Abstract
Introduction
Sleep disturbances are comorbid with chronic pain, exacerbating pain conditions. Experimental studies have implemented different sleep loss paradigms combined with quantitative sensory testing to better understand the sleep-pain relationship. However, knowledge of which sleep loss paradigms are most detrimental regarding hyperalgesia is lacking. The current review aims to differentiate the effect of fragmented sleep from partial or total sleep deprivation and determine whether sleep-loss-related hyperalgesia is due to curtailed/deprived consolidated sleep or sleep continuity disruption.
Methods
We searched the databases, including EBSCO, MEDLINE, Psychological Information Database (Psych INFO), Science Direct, and Web of Science, to identify 36 experimental studies involving 928 participants. The studies implemented different sleep loss paradigms, such as total sleep deprivation, sleep restriction, and disrupted sleep continuity on heat, cold, pressure, and mechanical pain thresholds in the general population. In addition, we considered the sex-dependent effect of sleep loss on various pain types.
Results
Total sleep deprivation exerted the strongest (SMD = -1.721; CI95: -2.358, -1.073; P<0.001), while fragmented sleep protocols induced the least (SMD = -0.294; CI95: -0.478, -0.110; P=0.007) hyperalgesic effect. The effect of sleep loss on heat pain was greatest, whereas on pressure pain was smallest. The sleep loss-related hyperalgesia on heat and pressure pain differed between men and women, while the cold pain threshold was sex-independent.
Conclusion
This meta-analysis confirms that depriving sleep entirely greatly affects pain perception while disrupted sleep continuity induces a small effect and requires two consecutive nights of disruptions.