Background and objectives One of the most frequently reported symptoms by patients with axial spondyloarthritis (AxSpA) is disease-related fatigue. The role of fatigue and its degree during the course of AxSpA still remains a challenge. The objective of this study was to characterise the patients with AxSpA accordingly to the evaluation of disease-related fatigue.
Materials and methods 120 patients were included in the cross-sectional study fulfilling the Assessment of Spondyloarthritis international Society (ASAS) classification criteria for AxSpA. Fatigue was evaluated using the first item of the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) questionnaire. Patients were divided into two groups: with the evaluation of fatigue ≤5 and >5. The following variables were chosen for characteristics of the groups: age, duration of the disease, the age of AxSpA onset, duration of morning stiffness, Ankylosing Spondylitis Disease Activity Score (ASDAS) (using c-reactive protein (CRP)), functional (BASFI) and metrological (BASMI) indices, the evaluation of enthesitis using the fourth item of the BASDAI questionnaire.
Results The mean BASDAI fatigue score was 5.0 (SD 2.59). In our data, 44.2% of patients experienced severe fatigue (score >5). The mean value of age, duration of morning stiffness, ASDAS, BASFI, BASMI and evaluation of enthesitis in the group with lower fatigue level was respectively 37.4 years (SD 9.63), 41 min (SD 37.97), 2.3 (SD 1.32), 2.2 (SD 2.09), 2.8 (SD 2.39) and 2.7 (SD 2.89). In the group with severe fatigue expression the mean age was 41.5 years (SD 10.09), duration of morning stiffness – 66.2 min (SD 43.06), ASDAS – 3.7 (SD 0.94), BASFI – 5.0 (SD 2.34), BASMI - 4.4 (SD 2.54), evaluation of enthesitis – 5.2 (SD 2.99). These variables were statistically different between groups. There was no difference between groups on duration of the disease and age of AxSpA onset.
Conclusions Patients with severe fatigue had a higher level of the disease activity, functional disability and spinal mobility impairment. These results suggest that the level of fatigue can be used as one of the clinical signs which show the expression of systemic inflammation and induced impairment of mobility in the course of the disease independent of the disease duration.