Background & Aims

Sleep is essential for human beings, with its potential functions linked to immunity, metabolism, mood, attention, memory consolidation, and many more still to be discovered [3; 4]. Studies have shown sleep to be associated with chronic pain, displayed by a vicious bi-directional relationship[1; 2]. That is, chronic pain patients often suffer sleep disturbance which often further exacerbates their pain[1]. Current methods to study sleep involve subjective assessment tools (i.e., sleep diaries), but these can be subject to recall bias and require an objective measurement technique to validate the data. The goal of this study was to incorporate an ecological momentary assessment (EMA) approach to examine the effect of exercise on chronic pain-related outcomes in 40 chronic pain (CP) patients compared to non-exercise standard-of-care.

Methods

Forty patients from a cohort of temporomandibular disorder (TMD) participants volunteered and were randomly assigned to an exercise or control (no exercise) intervention. The exercise group was trained to follow a designed exercise that focused on oral facial muscle movement and general muscle stretching, while the control group was asked to maintain their standard care. During the first visit and at the end of the intervention, blood was collected for peripheral blood mononuclear cells processing and patients received a wrist actigraphy watch (CamNTech). Participants were asked to complete CP questionnaires weekly over 30 days. Linear mixed models were used to determine the differences between exercise and control groups in physical activity and sleep quality.

Results

31 out of 40 participants completed the study with 16 participants in the exercise and 15 in the control groups. No group differences were found in age (t29=.87, p=.325), sex (?2=.11, p=.739), and race (?2=2.42, p=.489). The exercise and control groups reported similar and moderate levels of baseline chronic pain intensity (t29=-9,82, p=.421) and pain related interference (t29=.92, p=.367).
Results from Linear Mixed Model on actigraphy data confirmed that the exercise group had longer continuous vigorous activity (F1,638.05=5.35, p=.021) and shorter sedentary activity (F1,714.27=4.45, p=.035) than the controls. Moreover, the exercise group showed improved sleep quality than the controls. In particular, the exercise group had higher sleep efficiency (F1,222.65=187.08; p<.001), lower sleep fragmentation (F1,444.72=4.73; p=.03), longer actual sleep time (F 1,442.65=144.61; p<.001), and reduced sleep latency (F1,606.60=32.52; p<.001), after controlling for the baseline sleep quality.

Conclusions

Our findings highlight the protective role of exercise in enhancing sleep quality in CP patients. We used actigraphy data and ecological momentary assessment and found that continuous vigorous exercise can increase sleep duration and efficiency, reduce fragmentation of sleep, and improve sleep latency in a CP cohort. This study used a repetitive actigraphy approach to obtain a highly accurate measurement with high ecological validity. Future studies are needed to replicate these findings and further determine if and how sleep improvement could serve as an effective treatment for chronic pain.

References

[1] Finan PH, Goodin BR, Smith MT. The association of sleep and pain: an update and a path forward. The journal of pain 2013;14(12):1539-1552.
[2] Haack M, Simpson N, Sethna N, Kaur S, Mullington J. Sleep deficiency and chronic pain: potential underlying mechanisms and clinical implications. Neuropsychopharmacology 2020;45(1):205-216.
[3] Irwin MR. Sleep and inflammation: partners in sickness and in health. Nature Reviews Immunology 2019;19(11):702-715.
[4] Orze?-Gryglewska J. Consequences of sleep deprivation. International journal of occupational medicine and environmental health 2010;23(1):95-114.

Presenting Author

Yang Wang

Poster Authors

Yang Wang

PhD

School of Nursing, University of Maryland, Baltimore

Lead Author

Topics

  • Treatment/Management: Interventional Therapies – Other