Relationships between rumination and different types of rapid eye movement sleep in patients with chronic insomnia disorder.

BACKGROUND AND OBJECTIVE: Rumination, a common factor of chronic insomnia disorder (CID) caused by cognitive-emotional arousal, is associated with an increased amount of rapid eye movement (REM) sleep. However, the specific subtypes, such as phasic REM and tonic REM, that contribute to the increased REM sleep have not been reported. This study aimed to determine the association between rumination and different REM sleep subtypes in patients with CID. METHODS: This study enrolled 35 patients with CID and 27 age- and sex-matched healthy controls. The Immersion-Rumination Questionnaire evaluated participants' rumination, and the Insomnia Severity Index was used to assess insomnia severity. Finally, polysomnography was used to monitor objective sleep quality and quantification of different types of REM. RESULTS: The CID patients had higher rumination scores than the healthy controls. They had a shorter REM sleep duration, less phasic REM, a lower percentage of phasic REM time, and a higher percentage of tonic REM time. Spectral analysis revealed that the patients affected by insomnia had higher ß power during REM sleep, higher ß and σ power during phasic REM sleep, and higher ß, and γ power during tonic REM sleep. Partial correlation analysis showed that rumination in the CID patients correlated negatively with the duration of phasic REM sleep. Additionally, rumination correlated negatively with δ power in REM sleep and positively with ß power in REM sleep, tonic REM sleep, phasic REM sleep, N3and N2 sleep in the patients with CID. CONCLUSION: The CID patients had stronger rumination, reduced total and phasic REM sleep, and the stronger rumination was, the shorter phasic REM was and the higher fast (ß) wave power in REM sleep.

Changed nocturnal levels of stress-related hormones couple with sleep-wake states in the patients with chronic insomnia disorder: A clinical pilot study.

OBJECTIVES: To explore the relationship between nocturnal levels of stress-related hormones and different sleep-wake states in chronic insomnia disorder (CID) patients. METHODS: Thirty-three CID patients and 34 good sleepers were enrolled and completed assessment of sleep log, Pittsburgh Sleep Quality Index and Insomnia Severity Index. During a-overnight polysomnography monitoring, the patients' vein bleeds were continually collected at different time points (pre-sleep, deep-sleep, 5-min or 30-min waking, and morning waking-up). The control subjects' bleeds were collected only at 22:00 and morning waking-up. The serum hormones were detected using enzyme-linked immunosorbent assay. RESULTS: Compared with at pre-sleep, the level of cortisol was significantly higher at morning waking-up respectively in two-group subjects (Ps < 0.001), with insignificant inter-group differences in cortisol, corticotropin releasing hormone and copeptin at the two time-points. In the patients, the nocturnal secretion curves of three hormones were similar, with the highest concentration at morning waking-up, followed by 30-min waking, 5-min waking, pre-sleep, and deep-sleep. The patients' cortisol (Z = 79.192, P < 0.001) and copeptin (Z = 12.333, P = 0.015) levels were statistically different at different time-points, with higher cortisol at morning waking-up relative to deep-sleep, pre-sleep and 5-min waking (Ps < 0.05), and at 30-min waking relative to deep-sleep and pre-sleep (Ps < 0.05), and higher copeptin at morning waking-up relative to deep-sleep (P < 0.05). CONCLUSIONS: In CID, the nocturnal wakes were instantaneously accompanied by high level, and deep sleep was accompanied by the lowest levels, of stress-related hormones, especially in cortisol, supporting the insomniac hypothesis of increased nocturnal pulse-release of cortisol.