Objective To explore the distribution of forearm bone mineral density (BMD) and to compare the BMD of the forearm with that in the lumbar spine and left hip detected by dual-energy X-ray absorptiometry (DXA), and to explore the diagnostic value of the forearm BMD in rheumatoid arthritis (RA) patients. Methods BMD of the lumber vertebrae, left hip, and non-dominant forearm in 200 postmenopausal female patients with RA was examined using DXA at the same time. BMD of different sites was compared. The diagnostic BMD cut-off value at the central axial and influential factors of peripheral BMD were explored. Results (1) The mean age of the 200 postmenopausal female patients was 55.9±13.8 years. Based on their axial DXA data and fracture history, 170 patients (85.0%) had abnormal BMD (T score<-1.0). (2) Compared with abnormal axial BMD group, forearm BMD in normal axial group significantly decreased [(0.33±0.13) g/cm2 vs (0.44±0.06) g/cm2, t=4.29, P<0.01]. (3) Forearm BMD was significantly lower in patients whose disease duration was more than 1 year and positive of anti CCP antibody. (4) Forearm BMD was positively correlated with axial BMD. (5) The sensitivity and specificity for identifying osteoporosis in the lumber and left hip were 70.2% and 77.4%, and 74.1% and 70.6%, respectively, when the T-score threshold of forearm was defined as -2.65 and -2.5, respectively. (6) Multiple regression analysis showed that older age, long disease duration, and positive anti-CCP antibody were independent risk factors of abnormal forearm BMD in RA patients. Conclusion Forearm BMD is capable of screening osteoporosis defined by axial BMD in female RA patients. Patients with older age, longer disease duration, and positive anti-CCP antibody are vulnerable of BMD decrease. |