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There is an urgent need for safe, rapid-acting treatment strategies for adolescent depression. In depressed adults, slow wave sleep deprivation (SWSD) improved next-day mood without disrupting sleep duration, but SWSD has not been tested in adolescents. In a pilot study, the aim was to assess the effect of SWSD on sleep physiology and mood outcomes (depression, rumination, anhedonia) among adolescents with depressive symptoms. Sixteen adolescents (17.44 ± 1.46 yr, 12 female) completed three nights of polysomnographic sleep recording: Baseline, SWSD, and Recovery nights. Acoustic stimulation (tones of random pitch, duration, and volume) suppressed slow wave sleep (SWS) in real-time during SWSD. After each night, depression, rumination, and anhedonia severity were assessed. SWSD successfully suppressed SWS, increased N2, and had minimal impact on Rapid Eye Movement (REM), nocturnal awakenings, and total sleep time. While SWSD did not improve depression or anhedonia severity overall, lower baseline non-REM alpha activity and greater SWS rebound during recovery sleep correlated with SWSD-related reduction in clinician-rated depression severity. Next-day rumination severity decreased after SWSD, with sustained improvements following recovery sleep. However, rumination improvement was not associated with SWS suppression, but rather reduction in total sleep time and REM in exploratory correlation models. Small sample size and large proportion of females. SWSD did not improve depression in adolescents overall but a subset with low non-REM alpha activity and intact homeostatic sleep regulation may benefit from this approach. Findings from this pilot study also suggest that partial sleep deprivation may be a beneficial therapeutic strategy for rumination in adolescents. • Slow wave sleep deprivation improved mood in depressed adults in prior studies • Slow wave sleep was suppressed without disrupting sleep duration in adolescents • Rumination, not depression, improved following slow-wave sleep deprivation, driven by reduction in sleep duration and REM sleep • Lower baseline NREM alpha power and greater slow wave sleep rebound predicted individual differences in depression severity reduction • Slow wave sleep deprivation may benefit a subset of depressed adolescents; partial sleep deprivation may target rumination [ABSTRACT FROM AUTHOR]

Summary: Certain neurophysiological characteristics of sleep, in particular slow oscillations (SOs), sleep spindles, and their temporal coupling, have been well characterised and associated with human memory abilities. Delta waves, which are somewhat higher in frequency and lower in amplitude compared to SOs, and their interaction with spindles have only recently been found to play a critical role in memory processing of rodents, through a competitive interaction between SO–spindle and delta–spindle coupling. However, human studies that comprehensively address delta wave interactions with spindles and SOs, as well as their functional role for memory are still lacking. Electroencephalographic data were acquired across three naps of 33 healthy older human participants (17 female) to investigate delta–spindle coupling and the interplay between delta‐ and SO‐related activity. Additionally, we determined intra‐individual stability of coupling measures and their potential link to the ability to form novel memories in a verbal memory task. Our results revealed weaker delta–spindle compared to SO–spindle coupling. Contrary to our initial hypothesis, we found no evidence for an opposing dependency between SO‐ and delta‐related activities during non‐rapid eye movement sleep. Moreover, the ratio between SO‐ and delta‐nested spindles rather than SO–spindle and delta–spindle coupling measures by themselves predicted the ability to form novel memories best. In conclusion, our results do not confirm previous findings in rodents on competitive interactions between delta activity and SO–spindle coupling in older adults. However, they support the hypothesis that SO, delta wave, and spindle activity should be jointly considered when aiming to link sleep physiology and memory formation. [ABSTRACT FROM AUTHOR]

Objective: A well‐established bidirectional relationship exists between sleep and epilepsy. Patients with epilepsy tend to have less efficient sleep and shorter rapid eye movement (REM) sleep. Seizures are far more likely to arise from sleep transitions and non‐REM sleep compared to REM sleep. Delay in REM onset or reduction in REM duration may have reciprocal interactions with seizure occurrence. Greater insight into the relationship between REM sleep and seizure occurrence is essential to our understanding of circadian patterns and predictability of seizure activity. We assessed a cohort of adults undergoing evaluation of drug‐resistant epilepsy to examine whether REM sleep prior to or following seizures is delayed in latency or reduced in quantity. Methods: We used a spectrogram‐guided approach to review the video‐electroencephalograms of patients' epilepsy monitoring unit admissions for sleep scoring to determine sleep variables. Results: In our cohort of patients, we found group‐ and individual‐level delay of REM latency and reduced REM duration when patients experienced a seizure before the primary sleep period (PSP) of interest or during the PSP of interest. A significant increase in REM latency and decrease in REM quantity were observed on nights where a seizure occurred within 4 h of sleep onset. No change in REM variables was found when investigating seizures that occurred the day after the PSP of interest. Our study is the first to provide insight about a perisleep period, which we defined as 4‐h periods before and after the PSP. Significance: Our results demonstrate a significant relationship between seizures occurring prior to the PSP, during the PSP, and in the 4‐h perisleep period and a delay in REM latency. These findings have implications for developing a biomarker of seizure detection as well as longer term seizure risk monitoring. [ABSTRACT FROM AUTHOR]

Sleep and circadian rhythm disturbance are predictors of poor physical and mental health, including dementia. Long-term digital technology-enabled monitoring of sleep and circadian rhythms in the community has great potential for early diagnosis, monitoring of disease progression, and assessing the effectiveness of interventions. Before novel digital technology-based monitoring can be implemented at scale, its performance and acceptability need to be evaluated and compared to gold-standard methodology in relevant populations. Here, we describe our protocol for the evaluation of novel sleep and circadian technology which we have applied in cognitively intact older adults and are currently using in people living with dementia (PLWD). In this protocol, we test a range of technologies simultaneously at home (7–14 days) and subsequently in a clinical research facility in which gold standard methodology for assessing sleep and circadian physiology is implemented. We emphasize the importance of assessing both nocturnal and diurnal sleep (naps), valid markers of circadian physiology, and that evaluation of technology is best achieved in protocols in which sleep is mildly disturbed and in populations that are relevant to the intended use-case. We provide details on the design, implementation, challenges, and advantages of this protocol, along with examples of datasets. [ABSTRACT FROM AUTHOR]

Preclinical and human physiological studies indicate that topical, selective TASK 1/3 K+ channel antagonism increases upper airway dilator muscle activity and reduces pharyngeal collapsibility during anesthesia and nasal breathing during sleep. The primary aim of this study was to determine the effects of BAY2586116 nasal spray on obstructive sleep apnea (OSA) severity and whether individual responses vary according to differences in physiological responses and route of breathing. Ten people (5 females) with OSA [apnea-hypopnea index (AHI) = 47 ± 26 events/h (means ± SD)] who completed previous sleep physiology studies with BAY2586116 were invited to return for three polysomnography studies to quantify OSA severity. In random order, participants received either placebo nasal spray (saline), BAY2586116 nasal spray (160 lg), or BAY2586116 nasal spray (160 µg) restricted to nasal breathing (chinstrap or mouth tape). Physiological responders were defined a priori as those who had improved upper airway collapsibility (critical closing pressure ≥2 cmH2O) with BAY2586116 nasal spray (NCT04236440). There was no systematic change in apnea-hypopnea index (AHI3) from placebo versus BAY2586116 with either unrestricted or nasal-only breathing versus placebo (47 ± 26 vs. 43 ± 27 vs. 53 ± 33 events/h, P = 0.15). However, BAY2586116 (unrestricted breathing) reduced OSA severity in physiological responders compared with placebo (e.g., AHI3 = 28 ± 11 vs. 36 ± 12 events/h, P = 0.03 and ODI3 = 18 ± 10 vs. 28 ± 12 events/h, P ¼ 0.02). Morning blood pressure was also lower in physiological responders after BAY2586116 versus placebo (e.g., systolic blood pressure = 137 ± 24 vs. 147 ± 21 mmHg, P < 0.01). In conclusion, BAY2586116 reduces OSA severity during sleep in people who demonstrate physiological improvement in upper airway collapsibility. These findings highlight the therapeutic potential of this novel pharmacotherapy target in selected individuals. [ABSTRACT FROM AUTHOR]

In recent years, there has been an increased interest in elucidating the influence of the gut microbiota on sleep physiology. The gut microbiota affects the central nervous system by modulating neuronal pathways through the neuroendocrine and immune system, the hypothalamus-pituitary-adrenal axis, and various metabolic pathways. The gut microbiota can also influence circadian rhythms. In this study, we observed the gut microbiota composition of patients suffering from narcolepsy type 1, narcolepsy type 2, and idiopathic hypersomnia. We did not observe any changes in the alpha diversity of the gut microbiota among patient groups and healthy controls. We observed changes in beta diversity in accordance with Jaccard dissimilarities between the control group and groups of patients suffering from narcolepsy type 1 and idiopathic hypersomnia. Our results indicate that both these patient groups differ from controls relative to the presence of rare bacterial taxa. However, after adjustment for various confounding factors such as BMI, age, and gender, there were no statistical differences among the groups. This indicates that the divergence in beta diversity in the narcolepsy type 1 and idiopathic hypersomnia groups did not arise due to sleep disturbances. This study implies that using metabolomics and proteomics approaches to study the role of microbiota in sleep disorders might prove beneficial. • The gut microbiota of patients with central hypersomnia varies from controls due to BMI, age, gender, and diet differences. • Our study supports the hypothesis that narcolepsy type 2 and idiopathic hypersomnia could form one diagnostic unit. • We did not find any significant effect of the sleep predictors on the gut microbiota. [ABSTRACT FROM AUTHOR]

Recently, a Y727C variant in the dual-specific 3′,5′-cyclic nucleotide phosphodiesterase 11A (PDE11A-Y727C) was linked to increased sleep quality and reduced myopia risk in humans. Given the well-established role that the PDE11 substrates cAMP and cGMP play in eye physiology and sleep, we determined if (1) PDE11A protein is expressed in the retina or other eye segments in mice, (2) PDE11A-Y7272C affects catalytic activity and/or subcellular compartmentalization more so than the nearby suicide-associated PDE11A-M878V variant, and (3) Pde11a deletion alters eye growth or sleep quality in male and female mice. Western blots show distinct protein expression of PDE11A4, but not PDE11A1-3, in eyes of Pde11a WT, but not KO mice, that vary by eye segment and age. In HT22 and COS-1 cells, PDE11A4-Y727C reduces PDE11A4 catalytic activity far more than PDE11A4-M878V, with both variants reducing PDE11A4-cAMP more so than PDE11A4-cGMP activity. Despite this, Pde11a deletion does not alter age-related changes in retinal or lens thickness or axial length, nor vitreous or anterior chamber depth. Further, Pde11a deletion only minimally changes refractive error and sleep quality. That said, both variants also dramatically alter the subcellular compartmentalization of human and mouse PDE11A4, an effect occurring independently of dephosphorylating PDE11A4-S117/S124 or phosphorylating PDE11A4-S162. Rather, re-compartmentalization of PDE11A4-Y727C is due to the loss of the tyrosine changing how PDE11A4 is packaged/repackaged via the trans-Golgi network. Therefore, the protective impact of the Y727C variant may reflect a gain-of-function (e.g., PDE11A4 displacing another PDE) that warrants further investigation in the context of reversing/preventing sleep disturbances or myopia. [ABSTRACT FROM AUTHOR]

Neural regulation of sleep and metabolic homeostasis are critical in many aspects of human health. Despite extensive epidemiological evidence linking sleep dysregulation with obesity, diabetes, and metabolic syndrome, little is known about the neural and molecular basis for the integration of sleep and metabolic function. The RAS GTPase-activating gene Neurofibromin (Nf1) has been implicated in the regulation of sleep and metabolic rate, raising the possibility that it serves to integrate these processes, but the effects on sleep consolidation and physiology remain poorly understood. A key hallmark of sleep depth in mammals and flies is a reduction in metabolic rate during sleep. Here, we examine multiple measures of sleep quality to determine the effects of Nf1 on sleep-dependent changes in arousal threshold and metabolic rate. Flies lacking Nf1 fail to suppress metabolic rate during sleep, raising the possibility that loss of Nf1 prevents flies from integrating sleep and metabolic state. Sleep of Nf1 mutant flies is fragmented with a reduced arousal threshold in Nf1 mutants, suggesting Nf1 flies fail to enter deep sleep. The effects of Nf1 on sleep can be localized to a subset of neurons expressing the GABAA receptor Rdl. Sleep loss has been associated with changes in gut homeostasis in flies and mammals. Selective knockdown of Nf1 in Rdl-expressing neurons within the nervous system increases gut permeability and reactive oxygen species (ROS) in the gut, raising the possibility that loss of sleep quality contributes to gut dysregulation. Together, these findings suggest Nf1 acts in GABA-sensitive neurons to modulate sleep depth in Drosophila. Author summary: Growing evidence suggests fruit flies, like mammals, possess different forms of sleep including light and deep sleep. Despite major advances in our understanding of t genes regulating sleep duration, little is known about how different forms of sleep are regulated. Neurofibramin 1 is associated with numerous neurological phenotypes including dysregulated sleep and circadian rhythms. Here, we report that flies harboring mutations in Neurofibramin 1 fail to enter deep sleep. This phenotype can be localized to GABA-receptive neurons in the brain and selective loss of Neurofibramin 1 in these neurons is also associated with reduced longevity and gut dysregulation. Together, these findings provide insight into the neural basis of sleep depth in fruit flies. [ABSTRACT FROM AUTHOR]

Summary Chronic sleep restriction, common in today's 24/7 society, causes cumulative neurobehavioural impairment, but the dynamics of the build‐up and dissipation of this impairment have not been fully elucidated. We addressed this knowledge gap in a laboratory study involving two, 5‐day periods of sleep restriction to 4 hr per day, separated by a 1‐day dose–response intervention sleep opportunity. We measured sleep physiological and waking neurobehavioural responses in 70 healthy adults, each randomized to one of seven dose–response intervention sleep doses ranging from 0 to 12 hr, or a non‐sleep‐restricted control group. As anticipated, sleep physiological markers showed homeostatic dynamics throughout the study, and waking neurobehavioural impairment accumulated across the two sleep restriction periods. Unexpectedly, there was only a slight and short‐lived effect of the 1‐day dose–response intervention sleep opportunity. Whether the dose–response intervention sleep opportunity involved extension, further restriction or total deprivation of sleep, neurobehavioural functioning during the subsequent second sleep restriction period was dominated by prior sleep–wake history. Our findings revealed a profound and enduring influence of long‐term sleep–wake history as a fundamental aspect of the dynamic regulation of the neurobehavioural response to sleep loss. [ABSTRACT FROM AUTHOR]

This article, published in the journal Neuropediatrics, discusses a study on the use of pulsatile corticoid therapy (PCT) in children with genetic drug-resistant epilepsy. The study aimed to compare the epileptic burden in children before and after PCT treatment using objective and subjective approaches. The results showed that PCT led to a significant reduction in spike burden in the electroencephalogram (EEG) and improved sleep physiology, specifically an increase in fast spindle rates. Additionally, seizure frequency improved in the majority of patients, and no severe adverse effects were reported. The study suggests that PCT may be an effective treatment option for children with genetic drug-resistant epilepsy, leading to a reduction in epileptic burden and improvement in cognitive functioning. [Extracted from the article]

Good sleep is essential for our mental and physical health. Good sleep also makes our skin look more radiant and refreshed [1]. Tea rituals are known to promote sleep. They help to relax and unwind, they create a mood of calm, and they facilitate sleep. Therefore, tea-inspired ingredients are a good starting point to create cosmetic night-care concepts, especially ingredients derived from herbal teas that are free of stimulating substances. Greek mountain tea (Sideritis scardica) has a long tradition as natural remedy to calm body and mind. This unprocessed, caffeine-free, herbal tea has been used for centuries as natural sleep support. But there is more to mountain tea: it contains protective and regenerative phytochemicals that help our skin to recover overnight. Here we present Mountain Tea Pro (from now on called “Mountain Tea Extract”), a natural extract of organic Sideritis scardica herb from a traceable source, that brings together the concept of tea-inspired beauty rituals and activity-proven benefits for skin. It is a perfect cosmetic ingredient to create relaxing night-care, mood-enhancing self-care, and beauty-sleep product [ABSTRACT FROM AUTHOR]

Introduction: The onset of puberty is associated with a shift in the circadian timing of sleep, leading to delayed sleep initiation [i.e., later sleep onset time (SOT)] due to later bedtimes and/or longer sleep onset latency (SOL). Several genome-wide association studies (GWAS) have identified genes that may be involved in the etiology of sleep phenotypes. However, circadian rhythms are also epigenetically regulated; therefore, epigenetic biomarkers may provide insight into the physiology of the pubertal sleep onset shift and the pathophysiology of prolonged or delayed sleep initiation. Results: The gene-wide analysis indicated differential methylation within or around 1818 unique genes across the sleep initiation measurements using self-report, actigraphy (ACT), and polysomnography (PSG), while GWAS-informed analysis yielded 67 genes. Gene hits were identified for bedtime (PSG), SOL (subjective, ACT and PSG) and SOT (subjective and PSG). DNA methylation within 12 genes was associated with both subjective and PSG-measured SOL, 31 with both ACT- and PSG-measured SOL, 19 with both subjective and ACT-measured SOL, and one gene (SMG1P2) had methylation sites associated with subjective, ACT- and PSG-measured SOL. Conclusions: Objective and subjective sleep initiation in adolescents is associated with altered DNA methylation in genes previously identified in adult GWAS of sleep and circadian phenotypes. Additionally, our data provide evidence for a potential epigenetic link between habitual (subjective and ACT) SOL and in-lab SOT and DNA methylation in and around genes involved in circadian regulation (i.e., RASD1, RAI1), cardiometabolic disorders (i.e., FADS1, WNK1, SLC5A6), and neuropsychiatric disorders (i.e., PRR7, SDK1, FAM172A). If validated, these sites may provide valuable targets for early detection and prevention of disorders involving prolonged or delayed SOT, such as insomnia, delayed sleep phase, and their comorbidity. [ABSTRACT FROM AUTHOR]

Summary: Dementia is the seventh leading cause of mortality, and a major source of disability and dependency in older individuals globally. Cognitive decline (and, to a lesser extent, normal ageing) are associated with sleep fragmentation and loss of slow‐wave sleep. Evidence suggests a bidirectional causal link between these losses. Phase‐locked auditory stimulation has emerged as a promising non‐invasive tool to enhance slow‐wave sleep, potentially ameliorating cognitive decline. In laboratory settings, auditory stimulation is usually supervised by trained experts. Different algorithms (simple amplitude thresholds, topographic correlation, sine‐wave fitting, phase‐locked loop, and phase vocoder) are used to precisely target auditory stimulation to a desired phase of the slow wave. While all algorithms work well in younger adults, the altered sleep physiology of older adults and particularly those with neurodegenerative disorders requires a tailored approach that can adapt to older adults' fragmented sleep and reduced amplitudes of slow waves. Moreover, older adults might require a continuous intervention that is not feasible in laboratory settings. Recently, several auditory stimulation‐capable portable devices ('Dreem®', 'SmartSleep®' and 'SleepLoop®') have been developed. We discuss these three devices regarding their potential as tools for science, and as clinical remote‐intervention tools to combat cognitive decline. Currently, SleepLoop® shows the most promise for scientific research in older adults due to high transparency and customizability but is not commercially available. Studies evaluating down‐stream effects on cognitive abilities, especially in patient populations, are required before a portable auditory stimulation device can be recommended as a clinical preventative remote‐intervention tool. [ABSTRACT FROM AUTHOR]

No studies have looked at the effects of cumulative sleep restriction (CSR) on sleep architecture or the power spectrum of sleep EEG (electroencephalogram) in school-age children, as recorded by PSG (polysomnography). This is true for both typically developing (TD) children and children with ADHD (attention deficit/hyperactivity disorder), who are known to have more sleep difficulties. Participants were children (ages 6–12 years), including 18 TD and 18 ADHD, who were age- and sex-matched. The CSR protocol included a two-week baseline and two randomized conditions: Typical (six nights of sleep based on baseline sleep schedules) and Restricted (one-hour reduction of baseline time in bed). This resulted in an average of 28 min per night difference in sleep. Based on ANOVAs (analysis of variance), children with ADHD took longer to reach N3 (non-rapid eye movement), had more WASO (wake after sleep onset) (within the first 5.1 h of the night), and had more REM (rapid eye movement) sleep than TD children regardless of condition. During CSR, ADHD participants had less REM and a trend toward longer durations of N1 and N2 compared to the TD group. No significant differences in the power spectrum were found between groups or conditions. In conclusion, this CSR protocol impacted some physiological aspects of sleep but may not be sufficient to cause changes in the power spectrum of sleep EEG. Although preliminary, group-by-condition interactions suggest that the homeostatic processes in children with ADHD may be impaired during CSR. [ABSTRACT FROM AUTHOR]

To understand how memories are reactivated and consolidated during sleep, experimenters have employed the unobtrusive re‐presentation of memory cues from a variety of pre‐sleep learning tasks. Using this procedure, known as targeted memory reactivation (TMR), we previously found that reactivation of counter‐social‐bias training during post‐training sleep could selectively enhance training effects in reducing unintentional social biases. Here, we describe re‐analyses of electroencephalographic (EEG) data from this previous study to characterize neurophysiological correlates of TMR‐induced bias reduction. We found that TMR benefits in bias reduction were associated with (a) the timing of memory‐related cue presentation relative to the 0.1–1.5 Hz slow‐oscillation phase and (b) cue‐elicited EEG power within the 1–4 Hz delta range. Although cue delivery was at a fixed rate in this study and not contingent on the slow‐oscillation phase, cues were found to be clustered in slow‐oscillation upstates for those participants with stronger TMR benefits. Similarly, higher cue‐elicited delta power 250–1000 ms after cue onset was also linked with larger TMR benefits. These electrophysiological results substantiate the claim that memory reactivation altered social bias in the original study, while also informing neural explanations of these benefits. Future research should consider these sleep physiology parameters in relation to TMR applications and to memory reactivation in general. Memory can be reactivated during sleep via unobtrusive presentation of learning‐related sensory cues. This procedure, known as targeted memory reactivation, is effective in promoting memory consolidation during slow‐wave sleep. However, the physiological basis of memory change during sleep is under‐specified. We showed that effective memory reactivation was associated with memory cues clustered at slow‐oscillation upstates and stronger cue‐elicited delta power. These neurophysiological signals provide information that is useful for understanding sleep‐based memory reactivation and consolidation. [ABSTRACT FROM AUTHOR]

Background: K+ channel inhibition has been identified in animal models as a potential target to increase pharyngeal dilator muscle activity and treat obstructive sleep apnea (OSA). However, these findings have not yet been translated to humans.Research Question: Does a novel, potent, TASK 1/3 channel antagonist, BAY2586116, improve pharyngeal collapsibility in pigs and humans and secondarily, what is the optimal dose and mode of topical application?Study Design and Methods: Pre-clinical study: Pharyngeal muscle activity and upper-airway collapsibility via transient negative pressure application was quantified in 13 anesthetized pigs during placebo, 0.3, 3 and 30μg nasal drops of BAY2586116.Clinical Study: 12 people with OSA instrumented with polysomnography equipment, an epiglottic pressure catheter, pneumotachograph and nasal mask to monitor sleep and breathing performed up to four detailed upper airway sleep physiology studies. Participants received BAY2586116 or placebo nasal spray (160μg) prior to sleep via a double-blind, randomized, crossover design. Most participants also returned for three additional overnight visits: 1) nasal drops (160μg), 2) half dose nasal spray (80μg), and 3) direct endoscopic application (160μg). The upper-airway critical closing pressure (Pcrit) during sleep was quantified at each visit.Results: There were consistent and sustained improvements in pharyngeal collapsibility to negative pressure with 3 and 30μg of BAY2586116 versus placebo in pigs. Similarly, BAY2586116 improved pharyngeal collapsibility by an average of ∼2cmH2O versus placebo regardless of topical application mode and dose (mixed model p<0.008) in participants with OSA.Interpretation: Acute topical application of BAY2586116 improves upper-airway collapsibility in anesthetized pigs and sleeping humans with OSA. These novel physiology findings highlight the therapeutic potential to target K+ channel mechanisms to treat OSA.Clinical Trial Registration: NCT04236440. [ABSTRACT FROM AUTHOR]

Summary: Nightmares are a core feature of posttraumatic stress disorder, are poorly understood, and are associated with serious negative outcomes. Their biology has been difficult to study, and the feasibility of capturing them in the naturalistic home environment has been poor. This said, the published research and dominant scientific model has focused on nightmares as a manifestation of noradrenergic hyperarousal during rapid eye movement sleep. The current study used at‐home, participant‐applied devices to measure nightmare physiology in posttraumatic stress disorder treatment‐seeking veterans, by examining heartrate measures as indicators of noradrenergic tone, and sleep‐stage characteristics and stability in the sleep preceding time‐stamped nightmare awakenings. Our data indicate the high feasibility of participant‐administered, at‐home measurement, and showed an unexpected stability of ‐rapid eye movement sleep along with no evidence of heartrate elevations in sleep preceding nightmare awakenings. Altogether, these data highlight new opportunities for the study of nightmares while questioning the sufficiency of dominant models, which to date are largely theoretically based. [ABSTRACT FROM AUTHOR]

Summary: In adults, recent evidence demonstrates that sleep and circadian physiology change across lunar phases, including findings that endogenous melatonin levels are lower near the full moon compared to the new moon. Here, we extend these results to early childhood by examining circalunar fluctuations in children's evening melatonin levels. We analysed extant data on young children's circadian rhythms (n = 46, aged 3.0–5.9 years, 59% female). After following a strict sleep schedule for 5–7 days, children completed an in‐home, dim‐light circadian assessment (<10 lux). Salivary melatonin was assessed at regular 20‐ to 30‐min intervals until 1 h past each child's scheduled bedtime. Melatonin levels varied significantly across lunar phases, such that melatonin was lower in participants assessed near the full moon as compared to near the new moon. Significant differences were observed at 50 min (meanfull = 2.5 pg/ml; meannew = 5.4 pg/ml) and 10 min (meanfull = 7.3 pg/ml; meannew = 15.8 pg/ml) before children's scheduled bedtime, as well as at 20 min (meanfull = 15.5 pg/ml; meannew = 26.1 pg/ml) and 50 min (meanfull = 19.9 pg/ml; meannew = 34.3 pg/ml) after bedtime. To our knowledge, these are the first data demonstrating that melatonin secretion, a process regulated by the human circadian system, is sensitive to changes in lunar phase at an early age. Future research is needed to understand the mechanisms underlying this association (e.g., an endogenous circalunar rhythm) and its potential influence on children's sleep and circadian health. [ABSTRACT FROM AUTHOR]

The wakefulness-sleep cycle sets the pace of our life. Sleep research examines the transition between wakefulness and sleep, its hormonal regulation, and its pathological disruption. Understanding sleep mechanisms would improve quality-of-life well beyond sleep itself. To this aim, we invite contributions for the Collection "sleep physiology and circadian rhythms". [ABSTRACT FROM AUTHOR]

Undergraduate programs related to allied health are often pursued by students to prepare for entrance into professional programs, but many students also ask about what types of employment options they may have upon completion of the bachelor's degree. This experiential learning course in cardiovascular and sleep technology was designed to provide opportunities for students to gain hands-on clinical skills that could help them to enter professional programs or to find employment in an allied health field such as cardiopulmonary rehabilitation, cardiovascular technology, or sleep technology. The prerequisites for this course were the completion of two semesters of anatomy and physiology. This course was based on experiential learning and was structured into three modules: clinical exercise physiology, autonomic physiology, and sleep physiology. As part of the course students completed a 4-page scientific report for one designated topic within each of the modules. The two exams in the course were essay based. The design of this course required students to review key topics from anatomy and physiology, to comprehend peer-reviewed manuscripts, to gain hands-on experiences with sophisticated physiological equipment, to work as individuals and in groups, and to become better oral and written communicators. The sleep physiology module included an introduction to electroencephalography (EEG) and a student-led nap study, which may be an effective way to introduce students to sleep medicine. We are hopeful that the summary of this course will be useful to physiology educators as they work to provide the most meaningful experiences to their undergraduates in the health sciences. NEW & NOTEWORTHY Experiential learning in clinical exercise, autonomic regulation, and sleep physiology is an impactful way to train undergraduate biomedical students to enter a variety of careers in healthcare, graduate programs in the health professions, or traditional research graduate programs. A hands-on course such as Cardiovascular and Sleep Technology provides a way, in addition to or independent of original research, to provide clinically relevant training. [ABSTRACT FROM AUTHOR]

Summary: This work aimed to evaluate if a contact‐free radar sensor can be used to observe ultradian patterns in sleep physiology, by way of a data processing tool known as Locomotor Inactivity During Sleep (LIDS). LIDS was designed as a simple transformation of actigraphy recordings of wrist movement, meant to emphasise and enhance the contrast between movement and non‐movement and to reveal patterns of low residual activity during sleep that correlate with ultradian REM/NREM cycles. We adapted the LIDS transformation for a radar that detects body movements without direct contact with the subject and applied it to a dataset of simultaneous recordings with polysomnography, actigraphy, and radar from healthy young adults (n = 12, four nights of polysomnography per participant). Radar and actigraphy‐derived LIDS signals were highly correlated with each other (r > 0.84), and the LIDS signals were highly correlated with reduced‐resolution polysomnographic hypnograms (rradars >0.80, ractigraph >0.76). Single‐harmonic cosine models were fitted to LIDS signals and hypnograms; significant differences were not found between their amplitude, period, and phase parameters. Mixed model analysis revealed similar slopes of decline per cycle for radar‐LIDS, actigraphy‐LIDS, and hypnograms. Our results indicate that the LIDS technique can be adapted to work with contact‐free radar measurements of body movement; it may also be generalisable to data from other body movement sensors. This novel metric could aid in improving sleep monitoring in clinical and real‐life settings, by providing a simple and transparent way to study ultradian dynamics of sleep using nothing more than easily obtainable movement data. [ABSTRACT FROM AUTHOR]

Introduction: Many factors may be hidden behind the global fertility decline observed in Western countries. Alongside the progressively increased age of infertile couples, environmental and behavioural factors, including non-optimal lifestyle habits, should be considered. Among these, sleep disorders have been suggested to be linked to human fertility.Methods: This is a narrative review, describing first sleep physiology, its disturbances, and the tools able to quantify sleep dysfunction. Then, we consider all available studies aimed at investigating the connection between sleep disorders and human fertility, providing a comprehensive view on this topic.Results: Forty-two studies investigating the relationship between sleep habits and human reproduction were included. All the published evidence was grouped according to the aspect of human fertility considered, i.e. i) female reproductive functions, ii) male reproductive functions, iii) natural conception and iv) assisted reproduction. For each of the sub-groups considered, the connection between sleep dysregulation and human fertility was classified according to specific sleep characteristics, such as sleep duration, quality, and habits. In addition, possible physio-pathological mechanisms proposed to support the link between sleep and fertility were summarized.Conclusion: This review summarizes the most relevant findings about the intricate and still largely unknown network of molecular pathways involved in the regulation of circadian homeostasis, to which sleep contributes, essential for reproductive physiology. Thus, many mechanisms seem correlate sleep disorders to reproductive health, such as adrenal activation, circadian dysregulation, and genetic influences. This review highlights the need to properly designed trials on the topic. [ABSTRACT FROM AUTHOR]

The widely used guidelines for sleep staging were developed for the visual inspection of electrophysiological recordings by the human eye. As such, these rules reflect a limited range of features in these data and are therefore restricted in accurately capturing the physiological changes associated with sleep. Here we present a novel analysis framework that extensively characterizes sleep dynamics using over 7700 time-series features from the hctsa software. We used clustering to categorize sleep epochs based on the similarity of their time-series features, without relying on established scoring conventions. The resulting sleep structure overlapped substantially with that defined by visual scoring. However, we also observed discrepancies between our approach and traditional scoring. This divergence principally stemmed from the extensive characterization by hctsa features, which captured distinctive time-series properties within the traditionally defined sleep stages that are overlooked with visual scoring. Lastly, we report time-series features that are highly discriminative of stages. Our framework lays the groundwork for a data-driven exploration of sleep sub-stages and has significant potential to identify new signatures of sleep disorders and conscious sleep states. [ABSTRACT FROM AUTHOR]

Summary: Sleep is critical for health, cognition, and restorative processes, and yet, many experience chronic sleep restriction. Sleep interventions have been designed to enhance overnight sleep quality and physiology. Components of these interventions, like relaxation‐based progressive muscle relaxation (PMR), have been studied in isolation and have shown direct effects on sleep architecture, including increasing time in restorative, slow‐wave sleep (SWS). These relaxation methods have been understudied in naps, which are effective fatigue countermeasures that reduce deleterious effects of chronic sleep restriction. We hypothesised that PMR should boost SWS in a nap, as compared to an active control. We used a between‐subject design in which healthy young adults underwent PMR training or listened to Mozart music (control) prior to a 90‐min nap opportunity. We assessed changes in the amount and lateralisation of SWS, as evidence suggests left hemispheric lateralisation may be a proxy for recuperative sleep needs, and changes to state‐dependent anxiety and fatigue before and after the nap to assess intervention success. We found PMR participants spent ~10 min more in SWS, equivalent to 125% more time, than the control group, and concomitantly, significantly less time in rapid eye movement sleep. PMR participants also had greater right lateralised slow‐wave activity and delta activity compared to the control suggesting a more well‐rested brain profile during sleep. Further, pre‐sleep anxiety levels predicted nap architecture in the intervention group, suggesting benefits may be impacted by anxiety. The feasibility and accessibility of PMR prior to a nap make this an interesting research avenue to pursue with strong translational application. [ABSTRACT FROM AUTHOR]

One can be aware of the effort needed to memorize a new fact or to recall the name of a new acquaintance. Because of experiences like this, learning can seem to have only two components, encoding information and, after some delay, retrieving information. To the contrary, learning entails additional, intervening steps that sometimes are hidden from the learner. For firmly acquiring fact and event knowledge in particular, learners are generally not cognizant of the necessity of offline consolidation. The memories that persist to be available reliably at a later time, according to the present conceptualization, are the ones we repeatedly rehearse and integrate with other knowledge, whether we do this intentionally or unknowingly, awake or asleep. This article examines the notion that learning is not a function of waking brain activity alone. What happens in the brain while we sleep also impacts memory storage, and consequently is a critical component of learning. The idea that memories can change over time and become enduring has long been present in memory research and is foundational for the concept of memory consolidation. Nevertheless, the notion that memory consolidation happens during sleep faced much resistance before eventually being firmly established. Research is still needed to elucidate the operation and repercussions of repeated reactivation during sleep. Comprehensively understanding how offline memory reactivation contributes to learning is vital for both theoretical and practical considerations. • Recurring memory reactivation drives consolidation, producing enduring memories. • Reactivation need not be intentional; it occurs offline during wake and during sleep. • Memory storage can be probed during sleep using Targeted Memory Reactivation (TMR). • TMR combined with measuring sleep physiology shows how memory storage evolves. • Offline memory reactivation is a valuable component of sleep and learning. [ABSTRACT FROM AUTHOR]

To assess the effect of caffeine and sleep quality on the flight performance-related cognitive function. High levels of cognitive performance in pilots is required for flight safety. Students at a military flight school in Thailand were invited to participate in this study. Exclusion criteria was positive screening for caffeine use disorder. We examined three cognitive functions required for flight performance: (1) vigilance (Mackworth Clock Test), (2) situational awareness, including memory (Corsi block-tapping test) and spatial reasoning (mental rotation test), and (3) reaction time (Deary-Liewald task). Neuropsychological tasks were performed before and 30 minutes after drinking a bottle of 220 ml coffee containing 143 mg of caffeine. Sleep quality was measured by the Thai-Pittsburgh Sleep Quality Index. Twenty-nine healthy males without caffeine use disorder with a mean age of 25.1 years were enrolled. After low-dose caffeine intake (<3 mg/kg body weight), cognitive performance improved significantly in vigilance, situation awareness, and reaction time. Baseline cognitive performance was not different between high (HSQ) and low sleep quality (LSQ) groups. After drinking coffee, however, participants with HSQ demonstrated improvements in vigilance and reaction time, while the LSQ group had improved vigilance only. Low dose caffeine improved vigilance, situational awareness, and reaction time which were cognitive functions required for flight performance. The cognitive-enhancing effect of caffeine was more obvious in student pilots with high-quality sleep. [ABSTRACT FROM AUTHOR]

Moreover, the study by Estaki et al. could not establish the direction of the association between sleep and microbiome because it was a cross-sectional study with both sleep and microbiome measured at the same time. The human intestinal microbiome is the assembly of microorganisms that reside in our intestinal tract. First, although the associations reported by Estaki et al. may reflect true biologic links between specific gut microbes and sleep, they could also represent indirect effects or effects that are confounded by other factors associated with both sleep and gut microbiome. [Extracted from the article]

Growing evidence shows that sex differences impact many facets of human biology. Here we review and discuss the impact of sex on human circadian and sleep physiology, and we uncover a data gap in the field investigating the non-visual effects of light in humans. A virtual workshop on the biomedical implications of sex differences in sleep and circadian physiology led to the following imperatives for future research: i) design research to be inclusive and accessible; ii) implement recruitment strategies that lead to a sex-balanced sample; iii) use data visualization to grasp the effect of sex; iv) implement statistical analyses that include sex as a factor and/or perform group analyses by sex, where possible; v) make participant-level data open and available to facilitate future meta-analytic efforts. [ABSTRACT FROM AUTHOR]

Sleep is a universal physiological need in all species and is essential for the maintenance and recovery of various physiological functions of the body. In late years, the gut microbiota (GM), a vast and extraordinarily complex ecosystem located in human gastrointestinal tract that oversees an array of critical bodily functions, has become a popular focus among researchers. Accumulated evidences in this field have revealed that it exerts important roles in the regulation of some biological characteristics, especially metabolic, immunological and neurobehavioral functions. With the increasing comprehension of brain-gut axis, a bidirectional communication channel linking the brain and gut, the roles of GM in sleep are paid much attention to. Evidences have shown that the GM is essential for the maintenance of normal sleep physiology. In turn, it has also been demonstrated that the abnormal sleep patterns and duration affect the composition, diversity and function of the GM through the brain-gut-microbiota axis (BGMA). Present contributions have described several underlying factors that could be involved in the BGMA in sleep, such as the immune system, the vagus nerve, the neuroendocrine system, and bacterial metabolites. Furthermore, several interventions targeting the GM have been proved to be beneficial for amelioration of sleep problems. On this basis, in this review, we aim to explore the interaction between sleep and GM, and elucidate the therapeutic microbiota manipulations with potential promoting effects on sleep quality. [ABSTRACT FROM AUTHOR]

Subjective sleep disturbances are reported by humans with attention-deficit/hyperactivity disorder (ADHD). However, no consistent objective findings related to sleep disturbances led to the removal of sleep problems from ADHD diagnostic criteria. Dogs have been used as a model for human ADHD with questionnaires validated for this purpose. Also, their sleep physiology can be measured by non-invasive methods similarly to humans. In the current study, we recorded spontaneous sleep EEG in family dogs during a laboratory session. We analyzed the association of sleep macrostructure and deep sleep (NREM) slow-wave activity (SWA) with a validated owner-rated ADHD questionnaire, assessing inattention (IA), hyperactivity/impulsivity (H/I) and total (T) scores. Higher H/I and T were associated with lower sleep efficiency and longer time awake after initial drowsiness and NREM. IA showed no associations with sleep variables. Further, no association was found between ADHD scores and SWA. Our results are in line with human studies in which poor sleep quality reported by ADHD subjects is associated with some objective EEG macrostructural parameters. This suggests that natural variation in dogs' H/I is useful to gain a deeper insight of ADHD neural mechanisms. [ABSTRACT FROM AUTHOR]

This study is a comparative analysis between a neuropsychological perspective on dreams and a theological one that tries to better understand the manifestation of dream revelations. In the first phase is presented the natural physiology of sleep with its related stages (REM and NREM). Then we move on to the description of the manifestation of ordinary dreams and their functional role for the optimal parameters of our thinking, memory and behavior. The paper also presents some main theories about dream activation in the fields of neuropsychology. Subsequent research includes the theological perspective on people's trust in dreams. At the same time, there are presented the most illustrative Bible cases which include dreamlike revelations in the Old and the New Testament. After that, we will discuss and analyze both the phenomenon of incubatio (healing dreams), found in Eastern and Western Christianity, in the 1st millennium AD, as well as some events focused on the discovery of holy relics following some providential dreams. In conclusion, the research will show how people, and especially religious practitioners, can relate correctly to certain atypical dreams they have at some point in their lives. [ABSTRACT FROM AUTHOR]

Sufficient sleep and quality sleep considered as one of the most important human needs. Less sleep may make human nerves, anxiety and less concentrate. Therefor, this paper focuses on the sleep types, and a kind of sleep bed, in order to find out how such a bed improve quality of sleep, and how a specific game helps to make a child improve their quality sleep? Also, this paper focuses on some environment factors may have effect on the sleep quality such as temperature, mattress softness, luminosity, air pressure and humidity. For this purpose, this research relays on the two experiments, the first one would be preparing the room with such a bed and supplies the room with measurement tools such as pressure sensors, body thermometers in order to measure sleep quality and it takes 28 days. Also, conducting a Questionnaire. The second experiment would be comparing quality sleep between standard bed and Smart bed. [ABSTRACT FROM AUTHOR]

Sleep is entwined across many physiologic processes in the brain and periphery, thereby exerting tremendous influence on our well-being. Yet sleep exists in a social-environmental context. Contextualizing sleep health with respect to its determinants—from individual- to societal-level factors—would enable neuroscientists to more effectively translate sleep health into clinical practice. Key challenges and opportunities pertain to (i) recognizing and exploring sleep’s functional roles, (ii) clarifying causal mechanisms in relation to key outcomes, (iii) developing richer model systems, (iv) linking models to known contextual factors, and (v) leveraging advances in multisensory technology. Meeting these challenges and opportunities would help transcend disciplinary boundaries such that social-environmental considerations related to sleep would become an ever-greater presence in the clinic. [ABSTRACT FROM AUTHOR]

Sleep is essential for brain function in a surprisingly diverse set of ways. In the short term, lack of sleep leads to impaired memory and attention; in the longer term, it produces neurological dysfunction or even death. I discuss recent advances in understanding how sleep maintains the physiological health of the brain through interconnected systems of neuronal activity and fluid flow. The neural dynamics that appear during sleep are intrinsically coupled to its consequences for blood flow, cerebrospinal fluid dynamics, and waste clearance. Recognizing these linked causes and consequences of sleep has shed new light on why sleep is important for such disparate aspects of brain function. [ABSTRACT FROM AUTHOR]

Objective/background: The aim of this study was to examine the relationship between overnight consolidation of implicit statistical learning with spindle frequency EEG activity and slow frequency delta power during non-rapid eye movement (NREM) sleep in obstructive sleep apnea (OSA).Patients/methods: Forty-seven OSA participants completed the experiment. Prior to sleep, participants performed a reaction time cover task containing hidden patterns of pictures, about which participants were not informed. After the familiarisation phase, participants underwent overnight polysomnography. 24 h after the familiarisation phase, participants performed a test phase to assess their learning of the hidden patterns, expressed as a percentage of the number of correctly identified patterns. Spindle frequency activity (SFA) and delta power (0.5-4.5 Hz), were quantified from NREM electroencephalography. Associations between statistical learning and sleep EEG, and OSA severity measures were examined.Results: SFA in NREM sleep in frontal and central brain regions was positively correlated with statistical learning scores (r = 0.41 to 0.31, p = 0.006 to 0.044). In multiple regression, greater SFA and longer sleep onset latency were significant predictors of better statistical learning performance. Delta power and OSA severity were not significantly correlated with statistical learning.Conclusions: These findings suggest spindle activity may serve as a marker of statistical learning capability in OSA. This work provides novel insight into how altered sleep physiology relates to consolidation of implicitly learnt information in patients with moderate to severe OSA. [ABSTRACT FROM AUTHOR]

Background: Sleep is essential for child and adolescent health and well-being. There is an increasing interest in whether electronic media use affects children and young adolescents' sleep. Prior reviews have focused on a school-aged population. Moreover, it is crucial that research continuously addresses the processes of technology and media use and the implication on sleep. This systematic review examines the evidence of electronic media use related to sleep among 0-15-year-olds.Methods: Searches were carried out in four databases (CINAHL, Web of Science, EMBASE, and Medline). Inclusion criteria included age ≤ 15 years, and intervention, cohort, or cross-sectional studies from western countries. Methodological quality was rated using the Quality Assessment Tool for Quantitative Studies by two independent reviewers. Data was extracted using a standardized data extraction form. Synthesis was done by summarizing results across studies by age groups of 0-5, 6-12, and 13-15 years within four sleep domains: Bedtime and sleep onset; Sleep quality; Sleep duration; Daytime tiredness.Results: The search identified 10,719 unique studies, of which 109 fulfilled inclusion and exclusion criteria and were assessed for methodological quality. In total, 49 studies were included in the review. The study designs were randomized controlled trials (n = 3), quasi-experimental studies (n = 2), prospective cohort studies (n = 15), and cross-sectional studies (n = 29). Evidence for an association between electronic media use and sleep duration was identified, with stronger evidence for 6-15-years-olds than 0-5-year-olds. The evidence for a relationship between electronic media use and other sleep outcomes was more inconclusive. However, for 6-12-year-old children, there was evidence for associations of electronic media use with delayed bedtime and poor sleep quality. For 13-15-year-olds, there was evidence for associations between screen time and problems falling asleep, and between social media use and poor sleep quality.Conclusions: Overall, electronic media use was generally associated with shorter sleep duration in children and adolescents. Studies with stronger research design and of higher quality are needed to draw solid conclusions about electronic media's impact on other sleep outcomes. Public awareness and interventions could be promoted about the potential negative impact on children's sleep of electronic media devices that are used excessively and close to bedtime. [ABSTRACT FROM AUTHOR]

The article reports that Sleep disorders are disturbances that affect the ability to fall or stay asleep, syndromes of excessive sleep, or syndromes that produce abnormal behavior related to sleep. It mentions that include activity for the human being since during it essential physiological functions are carried out for the physical and psychic balance of the individual, such as restoring the homeostasis of the central nervous system, restoring cellular energy stores and consolidate memory.

Sleep is being emphasized as a factor that improves mental health and quality of life. Here, we aimed to investigate the association between the quality and duration of sleep and subjective cognitive decline in the Korean population. We used the 2018 Korean Community Health Survey data that are nationwide representative data collected by the Korea Centers for Disease Control and Prevention. Sleep quality was measured using the Korean version of Pittsburgh Sleep Quality Index. The study population comprised 206,719 individuals aged 19 years and over. We used multiple logistic regression for the analysis. Individuals of both sexes with poor sleep quality were more likely to experience subjective cognitive decline compared with the reference group (good sleep quality) (men, odds ratio (OR) = 1.97 [95% confidence interval (CI) 1.86–2.09]; women, OR = 1.75 [95% CI 1.67–1.84]). U-shape associations were found between sleep duration and subjective cognitive decline. Additionally, the presence of depressive symptom or stress and health-related behaviors, including smoking, drinking, and not walking, were high-risk factors for subjective cognitive decline. Our results indicate that poor sleep quality might contribute to subjective cognitive decline in the Korean population. We suggest the implementation of intervention measures for poor sleep behaviors to prevent cognitive decline. [ABSTRACT FROM AUTHOR]

Background: Sleep disturbances in autism spectrum disorder (ASD) represent a common and vexing comorbidity. Clinical heterogeneity amongst these warrants studies of the mechanisms associated with specific genetic etiologies. Duplications of 15q11.2-13.1 (Dup15q syndrome) are highly penetrant for neurodevelopmental disorders (NDDs) such as intellectual disability and ASD, as well as sleep disturbances. Genes in the 15q region, particularly UBE3A and a cluster of GABAA receptor genes, are critical for neural development, synaptic protein synthesis and degradation, and inhibitory neurotransmission. During awake electroencephalography (EEG), children with Dup15q syndrome demonstrate increased beta band oscillations (12–30 Hz) that likely reflect aberrant GABAergic neurotransmission. Healthy sleep rhythms, necessary for robust cognitive development, are also highly dependent on GABAergic neurotransmission. We therefore hypothesized that sleep physiology would be abnormal in children with Dup15q syndrome. Methods: To test the hypothesis that elevated beta oscillations persist in sleep in Dup15q syndrome and that NREM sleep rhythms would be disrupted, we computed: (1) beta power, (2) spindle density, and (3) percentage of slow-wave sleep (SWS) in overnight sleep EEG recordings from a cohort of children with Dup15q syndrome (n = 15) and compared them to age-matched neurotypical children (n = 12). Results: Children with Dup15q syndrome showed abnormal sleep physiology with elevated beta power, reduced spindle density, and reduced or absent SWS compared to age-matched neurotypical controls. Limitations: This study relied on clinical EEG where sleep staging was not available. However, considering that clinical polysomnograms are challenging to collect in this population, the ability to quantify these biomarkers on clinical EEG—routinely ordered for epilepsy monitoring—opens the door for larger-scale studies. While comparable to other human studies in rare genetic disorders, a larger sample would allow for examination of the role of seizure severity, medications, and developmental age that may impact sleep physiology. Conclusions: We have identified three quantitative EEG biomarkers of sleep disruption in Dup15q syndrome, a genetic condition highly penetrant for ASD. Insights from this study not only promote a greater mechanistic understanding of the pathophysiology defining Dup15q syndrome, but also lay the foundation for studies that investigate the association between sleep and cognition. Abnormal sleep physiology may undermine healthy cognitive development and may serve as a quantifiable and modifiable target for behavioral and pharmacological interventions. [ABSTRACT FROM AUTHOR]

Introduction: Background: increasingly, research suggests that lack of sleep is linked to adiposity worldwide, but few studies have been conducted in middle-aged and elderly Chinese subjects. The purpose of the present study was to analyze the association of siesta and nocturnal sleep duration with the prevalence of adiposity in middle-aged and elderly Chinese individuals. Methods: a total of 7,891 community dwelling Chinese subjects who had participated in the 2015 China Health and Retirement Longitudinal Study were included. A four-stage random sampling method was used to select participants. Siesta and nocturnal sleep duration was self-reported. Adiposity, including general obesity and abdominal obesity, was assessed. Multiple logistic analyses were conducted to explore the association between siesta, nocturnal sleep duration, and adiposity. Results: people with long siesta durations (≥ 1 hour/day) were significantly associated with an increased risk for abdominal obesity, independently and in all subgroup analyses, when compared to those without regular siesta. ORs after adjustment of confounding factors included: all subjects, OR = 1.45, 95 % CI, 1.23 to 1.70; middle-aged subjects, OR = 1.46, 95 % CI, 1.15 to 1.86; elderly, OR = 1.43, 95 % CI, 1.14 to 1.78. Conclusions: our data show that siesta duration plays a role in the prevalence of age-specific abdominal obesity. Individuals with long siesta durations are more likely to have abdominal obesity among the middle-aged and elderly population when compared to those without regular siesta. The results of this study need to be confirmed by further studies. [ABSTRACT FROM AUTHOR]

Objectives: Recent studies suggest that interindividual genetic differences in glial-dependent CSF flow through the brain parenchyma, known as glymphatic flow, may trigger compensatory changes in human sleep physiology. In animal models, brain perivascular spaces are a critical conduit for glymphatic flow. We tested the hypothesis that MRI-visible PVS volumes, a putative marker of perivascular dysfunction, are associated with compensatory differences in real-world human sleep behavior.Methods: We analyzed data from 152 cerebrovascular disease patients from the Ontario Neurodegenerative Disease Research Initiative (ONDRI). PVS volumes were measured using 3T-MRI. Self-reported total sleep time, time in bed, and daytime dysfunction were extracted from the Pittsburgh Sleep Quality Index.Results: Individuals with greater PVS volumes reported longer time in bed (+0.85 h per log10 proportion of intracranial volume (ICV) occupied by PVS, SE = 0.30, p = 0.006) and longer total sleep times (+0.70 h per log10 proportion of ICV occupied by PVS volume, SE = 0.33, p = 0.04), independent of vascular risk factors, sleep apnea, nocturnal sleep disturbance, depression, and global cognitive status. Further analyses suggested that the positive association between PVS volumes and total sleep time was mediated by greater time in bed. Moreover, despite having on average greater total sleep times, individuals with greater basal ganglia PVS volumes were more likely to report daytime dysfunction (OR 5.63 per log10 proportion of ICV occupied by PVS, 95% CI: 1.38-22.26, p = 0.018).Conclusions: Individuals with greater PVS volumes spend more time in bed, resulting in greater total sleep time, which may represent a behavioral compensatory response to perivascular space dysfunction. [ABSTRACT FROM AUTHOR]

Sleep spindles are a physiological marker of off-line memory consolidation. In young adults, sleep spindles are preferentially responsive to encoded information that is tagged as having future relevance. Older adults, on the other hand, show reduced capacity for future simulation and alterations in sleep physiology. Healthy young adults (n = 38) and older adults (n = 28) completed an adaptation night, followed by two in-laboratory polysomnography nights, in which they mentally simulated future events or remembered past events, recorded via written descriptions. We quantified the degree of future/past thinking using linguistic analysis of time orientation. In young adults, greater future thinking was linked to greater spindle density, even when controlling for gender, age, and word count (rp =.370, p =.028). The opposite was true for older adults, such that greater future thinking was associated with reduced spindle density (rp = −.431, p =.031). These patterns were selective to future thinking (not observed for past thinking). The collective findings implicate an impaired interaction between future relevance tagging and sleep physiology as a mechanism by which aging compromises sleep-dependent cognitive processing. [ABSTRACT FROM AUTHOR]

Background: Sleep restores physiology and neurochemical components of our body and is essential for physical and mental health. Sleep disorders (SDs) are associated with insulin resistance and metabolic disorders. The association between SDs and diabetes needs to be understood in the Indian population. Purpose: The purpose was to investigate the association between SD and diabetes in the Indian population. Methods: As a part of nationwide Niyantrita Madhumeha Bharata Abhiyaan-2017 (NMB-2017), a cross-sectional study was conducted and data was collected from seven zones of India, after screening through the Indian Diabetes Risk Score (IDRS). The sleep quality was assessed on a scale of 1 to 4 (very good = 1, very bad = 4). The time taken to fall asleep (sleep latency) was assessed on a scale of 0 to 5 ("0" = nil and "5" = >1.5 h). Stress was assessed by the perceived stress scale. Results: Bad sleep quality was positively (odds ratio 1.055, CI [1.001, 1.113], and P <.01) associated with self-reported known diabetes. Increased time taken to fall in sleep (sleep latency) was associated significantly with IDRS high risk (odds ratio 1.085, CI [1.008, 1.168], and P =.01), with an average sleep latency /time takes to fall in sleep (maximum range 5 [>1.5 h], mode 2 [10 to 30 min]) minutes. Moderate stress was significantly associated with bad sleep quality (odds ratio 1.659). Conclusion: A positive association of bad sleep quality and stress with diabetes, and an increased sleep latency in the IDRS high-risk population point to the role of modifiable risk factors. Behavioral modification and stress reduction by using yoga may be beneficial in the better management of diabetes. [ABSTRACT FROM AUTHOR]

The 'catalogue of knowledge and skills' for sleep medicine presents the blueprint for a curriculum, a textbook, and an examination on sleep medicine. The first catalogue of knowledge and skills was presented by the European Sleep Research Society in 2014. It was developed following a formal Delphi procedure. A revised version was needed in order to incorporate changes that have occurred in the meantime in the International Classification of Sleep Disorders, updates in the manual for scoring sleep and associated events, and, most important, new knowledge in sleep physiology and pathophysiology. In addition, another major change can be observed in sleep medicine: a paradigm shift in sleep medicine has taken place. Sleep medicine is no longer a small interdisciplinary field in medicine. Sleep medicine has increased in terms of recognition and importance in medical care. Consequently, major medical fields (e.g. pneumology, cardiology, neurology, psychiatry, otorhinolaryngology, paediatrics) recognise that sleep disorders become a necessity for education and for diagnostic assessment in their discipline. This paradigm change is considered in the catalogue of knowledge and skills revision by the addition of new chapters. [ABSTRACT FROM AUTHOR]

Refractive errors are common, especially in children and adolescents, leading to global health issues, academic implications and economic costs. Circadian rhythm and sleep habits may play a role. The study included 1130 children from the EDEN birth-cohort. Data were collected through parental questionnaires at age 2 and 5 for sleep duration and timing, and at age 5 for refractive error. At 5 years, 20.4% were prescribed glasses (2% for myopia, 11.9% for hyperopia and 6.8% for unknown reason). Children slept on average (SD) 11h05/night (± 30 min) and 10h49/night (± 48 min) at age 2 and 5, respectively. Average bedtime and midsleep was 8.36 pm (± 30 min), 2.06 am (± 36 min), and 8.54 pm (± 30 min), 2.06 am (± 24 min) at age 2 and 5, respectively. A U-shaped association was observed between sleep duration at age 2 and eyeglass prescription at age 5. Later midsleep and bedtime at age 2 were associated with an increased risk of eyeglass prescription at age 5. Associations became borderline significant after adjustment for confounding factors. Sleep duration and timing at age 2 were associated with subsequent refractive errors in preschoolers from general population. Sleep hygiene might be a target for refractive errors prevention. [ABSTRACT FROM AUTHOR]