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

Positivity Effect and Working Memory Performance Remains Intact in Older Adults After Sleep Deprivation

Background: Older adults perform better in tasks which include positive stimuli, referred to as the positivity effect. However, recent research suggests that the positivity effect could be attenuated when additional challenges such as stress or cognitive demands are introduced. Moreover, it is well established that older adults are relatively resilient to many of the adverse effects of sleep deprivation. Our aim was to investigate if the positivity effect in older adults is affected by one night of total sleep deprivation using an emotional working memory task. Methods: A healthy sample of 48 older adults (60-72 years) was either sleep deprived for one night (n = 24) or had a normal night's sleep (n = 24). They performed an emotional working memory n-back (n = 1 and 3) task containing positive, negative and neutral pictures. Results: Performance in terms of accuracy and reaction times was best for positive stimuli and worst for negative stimuli. This positivity effect was not altered by sleep deprivation. Results also showed that, despite significantly increased sleepiness, there was no effect of sleep deprivation on working memory performance. A working memory load × valence interaction on the reaction times revealed that the beneficial effect of positive stimuli was only present in the 1-back condition. Conclusion: While the positivity effect and general working memory abilities in older adults are intact after one night of sleep deprivation, increased cognitive demand attenuates the positivity effect on working memory speed.

The association between PSQI score and hypertension in a Chinese rural population: the Henan Rural Cohort Study

OBJECTIVES

This study investigated the association between poor sleep quality and hypertension, and evaluated how the Pittsburgh Sleep Quality Index (PSQI) score correlates with blood pressure and prevalent hypertension.

METHODS

A total of 27, 912 participants aged 18-79 years from the Henan Rural Cohort Study were included into the current study. PSQI score was classified as <3, 3-, 6-, ≥9. Multivariate logistic regression models and restricted cubic spline with hypertension as a dependent variable were conducted. A meta-analysis was conducted to validate the result of the cross-sectional study.

RESULTS

Altogether, 6,085 (21.80%) were poor sleepers and 9,056 (32.44%) suffered from hypertension. The odds ratios (ORs) (95% confidence intervals (CIs)) of participants with sleep quality of 3-, 6-, ≥9 were 1.16(1.07-1.26), 1.35(1.21-1.50) and 1.62 (1.39-1.88) compared to the participants with a score of less than 3 among participants excluding undiagnosed hypertension. ORs and 95% CIs per 3 increment score were higher for hypertension (1.16, 1.11-1.21) among total population, (1.18, 1.10-1.27) among men and (1.13, 1.08-1.19) among women. Compared to reference, poor sleep quality was associated with a higher odd of hypertension (OR 1.09, 95% CI 1.01-1.17) for total population, (1.14, 1.00-1.30) for men and (1.04, 0.95-1.13) for women. Moreover, the odds of hypertension were increased with increment of PSQI score after fitting restricted cubic splines (P_trend <0.01). The meta-analysis showed that pooled OR of hypertension was significantly higher for poor sleepers (1.62, 1.03-2.56, I² = 97.3%, P < 0.001).

CONCLUSIONS

Higher PSQI score was associated with increased odds of prevalent hypertension in both genders. In addition, poorer sleepers might suffer from hypertension.

The association between depressive and sleep symptoms for predicting incident disease onset after 6-year follow-up: findings from the English Longitudinal Study of Ageing

BACKGROUND

The independent effects of depressive symptoms and sleep problems for future physical illness risk have yet to be studied systematically across a variety of disease endpoints.

METHODS

We analysed data from 7395 participants (65.81 ± 9.39 years; 54.8% female) from the English Longitudinal Study of Ageing (ELSA). Baseline was wave 4 and participants were followed up for 6 years until wave 7. Sleep was measured using an adapted version of the Jenkins Sleep Problems questionnaire and depressive symptoms using the Centre for Epidemiological Studies Depression scale. Participants with the illness of interest at baseline [coronary heart disease (CHD), cancer, diabetes/high blood glucose, arthritis] were excluded from models predicting the onset of that illness at follow-up. Logistic regression was used, entering depressive symptoms and sleep problems simultaneously into models controlling for a wide range of covariates.

RESULTS

In fully adjusted models depressive symptoms predicted incident CHD (OR 1.11, 95% CI 1.04-1.20, p = 0.004) and diabetes/high blood glucose (OR 1.13, 95% CI 1.04-1.22, p = 0.002) independent of sleep problems; both depressive symptoms (OR 1.10, 95% CI 1.04-1.16, p = 0.002) and sleep problems (OR 1.14, 95% CI 1.02-1.26, p = 0.019) predicted incident arthritis.

CONCLUSIONS

Sleep problems and depressive symptoms, and a combination of both, were differentially associated with physical illness onset 6 years later. Our findings highlight the importance of taking into account somatic and affective experiences when looking across a variety of different physical illnesses.

Poor night's sleep predicts following day's salivary alpha-amylase under high but not low stress

Although sleep is linked to physiological stress systems like the autonomic nervous system (ANS), research is still limited regarding night-and-day interactions between nocturnal sleep characteristics, stress, and diurnal parameters of salivary alpha-amylase (sAA) as a surrogate marker of ANS activity. Fifty healthy university students rated their chronic stress burden and completed two five-day periods of ecological momentary assessment - under everyday conditions of both low stress (beginning of semester) and high stress (final examination preparation). Participants collected saliva six times daily and reported on the previous night's sleep (quality, latency, duration, disturbances) immediately after awakening. Additionally, a sub-sample wore actigraphs recording 'time in bed'. In contrast to previous assumptions, poor sleep predicted lower sAA awakening values, more decreased awakening responses, and steeper diurnal slopes the following day only under high stress, but not under low stress. Diurnal sAA parameters did not predict the following night's sleep characteristics. The sAA profile does not seem to be sensitive to everyday occurring sleep variations, but rather seems to be an indicator of more prolonged stress induced ANS dysregulation.

Physical Activity, Sleep, and Symptoms of Depression in Adults-Testing for Mediation

PURPOSE

Physical activity, sleep problems, and symptoms of depression contribute to overall well-being. The factors are reciprocally associated, but the nature of these associations remains unclear. The present study examined whether sleep problems mediated the association between physical activity and depressive symptoms.

METHODS

The eligible population (n = 3596) consisted of adults from the ongoing, population-based Cardiovascular Risk in Young Finns Study started in 1980. Participants' leisure-time physical activity was assessed with physical activity index (2007) and sleep problems with Jenkins' Sleep Questionnaire in 2007 and 2011. Depressive symptoms were measured using modified Beck Depression Inventory in 2007 and 2012, from which the items reflecting sleep problems were excluded. Mediation analyses, through which the associations between the variables were examined, were adjusted for sex and a set of health-related covariates assessed in 2007 and 2011.

RESULTS

Physical activity was associated with decreased levels of sleep problems and depressive symptoms (P < 0.05). The association between physical activity and depressive symptoms (b = -0.10, P < 0.01) was partly mediated by sleep problems (proportion mediated = 0.36, P < 0.01). The adjustment for depressive symptoms at baseline attenuated the mediation effect (proportion mediated = 0.30, P > 0.05).

CONCLUSIONS

Physical activity's favorable contribution to depressive symptoms was mediated partly by sleep, but the mediation effect disappeared after adjusting for the previous depressive symptoms in adulthood.

Developmental pathways towards mood disorders in adult life: Is there a role for sleep disturbances?

INTRODUCTION

Mood disorders are among the most prevalent and serious mental disorders and rank high among to the leading global burdens of disease. The developmental psychopathology framework can offer a life course perspective on them thus providing a basis for early prevention and intervention. Sleep disturbances, are considered risk factors for mood disorders across childhood, adolescence and adulthood. Assuming that sleep disturbances may play a pivotal role in the pathogenesis of mood disorders from a life course point of view, we reviewed the data on developmental pathways towards mood disorders in adult life in relation to sleep disturbances.

METHOD

From February 2017, a systematic search was conducted in PubMed, PsycINFO and Embase electronic databases for literature on developmental pathways to mood disorders in adult life in relation to sleep disturbances and to 1) pre-natal stress, 2) early brain developmental processes, and 3) temperaments, character and attachment style.

RESULTS

Eleven, 54 and 15 articles were respectively selected.

CONCLUSIONS

Experimental and clinical studies revealed that exposure to prenatal/early life stress results in sleep disturbances such as poor sleep and altered circadian regulation phases and may predict or even precipitate mood disorders in adulthood. Chronic sleep disruption may interfere with neuronal plasticity, connectivity and the developing brain thus contributing to the development of mood disorders. In addition sleep and circadian dysregulations have been shown to be related to those temperaments, character and attachment styles which are considered precursors of mood disorders. Sleep and circadian behaviours may serve as early targets regarding mood disorders.

Developmental Trajectories of Early Life Stress and Trauma: A Narrative Review on Neurobiological Aspects Beyond Stress System Dysregulation

Early life stressors display a high universal prevalence and constitute a major public health problem. Prolonged psychoneurobiological alterations as sequelae of early life stress (ELS) could represent a developmental risk factor and mediate risk for disease, leading to higher physical and mental morbidity rates in later life. ELS could exert a programming effect on sensitive neuronal brain networks related to the stress response during critical periods of development and thus lead to enduring hyper- or hypo-activation of the stress system and altered glucocorticoid signaling. In addition, alterations in emotional and autonomic reactivity, circadian rhythm disruption, functional and structural changes in the brain, as well as immune and metabolic dysregulation have been lately identified as important risk factors for a chronically impaired homeostatic balance after ELS. Furthermore, human genetic background and epigenetic modifications through stress-related gene expression could interact with these alterations and explain inter-individual variation in vulnerability or resilience to stress. This narrative review presents relevant evidence from mainly human research on the ten most acknowledged neurobiological allostatic pathways exerting enduring adverse effects of ELS even decades later (hypothalamic-pituitary-adrenal axis, autonomic nervous system, immune system and inflammation, oxidative stress, cardiovascular system, gut microbiome, sleep and circadian system, genetics, epigenetics, structural, and functional brain correlates). Although most findings back a causal relation between ELS and psychobiological maladjustment in later life, the precise developmental trajectories and their temporal coincidence has not been elucidated as yet. Future studies should prospectively investigate putative mediators and their temporal sequence, while considering the potentially delayed time-frame for their phenotypical expression. Better screening strategies for ELS are needed for a better individual prevention and treatment.

Glucocorticoid and inflammatory reactivity to a repeated physiological stressor in insomnia disorder

Despite known associations of insomnia disorder with alterations in cytokine and glucocorticoid (GC) production, neither the sensitivity of immune cells to a GC signal nor the reactivity of the hypothalamus-pituitary-adrenal (HPA) axis and inflammatory system to stress, or adaptation of these systems to repeated stress have been assessed in patients with insomnia. To investigate potential dysregulation in stress reactivity and adaptation to repeated exposure, a physiological stressor (the cold pressor test; CPT) was repeatedly administered to N = 20 participants with insomnia disorder (based on DSM-V, 18 females, age 30 ± 2.5 years) and N = 20 sex-matched healthy controls following an at-home actigraphy and in-laboratory PSG. HPA and inflammatory markers (serum cortisol, plasma interleukin [IL]-6) were measured at baseline/resting levels and following each of the three CPTs. In addition, sensitivity of monocytes to the synthetic GC dexamethasone was assessed in-vitro at baseline levels in order to examine the cortisol-IL-6 interplay at the cell level. Compared to healthy controls, individuals with insomnia disorder exhibited shorter sleep duration as assessed by actigraphy and PSG (p ≤ 0.05). HPA, but not inflammatory reactivity to the repeated CPT challenge was greater in insomnia disorder (p ≤ 0.05 for group effect), due to greater cortisol responses to the initial CPT (p ≤ 0.05). There were no between-group differences in the ability of the HPA to adapt to stress repetition nor in basal/resting levels of cortisol, IL-6, and GC sensitivity. These findings suggest that insomnia disorder potentiates HPA axis reactivity to initial/novel stressors, which may constitute a pathway underlying adverse health consequences in the long term.

Sympathetic Hyperactivity and Sleep Disorders in Individuals With Type 2 Diabetes

Introduction: Many studies on the impact of type 2 diabetes mellitus (T2DM) on sleep breathing have shown a higher prevalence and severity of sleep apnea-hypopnea syndrome (SAHS) in those with T2DM. Moreover, an increased activity of the sympathetic nervous system has been described in both pathologies. This cross-sectional study aimed to assess sympathetic activity in patients with T2DM, and to investigate the relationship between sympathetic activity and polysomnographic parameters. Materials and Methods: Thirty-six patients with T2DM without known clinical macrovascular nor pulmonary disease and 11 controls underwent respiratory polygraphy, and their cardiac variability and 24-h urine total metanephrines were measured. Results: SAHS was highly prevalent with a mean apnea-hypopnea index (AHI) in the range of moderate SAHS. In patients with T2DM, the nocturnal concentration of total metanephrines in urine were higher than diurnal levels [247.0 (120.0-1375.0) vs. 210.0 (92.0-670.0), p = 0.039]. The nocturnal total metanephrine concentration was positively and significantly associatedwith the percentage of sleeping time spent with oxygen saturation <90%(CT90). In the entire population and in subjects with T2DM, the multivariate regression analysis showed a direct interaction between the nocturnal concentration of urine metanephrines and the CT90. Conclusion: These findings suggest that the increase in sympathetic activity previously described in patients with T2DM could be mediated through nocturnal breathing disturbances. The diagnosis and treatment of SAHS may influence sympathetic activity disorders and may contribute to an improvement in T2DM and cardiovascular risk.

Multilevel Interactions of Stress and Circadian System: Implications for Traumatic Stress

The dramatic fluctuations in energy demands by the rhythmic succession of night and day on our planet has prompted a geophysical evolutionary need for biological temporal organization across phylogeny. The intrinsic circadian timing system (CS) represents a highly conserved and sophisticated internal "clock," adjusted to the 24-h rotation period of the earth, enabling a nyctohemeral coordination of numerous physiologic processes, from gene expression to behavior. The human CS is tightly and bidirectionally interconnected to the stress system (SS). Both systems are fundamental for survival and regulate each other's activity in order to prepare the organism for the anticipated cyclic challenges. Thereby, the understanding of the temporal relationship between stressors and stress responses is critical for the comprehension of the molecular basis of physiology and pathogenesis of disease. A critical loss of the harmonious timed order at different organizational levels may affect the fundamental properties of neuroendocrine, immune, and autonomic systems, leading to a breakdown of biobehavioral adaptative mechanisms with increased stress sensitivity and vulnerability. In this review, following an overview of the functional components of the SS and CS, we present their multilevel interactions and discuss how traumatic stress can alter the interplay between the two systems. Circadian dysregulation after traumatic stress exposure may represent a core feature of trauma-related disorders mediating enduring neurobiological correlates of trauma through maladaptive stress regulation. Understanding the mechanisms susceptible to circadian dysregulation and their role in stress-related disorders could provide new insights into disease mechanisms, advancing psychochronobiological treatment possibilities and preventive strategies in stress-exposed populations.

Animal models of PTSD: a challenge to be met

Recent years have seen increased interest in psychopathologies related to trauma exposure. Specifically, there has been a growing awareness to posttraumatic stress disorder (PTSD) in part due to terrorism, climate change-associated natural disasters, the global refugee crisis, and increased violence in overpopulated urban areas. However, notwithstanding the increased awareness to the disorder, the increasing number of patients, and the devastating impact on the lives of patients and their families, the efficacy of available treatments remains limited and highly unsatisfactory. A major scientific effort is therefore devoted to unravel the neural mechanisms underlying PTSD with the aim of paving the way to developing novel or improved treatment approaches and drugs to treat PTSD. One of the major scientific tools used to gain insight into understanding physiological and neuronal mechanisms underlying diseases and for treatment development is the use of animal models of human diseases. While much progress has been made using these models in understanding mechanisms of conditioned fear and fear memory, the gained knowledge has not yet led to better treatment options for PTSD patients. This poor translational outcome has already led some scientists and pharmaceutical companies, who do not in general hold opinions against animal models, to propose that those models should be abandoned. Here, we critically examine aspects of animal models of PTSD that may have contributed to the relative lack of translatability, including the focus on the exposure to trauma, overlooking individual and sex differences, and the contribution of risk factors. Based on findings from recent years, we propose research-based modifications that we believe are required in order to overcome some of the shortcomings of previous practice. These modifications include the usage of animal models of PTSD which incorporate risk factors and of the behavioral profiling analysis of individuals in a sample. These modifications are aimed to address factors such as individual predisposition and resilience, thus taking into consideration the fact that only a fraction of individuals exposed to trauma develop PTSD. We suggest that with an appropriate shift of practice, animal models are not only a valuable tool to enhance our understanding of fear and memory processes, but could serve as effective platforms for understanding PTSD, for PTSD drug development and drug testing.

Sleep Deprivation Alters the Pituitary Stress Transcriptome in Male and Female Mice

Poor sleep hygiene is a growing problem, with detrimental effects on many biological systems. The pituitary gland plays a crucial role in the regulation of sleep and the stress response, and its dysfunction leads to sleep-related disorders. However, the interaction between these critical functions remains unclear. Thus, we performed a comparative, whole-transcriptome, analysis to identify stress-induced genes and relevant pathways that may be affected by sleep deprivation. One day following 12 h of Paradoxical Sleep Deprivation (PSD), mice were restrained for 20 min. Gene expression changes in the pituitary were assessed via RNA-Seq and Gene Ontology in PSD and/or restrained groups compared to controls. We show that restraint triggers transcriptional responses involved in hormone secretion, the glucocorticoid response, and apoptosis in both sexes, with 285 differentially expressed genes in females and 93 in males. When PSD preceded restraint stress, the numbers of differentially expressed genes increased to 613 in females and 580 in males. The pituitary transcriptome of restraint+PSD animals was enriched for microglia and macrophage proliferation, cellular response to corticosteroids, and apoptosis, among others. Finally, we identify sex-specific differences in restraint-induced genes following PSD. These findings provide genetic targets to consider when studying sleep and the response to stress.

Dynamic heart rate response to multi-day unsupported ultra-endurance cycle racing: a case report

NEW FINDINGS

What is the main observation in this case? Ultra-endurance cycle racing is known to lead to suppressed heart rates as a product of time spent racing. This case report identifies a racer who experienced this phenomenon initially, but then uniquely experienced an overall increase in heart rate late in the race. What insight does it reveal? In this case, unique chronotropic disturbances to heart rate occurred as a result of the many extreme demands of ultra-endurance racing. Work should now focus on identifying the frequency of this response in other racers and whether the main causes are physiological, environmental or genetic in nature.

ABSTRACT

Participation in ultra-endurance cycling events, such as the Transcontinental Race, is increasing. These extremely demanding races provide a unique opportunity for field observation of the limits of human endurance physiology and, importantly, when these limits might be exceeded and cross over into pathology. The heart is of special interest in this field, and previous data suggest that 'reverse drift' of heart rate occurs as a product of time and load in races of 24-48 h, whereas transient structural abnormalities have been observed upon completion of running ultramarathons. Here, we report a unique case of a male cyclist racing in the Transcontinental Race over an extended period of 14 days characterized by extreme workloads and a low quantity and quality of sleep. The heart rate response was dynamic over the course of the race and defined by a U-shaped quadratic relationship. A larger scale study is required to determine the relevance of this information to the ultra-endurance cycling community.

Sleep characteristics, sources of perceived stress and coping strategies in adolescent athletes

The aim of the study was to examine sleep characteristics, scheduling of activities, perceived stress and coping strategies between periods of perceived high and low scheduling commitments in adolescent athletes. Twenty adolescents (10 male and 10 female) wore an Actiwatch during two 14-day testing periods, one in in January (JAN), which was deemed to be a period of low school and sport commitments, and one in March (MAR), during which there was a high volume of school and sport commitments. Actiwatches and sleep diaries assessed sleep quantity and quality, a daily schedule of all activities in 30-min increments was recorded and questionnaires related to perceived stress and coping strategies were administered. Time in bed and asleep, latency, efficiency and number of awakenings were not different between JAN and MAR (p > 0.05). Sleep durations were lower than their age-related recommendations (JAN 449 ± 47 min versus MAR 437 ± 31 min). Examination of differences between sexes showed shorter latency and higher sleep efficiency in female participants compared with male participants. Participants spent more time at school, completing homework, and travelling to and competing in sport, with reduced time spent on resting, social activities, physical activity and meal times during MAR compared with JAN (p < 0.05). Finally, stress levels were significantly increased during MAR compared with JAN, with no difference between sexes (p < 0.05). Adolescent athletes not attaining sufficient sleep quantity or quality during periods of low and high school and sport commitments, are experiencing increased perceived stress during these busy times but are using a wider range of coping strategies during this time.

The impact of stress on sleep: Pathogenic sleep reactivity as a vulnerability to insomnia and circadian disorders

Sleep reactivity is the trait-like degree to which stress exposure disrupts sleep, resulting in difficulty falling and staying asleep. Individuals with highly reactive sleep systems experience drastic deterioration of sleep when stressed, whereas those with low sleep reactivity proceed largely unperturbed during stress. Research shows that genetics, familial history of insomnia, female gender and environmental stress influence how the sleep system responds to stress. Further work has identified neurobiological underpinnings for sleep reactivity involving disrupted cortical networks and dysregulation in the autonomic nervous system and hypothalamic-pituitary-adrenal axis. Sleep reactivity is most pathologically and clinically pertinent when in excess, such that high sleep reactivity predicts risk for future insomnia disorder, with early evidence suggesting high sleep reactivity corresponds to severe insomnia phenotypes (sleep onset insomnia and short sleep insomnia). High sleep reactivity is also linked to risk of shift-work disorder, depression and anxiety. Importantly, stress-related worry and rumination may exploit sensitive sleep systems, thereby augmenting the pathogenicity of sleep reactivity. With the development of cost-effective assessment of sleep reactivity, we can now identify individuals at risk of future insomnia, shift-work disorder and mental illness, thus identifying a target population for preventive intervention. Given that insomniacs with high sleep reactivity tend to present with severe insomnia phenotypes, patient sleep reactivity may inform triaging to different levels of treatment. Future research on sleep reactivity is needed to clarify its neurobiology, characterize its long-term prospective associations with insomnia and shift-work disorder phenotypes, and establish its prognostic value for mental illness and other non-sleep disorders.

Early life stress and trauma: developmental neuroendocrine aspects of prolonged stress system dysregulation

Experience of early life stress (ELS) and trauma is highly prevalent in the general population and has a high public health impact, as it can trigger a health-related risk cascade and lead to impaired homeostatic balance and elevated cacostatic load even decades later. The prolonged neuropsychobiological impact of ELS can, thus, be conceptualized as a common developmental risk factor for disease associated with increased physical and mental morbidity in later life. ELS during critical periods of brain development with elevated neuroplasticity could exert a programming effect on particular neuronal networks related to the stress response and lead to enduring neuroendocrine alterations, i.e., hyper- or hypoactivation of the stress system, associated with adult hypothalamic-pituitary-adrenal axis and glucocorticoid signaling dysregulation. This paper reviews the pathophysiology of the human stress response and provides evidence from human research on the most acknowledged stress axis-related neuroendocrine pathways exerting the enduring adverse effects of ELS and mediating the cumulative long-term risk of disease vulnerability in adulthood.

Hematological indices as simple, inexpensive and practical severity markers of obstructive sleep apnea syndrome: a meta-analysis

Background

Clinical detection of inflammatory markers is useful to assess the degree of nocturnal hypoxia and predict the presence of complications in obstructive sleep apnea syndrome (OSAS) patients. Nowadays, some researchers proposed that hematological parameters could be substituted for novel disease-specific biochemical markers (such as C-reactive protein) because they were comparatively cheap, simple and practical. But there was a contradiction whether the hematological parameters were positively correlated with the OSAS severity.

Methods

Medical databases were searched included PubMed, Web of Science, Scopus, Cochrane Library, Clinical Trial, Embase and Google Scholar (up to March 29, 2018). We used weighted mean differences (WMDs) with 95% confidence intervals (CIs) from random-effects model.

Results

Seventeen studies were included in this meta-analysis and results were presented by different hematological parameters. Pooled analysis showed that OSAS was associated with a high level of WBC (white blood cell, 11 studies, 2,206 subjects, WMD: 0.58; 95% CI: 0.31 to 0.85; P<0.0001), NLR (neutrophil-to-lymphocyte ratio, 5 studies, 1416 subjects, WMD: 0.46; 95% CI: 0.13 to 0.80; P=0.007), MPV (mean platelet volume, 8 studies, 1,854 subjects, WMD: 0.63; 95% CI: 0.29 to 0.98; P=0.0004), PDW (platelet distribution width, 6 studies, 1,911 subjects, WMD: 0.76; 95% CI: 0.47 to 1.06; P<0.00001), PLR (platelet-to-lymphocyte ratio, 3 studies, 998 subjects, WMD: 21.76; 95% CI: 8.54 to 34.99; P=0.001), RDW (red cell distribution width, 5 studies, 1,701 subjects, WMD: 0.31; 95% CI: 0.11 to 0.51; P=0.002) and HCT (hematocrit, 3 studies, 662 subjects, WMD: 1.58; 95% CI: 0.52 to 2.64; P=0.003). But OSAS was associated with a low level of LYM (lymphocyte, 5 studies, 1,285 subjects, WMD: -0.27; 95% CI: -0.49 to -0.06; P=0.01). There was a gradual rising trend from mild OSAS to severe OSAS existed in all subgroups.

Conclusions

Hematological indices are comparatively Simple, Inexpensive and Practical Severity Markers of OSAS including WBC, LYM, NLR, MPV, PDW, PLR, RDW and HCT.

Are You Sleeping? Dyadic Associations of Support, Stress, and Worries Regarding Adult Children on Sleep

Purpose of the study

Sleep is a key factor in maintaining positive health and well-being throughout life. Although the negative outcomes of sleep problems are becoming better understood, less is known about how intergenerational relationships might affect sleep. Thus, this investigation examines the dyadic associations of support for, stress over, and worrying about adult children on sleep quality for husbands and wives.

Design and Methods

The sample included 186 heterosexual married couples drawn from the Family Exchanges Study. To account for nonindependence in the dyadic data and explore questions of mutual influence, we used actor-partner interdependence models.

Results

Husbands' and wives' reports of supporting their adult child and husbands' worry were associated with husbands' sleep quality. Conversely, wives' stress about supporting their adult child was associated with wives' sleep quality. Findings suggest that relationships with adult children have different associations for sleep quality among middle-aged husbands and wives.

Implications

Our findings have implications for health-related research with couples and families and for providers who work with individuals struggling with sleep problems. Assisting aging parents to be aware of and manage ways that stress, support, and concern for adult children relate to their sleep may benefit them in multifaceted ways.

Sleep Architecture and Hypothalamic-Pituitary-Adrenal Activity in Paradoxical and Psychophysiological Insomnia

Introduction:

There are controversial reports about association between sleep and Hypothalamic-Pituitary-Adrenal (HPA) activity. Studies have reported the influence of insomnia on HPA hormones. However, they usually ignored the heterogeneity of insomnia symptoms, so subtypes of the disorder have not been considered in the reports. The present study aimed to investigate the final and intermediate products of HPA system among a group of psychophysiological and paradoxical insomniac patients in comparison to a group of normal sleepers.

Methods:

We investigated the awakening serum level of Adrenocorticotropic Hormone (ACTH) and cortisol after one night Polysomnography (PSG) in 17 subjects with psychophysiological insomnia, 19 subjects with paradoxical insomnia and 17 subjects with normal sleep profile. Groups were matched for age and Body Mass Index (BMI). Serum levels of ACTH and cortisol were measured by Enzyme-Linked Immunosorbent Assay (ELISA) method.

Results:

Although, a tendency toward elevation of both ACTH and cortisol was observed among patients with paradoxical insomnia compared to both control and psychophysiological insomnia, the differences were not significant comparing three groups. According to regression analysis, higher Non-Rapid Eye Movement sleep (NREM) arousal and Pulse Transit Time (PTT) significantly predicted higher level of ACTH.

Conclusion:

These findings could suggest the personality traits hypothesis for paradoxical insomnia. Both cortical and subcortical arousal could lead to more HPA activity and higher ACTH level. Further studies are recommended to confirm the hypothesis.

Sleep quality components and mental health: Study with a non-clinical population

The deconstruction of sleep quality into its particular components may help to specify how each one of them influences mental health. Thus, to detail the understanding of the relationship between sleep quality and mental health, our study aims to assess the relationship between each component of the Pittsburgh Sleep Quality Index (PSQI) and depression, anxiety and stress. Also, we intend to analyse the moderating effects of gender, age and country on these relationships. The instruments PSQI and Depression Anxiety Stress Scale (DASS-21) were applied to a non-clinical population of 1552 participants from three different countries (Portugal, Spain and Brazil), aged over 18 years old. We estimated a multivariate regression model with AMOS Graphic 21.0 to test the seven proposed research hypotheses. The adjusted model explains 14.0%, 21.0% and 19.3% of the variances of depression, anxiety and stress, respectively. The conclusion of this study demonstrates that, with the exception of subjective sleep quality, all the other six components of the PSQI individually relate to mental health in non-clinical populations and that country is a significant moderator of these relationships.

Poor Sleep Quality Is Associated with Higher Hemoglobin A1c in Pregnant Women: A Pilot Observational Study

We hypothesized that poor sleep quality exacerbates glucose intolerance manifested as elevated glycosylated hemoglobin (HbA1c), which increases the risk for gestational diabetes. To test this, 38 pregnant and 22 non-pregnant (age, 18–35 years; body-mass index, 20–35 kg/m²) otherwise healthy women were enrolled in the study. Sleep quality was assessed during gestational week 24 (pregnant), or outside of the menstrual period (non-pregnant), using qualitative (Pittsburgh Sleep Quality Index) and objective (actigraphic wrist-watch) measures. Blood glucose, total cortisol, and depression status were evaluated. Eight pregnant and one non-pregnant women were lost to follow-up, or withdrew from the study. There was a higher incidence of poor sleep quality in pregnant (73%) relative to non-pregnant women (43%). Although actigraphic data revealed no differences in actual sleep hours between pregnant and non-pregnant women, the number of wake episodes and sleep fragmentation were higher in pregnant women. Poor sleep quality was positively correlated with higher HbA1c in both pregnant (r = 0.46, n = 26, p = 0.0151) and non-pregnant women (r = 0.50, n = 19, p = 0.0217), reflecting higher average blood glucose concentrations. In contrast, poor sleep was negatively correlated with cortisol responses in pregnant women (r = −0.46, n = 25, p = 0.0167). Three pregnant women had elevated one-hour oral glucose tolerance test results (>153 mg/dL glucose). These same pregnant women exhibited poor sleep quality. These results support the suggestion that poor sleep quality is an important risk factor that is associated with glucose intolerance and attendant health complications in pregnancy.

Sleep Duration Is Associated With Testis Size in Healthy Young Men

STUDY OBJECTIVES

Sleep is increasingly recognized to influence a growing array of physiological processes. The relationship between sleep duration and testis size, a marker of male reproductive potential, has not been studied.

METHODS

This was a preliminary cross-sectional analysis of the baseline data from 92 healthy men (mean ± standard deviation, age 33 ± 6 years, body mass index [BMI] 24.7 ± 6.1 kg/m2), of whom 66 underwent at-home actigraphy and 47 underwent in-laboratory polysomnography. Sleep duration and architecture were measured by actigraphy and polysomnography, testicular volume by Prader orchidometer, total testosterone by liquid chromatography tandem mass spectrometry, free testosterone by equilibrium dialysis, and luteinizing hormone and follicle-stimulating hormone (FSH) by immunochemiluminometric assay.

RESULTS

Sleep duration was correlated with testicular volume (r = .31, P = .046) and with FSH (r = -.30, P = .035), and rapid eye movement sleep was correlated with FSH (r = .44, P = .006). The significance of these findings did not change after adjustment for age and BMI, and were confirmed nonparametrically by resampling. A putative inverse U-shaped relationship between testicular volume and sleep duration was observed by polynomial regression (P = .049), but not with resampling (P = .068).

CONCLUSIONS

There is a positive linear and a possible inverse U-shaped relationship between sleep duration and testis volume. Longitudinal or interventional studies manipulating sleep are required to better define causality, and ultimately to establish how much sleep is needed to maximize male reproductive potential.

CLINICAL TRIAL REGISTRATION

Title: Hormonal Mechanisms of Sleep Restriction, Registry: ClinicalTrials.gov, Identifier: NCT02256865, URL: https://clinicaltrials.gov/ct2/show/NCT02256865.

Does Stress Explain the Effect of Sleep on Self-Control Difficulties? A Month-Long Daily Diary Study

Insufficient sleep is linked to increased stress and suboptimal self-control; however, no studies have examined stress as a reason for why sleep affects self-control. Moreover, it is unknown if there are individual differences that make people vulnerable to this dynamic. Daily diary entries from 212 university students across 30 days were used in a multilevel path model examining if stress explained how prior night sleep affected next-day self-control difficulties and exploring if individual differences in sleep duration, stress, or self-control qualified this effect. Increased stress partially mediated of the effect of reduced sleep duration on increased next-day self-control difficulty. Moreover, short sleep increased next-day stress more for individuals with higher typical stress. Daytime stress especially amplified self-control difficulty for individuals with shorter typical sleep duration. Findings implicate stress as a substantial factor in how sleep loss undermines self-control and identify individuals particularly susceptible to this effect.

Night shift work and osteoporosis: evidence and hypothesis

Osteoporosis is an important public health problem worldwide. Among the countries with a very high population risk of fractures, there are those with the highest level of economic development. Osteoporotic fractures are the main cause of disability among elderly people, and the resultant disabilities require particularly large financial support associated not only with the direct treatment of the fracture but also with the necessity for long-term rehabilitation and care for the disabled person. Many well-established factors can have impact on bone mass and fracture risk. Recently, it has been hypothesized that working during nighttime which leads to endocrine disorders may have an indirect impact on bone physiology among night shift workers. Therefore, it can be presumed that the night shift work may contribute to the etiology of osteoporosis. The aim of our work was to make a review of the epidemiological evidence on the association between night shift work and bone mineral density or fracture risk as well as to discuss the potential biological mechanisms linking the work under this system with the development of osteoporosis. We have identified only four studies investigating the association between system of work and bone mineral density or fracture risk among workers. The findings of three out of four studies support the hypothesis. None of the studies has investigated a potential relationship between night shift work and bone turnover markers. Given that there have been no epidemiological studies in European countries that would concern working populations and the noticeable difference in the risk of osteoporosis between communities, further studies are warranted to elucidate the problem. It is presumed that further in-depth studies will not only identify the underlying factors of the disease but also contribute to developing guidelines for policy makers and employers for primary prevention of osteoporosis in workplace.

Does sleep deprivation increase the vulnerability to acute psychosocial stress in young and older adults?

Sleep loss and psychosocial stress often co-occur in today's society, but there is limited knowledge on the combined effects. Therefore, this experimental study investigated whether one night of sleep deprivation affects the response to a psychosocial challenge. A second aim was to examine if older adults, who may be less affected by both sleep deprivation and stress, react differently than young adults. 124 young (18-30 years) and 94 older (60-72 years) healthy adults participated in one of four conditions: i. normal night sleep & Placebo-Trier Social Stress Test (TSST), ii. normal night sleep & Trier Social Stress Test, iii. sleep deprivation & Placebo-TSST, iv. sleep deprivation & TSST. Subjective stress ratings, heart rate variability (HRV), salivary alpha amylase (sAA) and cortisol were measured throughout the protocol. At the baseline pre-stress measurement, salivary cortisol and subjective stress values were higher in sleep deprived than in rested participants. However, the reactivity to and recovery from the TSST was not significantly different after sleep deprivation for any of the outcome measures. Older adults showed higher subjective stress, higher sAA and lower HRV at baseline, indicating increased basal autonomic activity. Cortisol trajectories and HRV slightly differed in older adults compared with younger adults (regardless of the TSST). Moreover, age did not moderate the effect of sleep deprivation. Taken together, the results show increased stress levels after sleep deprivation, but do not confirm the assumption that one night of sleep deprivation increases the responsivity to an acute psychosocial challenge.

Mediating effects of body mass index, physical activity, and emotional distress on the relationship between short sleep and cardiovascular disease

The current study investigated the mediating effects of body mass index (BMI), physical activity, and emotional distress on the association between short sleep duration (<7 hours per 24-hour period) and cardiovascular disease (CVD) and risk factors.We used data from the National Health Interview Survey, an ongoing nationally representative cross-sectional study of noninstitutionalized US adults (≥18 years) from 2004 to 2013 (N = 206,049). Participants provided information about anthropometric features (height and weight), sociodemographic factors, health behaviors (smoking and physical activity), emotional distress, and physician-diagnosed health conditions, including hypertension, coronary heart disease, diabetes, heart attack, stroke, kidney disease, and cancer. Structural equation modeling was used to assess the mediating effects of physical activity, BMI, and emotional distress on the relationship between short sleep and CVDs and risk factors (coronary heart disease, hypertension, diabetes, chronic kidney disease, heart attack, and stroke).Of the sample, 54.7% were female, 60.1% identified as white, 17.7% as Hispanic, and 15.4% as black. The mean age of the respondents was 46.75 years (SE = 0.12), with a mean BMI of 27.11 kg/m (SE = 0.02) and approximately 32.5% reported short sleep duration. The main relationship between short sleep and CVD and risk factors was significant (β = 0.08, P < .001), as was the mediated effect via BMI (indirect effect = 0.047, P < .001), emotional distress (indirect effect = 0.022, P < .001), and physical activity (indirect effect = -0.022, P = .035), as well as after adjustment for covariates, including age, race, sex, marital status, and income: short sleep and CVD (B = 0.15; SE = 0.01; P < .001), BMI (B = 0.05; SE = 0.00; P < .001), emotional distress (B = 0.02; SE = 0.00; P < .001), and physical activity (B = 0.01; SE = 0.00; P < .001).Our findings indicate that short sleep is a risk factor for CVD and that the relationship between short sleep and CVD and risk factors may be mediated by emotional distress and obesity, and negatively mediated by physical activity.

Integrating the Neurobiology of Minority Stress with an Intersectionality Framework for LGBTQ-Latinx Populations

The comprehensive lived experiences of lesbian, gay, bisexual, transgender, and queer (LGBTQ) individuals of color remain invisible in neurobiological studies of LGBTQ populations. Models of minority stress posit that LGBTQ and Latinx individuals experience and internalize sexual, ethnic, racial, and gender discrimination, which may adversely impact mental and physical health. However, the current minority stress models predominantly focus on single categorical social identities and do not account for interlocking systems and processes of oppression based on features of sexuality, race, ethnicity, sex, and gender, as explained by an intersectionality framework in feminist theory. Thus, it remains unclear how LGBTQ people of color internalize and navigate multiple cultural, institutional, and societal stressors, and, furthermore, how these sources of stress may affect health and well-being. A potential mechanism for this adverse internalization process is through the effects of stress on neurobiological regulation. This review will apply an intersectionality framework to the examination of how heterosexism, racism, and cissexism, as systems of oppression, create LGBTQ and Latinx lived experiences, and the differential impacts of these inequalities on neurobiological stress regulation. The overarching goal of this manuscript is to advocate for the application of intersectionality theory to advance the ecological validity of biopsychosocial models of multiple-minority stress.

Sleep quality and the cortisol awakening response (CAR) among law enforcement officers: The moderating role of leisure time physical activity

OBJECTIVE

The goal of this study was to investigate the role of leisure time physical activity (LTPA) on the association between sleep quality and the cortisol awakening response (CAR) in people with an occupation that exposes them to high levels of stress.

METHODS

Participants were 275 police officers (age = 42 years ± 8.3, 27% women) enrolled in the Buffalo Cardio-Metabolic Occupational Police Stress (BCOPS) study (conducted between 2004 and 2009). Officers provided four salivary cortisol samples (on awakening and 15, 30, and 45 min after awakening). Hours of leisure time physical activity were assessed using the Seven-Day Physical Activity Recall questionnaire. Sleep quality (good/poor) was evaluated using the Pittsburgh Sleep Quality Index (PSQI) scale. Analysis of covariance and repeated measures models were used to examine the association of sleep quality to the two aspects of CAR: cortisol levels (total area under the curve (AUCG), mean, and peak cortisol) and cortisol profiles (the overall pattern in cortisol level during the 45 min period following awakening, the increase in cortisol from baseline to average of post awakening values (mean increase), and area under the curve with respect to increase (AUCI)). Analyses were stratified by participant level of reported LTPA (sufficiently vs. insufficiently active, defined as ≥ 150 vs. < 150 min/week of moderate intensity activity, respectively). Since cortisol activity is known to be influenced by gender, we conducted additional analyses also stratified by gender.

RESULTS

Overall, results demonstrated that LTPA significantly moderated the association of sleep quality with CAR. Among participants who were sufficiently active, CAR did not differ by sleep quality. However, in those who were insufficiently active during their leisure time, poor sleep quality was associated with a significantly reduced level of total awakening cortisol secretion (AUCG (a.u.) = 777.4 ± 56 vs. 606.5 ± 45, p = 0.02; mean cortisol (nmol/l) = 16.7 ± 1.2 vs. 13.3 ± 0.9, p = 0.03; peak cortisol (nmol/l) = 24.0 ± 1.8 vs. 18.9 ± 1.5, p = 0.03 for good vs. poor sleep quality, respectively). The normal rise in cortisol after awakening was also significantly lower in inactive officers with poor sleep quality than in those with good sleep quality (mean increase (nmol/l) = 6.7 ± 1.5 vs. 2.3 ± 1.2, p = 0.03; AUCI (a.u.) = 249.3 ± 55 vs. 83.3 ± 44, p = 0.02 for those with good vs. poor sleep quality, respectively). While findings for male officers were consistent with the overall results, CAR did not differ by sleep quality in female officers regardless of LTPA level.

CONCLUSION

Findings of this study suggest that poor sleep quality is associated with diminished awakening cortisol levels and dysregulated cortisol patterns over time, but only among officers who were inactive or insufficiently active during their leisure time. In contrast, sleep quality was not associated with any measures of CAR in officers who reported sufficient activity, suggesting a potential protective effect of LTPA. In analyses stratified by gender, findings for male officers were similar to those in the pooled sample, although we found no evidence for a modifying effect of LTPA in women. Future longitudinal studies in a larger population are needed to confirm these findings and further elucidate the relationships between LTPA, sleep quality, and cortisol response.

Perceived discrimination and cardiovascular health disparities: a multisystem review and health neuroscience perspective

There are distinct racial disparities in cardiovascular disease (CVD) risk, with Black individuals at much greater risk than White individuals. Although many factors contribute to these disparities, recent attention has focused on the role of discrimination as a stress-related factor that contributes to racial disparities in CVD. As such, it is important to understand the mechanisms by which discrimination might affect CVD. Recent studies have examined these mechanisms by focusing on neurobiological mediators of CVD risk. Given this increase in studies, a systematic review of perceived discrimination and neurobiological mediators of CVD risk is warranted. Our review uses a multisystem approach to review studies on the relationship between perceived discrimination and (1) cardiovascular responses to stress, (2) hypothalamic-pituitary-adrenocortical axis function, and (3) the immune system, as well as (4) the brain systems thought to regulate these parameters of peripheral physiology. In addition to summarizing existing evidence, our review integrates these findings into a conceptual model describing multidirectional pathways linking perceived discrimination with a CVD risk.

Night Games and Sleep: Physiological, Neuroendocrine, and Psychometric Mechanisms

Context: Night games are a regular occurrence for team-sport athletes, yet sleep complaints following night competitions are common. The mechanisms responsible for reported sleep difficulty in athletes are not understood. Methods: An observational crossover design investigating a night netball game and a time-matched rest day in 12 netball athletes was conducted to ascertain differences in physiological (core temperature), psychometric (state and trait), and neuroendocrine (adrenaline, noradrenaline, and cortisol) responses. Results: Following the night game, athletes experienced reduced sleep durations, lower sleep efficiency, early awakenings, and poorer subjective sleep ratings compared with the rest day. No differences were found between core temperature, state psychometric measures, and cortisol at bedtime. Adrenaline and noradrenaline concentrations were elevated compared with the time-matched rest day prior to (26.92 [15.88] vs 12.90 [5.71] and 232.6 [148.1] vs 97.83 [36.43] nmol/L, respectively) and following the night game (18.67 [13.26] vs 11.92 [4.56] and 234.1 [137.2] vs 88.58 [54.08] nmol/L, respectively); however, the concentrations did not correlate to the sleep variables (duration, efficiency, and sleep-onset latency). A correlation (rs = −.611) between sleep efficiency and hyperarousal (trait psychometric measure) was found. Conclusions: Athletes experienced poor sleep following a night game. Furthermore, results suggest that athletes who have a tendency toward a high trait arousal may be more susceptible to sleep complaints following a night game. These data expand knowledge and refute frequently hypothesized explanations for poor sleep following night competition. The results may also help support staff and coaches target strategies for individual athletes at a higher risk of sleep complaints.

Sleep and emotional processing

A growing body of literature suggests that sleep plays a critical role in emotional processing. This review aims at synthesizing current evidence on the role of sleep and sleep loss in the modulation of emotional reactivity, emotional memory formation, empathic behavior, fear conditioning, threat generalization and extinction memory. Behavioral and neurophysiological evidence suggesting that rapid-eye movement (REM) sleep plays an important role in emotional processing is also discussed. Furthermore, we examine the relations between sleep and emotions by reviewing the functional neuroimaging studies that elucidated the brain mechanisms underlying these relations. It is shown that sleep supports the formation of emotional episodic memories throughout all the stages that compose memory processing. On the contrary, sleep loss deteriorates both the encoding of emotional information and the emotional memory consolidation processes. Research is also progressively providing new insights into the protective role of sleep in human emotional homeostasis and regulation, promoting adaptive next-day emotional reactivity. In this respect, evidence converges in indicating that lack of sleep significantly influences emotional reactivity. Moreover, notwithstanding some contradictory findings, the processing of emotionally salient information could mainly benefit from REM sleep. However, some crucial aspects of sleep-dependent emotional modulation remain unclear.

Hyperarousal and sleep reactivity in insomnia: current insights

Hyperarousal is a key component in all modern etiological models of insomnia disorder. Overall patterns in the literature suggest that over-active neurobiological and psychological systems contribute to difficulty sleeping. Even so, mixed results regarding the specific mechanisms linking hyperarousal to sleep disturbance limit current etiological conceptualizations. Similar basal arousal profiles between individuals with high vs low risk for insomnia in the absence of stress exposure suggest that dysregulated stress "response" rather than general hyperarousal may be a more pertinent marker of risk. In this report, we discuss evidence for hyperarousal in insomnia and explore the role of sleep reactivity. A trait characteristic, sleep reactivity is the degree to which stress disrupts sleep, manifesting as difficulty falling and staying asleep. Premorbid sleep reactivity has been shown to identify individuals at risk for future insomnia disorder, such as highly reactive sleepers (whose sleep systems are sensitive to stress) who are at elevated disease risk. Research points to genetics, family history of insomnia, gender, and environmental stress as factors that influence sleep reactivity. Importantly, stress-related cognitive-emotional reactivity (e.g., rumination, worry) may exploit the vulnerability of a highly reactive sleep system. We propose that sleep reactivity and cognitive-emotional reactivity may share a bidirectional relationship, conferring an insalubrious environment for sleep in response to stress. Future research on sleep reactivity is needed to identify its neurobiology, characterize its relationship with cognitive-emotional reactivity, and explore the potential clinical utility of sleep reactivity in treatment planning.

Short-Term Test-Retest Reliability of Respiratory Sinus Arrhythmia (RSA) in Young Adults

Abstract. Despite the burgeoning use of respiratory sinus arrhythmia (RSA), heart period (HP), and blood pressure (BP) to study individual differences in autonomic regulatory processes in young adults, few studies have examined the short-term reliability of such autonomic measures in emerging adulthood. If resting autonomic measures indeed reflect “trait-like” individual differences, they should have acceptable levels of test-retest reliability. We examined the 1-month test-retest reliability of resting measures of RSA as well as HP, systolic (SBP) and diastolic blood pressure (DBP) in a sample of 41 healthy young adults. Test-retest reliability of all four measures was good-to-excellent across the 1-month period. However, uncontrolled mean RSA declined from Time 1 to Time 2, suggesting that while individual differences in RSA were stable, mean RSA appeared to be sensitive to condition effects. Even with random variation, all of these measures were stable across one month, demonstrating acceptable short-term test-retest reliability in emerging adulthood.

Insomnia mediates the longitudinal relationship between anxiety and depressive symptoms in a nationally representative sample of adolescents

BACKGROUND

Anxiety and depression are commonly comorbid with each other, with anxiety often temporally preceding the development of depression. Although increasingly research has begun to investigate the role of sleep problems in depression, no study has examined insomnia as a mediator in the longitudinal relationship between anxiety and subsequent depression.

METHODS

The current study utilizes data from Waves I, II, and IV of the National Longitudinal Study of Adolescent to Adult Health, a nationally representative prospective study conducted over a 14-year period (n = 20,745, 50.5% female, M age at Wave I = 16.20). Participants completed portions of the Center for Epidemiologic Studies Depression Scale at Waves I and IV to assess depressive symptoms, a six-item anxiety measure at Wave I, and three items assessing insomnia, sleep quality, and sleep duration at Wave II.

RESULTS

Structural equation modeling indicated that insomnia and unrestful sleep significantly mediated the relationship between anxiety and subsequent depression. The relationship between anxiety and depression was not significantly mediated by sleep duration.

CONCLUSIONS

Findings suggest that anxiety may increase risk for the development of later depression through insomnia.

Insomnia and Nightmares as Markers of Risk for Suicidal Ideation in Young People: Investigating the Role of Defeat and Entrapment

STUDY OBJECTIVES

Although converging evidence has identified sleep problems as robust predictors of suicidal ideation in young people, the psychological processes driving these associations are not yet known. The current study aimed to test predictions, informed by the Integrated Motivational-Volitional (IMV) Model of Suicidal Behavior, concerning the role of feelings of defeat and entrapment within the sleep-suicide relationship.

METHODS

Volunteers aged 15 to 17 years (n = 1,045) from Scottish secondary schools completed an anonymous self-report survey assessing insomnia symptoms, nightmares, suicidal ideation, depressive symptomology, and feelings of defeat and entrapment.

RESULTS

Both insomnia symptoms and nightmares were associated with an increased likelihood of reporting suicidal ideation (independent of depression). Perceptions of both defeat and entrapment were elevated in young people who reported clinically salient insomnia and/or nightmares, relative to those who did not. The relationship between insomnia and suicidal ideation was fully mediated by perceptions of defeat and entrapment, whereas nightmares were indirectly associated with suicidal ideation through perceptions of defeat and entrapment.

CONCLUSIONS

Taken together, these findings provide novel insights into the psychological mechanisms linking sleep disturbance and suicidality by highlighting the role of defeat and entrapment. Clinically, these findings have the potential to improve suicide risk assessment and prevention in young people experiencing difficulties with their sleep.

A technology developed from concept of acupuncture and meridian system, the clinical effect of BIOCERAMIC resonance on psychological related sleep disturbance with findings on questionnaire, EEG and fMRI

Under the concept of meridian channels that belongs to traditional Chinese medicine, BIOCERAMIC Resonance (BR) has already been applied to many clinical medical research projects with functions mimicking of traditional acupuncture. Forty-five patients were recruited with chronic sleep disorders; 36 patients were given, applied to the device with BIOCERAMIC material and sound rhythm on chest skin surface; 9 patients were included as controls. All study participants completed a sleep pattern and quality of life questionnaire (assessment on psychological and physical causes of sleep disturbances), which was repeated before, during and after treatment. Electroencephalograph (EEG) recordings were analyzed before, during and after treatment. Functional MRI (fMRI) was also used for demonstration of BR effect for another 8 candidates. During the first 3 days of treatment, sleep quality improved in all 36 patients especially to psychological reasons; in 91.7% (33/36) treatment was associated with an elevation in the beta spectrum of the EEG (at 15-27 Hz). The result of fMRI found corresponding cerebral and cerebellar areas of activation and deactivation. BIOCERAMIC Resonance can improve sleep disorder due to psychological causes, with transient alter brain wave activity and functional activation on specific locations of brain.

The neurobiological basis of sleep: Insights from Drosophila

Sleep is a biological enigma that has raised numerous questions about the inner workings of the brain. The fundamental question of why our nervous systems have evolved to require sleep remains a topic of ongoing scientific deliberation. This question is largely being addressed by research using animal models of sleep. Drosophila melanogaster, also known as the common fruit fly, exhibits a sleep state that shares common features with many other species. Drosophila sleep studies have unearthed an immense wealth of knowledge about the neuroscience of sleep. Given the breadth of findings published on Drosophila sleep, it is important to consider how all of this information might come together to generate a more holistic understanding of sleep. This review provides a comprehensive summary of the neurobiology of Drosophila sleep and explores the broader insights and implications of how sleep is regulated across species and why it is necessary for the brain.

Chronic parenting stress and mood reactivity: The role of sleep quality

Sleep is a basic biological process supporting emotion regulation. The emotion regulation function of sleep may be particularly important in the context of chronic stress. To better understand how chronic stress and sleep interact to predict mood, 66 parents of children with autism completed daily diaries assessing parenting stress, negative mood, and sleep quality for 6 consecutive days. Hierarchical linear modelling revealed that daily negative mood was predicted by between-person differences in parenting stress and between-person differences in sleep efficiency. Further, between-person differences in sleep efficiency and within-person differences in sleep satisfaction moderated the impact of stress on mood. These data suggest that sleep disturbances may exacerbate the association between stress and mood in the context of chronic parenting stress. Further, high parenting stress appears to heighten the impact of transient sleep disturbances on mood.

Looking for light in the din: An examination of the circadian-disrupting properties of a medical intensive care unit

OBJECTIVE

Critically ill patients exhibit profound disturbances of circadian rhythmicity, most commonly in the form of a phase delay. We investigated the specific zeitgeber properties of a medical intensive care unit to develop a model that explained these abnormalities.

RESEARCH METHODOLOGY

Prospective, observational study conducted during 2013-2014. Twenty-four-hour ambient light (lux, 672 hours) and sound pressure levels (dBA, 504 hours) were measured in patient rooms. Patients and families were surveyed regarding their perceptions of the environment.

SETTING

University-based adult medical intensive care unit.

MAIN OUTCOME MEASURES

The timing and intensity of the ambient light-dark cycle and sound environment and the relationship of these measurements to patient/family perceptions.

RESULTS

Twenty-four-hour light-dark cycles were extremely weak and phase delayed relative to the solar cycle. Morning light averaged 12.1 (4.8, 37.2) lux, when only 24.9% ± 10.9% of available light was utilised; yet patients and families did not identify low daytime light levels as problematic. Median noise levels were invariably excessive (nighttime 47.9 [45.0, 51.3] dBA) with minimal variation, consistent with the absence of a defined rest period.

CONCLUSION

The intensive care unit functions as a near-constant routine protocol disconnected from solar time. Behavioural interventions to promote entrainment should be supported by objective measurements of light and sound.

Sleep Duration Modifies the Association of Overtime Work With Risk of Developing Type 2 Diabetes: Japan Epidemiology Collaboration on Occupational Health Study

Background

Evidence linking working hours and the risk of type 2 diabetes mellitus (T2DM) is limited and inconsistent in Asian populations. No study has addressed the combined association of long working hours and sleep deprivation on T2DM risk. We investigated the association of baseline overtime work with T2DM risk and assessed whether sleep duration modified the effect among Japanese.

Methods

Participants were Japanese employees (28,489 men and 4,561 women) aged 30–64 years who reported overtime hours and had no history of diabetes at baseline (mostly in 2008). They were followed up until March 2014. New-onset T2DM was identified using subsequent checkup data, including measurement of fasting/random plasma glucose, glycated hemoglobin, and self-report of medical treatment. Hazard ratios (HRs) of T2DM were estimated using Cox regression analysis. The combined association of sleep duration and working hours was examined in a subgroup of workers (n = 27,590).

Results

During a mean follow-up period of 4.5 years, 1,975 adults developed T2DM. Overtime work was not materially associated with T2DM risk. In subgroup analysis, however, long working hours combined with insufficient sleep were associated with a significantly higher risk of T2DM (HR 1.42; 95% CI, 1.11–1.83), whereas long working hours with sufficient sleep were not (HR 0.99; 95% CI, 0.88–1.11) compared with the reference (<45 hours of overtime with sufficient sleep).

Conclusions

Sleep duration modified the association of overtime work with the risk of developing T2DM. Further investigations to elucidate the long-term effect of long working hours on glucose metabolism are warranted.