Changed Interleukins are Associated with Sleep and/or Cognition in Chronic Insomnia Patients：A Pilot Study

Abstract Background : Epidemiological studies have found that insomnia is a risk factor for many diseases, such as stroke and cognitive impairment. Therefore, studying changes in markers associated with insomnia related cognitive changes is crucial to understanding insomnia. The objective of this study was to investigate whether exist difference between chronic insomnia disorder and healthy individuals for serum cytokines, if so, whether these cytokines changes are correlated with sleep and/or cognition. Methods : Forty-one patients with chronic insomnia disorder and 39 healthy demographic-matched controls were enrolled. The Pittsburgh Sleep Quality Index and the Hamilton Depression and Anxiety Rating Scales were used to assess sleep quality and emotion, respectively. The Montreal Cognitive Assessment (Chinese version) and Nine Box Maze Test were employed to assess cognition. Plasma pro-inflammatory (IL-1β, IL-2, IL-6sR, IL-6, IL-12p40, IL-12p70, IL-16, IL-17, IL-17F, IL-21, IL-22, and IL-23) and anti-inflammatory (IL-1RA, IL-4, IL-5, IL-10, IL-13, and IL-28A) cytokines were measured by enzyme-linked immunosorbent assay. Results : Patients with chronic insomnia disorder: made significantly more errors on the spatial reference memory, spatial working memory, and object recognition memory tasks of the Nine Box Maze Test; had a higher level of serum pro-inflammatory cytokines (IL-1β, IL-2, IL-6sR, IL-6, IL-21, and IL-23); and had lower level of serum anti-inflammatory cytokines (IL-4, IL-13, and IL-28A). In patients with chronic insomnia disorder, IL-2, IL-6, and IL-28A levels were negatively correlated with Pittsburgh Sleep Quality Index scores. Cytokines (IL-10, IL-13, IL-2, IL-1β, and IL-6) in serum of chronic insomnia disorder patients were positively or negatively correlated with cognitive function (object reference memory, spatial reference memory, and object recognition memory errors on the Nine Box Maze Test). Conclusion: Patients with chronic insomnia disorder had pro-/anti-inflammatory cytokineimbalance that may be associated with insomnia and/or cognitive dysfunction severity.