Trabecular bone score as a supplementary tool for the discrimination of osteoporotic fractures in postmenopausal women with rheumatoid arthritis

Rheumatoid arthritis (RA) is a risk factor for bone fragility, and its effect on fracture risk is independent of bone mineral density (BMD). The trabecular bone score (TBS) is a new indirect parameter of bone quality. In this study, BMD and the TBS were compared between female postmenopausal RA patients with and those without vertebral fractures (VFs).This study had a cross-sectional design. Two hundred seventy-nine postmenopausal women with RA aged 50 years or older were included in this study. TBS measurements were performed on the same vertebrae as those for the BMD measurements.Among the 279 subjects, 34 had VFs (12.5%). There was a significant difference in the TBS (P = .005) but not L-spine BMD (P = .142) between the subjects with and those without VFs. The odds ratio (OR) for the TBS per standard deviation decrease was significant, even after adjusting for confounding factors such as age, height, rheumatoid factor positivity, the disease activity score for 28 joints (DAS28), the cumulative dose of glucocorticoids (GCs), the time since menopause and osteoporosis drug use (OR = 2.86; 95% CI, 1.34-6.09), and L-spine BMD (OR = 2.57; 95% CI, 1.19-5.54). The TBS was negatively correlated with the cumulative dose of GCs, but not with the DAS28 or erythrocyte sedimentation rate. However, the correlation was an L-shaped nonlinear relationship.The TBS could be a supplementary tool for discriminating osteoporotic fractures in postmenopausal women with RA, and it may have a nonlinear relationship with the cumulative dose of GCs, but not with RA disease activity.