Online first

Acta Reumatológica Portuguesa - Online First: 2021-10-14
Original article

Sex differences in axial spondyloarthritis: data from a Portuguese spondyloarthritis cohort

Cunha R, Sousa E, Khmelinskii N, Ávila P, Couto M, Seixas M, Martins N, Bernardes M, Martins A, Silva Ad, Lourenço M, Miguel C, Tavares V, Valente P, Costa J, Rovisco J, Aguiar R, Afreixo V, Barcelos A


Background: Axial spondyloarthritis (axSpA), particularly ankylosing spondylitis was historically considered a male’s disease and has been under-recognized in women. Emerging evidence reveals sex differences in pathophysiology, disease presentation and therapeutic efficacy. Objective: To identify differences between sexes in a Portuguese cohort of patients with axSpA regarding clinical manifestations, disease activity, functional capacity, patient related outcomes and presence of sacroiliitis on x-ray or magnetic resonance imaging. Methods: Patients with ≥18 years fulfilling the ASAS- Assessment of Spondyloarthritis International Society classification criteria for axSpA registered in the electronic Rheumatic Diseases Portuguese Register ( were included in this multicentric cross-sectional study. Sociodemographic data, clinical features and imaging were collected from the first record in These variables were compared between sexes using Mann-Whitney test and Chi-Square test. Variables with a significant association with variable sex were considered in the multiple variable analysis to adjust the sex effect on the outcome variables. Statistical analysis was performed with R version 4.0.2 and p