Long-term effects on bone mineral density after four years of treatment with two intensive combination strategies, including initially high-dose prednisolone, in early rheumatoid arthritis patients: the COBRA-light trial

Summary: In this study, no difference in bone loss was observed between patients with early RA initially treated with COmbinatietherapie Bij Reumatoide Artritis (COBRA) (including initially 60 mg/day prednisolone) and patients treated with COBRA-light (including initially 30 mg/day prednisolone) during 4-year observation. Purpose: To assess changes in bone mineral density (BMD) after 4 years in early rheumatoid arthritis (RA) patients initially treated with COBRA-light or COBRA therapy. Methods: In a 1 year, open-label, randomised, non-inferiority trial, patients were assigned to COBRA-light (methotrexate 25 mg/week plus initially prednisolone 30 mg/day) or COBRA (methotrexate 7.5 mg/week, sulfasalazine 2 g/day plus initially prednisolone 60 mg/day) therapy. After 1 year, antirheumatic treatment was at the discretion of treating rheumatologists. BMD was measured at baseline and after 1, 2 and 4 years at hips and lumbar spine with dual-energy X-ray absorptiometry. BMD changes between treatment strategies on average over time were compared with GEE analysis. Results: Data from 155 out of 162 patients could be analysed: 68% were female with a mean age of 52 (SD 13) years. Both COBRA-light and COBRA therapy showed declines in BMD at the total hip of −3.3% and −1.7%, respectively (p = 0.12), and the femoral neck, −3.7% and −3.0%, respectively (p = 0.95). At the lumbar spine, both treatment groups showed minor decline in BMD over 4 years: −0.5% and −1.0%, respectively (p = 0.10). Conclusion: In a treat-to-target design in early RA, over 4 years, no differences between groups were found in change in BMD at total hip, femoral neck and the lumbar spine. At the hip, bone loss was around 3% in both groups, while mild bone loss was observed at lumbar spine, both in patients starting prednisolone 60 and 30 mg/day. These data suggest that the well-known negative effects of prednisolone can be modulated by modern treatment of RA.