fetching data ... 
Background: Radiographic axial spondyloarthritis (r-axSpA) is one of the most common chronic inflammatory rheumatic diseases, affecting approximately 0.2% of the population. While treatment has improved through the evolution of pharmacologic therapy, chronic fatigue often emerges as a prevalent issue in individuals with r-axSpA.
Objectives: The aim of this study was to evaluate the relationship between fatigue and inflammation and self-reported health data in a cross-sectional setting in patients with r-axSpA and its differences between sexes.
Methods: A total of 296 patients with r-axSpA (modified NY criteria) at the rheumatology clinic in Umeå University Hospital, northern Sweden, as well as patients in south-western Sweden (Sahlgrenska University Hospital, Södra Älvsborgs Hospital and Alingsås Hospital), were recruited. Study protocols have been described elsewhere (1, 2). Fatigue (visual analog scale 0-10 (VAS)) was examined in a multivariable linear regression analysis in relation to sleep patterns (a composite index of 3 questions each scaled from 1-5 on quality of sleep, frequency of waking up early and frequency of not being able to fall asleep), back pain (VAS), anxiety/depression (scale 1 to 3), body mass index (BMI), age, and C-reactive protein (CRP). Dietary nutrient intake was included as a nutrient density score (Nutrient Rich Foods index (NRF)), using data from a semi-quantitative food frequency questionnaire. The analysis was stratified by sex. Multiple choice questionnaire responses were compared between sexes by Fisher-Freeman-Halton Exact test.
Results: A complete data set was available for 290 patients, 64% male, and 92% HLA-B27+, disease duration (mean ± SD) of 33.0 ± 11.8 years. Fatigue was median (Q1, Q3) 4.7 (2.2, 6.4), females: 5.0 (2.4, 6.7) males: 4.2 (2.0, 6.3). About half (44%) of participants had severe fatigue (VAS scale ≥ 5) (females: 52%, males: 42%). Back pain scores were median (Q1, Q3)) 3.7 (2.0, 5.9), females: 4.6 (2.3, 6.3), males: 3.5 (1.8, 5.7), and CRP at 2.1 (0.84, 4.8), females: 2.1 (0.6, 4.0), males: 2.2 (1.0, 5.0). Sleep pattern, back pain and anxiety/ depression were associated with fatigue (Table 1). In males, only sleep pattern and back pain were related with fatigue. In females, sleep pattern, back pain, anxiety/depression as well as CRP were significantly related to fatigue. Females reported comparatively more difficulty falling asleep (Figure 1).
Linear multivariable regression analyses exploring factors related to fatigue in patients with r-axSpA.
| All participants (n = 290) | Males (n = 185) | Females (n = 105) | |||||||
|---|---|---|---|---|---|---|---|---|---|
| R 2 | 0.462 | 0.533 | 0.400 | ||||||
| Beta | P-value | 95% CI | Beta | P-value | 95% CI | Beta | P-value | 95% CI | |
| Sleep pattern (scale 3-15) | 0.209 | < 0.001 | (0.123, 1.269 ) | 0.226 | < 0.001 | (0.128, 2.391 ) | 0.183 | 0.033 | (0.015, 3.318 ) |
| Back pain (VAS) | 0.538 | < 0.001 | (0.440, 0.295 ) | 0.599 | < 0.001 | (0.487, 0.323 ) | 0.432 | < 0.001 | (0.250, 0.351 ) |
| Anxiety/ depression (scale 1-3) | 0.539 | 0.012 | (0.121, 0.635 ) | 0.268 | 0.282 | (-0.222, 0.712) | 1.065 | 0.012 | (0.236, 0.615 ) |
| NRF (score) | 0.095 | 0.314 | (-0.090, 0.957) | 0.025 | 0.822 | (-0.197, 0.757) | 0.217 | 0.200 | (-0.117, 1.895) |
| BMI (kg/m 2 ) | 0.000 | 0.994 | (-0.047, 0.281) | -0.016 | 0.562 | (-0.069, 0.247) | -0.011 | 0.830 | (-0.113, 0.552) |
| Age (years) | -0.007 | 0.464 | (-0.027, 0.047) | -0.003 | 0.780 | (-0.026, 0.038) | -0.025 | 0.193 | (-0.062, 0.091) |
| CRP (log10(mg/L)) | 0.198 | 0.422 | (-0.287, 0.012) | -0.225 | 0.407 | (-0.757, 0.019) | 1.220 | 0.022 | (0.184, 0.013 ) |
Abbreviations: BMI; Body Mass Index, CRP; C-reactive protein, NRF; Nutrient Rich Foods index, VAS; Visual Analog Scale.
Questionnaire responses on sleep habits and anxiety/ depression stratified by sex in 290 patients with r-axSpA.
Conclusion: A large proportion of patients with long-standing r-axSpA suffered from fatigue. We hypothesize that multimodal care aiming to reduce anxiety, improving sleeping patterns and reduce back pain might reduce fatigue.
REFERENCES: [1] Forsblad-d’Elia H et al. The Journal of rheumatology. 2021;48(3):352-60.
[2] Klingberg E et al. Arthritis research & therapy. 2012;14(3):R108.
Acknowledgements: We would like to thank research nurse Viktoria von Zweigbergk for her work with the Backbone study.
Disclosure of Interests: None declared.