Increased Pain Sensitivity with Sleep Deprivation

Sufficient and good quality sleep is a significant factor in any person’s overall health and well-being. Sleep is also, unfortunately, known to be a particularly precious and rare resource for many people in the United States, with the Centers for Disease Control and Prevention reporting that one in three adults living in the United States do not get enough sleep or rest every day and that an estimated 50 to 70 million Americans living with chronic sleep disorders that make it difficult for them to get enough quality sleep per night. [1] Sleep deprivation has many short- and long-term health effects, with one important effect being increased pain and pain sensitivity.

While sleep deprivation is a serious problem for any individual, the stakes are unfortunately heightened for those who experience chronic pain, as sleep deprivation has been found to have a significant impact on nociception. A December 2022 systematic review and meta-analysis by Chang et al. in Sleep Medicine Reviews reports that, for healthy individuals (ones without diagnosed chronic pain), there was moderate evidence supporting that partial sleep deprivation significantly increased spontaneous pain intensity, while, for people living with chronic pain, limited evidence (due to the relative dearth of data for patients of chronic pain in the experimental data reviewed by these researchers) supported that partial sleep deprivation significantly increased spontaneous pain intensity. Outlining the necessity for research into the actual biomechanical pathways through which sleep deprivation affects pain perception, the authors nonetheless strongly asserted that, as sleep is a modifiable factor, sleep quantity and quality is an important consideration in particular for those with chronic pain as improving their sleep has the potential to significantly reduce their overall pain. [2]

Another review released in December of 2022 (Kourbanova et al., Front. Neurosci.) explored whether the portion of the sleep cycle (REM, non-NREMs, or both) affected by sleep deprivation, the amount of sleep lost, or type of sleep disruption (partial or total sleep loss, duration, sleep fragmentation, or sleep interruptions) affected distinct components of the pain response in both rodents and humans. Kourbanova et al. found that the effects of sleep disturbances on pain were conserved between the two species and that the major driver for hypersensitivity to pain seemed to be the total amount of sleep lost rather than REM sleep loss per se. Furthermore, they reported that sleep loss caused by extended periods of sleeplessness (caused in-experiment by delaying sleep by four hours) increased heat and mechanical pain perception preferentially, while sleep loss caused by interrupted or limited sleep (caused in-experiment by repeatedly awakening the sleeper such that four hours of sleep overall were lost in a night) seemed to specifically modulate diffuse noxious inhibitory controls (DNIC): a type of descending controls which acts on nociceptive signals at the spinal cord level. Curiously, this latter effect on DNIC controls were only observed in female participants in experimental settings. The authors propose that this may provide some explanation for the strong incidence of fibromyalgia and temporomandibular joint disorder pain in women, both of which have demonstrated large DNIC changes within patients of the disease in clinical trials in response to interrupted sleep. [3]

As a whole, sleep and its effects on the human body remains an important area of study for both researchers and clinicians. Moving forward, with what we know about sleep deprivation’s impact on pain perception and sensitivity, it will be important both to gather more experimental data on sleep deprivation in chronic pain patients as well as to discern with more precision what biochemical processes lead to this increased nociception.

References

(1) Sleep Deprivation and Deficiency – What Are Sleep Deprivation and Deficiency? | NHLBI, NIH. https://www.nhlbi.nih.gov/health/sleep-deprivation.

(2) Chang, J. R.; Fu, S.-N.; Li, X.; Li, S. X.; Wang, X.; Zhou, Z.; Pinto, S. M.; Samartzis, D.; Karppinen, J.; Wong, A. Yl. The Differential Effects of Sleep Deprivation on Pain Perception in Individuals with or without Chronic Pain: A Systematic Review and Meta-Analysis. Sleep Medicine Reviews 2022, 66, 101695. https://doi.org/10.1016/j.smrv.2022.101695.

(3) Kourbanova, K.; Alexandre, C.; Latremoliere, A. Effect of Sleep Loss on Pain—New Conceptual and Mechanistic Avenues. Front. Neurosci. 2022, 16, 1009902. https://doi.org/10.3389/fnins.2022.1009902