Background: To investigate the prevalence and risk factors for vertebral fractures in patients with rheumatoid arthritis (RA) during an era of tight management.
Methods: We retrospectively reviewed 426 RA patients who had visited our outpatient RA clinic between July 2017 and June 2020. Among them, we included 107 patients (19 males and 88 females) who had undergone lateral X-ray of the thoracolumbar spine and dual-energy X-ray absorption spectroscopy for the assessment of osteoporosis. We assessed the disease activity score for 28 joints (DAS28), the history of medication for RA and osteoporosis, the number and location of vertebral fractures, and the bone mineral density (BMD). Two board-certified specialists determined osteoporotic vertebral fractures on a lateral X-ray of the thoracolumbar spine.
Results: The mean age, average disease duration, and average DAS28 of the analyzed patients were 67.9 years, 14.9 years, and 2.8, respectively. Vertebral fractures were found in 33 patients (30.8%). In this population, 84.8% of patients with vertebral fractures and 59.5% of those without vertebral fractures were treated for osteoporosis with active vitamin D3, bisphosphonate, and/or denosumab. RA patients with vertebral fractures had significantly higher DAS28 values, a higher rate of patients with a history of glucocorticoid use, and lower BMD in comparison to those than without vertebral fractures (p = 0.009, p = 0.004, and p = 0.01, respectively). Logistic regression analysis showed DAS28 (p = 0.038) and BMD (p = 0.004) were independent factors associated with the presence of vertebral fractures. The ordered logistic regression analysis also showed DAS28 (p = 0.043) and BMD (p = 0.024) were independent factors that explained the number of vertebral fractures.
Conclusions: Vertebral fractures were frequently observed in RA patients, even when patients were treated the recommended anti-osteoporotic agents. A high disease activity score and low BMD were associated with the presence and number of vertebral fractures in patients with RA.