Radiographic damage associated with low bone mineral density and vertebral deformities in rheumatoid arthritis: the Oslo-Truro-Amsterdam (OSTRA) collaborative study.

OBJECTIVE To examine variables associated with bone mineral density (BMD) and vertebral deformities in women with rheumatoid arthritis (RA) from 3 northwest European countries. METHODS Female patients were recruited from rheumatology clinics in Oslo, Norway; Truro, UK; and Amsterdam, The Netherlands (150 total, 50 per center, age 50-70 years, disease duration > or = 5 years). Demographic and clinical data were collected and BMD was measured by means of dual energy x-ray absorptiometry. Associations between demographic and clinical measures on the one hand and BMD and vertebral deformities on the other were investigated by single and multiple regression analyses. RESULTS Body mass index (BMI), medication use, RA damage measures, and BMD differed significantly between the 3 centers. Overall, Norwegian patients had the lowest BMI, used more corticosteroids and anti-osteoporotic drugs, had lower joint damage measured by Larsen score, and lower BMD at both spine and hip. High age, low BMI, and high cumulative dose of corticosteroids (last 2 years) are related to low BMD. A high Larsen score was associated with low BMD at the hip. Larsen score was the independent determinant of vertebral deformities after correction for center, age, BMI, and BMD. CONCLUSION Data from 3 countries on BMD and vertebral deformities in female patients aged 50-70 years with longstanding RA are presented, demonstrating an association between radiographic RA damage and low BMD and between radiographic RA damage and vertebral deformities.