Humoral Regulation of Sleep

Effects of three-duration Tai-Chi exercises on depression and sleep quality in older women

OBJECTIVE

This study aims to explore the effects of 24 weeks of three-duration Tai-Chi (TC) practice on depression and sleep quality in older women.

METHODS

A total of 124 older women were randomly divided into four groups: short-time group (SG, n = 31, mean age: 65.3), medium-time group (MG, n = 30, mean age: 65.7), long-time group (LG, n = 32, mean age: 64.9) and control group (CG, n = 31, mean age: 66.2). The Beck Depression Inventory (BDI) and Pittsburgh Sleep Quality Index (PSQI), and serum levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and 5-hydroxytryptamine (5-HT) were measured.

RESULTS

1) Within-group comparisons: Compared with the baseline, the 12th and 24th weeks showed reductions in TNF-α and IL-6 levels and increase in 5-HT level in the SG, MG and LG (p < 0.05). The LG at the 24th week had reduced BDI and PSQI scores (p < 0.05). Compared with the 12th week, the 24th week showed reductions in TNF-α and IL-6 levels (p < 0.01) and increase in 5-HT level (p < 0.05) in the SG, MG, and LG. 2) Between-group comparisons: The SG, MG, and LG had lower TNF-α and IL-6 levels and higher 5-HT level than the CG at 12th and 24th weeks (p < 0.05). At the 24th week, the LG had lower BDI and PSQI scores than the CG and lower TNF-α level than the SG and MG (p < 0.05). The MG had lower TNF-α levels than the SG in the 24th week (p < 0.01).

CONCLUSION

These results indicate that older individuals may undertake at least 12 weeks of TC exercise with a duration of 60 min per session to significantly improve depressive mood and sleep quality.

Physical Activity and Sleep Quality Association in Different Populations: A Meta-Analysis

The meta-analysis statistical methodology was used to test the effect of physical activity intervention on sleep quality. According to the preliminary results of the meta-analysis, moderating variables (age stage and physical activity intensity) were included for further study. On this basis, measures and schemes to improve sleep quality through physical activity were put forward. A preliminary Endnote X9 search of relevant literature from six electronic databases (Web of Science, Medline, PubMed, CNKI, PsycINFO and Wanfang) was performed. The results showed the following: (1) The overall test effect of physical activity intervention on sleep quality was not significant (p = 0.15). (2) Moderate- and low-intensity physical activity had significant effects on sleep quality (moderate intensity d = 2.56, p = 0.015; low-intensity d = 1.38, p = 0.03), while high-intensity physical activity had no obvious effect on sleep quality (d = 1.12, p = 0.32). (3) There were differences in the effect of physical activity on sleep quality at different ages. The effect of physical activity on sleep quality was more obvious in children and middle-aged and elderly people (children d = 1.24, p = 0.03; middle-aged and elderly people d = 1.98, p = 0.037), but not in young people (d = 1.32, p = 0.11). Conclusion: The overall effect of physical activity on sleep quality was not significant. Physical activity had an obvious effect on the sleep quality of children and middle-aged and elderly people but had no obvious effect on young people. Moderate-intensity physical activity had a certain effect on sleep quality, but high-intensity physical activity had no obvious effect on sleep quality. Future studies need to confirm these findings with a good large sample and moderating variables.

Effectiveness of Taijiquan in treating insomnia: A systematic review and meta-analysis of randomized controlled studies

BACKGROUND

Sleep efficiency of <80% based on actigraphy was defined as insomnia as self-reported difficulty falling asleep or waking up at night three to four times per week. It is known that adequate sleep is very important for human wellbeing, affecting people's work and life, insomnia will seriously damage our daily life. There is no recognized non-drug treatment. Studies have found that Taijiquan has a positive effect on insomnia patients. This systematic review and meta-analysis will evaluate the effect of Taijiquan on insomnia.

METHODS

To find all randomized controlled trials exploring the effects of Taijiquan on insomnia patients in Chinese and English, eight databases (Pubmed, Embase, Cochrane library, Web of Science, CNKI, CBM, VIP, and Wanfang Data) were searched. The retrieval time is from database construction to October 2021. Searches were conducted in both English and Chinese language. A meta-analysis by mean difference (MD) and 95% confidence interval (CI) was performed with RevMan 5.3. The risk of bias for each study was accounted for according to the Cochrane Handbook. Our primary outcome was Pittsburg Sleep Quality Index. We explored sources of heterogeneity by comparing effect sizes across different types of etiology, country, control group, and intervention type. The protocol was pre-registered with PROSPERO, CRD42021284511.

RESULTS

Twenty-one RCTs published between 2004 and 2021 with 2,022 participants were included in this study. Twenty-one randomized controlled studies showed that Tai Chi significantly improved PSQI scores in patients with cancer, muscle fibrosis, and sub-health insomnia [MD = -1.16, 95% CI (-1.62, -0.71), P < 0.01]; There is insufficient evidence of improvement in patients with cerebrovascular disease [MD = -0.54, 95% CI (-1.58, 0.51), P = 0.31]; 8-form, 10-form or 24-form Yang's Taijiquan had the same effect in improving PSQI [MD = -1.33, 95% CI (-1.85, -0.81), P < 0.01]. When there is no treatment, exercise, exercise and health education as the control, taijiquan has a significant effect on insomnia treatment, and there is no difference in efficacy compared with cognitive behavioral therapy and health education (usual care) alone.

CONCLUSIONS

The results of the study showed that Taijiquan significantly improved sleep quality in healthy adults and patients with chronic diseases, which suggests that Taijiquan may be considered as an alternative behavioral therapy in the treatment of insomnia. In the future, more high-quality, well-controlled randomized trials are needed to better inform clinical decisions.

Aerobic exercise modulates cytokine profile and sleep quality in elderly

Background

Sleep disturbance is a major problem for older adults which can be exacerbated by increased inflammation as aging is associated with increased circulating pro-inflammatory and lower anti-inflammatory cytokines. There is a need to develop alternative medicine techniques to help improve sleep quality in the elderly.

Objective

To investigate the effects of aerobic exercise training on the sleep quality and inflammatory cytokines in elderly subjects.

Material and methods

Forty previously sedentary elderly subjects participated in this study, their age ranged from 61- 67 years. All subjects were randomly assigned to supervised aerobic exercise intervention group (group A, n=25) or control group (group B, n=25). Polysomnographic recordings for sleep quality assessment, interleukin- 6 (IL-6), tumor necrosis factor- alpha (TNF-α) and interleukin-10 (IL-10) were measured before and after 6 months at the end of the study.

Results

There was a significant increase in total sleep duration, sleep efficiency and sleep onset latency in group(A) after 6 months of aerobic exercise training, while, wake time after sleep onset and rapid eye movement (REM) latency significantly reduced after 6 months of aerobic training compared with values obtained prior to aerobic exercise training. Also, the mean values of TNF- α and IL-6 decreased significantly and the mean value of IL-10 significantly increased in group (A) after the aerobic exercise training, however the results of the control group were not significant. Moreover, there were significant differences between both groups at the end of the study.

Conclusion

Exercise training can be considered as a non-pharmacological modality for modifying sleep quality and inflammation among elderly.

Alcohol Dependence and Its Relationship With Insomnia and Other Sleep Disorders

Sleep-related complaints are widely prevalent in those with alcohol dependence (AD). AD is associated not only with insomnia, but also with multiple sleep-related disorders as a growing body of literature has demonstrated. This article will review the various aspects of insomnia associated with AD. In addition, the association of AD with other sleep-related disorders will be briefly reviewed. The association of AD with insomnia is bidirectional in nature. The etiopathogenesis of insomnia has demonstrated multiple associations and is an active focus of research. Treatment with cognitive behavioral therapy for insomnia is showing promise as an optimal intervention. In addition, AD may be associated with circadian abnormalities, short sleep duration, obstructive sleep apnea, and sleep-related movement disorder. The burgeoning knowledge on insomnia associated with moderate-to-severe alcohol use disorder has expanded our understanding of its underlying neurobiology, clinical features, and treatment options.

The pathogenesis of obstructive sleep apnea

Obstructive sleep apnea (OSA) is a major source of cardiovascular morbidity and mortality, and represents an increasing burden on health care resources. Understanding underlying pathogenic mechanisms of OSA will ultimately allow for the development of rational therapeutic strategies. In this article, we review current concepts about the pathogenesis of OSA. Specifically, we consider the evidence that the upper airway plays a primary role in OSA pathogenesis and provide a framework for modelling its biomechanical properties and propensity to collapse during sleep. Anatomical and neuromuscular factors that modulate upper airway obstruction are also discussed. Finally, we consider models of periodic breathing, and elaborate generalizable mechanisms by which upper airway obstruction destabilizes respiratory patterns during sleep. In our model, upper airway obstruction triggers a mismatch between ventilatory supply and demand. In this model, trade-offs between maintaining sleep stability or ventilation can account for a full range of OSA disease severity and expression. Recurrent arousals and transient increases in airway patency may restore ventilation between periods of sleep, while alterations in neuromuscular and arousal responses to upper airway obstruction may improve sleep stability at still suboptimal levels of ventilation.

Ghrelin and its interactions with growth hormone, leptin and orexins: implications for the sleep-wake cycle and metabolism

Several studies have shown that ghrelin administration promotes wakefulness in rodents, while in human males it induces sleep but has no effect in women. Ghrelin also plays an important role in metabolism and appetite regulation, and as described in this review may participate in the energy balance during sleep. In this review, we summarize some of the effects induced by ghrelin administration on the sleep-wake cycle in relation to the effects of other hormones, such as growth hormone, leptin, and orexin. Finally we discuss the relationship between sleep deprivation, obesity and ghrelin secretion pattern.

Modulation of vigilance in the primary hypersomnias by endogenous enhancement of GABAA receptors

The biology underlying excessive daytime sleepiness (hypersomnolence) is incompletely understood. After excluding known causes of sleepiness in 32 hypersomnolent patients, we showed that, in the presence of 10 μM γ-aminobutyric acid (GABA), cerebrospinal fluid (CSF) from these subjects stimulated GABA(A) receptor function in vitro by 84.0 ± 40.7% (SD) relative to the 35.8 ± 7.5% (SD) stimulation obtained with CSF from control subjects (Student's t test, t = 6.47, P < 0.0001); CSF alone had no effect on GABA(A) signaling. The bioactive CSF component had a mass of 500 to 3000 daltons and was neutralized by trypsin. Enhancement was greater for α2 subunit- versus α1 subunit-containing GABA(A) receptors and negligible for α4 subunit-containing ones. CSF samples from hypersomnolent patients also modestly enhanced benzodiazepine (BZD)-insensitive GABA(A) receptors and did not competitively displace BZDs from human brain tissue. Flumazenil--a drug that is generally believed to antagonize the sedative-hypnotic actions of BZDs only at the classical BZD-binding domain in GABA(A) receptors and to lack intrinsic activity--nevertheless reversed enhancement of GABA(A) signaling by hypersomnolent CSF in vitro. Furthermore, flumazenil normalized vigilance in seven hypersomnolent patients. We conclude that a naturally occurring substance in CSF augments inhibitory GABA signaling, thus revealing a new pathophysiology associated with excessive daytime sleepiness.

Can high altitude influence cytokines and sleep?

The number of persons who relocate to regions of high altitude for work, pleasure, sport, or residence increases every year. It is known that the reduced supply of oxygen (O₂) induced by acute or chronic increases in altitude stimulates the body to adapt to new metabolic challenges imposed by hypoxia. Sleep can suffer partial fragmentation because of the exposure to high altitudes, and these changes have been described as one of the responsible factors for the many consequences at high altitudes. We conducted a review of the literature during the period from 1987 to 2012. This work explored the relationships among inflammation, hypoxia and sleep in the period of adaptation and examined a novel mechanism that might explain the harmful effects of altitude on sleep, involving increased Interleukin-1 beta (IL-1β), Interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) production from several tissues and cells, such as leukocytes and cells from skeletal muscle and brain.

Loss of polyubiquitin gene Ubb leads to metabolic and sleep abnormalities in mice

AIMS

Ubiquitin performs essential roles in a myriad of signalling pathways required for cellular function and survival. Recently, we reported that disruption of the stress-inducible ubiquitin-encoding gene Ubb reduces ubiquitin content in the hypothalamus and leads to adult-onset obesity coupled with a loss of arcuate nucleus neurones and disrupted energy homeostasis in mice. Neuropeptides expressed in the hypothalamus control both metabolic and sleep behaviours. In order to demonstrate that the loss of Ubb results in broad hypothalamic abnormalities, we attempted to determine whether metabolic and sleep behaviours were altered in Ubb knockout mice.

METHODS

Metabolic rate and energy expenditure were measured in a metabolic chamber, and sleep stage was monitored via electroencephalographic/electromyographic recording. The presence of neurodegeneration and increased reactive gliosis in the hypothalamus were also evaluated.

RESULTS

We found that Ubb disruption leads to early-onset reduced activity and metabolic rate. Additionally, we have demonstrated that sleep behaviour is altered and sleep homeostasis is disrupted in Ubb knockout mice. These early metabolic and sleep abnormalities are accompanied by persistent reactive gliosis and the loss of arcuate nucleus neurones, but are independent of neurodegeneration in the lateral hypothalamus.

CONCLUSIONS

Ubb knockout mice exhibit phenotypes consistent with hypothalamic dysfunction. Our data also indicate that Ubb is essential for the maintenance of the ubiquitin levels required for proper regulation of metabolic and sleep behaviours in mice.

Obesity and upper airway control during sleep

Mechanisms linking obesity with upper airway dysfunction in obstructive sleep apnea are reviewed. Obstructive sleep apnea is due to alterations in upper airway anatomy and neuromuscular control. Upper airway structural alterations in obesity are related to adipose deposition around the pharynx, which can increase its collapsibility or critical pressure (P(crit)). In addition, obesity and, particularly, central adiposity lead to reductions in resting lung volume, resulting in loss of caudal traction on upper airway structures and parallel increases in pharyngeal collapsibility. Metabolic and humoral factors that promote central adiposity may contribute to these alterations in upper airway mechanical function and increase sleep apnea susceptibility. In contrast, neural responses to upper airway obstruction can mitigate these mechanical loads and restore pharyngeal patency during sleep. Current evidence suggests that these responses can improve with weight loss. Improvements in these neural responses with weight loss may be related to a decline in systemic and local pharyngeal concentrations of specific inflammatory mediators with somnogenic effects.

Obesity and obstructive sleep apnea: pathogenic mechanisms and therapeutic approaches

Obstructive sleep apnea is a common disorder whose prevalence is linked to an epidemic of obesity in Western society. Sleep apnea is due to recurrent episodes of upper airway obstruction during sleep that are caused by elevations in upper airway collapsibility during sleep. Collapsibility can be increased by underlying anatomic alterations and/or disturbances in upper airway neuromuscular control, both of which play key roles in the pathogenesis of obstructive sleep apnea. Obesity and particularly central adiposity are potent risk factors for sleep apnea. They can increase pharyngeal collapsibility through mechanical effects on pharyngeal soft tissues and lung volume, and through central nervous system-acting signaling proteins (adipokines) that may affect airway neuromuscular control. Specific molecular signaling pathways encode differences in the distribution and metabolic activity of adipose tissue. These differences can produce alterations in the mechanical and neural control of upper airway collapsibility, which determine sleep apnea susceptibility. Although weight loss reduces upper airway collapsibility during sleep, it is not known whether its effects are mediated primarily by improvement in upper airway mechanical properties or neuromuscular control. A variety of behavioral, pharmacologic, and surgical approaches to weight loss may be of benefit to patients with sleep apnea, through distinct effects on the mass and activity of regional adipose stores. Examining responses to specific weight loss strategies will provide critical insight into mechanisms linking obesity and sleep apnea, and will help to elucidate the humoral and molecular predictors of weight loss responses.

Inflammatory Cytokines in Nonpathological States

During infection, inflammatory cytokines induce regulated changes in the host's internal milieu that create a hostile environment to an invading pathogen. Recent evidence indicates that these cytokines are constitutively produced, their production is increased by environmental stressors other than microbes, and they modulate "normal" physiological processes.