Restricted and disrupted sleep: Effects on autonomic function, neuroendocrine stress systems and stress responsivity

Coronavirus disease 2019 (COVID-19) and psychological distress in China: Does neighbourhood matter?

Using individual data (n = 937) obtained from an online questionnaire between 20th January and 13th February, the early stage of the outbreak of the Coronavirus Disease 2019 (COVID-19) in 2020, we explore the direct association between people's perceptions of Coronavirus Disease 2019 (COVID-19) and psychological distress. We further examine the moderating role of neighbourhood environment and this distress. We find that people living in infected communities tend to perceive higher level of psychological distress compared to people living in uninfected communities. People's expected duration of COVID-19 is associated with higher psychological distress and this is partially moderated by the perception of neighbourhood noise level and overall environment quality. Additional results quantify the evidence that a quiet and well maintained neighbourhood environment could reduce the negative influences of expectation of a long duration of COVID-19 on people's psychological distress.

Persistent Low Positive Affect and Sleep Disturbance across Adolescence Moderate Link between Stress and Depressive Symptoms in Early Adulthood

The purpose of this study was to characterize the association between recent major life events and depressive symptoms during early adulthood, and to determine whether adolescents with chronically low positive affect or persistent sleep disturbance were more vulnerable to the link between stress and depressive symptoms. Adolescents (n = 147; 63.9% female; 33.7% non-Hispanic white) were recruited in 10th-11th grade and re-assessed 2 and 4 years later. At each assessment, adolescents completed measures of positive affect and sleep disturbances. At the final assessment, participants reported on their exposure to major life events in the past 12 months. Exposure to more major life events in the past year was associated with greater depressive symptoms in early adulthood. Chronically low positive affect and persistent sleep disturbances throughout adolescence each independently moderated this relationship. Specifically, only participants reporting low positive affect across the three assessments showed a positive and significant association between major life events and depressive symptoms. Further, only participants reporting sleep disturbances at all three assessments showed a positive and significant association between major life events and depressive symptoms. Chronically low positive affect and persistent sleep disturbances during adolescence may be useful indicators of risk for depression during early adulthood. Further, interventions targeting adolescent sleep disturbances and improving positive affect may be useful in reducing the risk for depression following life stress during this high risk developmental phase.

Sleep Quality in Young Adult Informal Caregivers: Understanding Psychological and Biological Processes

BACKGROUND

Providing informal care for a relative or friend with medical or mental needs can extol a physical burden on the caregiver, including impaired aspects of sleep quality such as suboptimal sleep duration, lengthened sleep latency, frequent awakenings, daytime sleepiness, and poor self-rated sleep quality. Diminished sleep quality can worsen the health in the caregiver, including dysregulation of hypothalamic-pituitary-adrenal axis (HPA) activity. Few studies have attempted to describe sleep in young adults who provide regular informal care. This study examines subjective and objective indicators of sleep quality and diurnal cortisol rhythms among young adult caregivers relative to non-caregiving peers. We expect that caregivers will exhibit poorer objective and subjective sleep quality and greater dysregulation in diurnal cortisol indices, than demographically similar non-caregivers, and that caregivers with poorer sleep will exhibit pronounced cortisol dysregulation.

METHODS

Participant self-reported sleep quality over the prior month via the Pittsburgh Sleep Quality Index and objective sleep quality was observed via wrist actigraph for three consecutive days. Diurnal salivary cortisol was also measured across the three days of actigraph monitoring.

RESULTS

Informal caregivers exhibited more self-reported sleep disturbance and greater sleep latency than non-caregivers, as well as more objectively measured sleep fragmentation. Caregivers with a shorter sleep duration were observed to have flatter diurnal cortisol slopes than caregivers with a relatively longer sleep duration.

CONCLUSIONS

Young adult caregivers appear to be at risk for impairment in sleep quality, which in turn might impact health through HPA axis dysregulation. Longitudinal research is needed to identify these relationships across time.

Voluntary exercise ameliorates synaptic pruning deficits in sleep-deprived adolescent mice

Adolescence is a critical period for brain development and adequate sleep during this period is essential for physical function and mental health. Emerging evidence has detailed the neurological impacts of sleep insufficiency on adolescents, as was unveiled by our previous study, microglia, one of the crucial contributors to synaptic pruning, is functionally disrupted by lack of sleep. Here, we provided evidence featuring the protective effect and the underlying mechanisms of voluntary exercise (VE) on microglial functions in an adolescent 72 h sleep deprivation (SD) model. We identified that the aberrant hippocampal neuronal activity and impaired short-term memory performance in sleep-deprived mice were prevented by 11 days of VE. VE significantly normalized the SD-induced dendritic spine increment and maintained the microglial phagocytic ability in sleep-deprived mice. Moreover, we found that the amendment of the noradrenergic signal in the central nervous system may explain the preventative effects of VE on the abnormalities of microglial and neuronal functions caused by SD. These data suggested that VE may confer protection to the microglia-mediated synaptic pruning in the sleep-deprived adolescent brains. Therefore, physical exercise could be a beneficial health practice for the adolescents that copes the adverse influence of inevitable sleep insufficiency.

The mental health of Chinese women with polycystic ovary syndrome is related to sleep disorders, not disease status

BACKGROUND

Mental health disorders are highly prevalent in polycystic ovary syndrome (PCOS) cases. The etiology for anxiety/depression in women with PCOS still remains unclear, due to conflicting results.

AIM

To examine whether an association exists between the mental health of Chinese women with PCOS and various indicators such as their disease characteristics, biochemistry results and sleep status.

METHODS

During July 2018 and January 2020, our study included a total of 433 women diagnosed with PCOS at Chongqing Hospital of Traditional Chinese Medicine. Sleep-related variables were evaluated by the Pittsburgh Sleep Quality Index (PSQI), anxiety and depression values were quantified by the Hospital Anxiety and Depression Scale (HADS), and biochemistry results were collected from the medical records of the patients.

RESULTS

26.6% patients resulted as positive anxiety and 23.6% as positive depression. We found significant associations between anxiety/depression status and sleep conditions of PCOS patients. More specifically, anxiety significantly associated with sleep quality OR (95%CI) = 1.611 (1.147-2.261), sleep disturbance 2.326 (1.468-3.685) and daytime dysfunction 1.457 (1.122-1.891). Similarly, depression significantly associated with sleep quality 1.467 (1.043-2.063), sleep disturbance 1.624 (1.030-2.561) and daytime dysfunction 1.406 (1.077-1.836). There was no association detected between mental health and disease characteristics, as well as reproductive and metabolic indicators in PCOS.

LIMITATION

Cross-sectional nature of the data prevents causal associations, selection bias of a hospital-based population.

CONCLUSIONS

Sleep-related disorders might be involved in the etiology and development of the anxiety/depression observed in PCOS cases. We propose that management of sleep disorders should be an integral part of the disease management of women with PCOS.

Longitudinal Changes in Sleep: Associations with Shifts in Circulating Cytokines and Emotional Distress in a Cancer Survivor Population

BACKGROUND

Sleep disturbances are associated with numerous mood disorders. Similarly, anxiety and depression are associated with modulation of the psychoneuroimmune (PNI) axis. This study hypothesized that changes in both monitored and self-reported measures of sleep would relate to changes in circulating cytokine levels in an emotionally distressed population of cervical cancer survivors.

METHODS

Biospecimens, patient-reported outcome (PRO) measures, and actigraphy were collected from cervical cancer survivors enrolled in a biobehavioral clinical trial. Longitudinal changes over a 4-month period were examined. Sleep time measured by actigraphy and PRO were analyzed for correlative changes with emotional distress and serum cytokines (n = 71).

RESULTS

Longitudinal change in the actigraph measure of sleep time was inversely associated with changes in depression and anxiety (test for linear trend, p = 0.02 and p = 0.05 respectively), as well as acute-phase response/pro-inflammatory cytokines (test for linear trend, p = 0.003, interleukin (IL)-2; 0.022, IL-1β; 0.0002, IL-6; and 0.049, tumor necrosis factor α). Conversely, changes in self-reported sleep problems were related to an increase in depression and anxiety (p = 0.001 and p = 0.01 respectively), the T helper 2 (Th2) cytokine IL-5 (p = 0.027), and the counter-regulatory cytokine IL-10 (0.016).

CONCLUSION

This study showed that an increase in sleep time or decrease in sleep problems corresponded with a reduction in self-reported emotional distress and attenuation of pro-inflammatory, Th2, and counter-regulatory cytokines. Our results support sleep measurement as a meaningful biobehavioral variable in cancer survivorship. This study also indicates that sleep investigators should be aware that choice of methodology might influence concordance with different classes of immune parameters.

Cardiac autonomic modulation of adolescents with different levels of sleep quality

Evaluate the cardiac autonomic modulation of adolescents with different levels of sleep quality.

Methods

Adolescents aged 11 to 17 years who presented themselves an explanation of the project with consent form signed by participated in the study. Anthropometric and hemodynamic data collected, and questionnaires.

Results

Analysis of the variables, age, systolic blood pressure, diastolic blood pressure, waist circumference, body fat and body mass index among the groups with good and poor sleep quality did not present a significant difference (p>0.05) in any paired characteristics. Time domain analysis indicated lower values in the vagal modulation with poor sleep quality. In the frequency domain, LF component increased and HF component decreased significantly in the group with poor sleep quality. There was also a statistical difference in the LF/HF analysis, the group with poor sleep quality presented an increase in this variable.

Conclusion

The subjects with poor sleep quality present lower cardiac autonomic modulation.

Does Stress Trigger Seizures? Evidence from Experimental Models

This chapter describes the experimental evidence of stress modulation of epileptic seizures and the potential role of corticosteroids and neurosteroids in regulating stress-linked seizure vulnerability. Epilepsy is a chronic neurological disorder that is characterized by repeated seizures. There are many potential causes for epilepsy, including genetic predispositions, infections, brain injury, and neurotoxicity. Stress is a known precipitating factor for seizures in individuals suffering from epilepsy. Severe acute stress and persistent exposure to stress may increase susceptibility to seizures, thereby resulting in a higher frequency of seizures. This occurs through the stress-mediated release of cortisol, which has both excitatory and proconvulsant properties. Stress also causes the release of endogenous neurosteroids from central and adrenal sources. Neurosteroids such as allopregnanolone and THDOC, which are allosteric modulators of GABA-A receptors, are powerful anticonvulsants and neuroprotectants. Acute stress increases the release of neurosteroids, while chronic stress is associated with severe neurosteroid depletion and reduced inhibition in the brain. This diminished inhibition occurs largely as a result of neurosteroid deficiencies. Thus, exogenous administration of neurosteroids (neurosteroid replacement therapy) may offer neuroprotection in epilepsy. Synthetic neurosteroid could offer a rational approach to control neurosteroid-sensitive, stress-related epileptic seizures.

Hair Cortisol Concentration as a Biomarker of Sleep Quality and Related Disorders

Cortisol is the end product of the hypothalamic-pituitary-adrenal (HPA) axis, and its production is increased mainly in stressful situations or in chronic disorders accompanied by stress enhancement. Altered cortisol concentrations have been reported in a number of neuropsychiatric diseases and sleep disorders. Cortisol concentrations have been measured using several methods, and in several matrixes, such as blood, saliva, and urine. However, lately, hair cortisol, for several reasons, has emerged as a promising biomarker of long-term retrospective HPA activation. Several experimental approaches for cortisol measurement with the corresponding concentration reference ranges and a summary of findings from scientific literature on this field are presented. There is evidence of a close relationship between HPA functional alteration and the development of neuropsychiatric disorders. Sleep disorders are the most common manifestation in several neuropsychiatric conditions, and have also been associated to cortisol alterations in both adults and children. Many studies indicate that hair cortisol constitutes a valuable tool for further contributing to existing data on salivary, plasma, or urinary cortisol concentrations in patients with sleep disorders.

Mothers' sleep deficits and cognitive performance: Moderation by stress and age

There are well-known associations between stress, poor sleep, and cognitive deficits, but little is known about their interactive effects, which the present study explored in a sample of mothers of toddlers. Since certain types of cognitive decline start during the 20s and continue into later ages, we also explored whether mothers’ age interacted with stress and sleep in the prediction of cognitive functioning. We hypothesized that poorer sleep [measured using one week of 24-hour wrist actigraphy data] and having more chronic stressors [e.g., life events, household chaos, work/family role conflict] would be linked with poorer cognitive performance [both executive function and standardized cognitive ability tasks], and that the interactive combination of poorer sleep and more stressors would account for the effect. We also explored whether this process operated differently for younger versus older women. In a socioeconomically and geographically diverse community sample of 227 women with toddler-age children [age, M = 32.73 yrs, SD = 5.15 yrs], poorer cognitive performance was predicted by greater activity during the sleep period, shorter sleep duration, and lower night-to-night consistency in sleep; it was not associated with higher levels of stress. The interactive effects hypothesis was supported for sleep activity [fragmented sleep] and sleep timing [when mothers went to bed]. The combination of more exposure to stressors and frequent night waking was particularly deleterious for older women’s performance. For younger women, going to bed late was associated with poorer performance if they were experiencing high levels of stress; for those experiencing low levels of stress, going to bed late was associated with better performance.

Sleep, circadian system and traumatic stress

The human circadian system creates and maintains cellular and systemic rhythmicity essential for the temporal organization of physiological processes promoting homeostasis and environmental adaptation. Sleep disruption and loss of circadian rhythmicity fundamentally affects master homeostasic regulating systems at the crossroads of peripheral and central susceptibility pathways, similar to acute or chronic stress and, thus, may play a central role in the development of stress-related disorders. Direct and indirect human and animal PTSD research accordingly suggests circadian-system-linked sleep, neuroendocrine, immune, metabolic and autonomic dysregulation, linking circadian misalignment to PTSD pathophysiology. Additionally, there is evidence that sleep and circadian disruption may represent a vital pre-existing risk factor in the prediction of PTSD development, while sleep-related symptoms are among the most prominent in trauma-associated disorders. These facts may represent a need for a shift towards a more chronobiological understanding of traumatic sequel and could support better prevention, evaluation and treatment of sleep and circadian disruption as first steps in PTSD management. In this special issue, we highlight and review recent advances from human sleep and chronobiological research that enhances our understanding of the development and maintenance of trauma-related disorders.

Long working hours and burnout in health care workers: Non-linear dose-response relationship and the effect mediated by sleeping hours-A cross-sectional study

OBJECTIVES

Burnout among health care workers is highly prevalent and has profound impact on quality of care. Hospital on-duty schedules lead to long working hours and short sleeping hours; both are common factors associated with burnout. We examined the dose-response relationship and the potential mediating role of sleeping hours on the association between working hours and burnout among health care workers.

METHODS

We collected data on the burnout status, using the Mandarin version of the Copenhagen Burnout Inventory (subscales measure work-related and personal burnouts), working hours, sleeping hours, and relevant measures for 2081 health care personnel who underwent a routine health examination in a medical center in Taiwan during 2016-2017. Four subgroups were compared: physicians (n = 369), nurses (n = 973), technicians (n = 391), and administrators (n = 348).

RESULTS

Average weekly working hours are associated with burnout scores in a non-linear dose-response manner. Compared with a work week of 40 hours, the odds ratio of work-related burnout doubled when hours exceeded 60, tripled when hours exceeded 74, and quadrupled when hours exceeded 84. Physicians' burnout is less susceptible to incremental increases in working hours, compared to the situations in other health care workers. The proportions eliminated by reducing sleeping hours were 25%-73% for physicians and 7%-29% for nurses respectively.

CONCLUSIONS

Our findings suggest that working hours are associated with burnout, and the association was partially mediated by sleeping hours.

The effect of sleep on the salivary cortisol response to acute stressors: a review and suggestions

There have been steadily increasing studies on the relationship between sleep and stress. However, the findings regarding the effects of sleep on the acute stress response have been inconsistent. Elevated, blunted, or unchanged salivary cortisol stress response have been reported. Therefore, this study conducted a systematic review of previous studies to provide a comprehensive summary of the factors that influence the effects of sleep on the salivary cortisol stress response. We conducted a comprehensive electronic literature search in PubMed, PsycINFO, PsycARTICLES, Web of Science, MEDLINE, and EMBASE for human studies published in English (up to June 2019). Finally, 17 articles with participants aged 6.4-72 years were included in this review. We assessed the following factors: designing factors (sleep measurement, stress induction, cortisol sampling period, and time intervals between sleep measurement and the acute stress task), analyzing factors (cortisol analysis), and participants' characteristics (age, sex, and background stress levels); subsequently, we explained conflicting findings across the current literature. Further, we provide study design, analysis, and report suggestions for optimal assessment of the effects of sleep on the acute stress response. This summary of influencing factors and suggestions for future studies could help elucidate the impact of sleep on stress and advance the field.

Worry and insomnia as risk factors for depression during initial stages of COVID-19 pandemic in India

The biggest nationwide COVID-19 pandemic lockdown worldwide was enforced in India for an initial period of 21-days. Emerging evidence suggests that pandemic situations and associated lockdowns have an adverse impact on sleep and mental health. However, prediction of sleep health from sociodemographic characteristics and the public’s worry during the initial stages of the COVID-19 pandemic has not been extensively explored so far. It’s also unclear whether sleep outcomes mediate the association between worry and mental health during pandemic situations. A web-survey (N = 391) on sociodemographic characteristics, COVID-19 related worry, sleep health (insomnia and daytime sleepiness), and depression was conducted during the initial 21-days of the COVID-19 stringent lockdown in India. Multiple regression analyses showed that variables, including sex, age, income level, and worry score, contributed to the significant regression equation for insomnia but not for daytime sleepiness. Specifically, the female, younger, lower income, and highly worried populations contributed significantly more than the male, elderly, higher income, and less worried populations, respectively, to the prediction of insomnia. Mediation analyses showed that insomnia, but not daytime sleepiness, fully mediated the relationship between worry score and severity of depressive symptoms. We provide evidence that the female, younger, lower income, and worried populations may be at higher risk for insomnia during pandemic situations. Current evidence gives hope that improving sleep may reduce depressive symptoms during a pandemic situation. This underscores the importance of the implementation of effective public health policies in conjunction with strategical responses to the COVID-19 pandemic.

Effects of Sleep Deprivation on the Tryptophan Metabolism

Sleep has a regulatory role in maintaining metabolic homeostasis and cellular functions. Inadequate sleep time and sleep disorders have become more prevalent in the modern lifestyle. Fragmentation of sleep pattern alters critical intracellular second messengers and neurotransmitters which have key functions in brain development and behavioral functions. Tryptophan metabolism has also been found to get altered in SD and it is linked to various neurodegenerative diseases. The kynurenine pathway is a major regulator of the immune response. Adequate sleep alleviates neuroinflammation and facilitates the cellular clearance of metabolic toxins produced within the brain, while sleep deprivation activates the enzymatic degradation of tryptophan via the kynurenine pathway, which results in an increased accumulation of neurotoxic metabolites. SD causes increased production and accumulation of kynurenic acid in various regions of the brain. Higher levels of kynurenic acid have been found to trigger apoptosis, leads to cognitive decline, and inhibit neurogenesis. This review aims to link the impact of sleep deprivation on tryptophan metabolism and associated complication in the brain.

Sleep Extension: A Potential Target for Obesity Treatment

PURPOSE OF REVIEW

Sleep and obesity share a bidirectional relationship, and weight loss has been shown to enhance sleep. Aiming to extend sleep on its own or as part of a lifestyle intervention may attenuate health consequences of short sleep. This review highlights several sleep extension approaches, discusses feasibility of each, and summarizes findings relevant to obesity.

RECENT FINDINGS

Sleep extension in response to experimental sleep restriction demonstrates partial rescue of cardiometabolic dysfunction in some but not all studies. Adequate sleep on a nightly basis may be necessary for optimal health. While initial sleep extension interventions in habitually short sleepers have been met with obstacles, preliminary findings suggest that sleep extension or sleep hygiene interventions may improve glycemic control, decrease blood pressure, and enhance weight loss. Sleep extension has the potential to attenuate obesity risk and cardiometabolic dysfunction. There is tremendous opportunity for future research that establishes a minimum threshold for sleep extension effectiveness and addresses logistical barriers identified in seminal studies.

Acute and Chronic Stress in Daily Police Service: A Three-Week N-of-1 Study

On duty, police officers are exposed to a variety of acute, threatening stress situations and organizational demands. In line with the allostatic load model, the resulting acute and chronic stress might have tremendous consequences for police officers' work performance and psychological and physical health. To date, limited research has been conducted into the underlying biological, dynamic mechanisms of stress in police service. Therefore, this ecological momentary assessment study examined the associations of stress, mood and biological stress markers of a 28-year-old male police officer in a N-of-1 study over three weeks (90 data points). Four times a day (directly after waking up, 30 minutes later, 6 hours later, before going to bed), he answered questions about the perceived stress and mood using a smartphone application. With each data entry, he collected saliva samples for the later assessment of salivary cortisol (sCort) and alpha-amylase (sAA). In addition, data was collected after six police incidents during duty. sCort and sAA were not related to perceived stress in daily life and did not increase in police incidents. Regarding mood measures, deterioration of calmness, but not valence and energy was associated with perceived stress. The results suggest continued police service to constitute a major chronic stressor resulting in an inability to mount a proper response to further acute stress. As an indicator of allostatic load, psychological and biological hyporesponsivity in moments of stress may have negative consequences for police officers' health and behavior in critical situations that require optimal performance. Prospectively, this research design may also become relevant when evaluating the efficacy of individualized stress management interventions in police training.

A brief period of sleep deprivation leads to subtle changes in mouse gut microbiota

Not getting enough sleep is a common problem in our society and contributes to numerous health problems, including high blood pressure, diabetes and obesity. Related to these observations, a wealth of studies has underscored the negative impact of both acute and chronic sleep deprivation on cognitive function. More recently it has become apparent that the gut microbiota composition can be rapidly altered, modulates brain function and is affected by the aforementioned health problems. As such, changes in the microbiota composition may contribute to the behavioural and physiological phenotypes associated with sleep deprivation. It is unclear, however, whether a brief period of sleep deprivation can also negatively impact the gut microbiota. Here, we examined the impact of 5 hr of sleep deprivation on gut microbiota composition of male C57Bl6/J mice. Despite the fact that the overall microbial composition did not change between the control- and sleep-deprived groups, the relative abundance of the Clostridiaceae and Lachnospiraceae were slightly altered in sleep-deprived animals compared to controls. Together, these data suggest that depriving mice of sleep for 5 hr leads to subtle changes in the gut microbiota composition.

Traumatic stress and the circadian system: neurobiology, timing and treatment of posttraumatic chronodisruption

Background: Humans have an evolutionary need for a well-preserved internal 'clock', adjusted to the 24-hour rotation period of our planet. This intrinsic circadian timing system enables the temporal organization of numerous physiologic processes, from gene expression to behaviour. The human circadian system is tightly and bidirectionally interconnected to the human stress system, as both systems regulate each other's activity along the anticipated diurnal challenges. The understanding of the temporal relationship between stressors and stress responses is critical in the molecular pathophysiology of stress-and trauma-related diseases, such as posttraumatic stress disorder (PTSD). Objectives/Methods: In this narrative review, we present the functional components of the stress and circadian system and their multilevel interactions and discuss how traumatic stress can affect the harmonious interplay between the two systems. Results: Circadian dysregulation after trauma exposure (posttraumatic chronodisruption) may represent a core feature of trauma-related disorders mediating enduring neurobiological correlates of traumatic stress through a loss of the temporal order at different organizational levels. Posttraumatic chronodisruption may, thus, affect fundamental properties of neuroendocrine, immune and autonomic systems, leading to a breakdown of biobehavioral adaptive mechanisms with increased stress sensitivity and vulnerability. Given that many traumatic events occur in the late evening or night hours, we also describe how the time of day of trauma exposure can differentially affect the stress system and, finally, discuss potential chronotherapeutic interventions. Conclusion: Understanding the stress-related mechanisms susceptible to chronodisruption and their role in PTSD could deliver new insights into stress pathophysiology, provide better psychochronobiological treatment alternatives and enhance preventive strategies in stress-exposed populations.

Sleep problems in adolescence are prospectively linked to later depressive symptoms via the cortisol awakening response

Sleep disturbance is a symptom of and a well-known risk factor for depression. Further, atypical functioning of the HPA axis has been linked to the pathogenesis of depression. The purpose of this study was to examine the role of adolescent HPA axis functioning in the link between adolescent sleep problems and later depressive symptoms. Methods: A sample of 157 17-18 year old adolescents (61.8% female) completed the Pittsburgh Sleep Quality Inventory (PSQI) and provided salivary cortisol samples throughout the day for three consecutive days. Two years later, adolescents reported their depressive symptoms via the Center for Epidemiological Studies Depression Scale (CES-D). Results: Individuals (age 17-18) with greater sleep disturbance reported greater depressive symptoms two years later (age 19-20). This association occurred through the indirect effect of sleep disturbance on the cortisol awakening response (CAR) (indirect effect = 0.14, 95%CI [.02 -.39]). Conclusions: One pathway through which sleep problems may lead to depressive symptoms is by up-regulating components of the body's physiological stress response system that can be measured through the cortisol awakening response. Behavioral interventions that target sleep disturbance in adolescents may mitigate this neurobiological pathway to depression during this high-risk developmental phase.

Sleep and the athlete: narrative review and 2021 expert consensus recommendations

Elite athletes are particularly susceptible to sleep inadequacies, characterised by habitual short sleep (<7 hours/night) and poor sleep quality (eg, sleep fragmentation). Athletic performance is reduced by a night or more without sleep, but the influence on performance of partial sleep restriction over 1-3 nights, a more real-world scenario, remains unclear. Studies investigating sleep in athletes often suffer from inadequate experimental control, a lack of females and questions concerning the validity of the chosen sleep assessment tools. Research only scratches the surface on how sleep influences athlete health. Studies in the wider population show that habitually sleeping <7 hours/night increases susceptibility to respiratory infection. Fortunately, much is known about the salient risk factors for sleep inadequacy in athletes, enabling targeted interventions. For example, athlete sleep is influenced by sport-specific factors (relating to training, travel and competition) and non-sport factors (eg, female gender, stress and anxiety). This expert consensus culminates with a sleep toolbox for practitioners (eg, covering sleep education and screening) to mitigate these risk factors and optimise athlete sleep. A one-size-fits-all approach to athlete sleep recommendations (eg, 7-9 hours/night) is unlikely ideal for health and performance. We recommend an individualised approach that should consider the athlete's perceived sleep needs. Research is needed into the benefits of napping and sleep extension (eg, banking sleep).

Sleep restriction alters physiological and emotional responses to emotion induction

NEW FINDINGS

What is the central question of this study? The aim of the present study was to assess the effects of sleep restriction on self-report and autonomic responses to neutral and sad film clips. What is the main finding and its importance? Ratings of sadness and heart rate deceleration were greater while watching the sad clip, with no effect of sleep restriction, whereas heart rate variability and skin conductance were impacted by sleep restriction and, to a lesser extent, by film clips. The results suggest that autonomic function was adaptively altered by sleep restriction, in order to maintain a 'normal' response to emotional cues, despite mounting fatigue.

ABSTRACT

Habitual insufficient sleep has long-term health consequences via its impact on autonomic nervous system (ANS) function and on regulation of emotion. To our knowledge, the effects of insufficient sleep on emotion-induced ANS function have not been tested. The present study aimed to address this lacuna. Using an emotion induction procedure, the effects of sleep restriction on physiological responses to validated neutral and sad film clips were assessed in a two-by-two, pseudo-randomized, cross-over design. Thirty-one participants, aged 20-33 years, were assessed after sleeping for either 5 h (sleep restricted, SR) or 8 h (well rested, WR) per night, for three consecutive nights. Physiological measures included heart rate, heart rate variability, skin conductance response (SCR) and participants' ratings of affect and fatigue. There was no effect of sleep conditions on self-reported negative affect, but watching the sad clip reduced self-reported fatigue in the SR condition. There was greater heart rate deceleration while watching sad relative to neutral clips, independent of the sleep condition. Sleep restriction increased heart rate variability measures, with no effect of emotion induction. There was an interaction of emotion induction with sleep condition for SCR, with more SCRs to sad relative to neutral clips in the WR condition, and the opposite effect in the SR condition. Combined, the results suggest that the ANS response to an emotional cue was altered by sleep restriction. The results suggest an adaptive ANS response to mild, chronic sleep restriction, resulting in constant heart rate response and self-reported experience across WR and SR conditions, despite mounting fatigue.

Improvement of Aspects of Subjective Sleep Quality of Healthy Volunteers by Ingestion of Porcine Placental Extract: A Randomized Cross-Over Pilot Study

Objectives: This study assessed the effects of oral porcine placental extract (PPE) on sleep quality of healthy volunteers not satisfied with their sleep.

Design: This study used a randomized, placebo-controlled, double-blind, cross-over clinical pilot study.

Setting: This study was conducted under an outpatient multicenter setting in Japan.

Interventions: A total of 20 healthy Japanese volunteers aged between 28 and 73, whose Pittsburgh Sleep Quality Index global scores were between 6 and 10, successfully completed the study. At first, PPE at 300 mg/kg or placebo was ingested for 2 weeks. Then, after a 2-week washout period, each group ingested under a cross-over setting the opposite sample (placebo or PPE) for another 2 weeks.

Main Outcome Measures: Objective measurement of the sleep made with an activity tracker and subjective measurements of sleep quality by use of St. Mary's Hospital Sleep Questionnaire were done just before and after the administration time slots.

Results: No effect of PPE on the sleep length was observed. Several measures in the subjective St. Mary's Hospital Sleep Questionnaire, i.e., changes in Q5 (sleep depth) and Q9 (sleep wellness) between pre- and post-ingestions, were significantly different between groups in the direction of improvement of subjective sleep quality in the PPE group.

Conclusions: Although oral PPE at 300 mg/day for 2 weeks did not affect the length of sleep itself, it significantly improved several measures of subjective sleep quality. These results suggest that PPE might be a way to improve sleep quality without hypnotic drugs.

Clinical Trial Registration:www.umin.ac.jp/ctr/, identifier: UMIN000026468.

Boundarylessness and sleep quality among virtual team members - a pilot study from Germany

Background

In the course of globalisation and digitalisation, new ways of work are becoming increasingly prevalent. To remain competitive as an organisation, cooperation across time, place, and organisational boundaries is becoming necessary. Virtual teamwork offers these advantages, but can also be both, an opportunity and a burden, for employees. This pilot study aims to gain first insights into job demands and resources in virtual teamwork to provide a basis for further research from which appropriate health promotion and prevention measures can be derived.

Methods

In this pilot study, an online questionnaire was used to examine the relationship between boundarylessness as a job demand, psychological detachment as a personal resource, as well as perceived stress and sleep quality as health outcomes among 46 virtual team members from Germany. Data collection lasted from October 2019 to January 2020. Validated scales were used for the questionnaire, except for virtuality. Due to insufficient operationalisation to date, a virtuality scale was developed based on the current state of research. The data were analysed with ordinal logistic regression analyses and median split t-tests.

Results

The results indicate that perceived stress impaired sleep quality of virtual team members in this sample. In contrast, successful psychological detachment from work was positively related to sleep quality. A higher degree of virtuality coincided with higher levels of boundarylessness. Virtual team members with leadership responsibility showed higher levels of psychological detachment.

Conclusion

The present pilot study breaks ground and provides initial insights into the relationship between virtual teamwork and employee health in the German context. Further research, particularly on job demands in virtual teamwork, is needed to derive concrete health promotion and prevention measures.

Sleep duration and affective reactivity to stressors and positive events in daily life

OBJECTIVE

Experimental evidence suggests that inadequate sleep disrupts next-day affective processing and evokes greater stress reactivity. However, less research has focused on whether sleep predicts next-day affective reactivity to naturally occurring stressors and positive events in daily life, as well as the reversed direction of association (i.e., affective reactivity to daily events as predictors of subsequent sleep). The purpose of this study was to evaluate the within-person, bidirectional associations between nightly sleep duration and day-to-day fluctuations in affect related to stressors and positive events.

METHOD

Adults ages 33-84 (N = 1,982, 57% female) in the U.S. National Study of Daily Experiences II reported sociodemographics and chronic conditions at baseline, then completed telephone interviews for 8 consecutive days about their sleep duration, daily stressors, positive events, and affect.

RESULTS

Prior-night sleep duration moderated the link between current-day events and positive affect, but not negative affect. Specifically, nights of shorter-than-usual sleep duration predicted more pronounced decreases in positive affect in response to daily stressors, as well as smaller increases in positive affect in response to daily positive events. Results for the reversed direction of association showed no evidence for affective reactivity to daily events as predictors of subsequent sleep duration. People with more chronic conditions were more reactive to positive events, particularly after nights of longer sleep.

CONCLUSION

Affective reactivity to daily stressors and positive events vary based upon sleep duration, such that sleep loss may amplify loss of positive affect on days with stressors, as well as reduce positive affective responsiveness to positive events. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

The Jaw Epidemic: Recognition, Origins, Cures, and Prevention

Contemporary humans are living very different lives from those of their ancestors, and some of the changes have had serious consequences for health. Multiple chronic "diseases of civilization," such as cardiovascular problems, cancers, ADHD, and dementias are prevalent, increasing morbidity rates. Stress, including the disruption of traditional sleep patterns by modern lifestyles, plays a prominent role in the etiology of these diseases, including obstructive sleep apnea. Surprisingly, jaw shrinkage since the agricultural revolution, leading to an epidemic of crooked teeth, a lack of adequate space for the last molars (wisdom teeth), and constricted airways, is a major cause of sleep-related stress. Despite claims that the cause of this jaw epidemic is somehow genetic, the speed with which human jaws have changed, especially in the last few centuries, is much too fast to be evolutionary. Correlation in time and space strongly suggests the symptoms are phenotypic responses to a vast natural experiment-rapid and dramatic modifications of human physical and cultural environments. The agricultural and industrial revolutions have produced smaller jaws and less-toned muscles of the face and oropharynx, which contribute to the serious health problems mentioned above. The mechanism of change, research and clinical trials suggest, lies in orofacial posture, the way people now hold their jaws when not voluntarily moving them in speaking or eating and especially when sleeping. The critical resting oral posture has been disrupted in societies no longer hunting and gathering. Virtually all aspects of how modern people function and rest are radically different from those of our ancestors. We also briefly discuss treatment of jaw symptoms and possible clinical cures for individuals, as well as changes in society that might lead to better care and, ultimately, prevention.

Sleep and Parasympathetic Activity During Rest and Stress in Healthy Adolescents and Adolescents With Bipolar Disorder

OBJECTIVE

Sleep disruption contributes to the pathophysiology of mental disorders, particularly bipolar illness, but the biobehavioral mechanisms of this relationship are insufficiently understood. This study evaluated sleep duration, timing, and variability as prospective predictors of parasympathetic nervous system activity during rest and social stress in adolescents with bipolar disorder, reflecting sleep-related interference in stress regulatory systems that may confer vulnerability to mood episodes.

METHOD

Participants were adolescents with bipolar disorder (n = 22) and healthy adolescents (n = 27). Sleep duration and timing were measured by actigraphy for 1 week before a laboratory social stress task, during which high-frequency heart rate variability (HF-HRV) was indexed using electrocardiography. Multilevel models were used to evaluate group, sleep characteristics, and their interactions as predictors of initial HF-HRV and change in HF-HRV during rest and stress.

RESULTS

Associations between group and changes in HF-HRV during stress were moderated by sleep duration mean (z = 2.24, p = .025) and variability (z = -2.78, p = .006). There were also main effects of mean sleep duration on initial HF-HRV during rest (z = -5.37, p < .001) and stress (z = -2.69, p = .007). Follow-up analyses indicated that, in bipolar adolescents during stress, shorter and longer sleep durations were associated with lower initial HF-HRV (z = -5.44, p < .001), and greater variability in sleep duration was associated with less change in HF-HRV (z = -2.18, p = .029).

CONCLUSIONS

Sleep durations that are relatively short or long, which are characteristic of mood episodes, are associated with parasympathetic vulnerability to social stress in adolescents with bipolar disorder. Obtaining regular sleep of moderate duration may favorably affect responses to stress in bipolar youth.

Poor Sleep Quality Is Associated with Altered Taste Perception in Chinese Adults

BACKGROUND

Small clinical studies have suggested that individuals with insufficient sleep could experience taste dysfunction. However, this notion has not been examined in a large-scale, population-based study.

OBJECTIVE

This study aimed to examine whether overall sleep quality, as assessed by insomnia, daytime sleepiness, snoring, and sleep duration, was associated with the odds of having altered taste perception in a large population-based study.

DESIGN

This was a cross-sectional study that used data from a subcohort of the Kailuan study, an ongoing multicenter cohort study that began in 2006 in Tangshan City, China.

PARTICIPANTS/SETTING

The participants were 11,030 adults aged 25 years or older (mean age 53.7 ± 10.7 years), who were free of neurodegenerative diseases. All the participants had undergone questionnaire assessments and medical examinations at Kailuan General Hospital from June 2012 to October 2013.

MAIN OUTCOME MEASURES

Altered taste and olfactory perception were assessed via a questionnaire with two questions regarding whether participants had any problems with sense of taste or smell for ≥3 months.

STATISTICAL ANALYSES PERFORMED

The association between sleep quality and altered taste/olfactory perception was examined using a logistic regression model, adjusting for age, sex, lifestyle factors (eg, obesity, smoking, alcohol intake, and physical activity) and health status (eg, lipid profiles, blood pressure, modification use, and presence of chronic diseases).

RESULTS

Poor overall sleep quality was associated with a higher risk of having altered taste perception (adjusted odds ratio for low vs high sleep quality 2.03, 95% CI 1.42 to 2.91; P < 0.001). Specifically, insomnia, daytime sleepiness, and short sleep duration, but not prolonged sleep duration and snoring, were significantly associated with altered taste perception. A significant association between overall sleep quality and the risk of having altered olfactory perception was also observed (adjusted odds ratio for low vs high sleep quality 2.17, 95% CI 1.68 to 2.80; P < 0.001).

CONCLUSIONS

In this population-based study, poor sleep quality was associated with a high likelihood of altered taste perception.

EVIDENCE OF THE ASSOCIATION BETWEEN SLEEP DURATION AND BLOOD PRESSURE IN ADOLESCENTS: A SYSTEMATIC REVIEW

OBJECTIVE

To review the epidemiological evidence of the association between sleep duration and blood pressure in adolescents.

DATA SOURCES

We performed a systematic review of observational studies in Medline, Scopus, Lilacs, Web of Science, Science Direct databases and Virtual Libraries in English, Spanish and Portuguese published until September 2018. Studies were selected first by title and abstract, then by complete reading, according to the eligibility criteria. The reference list of selected articles was evaluated in order to retrieve relevant studies.

DATA SYNTHESIS

Initially, 1,455 articles were retrieved. After exclusion due to duplicity or not meeting the eligibility criteria, 13 articles were included in the review. Studies varied greatly in sample size (143 to 6,940 patients), methods of measuring blood pressure and sleep duration, cutoff points, categorization and adjustment of variables. The main evidence from the studies is that short sleep duration is associated with high blood pressure in adolescence, although the presence of association between high blood pressure and long sleep duration is possible, but not clear in the literature.

CONCLUSIONS

Sleep duration, especially short duration, is associated with high blood pressure in adolescents. Such evidence draws attention to implications on cardiovascular health in this age group.

Cognitive function and brain plasticity in a rat model of shift work: role of daily rhythms, sleep and glucocorticoids

Many occupations require operations during the night-time when the internal circadian clock promotes sleep, in many cases resulting in impairments in cognitive performance and brain functioning. Here, we use a rat model to attempt to identify the biological mechanisms underlying such impaired performance. Rats were exposed to forced activity, either in their rest-phase (simulating night-shift work; rest work) or in their active-phase (simulating day-shift work; active work). Sleep, wakefulness and body temperature rhythm were monitored throughout. Following three work shifts, spatial memory performance was tested on the Morris Water Maze task. After 4 weeks washout, the work protocol was repeated, and blood and brain tissue collected. Simulated night-shift work impaired spatial memory and altered biochemical markers of cerebral cortical protein synthesis. Measures of daily rhythm strength were blunted, and sleep drive increased. Individual variation in the data suggested differences in shift work tolerance. Hierarchical regression analyses revealed that type of work, changes in daily rhythmicity and changes in sleep drive predict spatial memory performance and expression of brain protein synthesis regulators. Moreover, serum corticosterone levels predicted expression of brain protein synthesis regulators. These findings open new research avenues into the biological mechanisms that underlie individual variation in shift work tolerance.

Psychological interventions to improve sleep in college students: A meta-analysis of randomized controlled trials

Sleep disturbances and insomnia are common in college students, and reduce their quality of life and academic performance. The aim of this meta-analysis was to evaluate the efficacy of psychological interventions aimed at improving sleep in college students. A meta-analysis was conducted with 10 randomized controlled trials with passive control conditions (N = 2,408). The overall mean effect size (Hedges' g) of all sleep-related outcomes within each trial was moderate to large (g = 0.61; 95% confidence interval: 0.41-0.81; numbers-needed-to-treat = 3). Effect sizes for global measures of sleep disturbances were g = 0.79; 95% confidence interval: 0.52-1.06; and for sleep-onset latency g = 0.65; 95% confidence interval: 0.36-0.94. The follow-up analyses revealed an effect size of g = 0.56; 95% confidence interval: 0.45-0.66 for the combined sleep-related outcomes based on three studies. No significant covariates were identified. These results should be interpreted cautiously due to an overall substantial risk of bias, and in particular with regard to blinding of participants and personnel. Nevertheless, they provide evidence that psychological interventions for improving sleep are efficacious among college students. Further research should explore long-term effects and potential moderators of treatment efficacy in college students.

Sleep Duration and Behaviours: A Descriptive Analysis of a Cohort of Dogs up to 12 Months of Age

Sleep is a vital behaviour that can reflect an animal's adaptation to the environment and their welfare. However, a better understanding of normal age-specific sleep patterns is crucial. This study aims to provide population norms and descriptions of sleep-related behaviours for 16-week-old puppies and 12-month-old dogs living in domestic environments. Participants recruited to a longitudinal study answered questions relating to their dogs' sleep behaviours in surveys issued to them when their dogs reached 16 weeks (n = 2332) and 12 months of age (n = 1091). For the statistical analysis, subpopulations of dogs with data regarding sleep duration at both timepoints were used. Owners of 16-week-old puppies perceived their dogs to sleep longer during the day and over a 24 h period, but for less time during the night than owners of 12-month-old dogs. At both timepoints, dogs were most commonly settled to sleep by being left in a room/area without human company. However, of dogs that had access to people overnight, 86.7% and 86.8% chose to be around people at 16 weeks and 12 months of age, respectively. The most common sleeping place was in a kennel/crate at 16 weeks (49.1%), and a dog bed at 12 months (31.7%). Future research within this longitudinal study will investigate how sleep duration and behaviours change with age and impact on a dog's health and behaviour.

The relationship between sleep and autonomic health

Objective: To examine the relationship between sleep and resting autonomic nervous system (ANS) functioning in college students. Participants: Participants were 141 undergraduate students (52 males) recruited from a large southeastern university during September-October 2017. Methods: Participants completed self-report inventories (demographic and sleep characteristics). Resting state skin conductance (SC) and heart rate variability (HRV) were measured in a laboratory setting for ANS functioning. Results: SC was positively associated with sleep quality (p = 0.027), sleep latency (p = 0.040), and use of sleep medication (p < 0.001). Analyses yielded a negative association between the standard deviation of the normal-normal interval of heart beats (SDNN) and the self-reported amount of time to fall asleep each night (p = 0.041). Sleep efficiency was negatively correlated with low frequency HRV (p = 0.002). Conclusions: Sleep components are associated with resting ANS activity, and targeted interventions focused on improved ANS functioning may benefit sleep quality in college students.

Sleep and COVID-19: considerations about immunity, pathophysiology, and treatment

The fear and uncertainty caused by the coronavirus disease 2019 (COVID-19) pandemic, threats to survival are one of the main problems of everyday life; however, mental health care must also be considered a priority. During social isolation also called self-quarantine, the restricted mobility and social contact, concern about financial resources and availability of supplies, fear of infection, questions about the duration of self-quarantine, cause anxiety, depression, stress, insomnia and reduced the quality and quantity of sleep, that may present a greater risk to the health of the general population. Sleep disorders are increasingly becoming a major health issue in modern society, and are influenced by retinal stimulation by electronic devices, as well extended and/or night shift-work, which may aggravate the systemic and lung inflammation during viral infections. Sleep disorders can induce pro-inflammatory states and be harmful during the COVID-19 pandemic. The possible interactions between many drugs used to treat COVID-19, and those used to treat sleep disorders are unknown, mostly due to the lack of a standard protocol to treat these patients. Insufficient sleep or irregular sleep-wake cycles may impair health, immune system, induce pro-inflammation state, and may lead to increased vulnerability to viral infections, involving inflammatory and oxidative/antioxidant imbalance. In this sense, obstructive sleep apnea has been associated with recognized COVID-19 risk comorbidities and considered a risk factor for COVID-19. During the COVID-19 pandemic, health care cannot stop, and telemedicine has presented itself as an alternative method of delivering services. When a face-to-face visit is mandatory, or in locations with minimal community transmission where sleep centers have resumed activities, it is important that the sleep center facilities are properly prepared to receive the patients during the COVID-19 pandemic, and follow all relevant safety rules. In this work we gathered a group of researchers, specialists in aspects related to chronobiology, sleep, sleep disorders, and the immune system. Thus, we conducted a narrative review in order to address the relationship between COVID-19 and sleep, as well as its immunological aspects and strategies that may be applied in order to mitigate the harmful effects on health that affects everyone during the pandemic.

Association between sleep disorder and quality of life in patients with type 2 diabetes: a cross-sectional study

BACKGROUND

We investigated the association between sleep symptoms, which cause sleep disorder, and quality of life (QoL) among people with type 2 diabetes (T2D).

METHODS

In this cross-sectional study of 342 people with T2D, the Japan National Health and Wellness Survey (NHWS) database 2016 were used. We treated the respondents who reported experiencing any of the sleep symptoms as having sleep disorders. To examine health-related QoL (HRQoL), we used the physical component summary (PCS) and the mental component summary (MCS) from the 36-Item short-form and the EuroQol 5 Dimension (EQ-5D) survey instruments. Overall activity impairment was used for assessment of the effect on the individual's ability to perform regular daily activities. We used t-test and one-way ANOVA test for comparison QoL scores between the participants with and without sleep disorders.

RESULTS

66.4% of the participants with T2D reported having a sleep disorder. The PCS, MCS, EQ-5D, and overall activity impairment of people with sleep disorder was significantly poorer than those of the people without. Specific sleep symptoms, such as waking up to go to the bathroom, daytime sleepiness, and waking up too early (before the alarm clock), had high prevalence (35.4, 27.8 and 20.2%). The participants who experienced waking up to go to the bathroom or daytime sleepiness demonstrated significantly poorer QoL on all scores related to QoL, but those who experienced waking up too early only demonstrated significantly poorer QoL on the EQ-5D.

CONCLUSIONS

Two-thirds of people with T2D in this study suffer from sleep disorders. The people who experience waking up to go to the bathroom or daytime sleepiness had significantly poorer QoL than those without these symptoms. Thus, sleep disorders, especially the symptoms of waking up to go to the bathroom or daytime sleepiness, might be the treatment targets for QOL of people with T2DM.

Sleep deprivation and adrenalectomy lead to enhanced innate escape response to visual looming stimuli

Optimal selections of innate behaviors that enable animals to adapt to particular conditions, whether environmental or internal, remain poorly understood. We report that mice under acute (8 h) sleep deprivation had an enhanced innate escape response and upregulation of c-fos expression in multiple brain areas that regulate wakefulness. By comparison, adrenalectomized mice under the same sleep deprivation condition displayed an even more exaggerated escape response and these wake-regulating brain areas were even more active. This suggests that acute sleep deprivation enhances innate escape response, possibly by altering wake state without causing significant anxiety. We also report that the hypothalamic-pituitary-adrenal axis feedback under sleep deprivation prevents an exaggerated escape response by modulating wake-regulating brain areas. Taken together, our findings suggest that animals prioritize escape response over sleep, as the need of both behaviors simultaneously increase. We also provide an insight into the neural mechanisms underlying the interaction between sleep and innate escape response.

Association of sleep duration with stroke, myocardial infarction, and tumors in a Chinese population with metabolic syndrome: a retrospective study

Background

Previous studies have suggested that abnormal sleep duration is associated with increased risk of metabolic syndrome (MetS). However, evidence on the association of sleep duration with stroke, myocardial infarction (MI) and tumors in populations with MetS is limited.

Methods

A total of 8968 participants (2754 with MetS at baseline) were recruited in this retrospective study between March 2012 and December 2012. The baseline characteristics and information on sleep duration were collected by self-reported questionnaires. In addition, physical examination and blood test were also performed. The outcome events in this study were new onset of stroke, MI and tumors during subsequent follow-up. Multivariate logistic regressions were adopted to investigate the relationships between sleep duration and outcome events among different sleep duration groups (< 6 h, 6–7 h, 7–8 h [reference], 8–9 h, and > 9 h per day) in participants with MetS.

Results

The mean self-reported total sleep duration was 7.8 ± 1.2 h. Compared with participants with MetS slept for 7–8 h per day, the adjusted odds ratios (ORs) for those slept for > 9 h in stroke, MI and tumors were 2.014 (95% confidence interval [CI]: 1.184–3.426, P = 0.010), 1.731 (95% CI: 0.896–3.344, P = 0.102) and 2.159 (95% CI: 0.991–4.704, P = 0.053), respectively, whereas the adjusted ORs for those slept for < 6 h in stroke, MI and tumors were 2.249 (95% CI: 0.973–5.195, P = 0.058), 1.213 (95% CI, 0.358–4.104, P = 0.756) and 1.743 (95% CI, 0.396–7.668, P = 0.462), respectively.

Conclusions

Long sleep duration (> 9 h) significantly increased the risk of stroke but not MI and tumors in individuals with MetS compared with 7–8 h of sleep duration. Short sleep duration (< 6 h) was not associated with the increased risk of stroke, MI and tumors in individuals with MetS.

Effect of repetitive transcranial magnetic stimulation on the cognitive impairment induced by sleep deprivation: a randomized trial

OBJECTIVE

Currently, an efficient method for improving cognitive impairment due to sleep deprivation (SD) is lacking. The aim of this study is to evaluate the effect of high-frequency repetitive transcranial magnetic stimulation (rTMS) during SD on reversing the adverse effects of SD.

METHODS

A total of 66 healthy people were randomized into the rTMS group and sham group. Both groups were deprived of sleep for 24 h. During SD, participants were asked to complete several cognitive tasks and underwent mood assessments. Saliva cortisol levels, plasma concentrations of brain-derived neurotrophic factor (BDNF), precursor BDNF (proBDNF), and tissue-type plasminogen activator (tPA), and frontal blood activation were detected before and after SD. The rTMS group received real rTMS stimulation for 2 sessions of 10 Hz rTMS (40 trains of 50 pulses with a 20-second intertrain interval) to the left dorsolateral prefrontal cortex and the sham group received sham stimulation during SD.

RESULTS

Twenty-four hours of SD induced a reduced accuracy in the n-back task, increases in both anxiety and depression, increased cortisol levels, decreased frontal blood activation and decreased BDNF levels in healthy people. Notably, rTMS improved the hyperactivity of the hypothalamic-pituitary-adrenal axis and decreased frontal blood activation induced by SD, and reduced the consumption of plasma proBDNF.

CONCLUSIONS

Twenty-four hours of SD induced a cognitive impairment. The administration of high-frequency rTMS during sleep deprivation exerted positive effects on HPA axis and frontal activation and might help alleviate cognitive impairment in the long term.

Sleep, circadian rhythms and health

At the core of human thought, for the majority of individuals in the developed nations at least, there is the tacit assumption that as a species we are unfettered by the demands imposed by our biology and that we can do what we want, at whatever time we choose, whereas in reality every aspect of our physiology and behaviour is constrained by a 24 h beat arising from deep within our evolution. Our daily circadian rhythms and sleep/wake cycle allow us to function optimally in a dynamic world, adjusting our biology to the demands imposed by the day/night cycle. The themes developed in this review focus upon the growing realization that we ignore the circadian and sleep systems at our peril, and this paper considers the mechanisms that generate and regulate circadian and sleep systems; what happens mechanistically when these systems collapse as a result of societal pressures and disease; how sleep disruption and stress are linked; why sleep disruption and mental illness invariably occur together; and how individuals and employers can attempt to mitigate some of the problems associated with working against our internal temporal biology. While some of the health costs of sleep disruption can be reduced, in the short-term at least, there will always be significant negative consequences associated with shift work and sleep loss. With this in mind, society needs to address this issue and decide when the consequences of sleep disruption are justified in the workplace.

The effects of recovery sleep on pain perception: A systematic review

Experimental studies highlight profound effects of sleep disruptions on pain, showing that sleep deprivation (SD) leads to hyperalgesic pain changes. On the other hand, given that sleep helps normalizing bodily functions, a crucial role of restorative sleep in the overnight restoration of the pain system seems likely. Thus, a systematic review of experimental studies on effects of recovery sleep (RS; subsequently to SD) on pain was performed with the aim to check whether RS resets hyperalgesic pain changes occurring due to SD. Empirical animal and human studies including SD-paradigms, RS and pain assessments were searched in three databases (PubMed, Web of Science, PsycINFO) using a predefined algorithm. 29 studies were included in this review. Most results indicated a reset of enhanced pain sensitivity and vulnerability following RS, especially when total SD was implemented and pressure pain or painful symptoms (human studies) were assessed. Further research should focus on whether and how recovery is altered in chronic pain patients, as this yields implications for pain treatment by enhancing or stabilizing RS.

Interleukin-6 is associated with acute concussion in military combat personnel

BACKGROUND

Concussion is the most common type of TBI, yet reliable objective measures related to these injuries and associated recovery processes remain elusive, especially in military personnel. The purpose of this study was to characterize the relationship between cytokines and recovery from acute brain injury in active duty service members. Inflammatory cytokines (IL-6, IL-10, and TNFα) were measured acutely in blood samples within 8 h following a medically diagnosed concussion and then 24 h later.

METHODS

Participants (n = 94) were categorized into two groups: 1) military personnel who sustained provider-diagnosed concussion, without other major medical diagnosis (n = 45) and 2) healthy control participants in the same deployment environment who did not sustain concussion or other illness or injuries (n = 49). IL-6, IL-10, and TNFα concentrations were measured using an ultrasensitive single-molecule enzyme-linked immunosorbent assay. Differences in cytokine levels between concussed and healthy groups were evaluated at two time points (time point 1 ≤ 8 h after injury; time point 2 = 24 h following time point 1).

RESULTS

At time point 1, IL-6 median (IQR) concentrations were 2.62 (3.62) in the concussed group, which was greater compared to IL-6 in the healthy control group (1.03 (0.90); U = 420.00, z = - 5.12, p < 0.001). Compared to healthy controls, the concussed group did not differ at time point 1 in IL-10 or TNFα concentrations (p's > 0.05). At time point 2, no differences were detected between concussed and healthy controls for IL-6, IL-10, or TNFα (p's > 0.05). The median difference between time points 1 and 2 were compared between the concussed and healthy control groups for IL-6, IL-10, and TNFα. Change in IL-6 across time was greater for the concussed group than healthy control (- 1.54 (3.12); U = 315.00, z = - 5.96, p < 0.001), with no differences between groups in the change of IL-10 or TNFα (p's > 0.05).

CONCLUSION

Reported here is a significant elevation of IL-6 levels in concussed military personnel less than 8 h following injury. Future studies may examine acute and chronic neurological symptomology associated with inflammatory cytokine levels, distinguish individuals at high risk for developing neurological complications, and identify underlying biological pathways to mitigate inflammation and improve outcomes.

Shorter and longer durations of sleep are associated with an increased twelve-month prevalence of psychiatric and substance use disorders: Findings from a nationally representative survey of US adults (NESARC-III)

The lack of comprehensive data on the association between psychiatric and substance use disorders and habitual sleep duration represents a major health information gap. This study examines the 12-month prevalence of mental disorders stratified by duration of sleep. Data were drawn from face-to-face interviews conducted in the National Epidemiologic Survey on Alcohol and Related Conditions III, a nationally representative survey of US adults (N = 36,309). There were 1893 (5.26%) participants who reported <5h of sleep/night; 2434(6.76%) 5 h/night; 7621(21.17%) 6 h/night; 9620(26.72%) 7 h/night; 11,186(31.07%) 8 h/night, and 3245(9.01%) ≥9 h/night. A U-shaped association was observed between sleep duration and all mental disorders. The prevalence of mental disorders was 55% for individuals with <5 h/night and 47.81% for ≥9 h/night, versus 28.24% for the 7 h/night (aOR = 1.90 and 1.39 respectively). The greatest odds ratios were for the <5 h/night group, with an increased risk above 3-fold for panic disorder (PD), post-traumatic stress disorder (PTSD), psychotic disorder, and suicide attempt; between 2 and 3 fold for major depressive disorder (MDD), bipolar disorder (BD), and generalized anxiety disorder (GAD); and between 1 and 2 fold for tobacco and drug use disorders, specific and social phobias. The ≥9 h/night group had an increased risk above 1 to 2-fold regarding tobacco and drug use disorders, MDD, BD, PD, social phobia, GAD, PTSD, psychotic disorder, and suicide attempt. U-shaped associations exist between sleep duration and mental disorders, calling for respect to recommendations for adequate sleep duration in routine clinical care as well as to actions for primary prevention in public health settings.