Those who have chronic pain often have trouble sleeping. It is not surprising that pain can keep someone from falling asleep or can cause premature awakenings. Unfortunately, sleep is a healing state, so the lack of sleep caused by pain may actually disrupt recovery of what is causing the pain. But, until recently, this had never really been confirmed. Does worsened sleep exacerbate pain?
In order to test this, a group of researchers studied the sleep of military veterans. These individuals all had complaints of “chronic musculoskeletal pain,” meaning the pain had been around for a while. Each individual completed questionnaires that gauged pain severity, and depression/anxiety symptoms. They also underwent in-lab sleep studies that quantified sleep quality. All of these measures were collected before the experiment started, 3 months later, and 12 months later. Meanwhile, each participant was undergoing therapeutic pain treatment.
The research team used a statistical modeling approached called structural equation modeling in order to determine the directionality in the relationship between sleep and pain. In other words, this analysis allowed them to see whether poor sleep worsened pain or whether pain worsened sleep. This test was repeated at each time point.
The results showed that the change in sleep complaints between the baseline time point and 3 months significantly predicted changes in pain between the baseline time point and 12 months. In other words, less sleep complaints meant less pain later on. It was also noted that changes in pain also predicted changes in sleep, but this relationship was not quite as strong. When examining depression and anxiety, it was found that these measures did not predict changes in sleep or changes in pain.
Taken together, the results of the study suggest that there certainly is a bidirectional relationship between pain and sleep. Losing sleep can exacerbate pain, and pain can disrupt sleep. If you are somebody with untreated sleep apnea and also chronic pain, treating the apnea will improve sleep and might help to lessen pain. If you are somebody without untreated apnea, improving sleep (by whatever means necessary, as consulted by a physician) may improve pain as well, which may, in effect, improve subsequent sleep.
Source: Koffel, E., Kroenke, K., Bair, M. J., Leverty, D., Polusny, M. A., & Krebs, E. E. (2015). The Bidirectional Relationship Between Sleep Complaints and Pain: Analysis of Data From a Randomized Trial.