To investigate sleep problems, and the relationship between sleep and disease activity, in Belgian patients with established rheumatoid arthritis (RA).
This cross-sectional, observational, multicenter study assessed sleep quality using the Athens Insomnia Scale (AIS) and Pittsburgh Sleep Quality Index (PSQI), and daytime sleepiness using the Epworth Sleepiness Scale (ESS). Additional patient-reported outcomes included visual analog scales (VAS) for fatigue and pain, the Medical Outcomes Study Short Form-36 Health Survey, the Health Assessment Questionnaire-Disability Index (HAQ-DI), and the Positive and Negative Affect Schedule. Multivariate regression and structural equation modeling identified factors associated with sleep quality, with the 28-joint Disease Activity Score [DAS28-C-reactive protein (CRP)] as a continuous or categorical variable. Analyses were performed on the total population and on patients stratified by disease activity status: remission/low (DAS28-CRP ≤ 3.2) or moderate to high (DAS28-CRP > 3.2).
Among 305 patients, mean (SD) age was 57.00 (12.38) years and mean (SD) disease duration was 11.77 (9.94) years. Mean (SD) AIS, PSQI, and ESS scores were 6.8 (4.79), 7.8 (4.30), and 7.3 (4.67), respectively. Mean (SD) VAS fatigue, VAS pain, and HAQ-DI were 45.22 (26.29), 39.04 (26.21), and 1.08 (0.75), respectively. There were significant positive relationships between DAS28-CRP and AIS/PSQI, but a significant negative relationship between DAS28-CRP and ESS. Several potentially confounding factors were identified.
Poor control of RA is associated with a reduction in sleep quality and decreased daytime sleepiness, which is likely explained by pain-related alertness. Future prospective studies are needed to confirm potential relationships between sleep quality, sleepiness, and RA treatment.