AB0356 COMPARISION FOREARM BONE MINERAL DENSITY BETWEEN LUMBAR SPINE AND HIP: A USEFUL TOOL TO SCREEN OSTEOPOROSIS IN FEMALE PATIENTS WITH RHEUMATOID ARTHRITIS

Abstract

Background DXA is widely used in clinical practise in BMD measurement of osteoporosis. Forearm and axial BMD is the most common site to define in clinical practise. However, the relationship between forearm and axial BMD is not confirmed in RA patients. Objectives To compare the forearm (bone mineral density) BMD between lumbar spine and left hip BMD by dual-energy X-ray abosorptionmetry (DXA), and explore the diagnostic value of the forearm BMD in rheumatoid arthritis (RA) patients. Methods In the study, 200 female patients with established RA underwent DXA of the lumber, left hip and non-superiority forearm DXA at the same time. We compared BMD at different sites, and the diagnostic cut-off value of abnormal axial BMD by forearm BMD was explored. Data analysis was performed by independent-sample t test and Pearson’s correlation test. The area under the receiver operating characteristic curve (AUC) and calibration of predictions were assessed. Sensitivity and specificity were calculated to determine the correlation between cases of osteoporosis detected by the axial DXA scan and forearm. Results (1) The mean age of the 200 female patients was (55.9±13.8) years. Twenty (10.0%) patients had the fragility fracture history. Based on their axial DXA data and fracture history, 30 (15.0%) patients had normal BMD (T score≥-1.0), 170 (85.0%) patients had abnormal BMD. The mean forearm BMD was (0.35±0.13) g/cm2, and T score was -2.3±1.9. (2) Compared with abnormal axial BMD group, forearm BMD in normal axial group was significantly decreased [(0.33±0.13) g/cm2 vs (0.44±0.06) g/cm2, t=4.29, P Conclusion Our study has confirmed that DXA measurement performed of forearm analysis is capable of screening osteoporosis defined by axial BMD in female RA patients.