Multidimensional contributors to disease burden in axial spondyloarthritis: role of central sensitization, catastrophizing and sleep disturbance

Abstract Introduction Axial spondyloarthritis (axSpA) imposes a multidimensional burden that is not fully explained by inflammation. Central sensitization (CS), pain catastrophizing (PC), and sleep disturbance may amplify symptoms and worsen outcomes. This study aimed to assess the prevalence and impact of CS, PC, and sleep disturbances in axSpA patients and their associations with disease activity, function, and quality of life compared with controls. Methods This cross-sectional study included adults with axSpA (ASAS 2009) and healthy controls recruited from a tertiary clinic (April 2024–April 2025). The assessments included demographics; CSI, PCS, JSS, fibromyalgia (ACR-2016), fibromyalgianess (WPI + SSS); and axSpA outcomes (BASDAI, ASDAS, BASFI, BASMI, ASQoL, CRP, and MASES). Statistical analyses included group comparisons, correlations, and multivariable regressions. Results We enrolled 100 axSpA patients and 50 controls. The median scores were greater in the axSpA patients for the CSI (42 vs. 28), PCS (32 vs. 12.5), and JSS (12 vs. 6) (all p < 0.001). The prevalence was greater for CS (59% vs. 20%), PC (53% vs. 18%), and fibromyalgia (43% vs. 18%). The WPI was strongly correlated with the SSS ( r = 0.92). In the axSpA patients, the CSI was correlated with the BASDAI ( r = 0.58), ASDAS ( r = 0.43), BASFI ( r = 0.45), and ASQoL ( r = 0.68) (all p ≤ 0.001). The PCS and JSS are also correlated with disease activity, disease function, and ASQoL. Independent predictors were CSI—female sex, higher SSS, and worse ASQoL; PCS—ASQoL; JSS—higher SSS and arthritis, with lower scores in patients on TNF inhibitors or pain-modulating therapy. Conclusion CS, PC, sleep disturbance, and FM/FMness are highly prevalent in axSpA patients and are independently associated with worse outcomes. Incorporating nociplastic and psychosocial dimensions into assessment and care is crucial to reduce disease burden.