“The majority of evidence so far points to a proinflammatory response,” said Roth. Pain is triggered by inflammation, and studies show that sleep disruption activates inflammatory and pain mediators, like interleukin-6 and tumor necrosis factor.2
Stages of Sleep and Sociodemographic Moderators
Types of sleep disturbance make a difference. The sleep apnea study shows that fragmented sleep increases pain sensitivity. Stages of sleep are also important.
“Even loss of light sleep increases pain sensitivity, but loss of deeper stages of sleep are progressively more important, and loss of REM sleep is the most important,” said Roehrs.
In addition to types of sleep lost, other factors like race, age, and sex, may also play a role. A 2014 study published in Arthritis & Rheumatology looked at the onset of new widespread pain in more than 4,000 people aged older than 50 years.
For those who developed pain during the three years of the study, nonrestorative sleep was the strongest predictor of new-onset widespread pain.3
“Age is a well-documented risk factor for sleep disturbance, [and] other risk factors may include sex and race. There is some evidence that women may sleep less and report more insomnia. There is also some evidence that African Americans have more sleep disturbance than Caucasians,” said Roehrs.
Clinical Applications and Sleep Hygiene
“One future clinical application is to screen patients for sleep disturbance before admission to the hospital for elective surgery. Pretreatment of insomnia or sleep apnea may improve surgical outcomes and decrease the need for analgesia,” said Roth.
The team at Henry Ford is already working on that study. “Early results show that increasing sleep before surgery in patients with sleep disturbance may decrease pain scores and the use of analgesics by about 30%,” said Roehrs.
Other areas of future research should include how sleep may affect men, women, children, and people of different races as well as a better understanding of how sleep increases pain sensitivity on a physiologic level.1
“We also need more research on how sleep disturbance may move acute pain into chronic pain. I suspect that it plays a critical role,” said Roehrs.
The prevalence of excessive sleepiness in the general populations may be as high as 25%. Estimated sleep duration for Americans has declined from eight hours per night in the 1960s to seven hours or less currently, and more than 20% of Americans now get less than six hours.4
That’s why sleep hygiene is important for everyone. Sleep hygiene involves more than just keeping regular hours for sleeping and waking and avoiding daytime naps or stimulants in the evening. It’s also important to exercise regularly, get exposure to natural sunlight, and maintain a regular bedtime routine.4
“One of the most important things you can do is spend more time in bed. We had so much trouble getting research subjects to practice good sleep hygiene that we paid them $100 to spend two more hours in bed. They ended up increasing their sleep time by one hour,” said Roehrs.
Chris Iliades, MD, is a full-time freelance writer based in Cape Cod, Massachusetts. This article was medically reviewed by Pat F. Bass III, MD, MS, MPH.
- Finan PH et al. “The association of sleep and pain: an update and a path forward.” J Pain. 2013; 14(12):1539-1552.
- Roehrs TA et al. “Pain sensitivity and recovery from mild chronic sleep loss.” Sleep. 2012;35(12):1667-1672.
- Mcbeth J et al. “Predictors of new-onset widespread pain in older adults: results from a population-based prospective cohort study in the UK.” Arthritis & Rheumatology. 2014; 66: 757–767. doi: 10.1002/art.38284.
- National Sleep Foundation. Sleep Hygiene. Available here: http://sleepfoundation.org/ask-the-expert/sleep-hygiene