Etanercept Increases Bone Mineral Density in Ankylosing Spondylitis, but Does Not Prevent Vertebral Fractures: Results of a Prospective Observational Cohort Study.

OBJECTIVE: Ankylosing spondylitis (AS) is characterized by chronic inflammation leading to ankylosis, but also to low bone mineral density (BMD) and vertebral fractures (VFx). Treatment with tumor necrosis factor-α blockers decreases inflammation and has shown to be effective in increasing BMD. We studied the effects of etanercept (ETN) on BMD and VFx in patients with AS after 2 years of treatment. Further, we studied changes in bone turnover markers and radiological damage. METHODS: Patients with active AS, treated with ETN for 2 years, were included. BMD lumbar spine and hip were measured at baseline and after 2 years, as well as radiological damage (modified Stoke Ankylosing Spondylitis Spinal Score with the addition of the thoracic spine), VFx (Genant method), and change in bone turnover markers. RESULTS: Forty-nine patients with AS were included. After 2 years of ETN, hip BMD increased by 2.2% (p = 0.014) and lumbar spine BMD by 7.0% (p < 0.001). The Bath Ankylosing Spondylitis Disease Activity Index decreased significantly (p < 0.001), as well as C-reactive protein and erythrocyte sedimentation rate (p < 0.001). Despite ETN therapy, the number of patients with VFx more than doubled (from 6 to 15 patients, p = 0.003). Also, the radiological damage increased significantly over time (from 12.1 to 18.5, p < 0.001); however, no significant change in bone turnover markers was found. CONCLUSION: This prospective longitudinal observational cohort study showed that after 2 years of ETN, BMD of the hip and spine increased significantly, but the number of patients with VFx and the severity of VFx increased as well. Besides that, radiological progression, including the thoracic spine, increased significantly. Thus, the favorable bone-preserving effect is accompanied by unfavorable outcomes on VFx and radiological damage.

Problems in work participation and resource use should not be underestimated in patients with early spondyloarthritis.

OBJECTIVE: To explore the effect of early spondyloarthritis (SpA) on worker participation and to investigate variables associated with work outcomes as well as the effect on resource use. METHODS: Patients included in an early SpA cohort completed a questionnaire comprising items on employment status, sick leave, presenteeism, and resource use. Logistic regressions were used to investigate the associations between work status and clinical characteristics, and linear regressions were used to investigate the association between at-work productivity loss and clinical characteristics. Resource use across patient groups with different employment status was investigated with linear regression analyses. RESULTS: One hundred forty patients participated in our study. Of the patients, 69% were male, the mean age was 41 years, and the disease duration was 4.8 years. Twenty-six patients (19%) were not employed because of SpA. Among 114 employed patients, sick leave was reported in 28% in the previous year. Forty-one percent of the patients reported reduced productivity at work. Multivariable regression analyses showed that high Bath Ankylosing Spondylitis Metrology Index and Ankylosing Spondylitis Quality of Life score were associated with not being employed and with reduced productivity at work. Annual costs of productivity loss attributable to sick leave and presenteeism amounted to €2000 per patient. Patients who reported sick leave show a higher (health-related) resource use. CONCLUSION: After only 5 years of diagnosis, a considerable proportion of patients with SpA is not employed, and those working have substantial sick leave and productivity loss. Among patients reporting sick leave, resource use is higher. Alertness to work participation even in patients with a short disease duration is urgently needed.