no significant change of blood biochemical examination and Lansbury's index, but resulted in a significant attenuation of bone loss rate.