Levels Of Plasma Neuropeptide Y In Patients With Primary Insomnia And Normal Controls: A Case-control Study

Objectives:To study the plasma neuropeptide Y (NPY) concentrations in patients with primary insomnia (PI) and normal controls group (CG), and to discuss the possible action and significance of plasma NPY in pathophysiology of primary insomnia.Methods:42 patients with primary insomnia and 38 normal controls were detected and enrolled in the study through strict structural clinical interview, using the diagnostic criteria for PI of Diagnostic and Statistical Manual of Mental Disorders, Fourth edition (DSM-IV). Then all the subjects were investigated by questionaires including the Pittsburgh Sleep Quality Index(PSQI), Glasgow Sleep Effort Scale(GSES), Dysfunctional Beliefs and Attitudes about Sleep(DBAS), Multidimensional Fatigue Inventory(MFI), State-Trait Anxiety Inventory(STAI), and Beck Depression Inventory(revised edition)(BDI-R). At 7am to 9am the next morning, 2ml blood of all the subjects were collected from vein of the arm when limosis, then plasmas were collected by centrifugal separation(4℃3000r/m). The plasma NPY concentration was determined by enzyme-linked immuno sorbent assay(ELISA). The SPSS 13.0 analysis soft ware was used to build up a data base and do the statistics to study the association between plasma NPY and PI.Results:The results showed that 1,The plasma NPY concentrations in patients with primary insomnia were significantly higher than those in normal controls(5.11007±2.866079 v. s.7.00642±3.438649 ng/ml, p<0.05).2,Compared with CG, the scores of PSQI,GSES,DBAS,MFI,STAI,BDI-R in patients with primary insomnia were significantly different(p<0.05).3,Gender, age and the scores of PSQI,GSES,DBAS,MFI,STAI,BDI-R in patients with primary insomnia were not associated with the levels of plasma NPY.Conclusions:The plasma NPY concentrations of patients with primary insomnia and normal controls were first detected and compared, and results showed that the plasma NPY levels of the former were significantly lower than those of the latter. The NPY system may take part in the pathophysiological proeess of primary insomnia, and the plasma NPY level may be a reference in diagnosis of primary insomnia, which may provide a new clue in prophylaxis and treatment of PI.