Impact of Bone Mineral Density and Bone Structural Properties on Postmenopausal Women With Rheumatoid Arthritis in Japan: A Cross-Sectional Study

Introduction There has been no study on bone structural properties in postmenopausal women with rheumatoid arthritis (RA) in Japan. This study investigated bone mineral density (BMD) and bone structural properties in Japanese postmenopausal women with RA. Methods The study had a cross-sectional design and included 119 postmenopausal women aged 50-80 years with RA symptoms for more than five years. BMD, trabecular bone score (TBS), and results of hip structure analysis (HSA) were measured on dual-energy X-ray absorptiometry scans. The control group consisted of 288 women aged 50-80 years without RA. The RA group and control group using bisphosphonates were compared after propensity score matching for age, body mass index, and fracture history. Women in the RA group were also compared according to the use of glucocorticoids (GCs). Results After the propensity matching score, there were no other significant differences in BMD, TBS, and HSA parameters between the RA group and the control group. In the RA group, the TBS was lower in patients on GCs than those not on GCs (1.272 vs 1.313, p=0.008). There were no other significant differences in BMD and HSA parameters between patients in the RA group according to the use of GCs. Conclusion Although there were no differences in BMD, the TBS was lower in patients on GCs than those not on GCs in the RA group. It is thus important for physicians who administer GCs to treat patients with RA to be aware of not only BMD but also TBS.