Vigorous physical activity and physical function are strongly associated with better health in patients with long-standing radiographic axial spondyloarthritis

OBJECTIVES: To evaluate the impact of physical function and level of physical activity on health status and health-related quality of life (HRQoL) in patients with long-standing radiographic axial spondyloarthritis (r-axSpA). METHODS: In total, 141 patients with long-standing r-axSpA were included in this cross-sectional cohort study. Assessments included physical function (Bath Ankylosing Spondylitis Functional Index (BASFI)), spinal mobility (modified Bath Ankylosing Spondylitis Metrology Index (BASMI)), muscle function for leg strength (Timed Stands Test (TST)) and handgrip force (Grippit), amount of self-reported physical activity (vigorous physical activity, moderate physical activity, sedentary behavior), health status by ASAS Health Index (ASAS HI) and HRQoL with Short Form Survey Instrument 36-Item. Multivariable linear regression was used to analyze associations between health status, HRQoL, physical activity, muscle function, and physical function. RESULTS: The mean (SD) age was 60 (12) years, diagnosis duration was 25 (10) years, and 57% were male. Physical function and vigorous physical activity were the strongest determinants of health status and HRQoL. The models explained approximately 50% of the variation in ASAS HI and the physical aspects of HRQoL and 21% of the mental aspects of HRQoL. Participants displayed good health status (62%) by ASAS HI ≤ 5, reached the recommended level of health-enhancing physical activity (77%), had normal muscle function (TST 82% and Grippit 91%), and demonstrated physical function (55%), and spinal mobility (45%) within reference values. CONCLUSION: This study highlights the importance of regular vigorous physical activity in older individuals living with long-standing r-axSpA since it was strongly associated with health status and HRQoL.