Vertebral osteoporosis in rheumatoid arthritis patients: effect of low dose prednisone therapy

The effect of low dose prednisone therapy on spinal bone mass is controversial. We measured lumbar trabecular and cortical bone mineral density (BMD) in 74 rheumatoid arthritis (RA) patients by dual energy quantitative computerized tomography in a cross-sectional study. The presence of vertebral deformities was evaluated on a lateral spine radiograph. Patients who had never been treated with corticosteroids (n = 44) were compared with patients on long-term low dose (less than or equal to 10 mg/day) prednisone therapy (n = 30). After correction for confounding variables the lumbar BMD was highly significantly influenced by prednisone therapy in postmenopausal patients (estimated influence -31.2% on trabecular BMD and -37.2% on cortical BMD). Vertebral deformities were also significantly more frequent in prednisone treated postmenopausal patients. No negative effect of prednisone treatment could be demonstrated in male patients. In contradiction to previous reports we conclude that long-term prednisone therapy may be associated with development of spinal osteoporosis in postmenopausal RA patients, even when low doses are used.