It’s hard to sleep restfully when you’re in pain. Researchers recently analyzed the quality of sleep in patients with rheumatoid arthritis.
This new study found that poorly controlled rheumatoid arthritis often resulted in sleep disturbances.
Interestingly, though, one of the hallmarks of poor sleep — daytime sleepiness — was decreased in patients participating in this study. The researchers suggested that this finding may have to do with what they call “pain alertness.”
The investigators in this study, who were led by R. Westhovens, MD, PhD, in the Skeletal Biology and Engineering Research Center and KU Leuven Department of Development and Regeneration, and Rheumatology at the University Hospitals of Leuven in Belgium, examined sleep problems in patients with rheumatoid arthritis (RA).
RA is controlled with disease-modifying antirheumatic drugs (DMARDs), including Enbrel (etanercept), Remicade (infliximab) and Humira (adalimumab).
“The availability of biologic DMARD has improved prospects for patients with established RA, by allowing better control of pain and disease activity. Further, biologic DMARD have been reported to positively influence fatigue and sleep quality in patients with RA,” the authors wrote in the study's introduction.
To analyze how disease activity impacted RA patient sleep patterns, these researchers used a number of patient-reported measurement tools to assess insomnia (inability to fall or stay asleep), daytime sleepiness and overall sleep quality.
A total of 305 RA patients participated in this study. Their average age was 57, and patients had been living with RA for an average of almost 12 years.
The Athens Insomnia Scale (AIS) is an eight-item survey that measures sleep difficulty. It’s rated on a scale of 0 to 25, with a score of 6 being used to diagnose insomnia. The average AIS score among participants was 6.8.
The Pittsburgh Sleep Quality Index (PSQUI) measures sleep quality over the past four weeks with 24 questions, which are rated on a scale of 0 to 3. A total score of 5 or more indicates poor sleep, and patients in this study had an average score of 7.8.
The Epworth Sleepiness Scale (ESS) assesses daytime sleepiness over the past two weeks. A scale of 0 to 3 is used for scoring, and a total score of 9 or higher reflects excessive daytime sleepiness. Study members had an average ESS score of 7.3.
To measure fatigue and pain, the researchers used the Visual Analog Scales (VAS) with a scoring system of 0 to 100, with higher scores indicating more fatigue or pain. The average score for pain was 45.22 and for fatigue was 39.04.
The 28-joint Disease Activity Score C-reactive protein (DAS28-CRP) was used to assess the patient’s RA disease status, with remission or low activity being scored at 3.2 or lower and moderate to high activity being indicated with a score of greater than 3.2. Patients in this study had DAS28-CRP scores of 3.54.
Dr. Westhovens and colleagues found that patients with higher disease activity also had higher insomnia scores and lower overall sleep quality.
However, there was an inverse relationship between disease activity and daytime sleepiness.
The study also found that emotional, mental and general health, along with overall vitality, influenced sleep quality in RA patients.
“Poor control of RA is associated with a reduction in sleep quality and decreased daytime sleepiness, which is likely explained by pain-related alertness.“
The authors of this study called for additional studies to explore the relationships between sleep quality, sleepiness and RA treatment.
Findings from this study were published in the December issue of the Journal of Rheumatology.
No conflicts of interest were reported.