Are you experiencing pain? If yes, consider asking the next question: how well did you sleep last night?
The fact that pain interferes with sleep has been documented in many chronic pain populations. Numbers speak for themselves: insomnia - diagnosed with polysomnographic measures - was shown to be prevalent in 72% of adults with chronic pain. Chronic pain patients take longer to fall asleep, have more awakenings and thus spend more time awake during the night in comparison with the general population. Therefore, it is important to question patients with chronic pain about their quality of sleep.
The relationship between sleep and pain is bidirectional. Sleep disturbances themselves can modulate the sensation of pain and evidence suggests a sleep-pain vicious cycle. However, studies on the temporal association between sleep and pain postulate that the pathway leading from chronic pain to poor sleep is not as strong as the pathway leading from poor sleep to increased pain. Furthermore, different mechanisms are involved in the increase of pain following a poor night’s sleep.
Recently, a fMRI study reported that acute sleep deprivation in healthy subjects increases pain reactivity in the primary sensory cortex and reduces activity in the insula and striatum (i.e. brain areas involved in descending pain inhibition). Also, subjects undergoing sleep deprivation report pain at a lower temperature than when sleep-rested. Therefore, sleep loss amplifies the perception of pain.
Moreover, sleep regulates the production of inflammatory cytokines (e.g. TNF-α, IL-1β or IL-6). The latter are involved in the self-maintaining inflammatory responses in people with rheumatoid arthritis or haemophilic arthropathy. An increased concentration of cytokines was found in subjects with sleep deprivation, which is associated with chronic pain.
Those mechanisms show how pain and sleep are closely interlinked. This highlights why evaluating and managing sleep in chronic pain patients is advised in pain management. Today, this is probably more important than ever before, considering the rise of chronic pain conditions and the decline in sleep time in the past decades.
Valérie-Anne Chantrain
Valérie-Anne worked as physiotherapist at the sleep laboratory of the Cliniques universitaires Saint-Luc, Brussels (Belgium). She is now involved in the research project entitled “Gaining insight into the complexity of pain in people with haemophilia” at the University of Antwerp and UCLouvain. Her particular interest and expertise in sleep medicine led her to explore the complex interplay between sleep and pain.
2023Pain in Motion
References and further reading:
1. Mathias JL, Cant ML, Burke ALJ. Sleep disturbances and sleep disorders in adults living with chronic pain: a meta-analysis. Sleep Med 2018; 52: 198-210.
https://pubmed.ncbi.nlm.nih.gov/30314881/
2. Gerhart JI, Burns JW, Post KM, et al. Relationships Between Sleep Quality and Pain-Related Factors for People with Chronic Low Back Pain: Tests of Reciprocal and Time of Day Effects. Ann Behav Med 2017; 51(3): 365-75.
https://pubmed.ncbi.nlm.nih.gov/27844327/
3. Van Looveren E, Bilterys T, Munneke W, et al. The Association between Sleep and Chronic Spinal Pain: A Systematic Review from the Last Decade. J Clin Med 2021; 10(17).
https://pubmed.ncbi.nlm.nih.gov/34501283/
4. Krause AJ, Prather AA, Wager TD, Lindquist MA, Walker MP. The Pain of Sleep Loss: A Brain Characterization in Humans. J Neurosci 2019; 39(12): 2291-300.
https://pubmed.ncbi.nlm.nih.gov/30692228/
5. Kundermann B, Spernal J, Huber MT, Krieg JC, Lautenbacher S. Sleep deprivation affects thermal pain thresholds but not somatosensory thresholds in healthy volunteers. Psychosom Med 2004; 66(6): 932-7.
https://pubmed.ncbi.nlm.nih.gov/15564360/
6. Bjurstrom MF, Olmstead R, Irwin MR. Reciprocal Relationship Between Sleep Macrostructure and Evening and Morning Cellular Inflammation in Rheumatoid Arthritis. Psychosom Med 2017; 79(1): 24-33.
https://pubmed.ncbi.nlm.nih.gov/27428854/
7. Calcaterra I, Iannuzzo G, Dell'Aquila F, Di Minno MND. Pathophysiological Role of Synovitis in Hemophilic Arthropathy Development: A Two-Hit Hypothesis. Front Physiol 2020; 11: 541.
https://www.frontiersin.org/articles/10.3389/fphys...
8. Simpson NS, Scott-Sutherland J, Gautam S, Sethna N, Haack M. Chronic exposure to insufficient sleep alters processes of pain habituation and sensitization. Pain 2018; 159(1): 33-40.
