Poor sleep and chronic pain prove pesky bedfellows


Early in his career as a pain researcher, Daniel Whibley, PhD, was struck by an article that drew parallels between methods of torture and the experiences of patients with insomnia and chronic pain.

The author of that article, Nicole Tang, DPhil, observed that two methods used by torturers – pain infliction and sleep deprivation – harm people in ways that also are experienced by many patients with pain and sleep conditions.

Patients are “essentially living in this perpetually undesirable, at best, situation where both of these features are playing out in their lives,” said Dr. Whibley, a research assistant professor of physical medicine and rehabilitation at the University of Michigan, Ann Arbor.

The problems create a “kind of vicious circle,” he said. Pain disrupts sleep. Insufficient sleep worsens pain.

Studies have established important relationships between the conditions, but investigators are still trying to clarify the mechanisms that connect them and the best ways to intervene to improve patient outcomes.

To that end, Dr. Whibley has developed an intervention known as Move & Snooze to benefit patients with pain associated with osteoarthritis.

The program includes remote exercise coaching and an automated 6-week course of digital cognitive-behavioral therapy for insomnia (CBT-I). Dr. Whibley’s hypothesis is that addressing sleep disturbances will help patients stay engaged with the physical activity component of the program and help with pain management.

He and his colleagues have tested the intervention in a feasibility study and are in the process of securing grant funding to test it in a large, nationwide trial.

Losing sleep for science

Michael Smith, PhD, is examining the sleep-pain connection from a different angle.

Dr. Smith, the director of the Behavioral Medicine Research Laboratory at Johns Hopkins University, Baltimore, is recruiting healthy adults to endure restless nights and painful stimuli.

His team is conducting a study known as Sleep-MOR that aims to reveal how different types of sleep disturbances influence pain and a person’s response to opioids.

Nearly three dozen participants have completed the study so far, Dr. Smith said, out of what he hopes will be 200 in all.

Participants are randomly assigned to sleep normally or to undergo an experimental condition that is designed to mimic the sleep disturbances of insomnia or obstructive sleep apnea (OSA).

In a “forced awakening” group, participants are awakened for 20-minute intervals every hour and for a full hour-long window during the night. In this condition, they could sleep for about four hours in all. Forced awakening is intended to represent insomnia

A “sleep fragmentation” group is meant to represent patients with OSA. About 30 times per hour, tones and tactile buzzers rouse sleeping participants without fully waking them up. Although the experiment involves brief arousals such as those experienced by patients with OSA, it does not capture another important feature of sleep apnea – the cessation of breathing, Dr. Smith noted.

The next day, researchers perform pain testing and brain imaging and see how opioid receptors respond to pain medication.

“Some of the forms of sleep loss that we are studying may actually alter the efficacy of the binding of those receptors, and that might then require you to have higher doses of an opioid to get the same effect,” Dr. Smith said. “That’s our hypothesis.”

If that bears out, disturbed sleep may play a role in the development of opioid use disorder and have implications for patients who receive opioids after surgery, he said.

In the lab, researchers examine pain thresholds using techniques such as thermal pain testing, in which a thermode attached to a participant’s arm heats up. The temperature “slowly goes up and the patient just says: ‘Ouch,’ when it first hurts. Then we have their pain threshold,” Dr. Smith said.


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