Research is investigating the implications of the pain-sleep relationship. Some therapies offer patients relief from both.

No matter where it hurts, the link between pain and poor sleep is undeniable.

“As one who has treated patients with acute and chronic pain for decades, I am well aware of the multiple bidirectional relationships between pain and sleep deprivation,” says Daniel Carr, MD, professor of Public Health and Community Medicine and program director, Pain, Research Education & Policy at Tufts University. “Although widely appreciated for chronic pain (eg, fibromyalgia), the vicious cycle of sleep disruption, increased pain, and disruption of recovery is also well described in acute pain, such as after surgery. Interestingly, not only does sleep deprivation worsen pain and vice versa, but some medicines used to treat pain (eg, opioids) interfere with sleep architecture and reduce the normally restorative effect of sleep.” Carr is also president of the American Academy of Pain Medicine.

The bidirectional relationship between sleep and pain is being teased apart in numerous studies. Fascinating findings show that not only will a reduction in pain improve sleep, but, conversely, a good night’s sleep also will help lessen pain.

Making the Connection

The National Sleep Foundation (NSF) went to the public to find out how significant the issue of sleep and pain is. The 2015 Sleep in America Poll: Sleep and Pain surveyed 1,029 adults and found that those experiencing chronic pain got either a very poor (25%) or fair (38%) night’s sleep compared to those without pain who reported that they got a very good night’s sleep (65%). Overall, those with chronic pain and acute pain reported they could get a good night’s sleep only 39% and 47% of the time, respectively.1

“The critical issue for the survey is that there’s obvious connection,” says Tim Roehrs, PhD, director of research at the Sleep Disorders and Research Center of Henry Ford Health System and professor in the Department of Psychiatry and Behavioral Neurosciences, School of Medicine at Wayne State University. He was the chair of the task force responsible for the 2015 poll. “The data is leading us to an appreciation that disrupted sleep leads to pain. For the survey, we were trying to determine the chicken or the egg—what came first, pain and then disrupted sleep or disrupted sleep and pain. Second, we wanted to determine the significance we have in terms of treating and coordinating sleep disturbance and pain.”

The fact that there is a connection between pain and sleep is just the starting point for researchers. There are still no clear-cut answers why this is the case.

Nicole K.Y. Tang, PhD, is a sleep researcher at the University of Warwick in the United Kingdom, where a study found that cognitive behavioral therapies (CBT) were effective in tackling insomnia for chronic pain.2 She says, “There is good evidence to suggest that the association between sleep and pain is broadly reciprocal, but the interaction between the two conditions is probably more complex than we think. For example, we are now starting to understand that when pain is chronic, the disruptive effect of sleep disturbances on subsequent pain is stronger and more consistent than the effect of pain on subsequent sleep. We have also started to appreciate that the interaction behaves differently when sleep or pain is changed in the positive rather than negative direction. In a recent meta-analysis, my research team found that successful nondrug treatments for insomnia were associated with not only a large improvement in sleep quality, but also a small improvement in pain and moderate improvement in fatigue immediately after treatment. The effect of sleep quality and fatigue improvement maintained at follow-up (between 3 and 12 months) when a moderate improvement in depression symptoms also emerged. The healing effect of sleep may not be immediate and it may take time to see the effect.”

Physical pain (such as osteoarthritis or fibromyalgia) isn’t the only type that the NSF poll connected to poor sleeping habits. Poll participants were asked about their levels of stress and how that affected their sleep. Of the respondents, 12% reported that they had been under severe or very severe stress in the 7 days prior to taking the poll, with 83% of these severe or very severely stressed patients reporting poor sleep.

There is a possible connection between stress-induced poor sleep and pain, according to Roehrs. “What we think happens, though we haven’t verified it, is that there is an activation of proinflammatory cytokines, which activates the pain system as a defensive response due to a potentially damaging situation,” he says.

Doing the Research

pain post surgery

Studies have found that improving sleep pre-surgery helps reduce the need for painkillers post-surgery.

Gathering data and making connections is only one of the avenues researchers are taking to better understand the bidirectional relationship between sleep and pain.

Roehrs of the Henry Ford Medical Center outlined a number of research studies that he has been or is currently involved in that look at different aspects of the sleep-pain relationship. One study that is just gearing up involves the effect of using the drug Lyrica on patients with fibromyalgia who have pain and insomnia. “We’re hypothesizing that it will lessen their pain,” Roehrs says. “Lyrica is an antiseizure drug, and the theory is that fibromyalgia’s cause is a hypersensitive nervous system.”

In another study, patients who were scheduled to undergo elective surgery and had identified inadequate sleep agreed to extend their nightly time in bed in the week prior to their surgery to see if increased bedtime would lessen pain and the need for opioids, which have a tendency after long-term use to disrupt sleep.3 “The patients in the study had hip or knee replacement surgery, and we found that 4 days after surgery, they had reduced self-reported pain and reduced opioid use by 30%,” Roehrs says.

Roehrs was also involved in a similar study, this time treating patients with obstructive sleep apnea prior to inpatient elective surgery. In a 2-day follow-up post-surgery, patients, again, reported a 30% decrease in the use of opioids.4

With recent reports of an uptick in prescription opioid abuse by patients, the ability to minimize acute pain (and, thus, opioid abuse) is significant. “The biggest predictor of opioid use is acute pain,” Roehrs says. “Patients will continue to use opiates and develop opioid dependence because of chronic pain.”

Opioid use can impair the ability to treat sleep disorders directly. Research on patients in Veterans Administration hospitals found that opioid use lowered adherence to the use of CPAP by patients who had OSA experiencing pain and that pain was not lowered by following treatment with CPAP. Adherence to CPAP was significantly higher in the control group not using opioid medications, according to the conclusions of the study.5

Treating the Patient

The avenues for treating sleep disruptions related to pain are varied.

While it has been shown that long-term opioid use can significantly impact sleep architecture, it can have a place in the short term. “Pharmacological options are recommended for acute insomnia for use of up to around 4 weeks,” says Tang from the University of Warwick. “Drugs are relatively more convenient and fast-acting, but they are tools with their own sets of limitations, eg, residual daytime sleepiness; altered sleep architecture and hence possibly compromised sleep quality; tolerance; rebound insomnia; drug interaction, etc. People should think carefully about the possible side effects and weigh up the pros and cons when they make treatment decisions.”

Roehrs notes that pharmacological options are one avenue for treating sleep disorders and pain, but there are other avenues to consider as well.

The first step is to identify the sleep disorder, whether it’s sleep insufficiency, apnea, or insomnia, or some other disorder. The next step can be as simple as sleep extension—making sleep a priority and increasing the number of hours the patient sleeps—medical options, or the aforementioned pharmacological options.

In her research, Tang has found CBT to be an effective option in treating patients with pain and sleep disruptions. Tang’s research has examined the effectiveness of the way CBT is delivered via the Internet or in person.

“It’s hard to say which approach is more effective, in the absence of a direct comparison between Internet-delivered CBT versus CBT delivered in person,” she says. “There are data suggesting that Internet CBT and bibliography-based CBT for insomnia can achieve significant reduction in insomnia symptoms, at a magnitude comparable to that reported in CBT-I delivered in person. That said, I do think having the human touch does give face-to-face CBT an edge, with the flexibility to tailor the treatment progress according to the patient’s needs and motivation.”

One new option that is just coming on the scene is Quell, an over-the-counter device available through medical device provider NeuroMetrix. Quell received Class 2 approval by the US Food and Drug Administration (FDA) last year for chronic pain. As part of the approval, it was cleared for use to treat a patient for pain while sleeping.

The TENS [transcutaneous electrical nerve stimulation] device is worn by the patient on either upper calf. “By using nerve stimulation, it has a beneficial effect on sleeping,” says Shai Gozani, president and CEO of NeuroMetrix. Quell is patient-controlled via an app, and allows the patient to monitor a number of functions, including sleep. At night, Quell operates at a lower stimulation level. “It has to be smart so it doesn’t wake up the patient,” says Gozani. Quell is available through a number of consumer channels, and some physicians dispense it—using a model similar to that of the modern electronic toothbrushes, which are both at retail outlets and dispensed by some dentists.

Good Bed Hygiene

One of the findings of the Sleep in America poll was that, even for those with chronic pain, the people who made sleep a priority—setting a regular bedtime, and practicing proper bed hygiene—were able to have a better night’s sleep. Roehrs adds that making sleep a priority is one of the primary missions of the NSF, and a point he typically emphasizes when he speaks to lay audiences. “I tell them to get prone as often as possible,” he says. “Sleep is really the foundation of health.”

While working on this article, C.A. Wolski did his own experiment—on himself—observing how his own chronic pain was lessened after a good night’s sleep. Backing up the researchers, he found that his pain was much less after a good night sleep than after a poor night’s.

REFERENCES

1. National Sleep Foundation. 2015 Sleep and Pain. https://sleepfoundation.org/sleep-polls-data/sleep-in-america-poll/2015-sleep-and-pain. Accessed July 15, 2016.
2. Tang NK, Lereya T, Boulton H, Miller MA, Wolke D, Cappuccio FP. Nonpharmacological treatments of insomnia for long-term painful conditions: a systematic review and meta-analysis of patient-reported outcomes in randomized controlled trials. SLEEP. 2015;38(11):1751–64.
3. Roehrs T, Randall S, Roth T. Increasing preoperative sleep reduces postoperative pain and analgesic use. SLEEP Abstract Supplement. 2013;36.
4. Kunal A, Mohammed AJ, Bazan L, Mordis C, Roehrs T. Preoperative continuous positive airway pressure in obstructive sleep apnea patients decreases opioid use and pain during post-operative inpatient days. J Sleep Med Disord. 2016;3(3):1048.
5. Jaoude P, Lal A, Vermont L, Porhomayon J, El-Solh AA. Pain intensity and opioid utilization in response to CPAP therapy in veterans with obstructive sleep apnea on chronic opioid treatment. J Clin Sleep Med. 2016 May 25. pii: jc-00502-15. [Epub ahead of print]