Insomnia, sleep disorders, and impaired sleep have always been considered significant factors in regards to fibromyalgia syndrome and even explored as a cause to the syndrome. It is during deep sleep that people produce significant amounts of growth hormone which repair and maintain muscles. Therefore lack of deep sleep and interrupted sleep, which are predominate features with FM, have long been considered factors in pain intensity along with lack of overall time sleeping. Lack of sleep, therefore, must relate to pain levels. A recent study in the Journal of Pain, 2012, suggests this is not necessarily the case.
74 people with fibromyalgia were asked to be a part of the University of Florida study and were observed over a 14 day time period. Given the small test group and time frame of the study, we have to take these results with a grain of salt. In the study set up, fibromyalgia patients had a sleep diary where they would record how their sleep went and they also were to rate their pain levels every evening.
“For this study, a research team from the University of Florida hypothesized that decreased total sleep time would predict higher clinical pain in a sample of patients with fibromyalgia…Results of the analysis showed that four sleep measures evaluated in the study failed to significantly predict clinical pain. The authors noted that the effects of impaired sleep, such as fatigue and inactivity, may play more significant roles in clinical pain than measures of sleep duration or insomnia. Sciencedaily.com“
Why the results are surprising
These results are surprising because we would expect the opposite. Historically other studies have shown disruptive sleep patterns in people with chronic pain conditions will produce increased pain. Lack of sleep is, in fact, a factor that can produce pain in healthy people as well. Given the majority of fibromyalgia patients have disrupted sleep one would expect the results to show a decreased duration of sleep would increase pain the next day.
Why we cannot draw firm conclusions
The study is only 74 people so this is not a large study and we cannot draw any conclusions from one small study. Secondly, the duration of the study itself was short, only over a span of two weeks, which given the nature of chronic pain and sleep disorders is hardly significant. A few days of less sleep can get someone, who regularly gets disrupted sleep, into a sleep deprivation state running on adrenaline. For the short term, this will actually make them function fairly well on a pain basis. They will be in ‘fight or flight’ mode and not feel as much pain, or at least, not right away. However, accumulated sleep deprivation will cause the pain to build up such that we often see with FM the morning muscle pain being severe in the morning and becoming less severe as the day goes on. Ironically, also with short, disrupted sleep someone with FM may feel very alert in the morning because they have not actually gotten much sleep. They do not feel the pain from being in one position for a long period of time so there is no muscle aches from that. The lack of sleep, initially, makes them feel alert, energized and with no morning stiffness and pain. Whereas, longer durations of sleep are often still of poor quality leaving someone with FM still feeling groggy. They will often wake up with morning stiffness and pain from laying in one position for too long if they have managed to be asleep for any length of time. It is not necessarily a duration that is a factor but quality. Therefore, it is not necessarily the case that decreasing the total sleep time would increase the pain the next day with someone with FM. Ten hours of poor quality sleep where the person woke up frequently and spent very little time in deep sleep cannot be compared to five solid good hours of sleep. Ten hours of poor quality sleep may leave the person feeling groggy, stiff and sore, while the five hours of restorative sleep may leave them feeling alert and well-rested.
Nevertheless, fibromyalgia patients suffer from poor quality sleep and, at times, other sleep disorders such as restless leg syndrome (RLS) or sleep apnea. Whether the duration of their sleep affects the intensity or not certainly lack of sleep affects fatigue, mood and likely even overall health. It is vital for FM to try and maintain healthy sleep habits and a regular sleep cycle. Quality of sleep is just as important as the quantity of sleep.
Meta-analysis: sleep disturbances and fibromyalgia
Health-related quality of life regarding sleep and fibromyalgia
Fibromyalgia and sleep issues