Abstract
Poor sleep quality and sleep disorders are the most common problems in people, affecting health-related quality of life. Various studies show an association between sleep disorders and altered levels of stress hormones and inflammatory cytokines measured in saliva. The main objective of this article is to provide an analysis of the current evidence related to changes in inflammatory markers in the saliva and their associations with sleep quality measurement (both objective and subjective methods) in healthy subjects and in sleep-related disorders. To that end, a scoping review was carried out, following the PRISMA criteria in the bibliographic search in several databases: PubMed, EBSCO, and SCOPUS. Eleven of the articles are from the adult population and two from the child-youth population. They mainly measure the relationship between sleep and interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNFα) alpha, as well as other inflammatory markers such as myeloperoxidase (MPO) and prostaglandin-endoperoxide synthase 2. An analysis shows the relationship between these salivary biomarkers and sleep quality, especially in the case of IL-6 in both healthy subjects and several pathologies associated with sleep-disorders. The results for TNFα and IL-1β measurements are still inconclusive and the difference with IL-6 was assessed. Two studies reported interventions that result in sleep improvement and are accompanied by the normalization of inflammatory changes detected in the saliva. As it is an easy-to-apply and non-invasive method, the measurement of salivary cytokines can be very useful in chronobiology studies. Further studies are required to determine the sensitivity of salivary inflammatory markers in monitoring biological rhythms and acting as biomarkers in the detection of sleep disorders and sleep interventions.
Highlights
Sleep is a vital physiological process with important restorative functions [1]
Contrary to the initial hypothesis, in children and adolescents, salivary cytokine levels were higher in those who experienced better sleep [47]. These results show that it is necessary to continue this research in order to determine the sensitivity of salivary IL-6 to differences and alterations in the duration and quality of sleep, especially in children and adolescents, since this study indicates that children with longer and more efficient sleep have higher levels of pro-inflammatory mediators in saliva upon waking
Sleep influences cytokine levels and its alteration is associated with adverse effects on metabolism and increased levels of pro-inflammatory molecules
Summary
Sleep is a vital physiological process with important restorative functions [1]. poor quality of sleep is a common problem, to the extent that according to various studies, between 37.2% and 69.4% of adults sleep poorly [2].Chronic sleep deprivation and sleep fragmentation are prevalent conditions in modern lifestyles and in several clinical settings [3,4,5,6]. Sleep disorders produce daytime sleepiness, decreased psychomotor performance, and degraded mood [10,11,12] and several studies demonstrated that sleep disorders promote cardiovascular and metabolic disorders [5,13]. For this reason, sleep problems are a growing concern for global public health, since shorter sleep or sleep fragmentation have been shown to negatively influence the risk of inflammatory disease and to contribute to mortality [14], possibly due to the effects of sleep disturbance on inflammatory mechanisms. This endocrine environment during early sleep supports the production of pro-inflammatory and/or Th1 cytokines such as interleukin (IL)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
