Abstract
Objectives: Rheumatoid arthritis (RA) is a systemic chronic inflammatory disease which presents with polyarthritis in addition to extra-articular manifestations. Historically, studies have shown a link between RA and adverse musculoskeletal outcomes but these studies were reported before the widespread use of biologic therapies. The aim of this study was therefore to investigate associations between RA, RA medications and bone mineral density, falls and fractures, using UK Biobank data. Methods: Diagnosis of RA was made using Hospital Episode Statistics (HES) ICD-10 coding. We assessed RA relationships with estimated bone mineral density (eBMD) from heel quantitative ultrasound measurements, self-reported falls (in last year) and HES recorded fracture, adjusted for age, ethnicity, BMI, smoking status, and physical activity. Results: Of 502,543 participants, 3849 (1.4%) of women and 1643 (0.7%) of men had a diagnosis of RA. Median age of the participants was 57 years (IQR 50-63) in women and 58 (IQR 50-64) in men. RA was associated with lower eBMD (men: β -0.244, 95% CI -0.378, -0.110 p < 0.001; women: β -0.217, 95% CI -0.297, -0.138 p < 0.001) a reported fall in the last year (men: OR 1.54, 95% CI 1.26, 1.87 p < 0.001; women: OR 1.36, 95% CI 1.19, 1.56 p < 0.001) and fracture in women (OR 1.76, 95% CI 1.43, 2.16 p < 0.001). Corticosteroid therapy in men (β -0.934, 95% CI -1.565, -0.304 p = 0.004) and disease modifying anti-rheumatic drug (DMARD) use in both sexes (men: β -0.437, 95% CI -0.761, -0.112 p = 0.008; women: β -0.243, 95% CI -0.421, -0.065 p = 0.007), but not biologic therapy, were associated with a lower eBMD with RA. Conclusions: RA was associated with lower eBMD, increased falls and fracture. Corticosteroid and DMARD therapy, but not biologic therapy, were associated with lower eBMD.