Changed Differences Of Cognitive Function, And Levels Of CRH And IL-1β In The Patients With Primary Insomnia And Insomnia Comorbided With Depression

Background: Insomnia is a common physiological and psychological disorder, and can lead to impaired social activities, interpersonal relationships and occupational mobilities. According to the According to diagnostic and statistical manual of mental disorders-IV (DSM- IV), the insomnia is classed into primary insomnia (PI) and secondary insomnia. The insomnia comorbided with anxiety, depression and other mental disorders can account for most of the incidence of insomnia. Most previous studies of insomnia did not distinguish patients with different forms of insomnia, and the results are often interfered by depression, anxiety and other factors. Therefore cognitive function and pathogenesis mechanism of PI remain to be identified.Objective: To explore changed differences of cognitive function and plasma levels of CRH and IL-1βin the patients with PI and insomnia comorbided with depression (ICD), and whether the changed secretion of corticotropin releasing hormone (CRH) and Interleukin-1β(IL-1β) involved in impairment of cognitive function?Methods: According to the diagnostic criteria in the DSM- IV, cases of PI and ICD were selected, and compared with the normal controls. After the background information was collected, the severity of depression was evaluated by Hamilton Depression Rating Scale (HMAD-17 Edition), the quality of sleep was evaluated by Pittsburgh Sleep Quality Index (PSQI), and the overall cognitive function was determined by Montreal Cognitive Assessment Scale (MoCA). Then, the objective memories, including spatial working memory, spatial reference memory, objective working memory, object reference memory and object recognition memory were respectively detected by"nine boxes maze"and delayed picture recognition tests. The subjective memory was assessed by themselves on a 5-point scale ranging from'0'(extremely severe problem) to'4'(no problem). About 2 ml venous blood was obtained at 4 P.M., the serum was kept under–80℃. The serum concentrations of CRH and IL-1βwere detected by Enzyme-linked immunosorbent assay using CRH and IL-1βkits.Results:①The background information was similar among groups with no significant differences in gender, age and educated years.②PSQI scores in both PI group and ICD group were higher than those in the control group (χ~2 = 8.653, Ps < 0.001;χ~2 = 10.165 Ps < 0.001, respectively), but there was no significant difference between the both patient groups. HAMD score in the ICD group was higher than that in the PI group (F = 23.331, Ps < 0.001), and that in the PI group was higher compared to the control group (F=481.623, Ps<0.001). These results suggested that there was similar severity of insomnia, and good discrimination of depressive severity between patient groups.③Compared to the controls, the self-evaluated memory (χ~2=4.562, Ps<0.001) and object recognition memory (χ~2=4.432, Ps<0.001) were worse in the mild PI patients, and the spatial working memory was also worse in the severe PI patients (χ~2=3.529, Ps<0.001). For the ICD patients, the self-evaluated memory (χ~2=5.803 Ps<0.001), spatial working memory (χ~2=4.155, Ps<0.001) and object recognition memory (χ~2=4.752, Ps<0.001) were worse in the mild patients, however, object (χ~2=2.461 P=0.008) and spatial reference memory (χ~2=3.955, Ps<0.001) were also worse in the severe patients relative to the controls.④Serum levels of CRH (χ~2=5.826, Ps<0.001;χ~2=4.362, Ps<0.001) and IL-1β(χ~2=6.485, Ps<0.001;χ~2=6.654, Ps<0.001) in the PI and ICD patients were higher than those in the control group. There was a significantly increased CRH and decreased IL-1βin the PI group compared to the ICD group (χ~2=2.245, Ps<0.001;χ~2=6.655, Ps<0.001).⑤Correlation analysis showed that scores of MoCA and self-evaluated memory negatively correlated to the IL-1βlevel (r =–0.295, P=0.022; r =–0.278, P=0.032). The errors of spatial working memory positively correlated to HAMD score (r = 0.295, P=0.001) and PSQI score (r = 0.210, P=0.029), respectively. The errors of spatial reference memory positively correlated to HAMD score (r = 0.204, P=0.007), IL-1βlevel(r = 0.276, P=0.045) . PSQI score positively correlated to the levels of CRH (r = 0.529 P=0.003) and IL-1β(r = 0.548 ,Ps<0.001), and HAMD score positively correlated to the IL-1βlevel (r = 0.809, Ps<0.001).Conclusion: PI damaged subjective memory and object recognition memory, the severe PI also damaged spatial working memory. ICD could damage the various functions of memory, especially in severe patients, including subjective memory, object reference memory, spatial reference memory, spatial working memory and object recognition memory. PI patients might have more obvious secretion of CRH than ICD patients, but a more increment of IL-1βoccurred in the ICD patient other than PI patients. CRH could more contribute to insomnia, and IL-1βcould more contribute to depression. IL-1βcould involve the impairment of cognitive function in patients with chronic insomnia.