The Imbalance of Circulating Pro-Inflammatory Cytokines Interleukin-12 and Interferon Gamma and Anti-Inflammatory Cytokine Interleukin-1Ra in Chronic Insomnia Disorder

A growing body of literature suggests that cytokines can play an important role in chronic insomnia disorder (CID); however, the underlying mechanisms are still unknown. Here we show that serum levels of pro-inflammatory mediators including IL-12, IFN-γ and ICAM-1 are elevated in CID group when compared with healthy controls, and that the REM sleep duration diminishes with increased concentrations of IL-12 and IFN-γ in individuals with CID. Furthermore, we find that lowered serum concentration of IL-1ra is negatively correlated with severity of insomnia in CID group. These data add to the evidence that the imbalance of circulating pro-inflammatory mediators IL-12, IFN-γ, and ICAM-1 and anti-inflammatory cytokine IL-1ra is important in CID pathogenesis.