Improving sleep quality may reduce the harmful effects of severe pain on cognitive performance in patients with fibromyalgia, a study says.
The study, “Subjective sleep quality as a mediator in the relationship between pain severity and sustained attention performance in patients with fibromyalgia,” was published in the Journal of Sleep Research.
Fibromyalgia is a complex condition characterized by widespread muscle pain, fatigue, sleep disturbance, and memory and mood issues. Recent studies have shown that poor sleep quality, considered one of the hallmarks of the condition, is linked to pain severity and poor cognitive performance.
“Improving sleep has been shown to reduce pain in patients with fibromyalgia. The role of sleep in the relationship between pain severity and cognitive performance in patients with fibromyalgia warrants investigation,” the investigators wrote.
In this study, they set out to analyze the relationship between sleep quality, pain severity, and cognitive performance in a group of patients with fibromyalgia.
The cross-sectional study enrolled 80 patients with fibromyalgia — 71 women and nine men — with a median age of 48.5 years.
Cognitive performance was measured using the Psychomotor Vigilance Task (a test that measures sustained attention and is sensitive to lack of sleep) pain severity by way of the Brief Pain Inventory-Short Form, and sleep quality through sleep diaries documenting seven consecutive nights.
After normalizing the findings for potential demographic-related confounding factors, the investigators performed a series of correlation and regression analyses to assess the role of sleep quality in the relationship between pain severity and cognitive performance.
Correlation analysis showed that pain severity was strongly associated with poor sustained attention and poor sleep. In addition, the researchers found that the effects of severe pain on sustained attention were substantial and their degree of severity could be used to estimate patients’ sleep quality.
However, after adding sleep quality to their regression model, they found that the effects of severe pain on sustained attention were no longer statistically meaningful, suggesting that quality of sleep acts as a mediator between pain severity and cognitive performance in patients with fibromyalgia.
“In conclusion, sleep quality mediates the pain severity-cognitive performance relationship: pain affects sleep quality, which in turn impairs sustained attention. Improving the quality of sleep may offset the detrimental effects of pain on sustained attention. In light of these results, multidisciplinary interventions should be developed to reduce pain and enhance SQ [sleep quality], which could improve health outcomes for patients with fibromyalgia,” they concluded.