Disease activity and sleep quality in rheumatoid arthritis: a deeper look into the relationship

ABSTRACT

Objectives: This study looks deeper into the relationship between rheumatoid arthritis (RA) disease activity and distinct dimensions of sleep quality.

Methods: The Pittsburgh Sleep Quality Index (PSQI) was administered to a cohort of 147 RA patients. Health-related quality of life (HRQoL) and fatigue were measured with the SF-12 and Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) instruments, respectively, whereas RA activity was determined with the Disease Activity Score 28 joints (DAS28). Ethical approval for the study and informed consent from the participants were obtained.

Results: Most patients were females (78.2%), and the mean age of the entire sample was 63.7 years. Most participants (77.6%) were poor sleepers (i.e. PSQI ≥ 5) who suffered from fatigue more than good sleepers (FACIT-F: 21.6 vs. 39.3, p < 0.001). Overall sleep quality correlated, in the expected directions, with disease activity (Spearman’s rho = 0.87, p < 0.001), physical health (−0.66, p < 0.001), mental health (−0.71, p < 0.001), and fatigue (0.87, p < 0.001). PSQI and its component scores differed across patient subgroups with increasing RA activity, even after adjusting for confounding variables.

Conclusion: RA disease activity distinctly affects sleep quality, and given the already demonstrated importance of good sleep, this ‘deeper look’ might contribute to the effort to improve HRQoL in RA patients.

KEYWORDS:

• Rheumatoid arthritis
• sleep
• health-related quality of life
• fatigue
• Pittsburgh sleep quality index
• Greece

Article Highlights

• The relationship between sleep quality and RA disease activity, although previously shown to exist, is still poorly understood.

• Most RA patients are poor sleepers (PSQI ≥ 5), and suffer more from fatigue (according to FACIT-F scores) than the good sleepers.

• Sleep quality correlated, in the expected directions, with disease activity, physical health, mental health and fatigue, and differed significantly across patient subgroups with increasing RA activity, even after adjusting for confounding variables.

• Due to the cross sectional design of the study, direction of causality cannot be inferred. Many of the covariates adopted as potential confounders of sleep quality, may in fact be the result of poor sleep quality, rather than the cause.

• Given the already demonstrated importance of good sleep, these results might contribute to the effort to improve HRQoL in RA patients.

Acknowledgments

We are grateful to the patients who willingly participated in this study.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer Disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Author contributions

NK conceived the study and the methodological design, interpreted the results, performed the statistical analysis and prepared the manuscript. ES assisted in the literature review and contributed to statistical analysis and preparation of the manuscript. GK performed measurements and assisted in the statistical analysis and in literature review. AK assisted in data collection, results interpretation and revised the manuscript for intellectual content.

Additional information

Funding

This study was not funded.