Reduced sleep quality is highly prevalent and associated with physical function and cardiorespiratory fitness in patients with axial spondyloarthritis: a cross-sectional study.

OBJECTIVES: To assess sleep quality, and its associations with physical function, cardiorespiratory fitness, and spinal mobility, in axial spondyloarthritis (axSpA) patients. METHOD: Baseline data from the Exercise for Spondyloarthritis trial were used. Assessments included [Pittsburgh Sleep Quality Index (PSQI), 0-21, 21 = worst], performance-based physical function [Ankylosing Spondylitis Performance Index (ASPI), seconds, higher = worse], patient-reported physical function [Bath Ankylosing Spondylitis Functional Index (BASFI), 0-10, 10 = worst], cardiorespiratory fitness [peak oxygen uptake (VO2peak), mL/kg/min, lower = worse], and spinal mobility [Bath Ankylosing Spondylitis Metrology Index (BASMI), 0-10, 10 = worst]. Associations were examined in separate models using multiple linear regression. RESULTS: Ninety-nine patients with axSpA were included, 53% female, mean age 46 years, and 72% with high disease activity (ASDAS-C-reactive protein ≥ 2.1), of whom 84 (85%) had reduced sleep quality. Sleep disturbance was most frequently reported (65%), followed by poor subjective sleep quality (53%), daytime dysfunction (41%), and increased sleep latency (41%). Positive associations were observed between PSQI and ASPI [ß = 0.10, 95% confidence interval (CI) 0.01, 0.19] and PSQI and BASFI (ß = 0.85, 95% CI 0.51, 1.20), and there was an inverse association between PSQI and VO2peak (ß = -0.14, 95% CI -0.27, -0.01), adjusted for age and sex. There was no association between PSQI and BASMI. CONCLUSION: Reduced sleep quality was common in axSpA patients with moderate to high disease activity. Better sleep quality was associated with better physical function and higher cardiorespiratory fitness. There was no association between sleep quality and spinal mobility. TRIAL REGISTRATION: ClinicalTrials.gov NCT02356874.

High-intensity cardiorespiratory and strength exercises reduced emotional distress and fatigue in patients with axial spondyloarthritis: a randomized controlled pilot study.

OBJECTIVE: To investigate the effect of high-intensity exercise on emotional distress, fatigue, and ability to do a full day's activities in patients with axial spondyloarthritis (axSpA). METHOD: A total of 28 physically inactive axSpA patients were randomized to either an exercise group (EG), which performed 12 weeks of cardiorespiratory and strength exercises, or a control group (CG), which received treatment as usual. The outcomes reported in this paper are secondary outcomes in the trial and included emotional distress (General Health Questionnaire-12, 0-36, 36 = worst), fatigue [numeric rating scale (NRS), 0-10, 10 = worst], and ability to do a full day's activities (NRS, 0-10, 10 = worst). Post-intervention differences were assessed by analysis of covariance with baseline values as covariates. RESULTS: Twenty-four patients were included in the analyses. All patients in the EG followed the exercise protocol. The EG had a statistically significant beneficial effect [mean group differences (95% confidence interval)] on emotional distress [-5.8, (-9.7, -1.9), p < 0.01], fatigue [-2.4, (-4.3, -0.4), p = 0.02], and ability to do a full day's work [-2.2, (-3.9, -0.4), p = 0.02] compared to the CG. CONCLUSION: This pilot study showed promising effects of cardiorespiratory and strength exercises on emotional distress, fatigue, and ability to do a full day's activities in patients with axSpA. The findings need to be confirmed in a larger trial.

Circulating levels of inflammatory cytokines and cytokine receptors in patients with ankylosing spondylitis: a cross-sectional comparative study.

OBJECTIVES: Insight into the most important inflammatory pathways in ankylosing spondylitis (AS) could be of importance in risk stratification and the development of treatment strategies. Therefore, we aimed to compare circulating levels of inflammatory biomarkers between AS patients and controls, and explore associations between these biomarkers and clinical measures of disease activity. METHOD: In a cross-sectional study, 143 AS patients were compared with 124 population controls. Blood samples were analysed by immunoassays for interleukin (IL)-6, IL-17a, IL-23, soluble tumour necrosis factor receptor 1 (sTNF-R1) and 2 (sTNF-R2), and osteoprotegerin (OPG). Disease activity was measured by the AS Disease Activity Score (ASDAS) and the Bath AS Disease Activity Index (BASDAI). RESULTS: Analysis of covariance (ANCOVA) demonstrated elevated plasma levels of sTNF-R1 [geometrical mean 0.94 (95% CI 0.88-1.00) vs. 0.83 (95% CI 0.78-0.89) ng/mL, p < 0.01] and OPG (2.3, 95% CI 2.1-2.4 vs. 2.0, 95% CI 1.9-2.2 ng/mL, p = 0.02) and, although not significant, of IL-23 (122, 95% CI 108-139 vs. 106, 95% CI 93-120 pg/mL, p = 0.07) in AS patients vs. CONTROLS: More AS patients had a high level of sTNF-R2 than controls (22 vs. 1, p < 0.01). No differences between the groups were seen for IL-6 and IL-17a. In patients, no significant associations were seen between inflammatory markers and disease activity measures after adjusting for personal characteristics. CONCLUSION: Significantly higher plasma levels of sTNF-R1, sTNF-R2, and OPG and numerically but non-significantly higher levels of IL-23 were found in AS patients compared to controls, indicating that these cytokines and cytokine receptors are important inflammatory pathways. Clinical measures of disease activity were not significantly correlated with circulating inflammatory markers.