Effects of disease and corticosteroids on appendicular bone mass in postmenopausal women with rheumatoid arthritis: comparison with axial measurements

The potential value of measurements of peripheral bone mass in rheumatoidarthritis (RA) as an assessment of long-term disease activity has recentlyreceived renewed attention. This study examines the effects of RA andcorticosteroid therapy on newer methods of measuring peripheral bone mass,comparing the results with dual-energy X-ray absorptiometry (DXA) at axialsites. Peripheral quantitative computed tomography of the radius,ultrasound of the calcaneus, and DXA of the hip and spine were comparedbetween 29 controls and 46 women with RA of whom 25 were receiving low-dosecorticosteroid therapy. Bone mass was significantly reduced in the RAgroups for: (i) radial trabecular (36.1%) and total (15.6%) measurementsites; (ii) calcaneal ultrasound attenuation (31.7%) and velocity (6.6%);and (iii) femoral neck (15.4%) bone mineral density. Lumbar spine andradial cortical measurements were not significantly affected. There were nosignificant differences between the RA groups. Disease activity andphysical activity did appear to be responsible for much of the reduction inbone mass. These results demonstrate that RA is associated with significantbone loss at the hip, radius and calcaneus, but not at the lumbar spine. Inthis small study, low-dose corticosteroids had little additionaldeleterious effect.