Physical activity is associated with physical and global function in patients with axial spondyloarthritis, independent of disease activity

Objectives: To investigate whether physical activity is independently associated with physical and global function in patients with axial spondyloarthritis (axSpA), and to analyse the relationship between subtypes of physical activity (work, transport, and recreation) and functional impairment. Methods: One-hundred-and-eighty-five patients were included. Physical function was assessed using BASFI, and global function was assessed using the ASAS health index (HI). Physical activity was measured using the Global Physical Activity Questionnaire. Levels of physical activity were categorised as low, moderate or high. The associations between levels of physical activity and the BASFI and ASAS HI scores were analysed using multivariate regression analysis. Results: Of the 185 patients, 46, 63 and 76 reported low, moderate and high levels of physical activity, respectively. There was a negative correlation between the BASFI and total physical activity. Multivariate linear regression analysis revealed that a high level of physical activity was independently associated with BASFI after adjusting for age, ASDAS. sacroiliitis and syndesmophyte number (beta (95% CI) =-0.88 (-1.49--0.26); p=0.006). One-hundred-and-forty-six had good global functioning (ASAS HI=5). Multivariate logistic regression analysis revealed that moderate physical activity was independently associated with good global functioning (OR (95% CI) = 2.82 (1.02-7.86); p = 0.047). Recreational activity, but not work- and transport-related activity, showed a significant relationship with ASAS HI scores (beta (95% CI) =-0.55 (-1.02-0.08); p = 0.023). Conclusions: Physical activity in those with axSpA is associated independently with physical and global functioning. Among the subtypes of physical activity, recreational activity is related to global functioning.