Lan Xia, Yi-Jun Ge, Fang Wang, Ping Qu and Gui-Hai Chen

Objectives: To explore the changes of serum levels of tumor necrosis factors (TNF-α and TNF-β) and their soluble receptors (sTNF-R1 and sTNF-R2), and analyze their relationship between sleep quality and memory in the patients with chronic insomnia disorder (CID).

Methods: Forty-four CID patients and 39 normal controls were enrolled in this study. Pittsburgh Sleep Quality Index (PSQI) and Nine-Box Maze Test (9BMT) were used to assess the sleep quality and memory function, respectively. The serum levels of TNF-α, TNF-β, sTNF-R1 and sTNF-R2 were examined by protein-chip.

Results: Compared to the controls, the CID patients had significantly higher error numbers of the spatial working and object recognition memories (Ps < 0.05) in the 9BMT, with higher serum levels of TNF-α and TNF-β (Ps < 0.001), and lower levels of sTNF-R1 and sTNF-R2 (Ps < 0.001). The partial correlation analysis showed that the serum TNF-α and TNF-β positively but sTNF-R1 and sTNF-R2 negatively correlated with PSQI scores (Ps < 0.001). In the CID patients, the TNF-α positively correlated with the errors in the spatial working and object recognition memories (Ps < 0.05), whereas the TNF-β only positively correlated with the errors in the spatial working memory (P < 0.05).

Conclusions: The CID patients had increased TNF-α and TNF-β and decreased sTNF-R1 and sTNF-R2 in peripheral blood, with the former being linked to specific memory impairments.