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An increase in artificial night lighting has blurred the boundaries of day and night and transformed the natural day-night environment with alteration in the temporal niche of the animals. Male zebra finches were exposed to a dim light at night (dLAN) protocol (Light: dLAN, 12L = 200 lux: 12dLAN = 5 lux) with controls on darkness at night (Light: dark, 12L = 200 lux: 12D = 0 lux) for six weeks. We assayed sleep-wake, daily behaviors, mood, and cognition, as well as changes in physiological parameters. Dim light at night increased sleep frequency, delayed sleep onset, advanced awakening latency, and caused a reduction in total sleep duration. dLAN birds did not associate (physical association) with novel object and birds spent significantly lesser time on perch with novel object as compared to LD. In colour learning task, night illuminated birds took more time to learn and made more error, compared to LD. dLAN significantly altered the 24-h daily behavioral rhythm (amplitude and acrophase) of feeding, drinking, preening, and perch-hopping behavior. In particular, birds extended their feeding hours in the nighttime under dLAN, with no difference in total food intake. Birds under dLAN increased fattening and hence significantly increased body mass. Our results show that dim light at night altered feeding rhythm, caused decrease in sleep behavior, and negatively affected learning and memory performance in male zebra finches.

Sleep problems are frequently reported in infants treated with propranolol for infantile hemangiomas, possibly serving as a marker for a negative impact on central nervous system function. In this cohort study, we objectively investigate the sleep behavior of infants with infantile hemangiomas on propranolol compared to a healthy, untreated control group. Sleep of propranolol-treated infants and controls was investigated using ankle actigraphy and a 24-h diary for 7–10 days at ages 3 and 6 months. The main outcome measures were the Number of Nighttime Awakenings and Sleep Efficiency. The main secondary outcome measures included 24-hour Total Sleep, daytime sleep behavior, and parent-rated infant sleep quality and behavioral development based on the Brief Infant Sleep Questionnaire (BISQ) and the age-appropriate Ages-and-Stages Questionnaire (ASQ), respectively. Fifty-four term-born infants were included in each cohort. No group difference in any investigated parameter was seen at age 3 months. At age 6 months, the propranolol group exhibited a decrease in Sleep Efficiency and a trend towards an increased Number of Nighttime Awakenings compared to the control group. Treated infants at 6 months also had shorter daytime waking periods. 24-hour Total Sleep was unaffected by propranolol. No negative impact of propranolol on subjective sleep quality and behavioral development was noted.Conclusion: Propranolol exerts a measurable yet mild impact on objectively assessed infants’ sleep measures. Behavioral developmental scores were unaffected. Our results support propranolol as first-line therapy for complicated infantile hemangiomas. What is Known:• Sleep disorders are frequently reported in infants with infantile hemangiomas treated with propranolol and often lead to treatment discontinuation.• Investigations of the sleep pattern in this patient group using objective measures are lacking. What is New:• The sleep pattern of propranolol-treated infants is assessed using actigraphy and a 24-h sleep diary and compared to healthy, untreated controls.• Propranolol leads to a decreased sleep efficiency at night and an increased demand of daytime sleep, yet effects are mild overall.

Funding Information: This research is based on work supported in part by the Office of the Director of National Intelligence (ODNI), Intelligence Advanced Research Projects Activity (IARPA), via IARPA Contract No. 2017-17042800007. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies, either expressed or implied, of ODNI, Publisher Copyright: © 2021, The Author(s). Copyright: Copyright 2021 Elsevier B.V., All rights reserved. Previous studies of seasonal effects on sleep have yielded unclear results, likely due to methodological differences and limitations in data size and/or quality. We measured the sleep habits of 216 individuals across the U.S. over four seasons for slightly over a year using objective, continuous, and unobtrusive measures of sleep and local weather. In addition, we controlled for demographics and trait-like constructs previously identified to correlate with sleep behavior. We investigated seasonal and weather effects of sleep duration, bedtime, and wake time. We found several small but statistically significant effects of seasonal and weather effects on sleep patterns. We observe the strongest seasonal effects for wake time and sleep duration, especially during the spring season: wake times are earlier, and sleep duration decreases (compared to the reference season winter). Sleep duration also modestly decreases when day lengths get longer (between the winter and summer solstice). Bedtimes and wake times tend to be slightly later as outdoor temperature increases.

Amyloid precursor protein (APP) can generate neurotoxic β-amyloid 42 (Aβ42) by proteolytic process, which plays a crucial role in the pathogenesis of Alzheimer’s disease (AD). Individuals with mild to moderate AD exhibit sleep disturbance, even before the onset of AD. The purpose of this study is to verify the effect of APP on sleep behavior by using an APP overexpressing Drosophila AD model. APP-overexpressed flies were grouped by age, and their sleep amounts were monitored. Our results demonstrated that APP overexpression had no impacts on sleep amounts in young (4–7 days after eclosion, 4–7AE) flies. However, APP overexpression contributed to lower day and total sleep amounts in the middle-aged (11–14AE) flies. Moreover, old-aged (40AE) flies with overexpressing APP exhibited increased number of sleep bouts and decreased sleep time, indicating sleep fragmentation in these flies. Our results indicated that overexpression of APP in neurons has distinct effects on sleep behavior at different ages, but the specific mechanisms underlying the sleep regulation by APP are needed for further study. In addition, our data also suggest that sleep disturbance in AD animals can be caused by APP expression alterations, which provide a potential treating target for sleep intervention and therapy for AD patients.

STUDY OBJECTIVES: Despite considering it as a common geriatric condition, sarcopenia is linked to various behavioral factors that may be changeable. As sleep is one of the important routines in physiological homeostasis, further investigating the underlying relationships of sleep behavior with sarcopenia is urgently needed. We examined the association between sleep parameters (ie, sleep duration, bedtime, wake time, or midsleep time) and sarcopenia risks in older adults, in the total sample and age group subsamples. METHODS: A total of 1,068 older adults in Taiwan were included. Data on bedtime, wake time, and sleep duration were collected through telephone interview. Midsleep time was calculated by the midpoint of bedtime and wake time. Sarcopenia was screened by the SARC-F questionnaire composed of 5 questions (the strength, assistance in walking, rising from a chair, climbing stairs, and falls) as well as higher scores was related to greater risks. Generalized additive models were conducted to examine the nonlinear relationships between sleep parameters and sarcopenia risks. RESULTS: The covariate-adjusted analysis showed that a reverse J-shaped relationship for sleep duration and sarcopenia risk (P < .001) and a significant association for wake time and the SARC-F score (P = .009) in total sample, with considering age-related interaction. No associations were found in the other sleep parameters (bedtime and midsleep time) and sarcopenia in older adults. Similar associations were observed between wake time and the SARC-F score across age groups, while diverse associations of sleep duration with the SARC-F score were found in different age groups. CONCLUSIONS: The sleep pattern is significantly associated with sarcopenia risks in aging adults. Improving inappropriate sleep behaviors in older adults is suggested to prevent a decline in muscle function and promote healthy aging. CITATION: Huang W-C, Lin C-Y, Togo F, et al. Nonlinear associations between sleep patterns and sarcopenia risks in older adults. J Clin Sleep Med. 2022;18(3):731–738.

Sleep is a highly conserved state across the animal kingdom. However, sleep duration, behavior and associated neural activity show great diversity across taxonomic groups, and sometimes even within the same species. Understanding sleep functions depends on understanding when sleep emerged, which of its characteristics have persisted throughout evolution, and what accounts for the similarities and differences in sleep behavior and neurophysiology across different species. Here, we provide an overview of the latest findings in comparative sleep neurophysiology and highlight remarkable examples of sleep flexibility. We discuss the implications that these findings have on the proposed functions of sleep.

Objectives The number of elderly people is growing rapidly and aging is found to affect activities of daily living. Older adults are found to perform less physical activity when compared to younger ones. In the perspective of movement behavior, it is not well understood how are elderly different from younger ones. It is not known whether they produce only low frequency movement accelerations or the overall number of movements produced are reduced in elderly. It is also not known how elderly and younger ones perform movement transitions throughout the duration of a day and during night-time sleep. Material and methods In this study, 10 healthy young and 10 healthy old participants wore inertial measurement unit at their lower back for 3-days. The 24 hours of day were divided into four 6 hour time zones and transitions made by young and elderly were investigated. All participants performed their regular daily activities unhindered and longitudinal multi-day signals for acceleration and angular velocity were analyzed. Time-frequency analysis was performed using wavelet transform and frequency content of each movement performed was computed. Results We found that both young and older adults performed significantly more low amplitude movements than medium and high amplitude movements. Healthy young adults produced significantly more movements at 1.1 Hz than older adults. Healthy young adults were also found to have produced significantly smaller number of transitions in the mid-phases of sleep. They were also found to produce significantly larger accelerations during night-time sleep transitions than their older counterparts. Conclusion The advantages of collecting longitudinal data about human movement and sleep transition data can lead us to important clinical diagnosis. The information from longitudinal assessment can help develop lifestyle interventions for disease prevention, monitoring of chronic diseases to prevent or slow disease progression among elderly people.

Sleep is an extremely complex state that exhibits substantial diversity in human populations, and rapidly accumulating research indicates many of these differences are at least partially attributable to genetic contributions. Genetic polymorphisms affecting sleep timing, length, and quality have all been identified, along with other features further influencing how an individual’s sleep behavior is affected by their environment. These range from the subtle and unnoticeable without advanced analytic tools to the profound and pathologic with impacts upon everyday life. This chapter overviews findings on the breadth of genetic contributions to sleep patterns, as well as other biological factors that interact with genetics to affect sleep, such as sex, hormonal regulation, and comorbid diseases.

Insufficient sleep duration and quality are associated with various adverse health outcomes. Whereas sleep disorders have been studied in a few skin conditions, data in a more comprehensive dermatology population are lacking. We sought to describe the prevalence, causes, and consequences of sleep disorders in dermatology patients. In this cross-sectional, single-center study, dermatology patients completed a questionnaire addressing skin-related and non-skin-related health, sleep behavior, causes, and consequences of sleep disorders. According to the Regensburg Insomnia Scale, 27.92% of the 634 participants had insomnia (177 of 634 patients). Of these 177 patients, 115 (64.97%) were subjectively sleep disturbed, with skin-related causes accounting for 55.65% (64 of 115 patients), non-skin-related accounting for 33.04% (38 of 115 patients), and combined accounting for 11.30% (13 of 115 patients). Itch was the leading cause of skin-related sleep disorders (64.49%, 50 of 77 patients), followed by skin-related pain (55.84%, 43 of 77 patients) and skin-related fearful thoughts (54.55%, 42 of 77 patients). Sleep disorders reduced daytime performance in 68.70% (79 of 115 patients) and sleep quality of relatives in 20.87% (24 of 115 patients). The prevalence of insomnia among different diagnostic categories ranged from 20.31% to 50.00%. The most common strategy to improve sleep was taking sleep medication (57.39%, 66 of 115 patients). We conclude that sleep disorders are highly prevalent in dermatology patients, often leading to reduced daytime performance, impaired sleep among the patients' relatives, and increased use of substances.

123I-metaiodobenzylguanidine (MIBG) cardiac scintigraphy was performed to assess cardiac autonomic dysfunction and demonstrate its correlation with clinical and polysomnographic characteristics in patients with isolated rapid eye movement (REM) sleep behavior disorder. All subjects including 39 patients with isolated REM sleep behavior disorder and 17 healthy controls underwent MIBG cardiac scintigraphy for cardiac autonomic dysfunction assessment. The isolated REM sleep behavior disorder was confirmed by in-lab overnight polysomnography. A receiver operating curve was constructed to determine the cut-off value of the early and delayed heart-to-mediastinum ratio in patients with isolated REM sleep behavior disorder. Based on each cut-off value, a comparison analysis of REM sleep without atonia was performed by dividing isolated REM sleep behavior disorder patients into two groups. MIBG uptake below the cut-off value was associated with higher REM sleep without atonia. The lower heart-to-mediastinum ratio had significantly higher REM sleep without atonia (%), both with cut-off values of early (11.0 ± 5.6 vs. 29.3 ± 23.2%, p = 0.018) and delayed heart-to-mediastinum ratio (9.1 ± 4.3 vs. 30.0 ± 22.9%, p = 0.011). These findings indicate that reduced MIBG uptake is associated with higher REM sleep without atonia in isolated REM sleep behavior disorder.

The maturation of sleep behavior across a lifespan (sleep ontogeny) is an evolutionarily conserved phenomenon. Mammalian studies have shown that in addition to increased sleep duration, early life sleep exhibits stark differences compared to mature sleep with regard to the amount of time spent in certain sleep states. How intrinsic maturation of sleep output circuits contributes to sleep ontogeny is poorly understood. The fruit fly Drosophila melanogaster exhibits multifaceted changes to sleep from juvenile to mature adulthood. Here, we use a non-invasive probabilistic approach to investigate changes in sleep architecture in juvenile and mature flies. Increased sleep in juvenile flies is driven primarily by a decreased probability of transitioning to wake, and characterized by more time in deeper sleep states. Functional manipulations of sleep-promoting neurons in the dFB suggest these neurons differentially regulate sleep in juvenile and mature flies. Transcriptomic analysis of dFB neurons at different ages and a subsequent RNAi screen implicate genes involved in distinct molecular processes in sleep control of juvenile and mature flies. These results reveal that dynamic transcriptional states of sleep output neurons contribute to changes in sleep across the lifespan.

Cerebral palsy (CP) represents the most common motor impairment in childhood. The presence of sleep problems has not yet been investigated with an instrument specifically designed for this population. In this hospital-based, prospective study, N = 100 children (M = 7.9, range: 2–18 years) with CP were included. All patients underwent pediatric neurologists’ screening incorporating instruments (Data Collection Form, Gross Motor Functions Classification System, GMFCS, Bimanual Fine Motor Function, BFMF) recommended by the “Surveillance of Cerebral Palsy in Europe (SCPE)”. Parents completed the “Sleep Questionnaire for Children with Severe Psychomotor Impairment (SNAKE)”. Children’s sleep behavior was increasingly conspicuous, with greater gross motor (SNAKE scales: disturbances remaining asleep, daytime sleepiness) and fine motor (additionally SNAKE scale arousal and breathing problems) functional impairment. Overall, a proportion of children showed sleep behavior outside the SNAKE’s normal range. No relevant sleep differences were identified between different CP subtypes and comorbidities. Applying a population-specific questionnaire, children’s functional impairment seems to be more relevant to their sleep behavior than the CP subtype or CP comorbidities.

Background Disrupted nighttime sleep has been associated with heart failure (HF). However, the relationship between daytime napping, an important aspect of sleep behavior commonly seen in older adults, and HF remains unclear. We sought to investigate the association of objectively assessed daytime napping and risk of incident HF during follow‐up. Methods and Results We studied 1140 older adults (age, 80.7±7.4 [SD] years; female sex, 867 [76.1%]) in the Rush Memory and Aging Project who had no HF at baseline and were followed annually for up to 14 years. Motor activity (ie, actigraphy) was recorded for ≈10 days at baseline. We assessed daytime napping episodes between 9 am and 7 pm objectively from actigraphy using a previously published algorithm for sleep detection. Cox proportional hazards models examined associations of daily napping duration and frequency with incident HF. Eighty‐six participants developed incident HF, and the mean onset time was 5.7 years (SD, 3.4; range, 1–14). Participants who napped longer than 44.4 minutes (ie, the median daily napping duration) showed a 1.73‐fold higher risk of developing incident HF than participants who napped 1.7 times/day (ie, the median daily napping frequency) showed a 2.20‐fold increase compared with participants who napped Conclusions Longer and more frequent objective napping predicted elevated future risk of developing incident HF. Future studies are needed to establish underlying mechanisms.

Dopamine, orexin (hypocretin), and adenosine systems have dual roles in reward and sleep/arousal suggesting possible mechanisms whereby drugs of abuse may influence both reward and sleep/arousal. While considerable variability exists across studies, drugs of abuse such as cocaine induce an acute sleep loss followed by an immediate recovery pattern that is consistent with a normal response to loss of sleep. Under more chronic cocaine exposure conditions, an abnormal recovery pattern is expressed that includes a retention of sleep disturbance under withdrawal and into abstinence conditions. Conversely, experimentally induced sleep disturbance can increase cocaine seeking. Thus, complementary, sleep-related therapeutic approaches may deserve further consideration along with development of non-human models to better characterize sleep disturbance-reward seeking interactions across drug experience.

Rapid eye movement (REM) sleep behavior disorder (RBD) and REM sleep without atonia (RWA) have assumed much clinical importance with long-term data showing progression into neurodegenerative conditions among older adults. However, much less is known about RBD and RWA in younger populations. This study aims at comparing clinical and polysomnographic (PSG) characteristics of young patients presenting with RBD, young patients with other neurological conditions, and normal age-matched subjects.A retrospective chart review was carried out for consecutive young patients (25 years) presenting with clinical features of RBD; and data were compared to data from patients with epilepsy, attention deficit hyperactivity disorder (ADHD), and autism, as well as normal subjects who underwent PSG during a 2-year-period.Twelve patients fulfilling RBD diagnostic criteria, 22 autism patients, 10 with ADHD, 30 with epilepsy, and 14 normal subjects were included. Eight patients with autism (30%), three with ADHD (30%), one with epilepsy (3.3%), and six patients who had presented with RBD like symptoms (50%) had abnormal movements and behaviors during REM sleep. Excessive transient muscle activity and/or sustained muscle activity during REM epochs was found in all patients who had presented with RBD, in 16/22 (72%) autistic patients, 6/10 (60%) ADHD patients compared to only 6/30 (20%) patients with epilepsy and in none of the normal subjects.We observed that a large percentage of young patients with autism and ADHD and some with epilepsy demonstrate loss of REM-associated atonia and some RBD-like behaviors on polysomnography similar to young patients presenting with RBD.Troubles du comportement en sommeil paradoxal et sommeil paradoxal sans atonie musculaire chez les jeunes. Contexte: Les troubles du comportement en sommeil paradoxal (TCSP) et le sommeil paradoxal sans atonie musculaire ont acquis une grande importance clinique. En effet, des données à long terme ont montré de quelle façon ils pouvaient progresser chez des adultes âgés atteints de maladies neurodégénératives. Toutefois, on en sait beaucoup moins au sujet des TCSP et du sommeil paradoxal sans atonie musculaire au sein des groupes d’âges plus jeunes. Cette étude entend donc comparer les caractéristiques cliniques et polysomnographiques (PSG) de jeunes patients donnant à voir des signes de TCSP à celles d’autres jeunes patients atteints d’autres troubles neurologiques et de sujets en bonne santé appariés en fonction de l’âge. Méthodes: Nous avons passé en revue de façon rétrospective les dossiers de jeunes patients (25 ans) donnant à voir des signes cliniques de TCSP et ayant été vus consécutivement. Les données recueillies ont été comparées aux données de patients atteints d’épilepsie, de troubles de l’attention avec hyperactivité et d’autisme ainsi qu’à celles de sujets en bonne santé soumis à des examens de PSG pendant une période de deux ans. Résultats: Au total, on a diagnostiqué chez 12 patients des TCSP. Ajoutons que 22 d’entre eux étaient atteints d’autisme alors que 10 étaient atteints de troubles de l’attention avec hyperactivité et 30 d’épilepsie. Mentionnons par ailleurs que 14 sujets en bonne santé ont été inclus dans cette étude. Après analyse, il s’est avéré que 8 patients atteints d’autisme (30 %), 3 de troubles de l’attention avec hyperactivité (30 %), 1 d’épilepsie (3,3 %) et 6 ayant donné à voir des symptômes ressemblant à ceux des TCSP (50 %) montraient des mouvements et des comportement anormaux en sommeil paradoxal. Des signes d’activité musculaire transitoire excessive et/ou d’activité musculaire durable lors d’épisodes de sommeil paradoxal ont été détectés chez tous les patients satisfaisant aux critères des TCSP, chez 16 patients autistes sur 22 (72 %), chez 6 patients atteint de troubles de l’attention avec hyperactivité sur 10 (60 %) en comparaison avec seulement 6 patients épileptiques sur 30 (20 %) et aucun parmi les sujets en bonne santé. Conclusion: Lors d’examens polysomnographiques, nous avons en définitive observé qu’une forte proportion de jeunes patients atteints d’autisme et de troubles de l’attention avec hyperactivité, ainsi que quelques-uns atteints d’épilepsie, donnaient à voir des signes de perte de sommeil paradoxal associés à l’atonie musculaire ainsi que des comportements ressemblant à ceux de jeunes patients atteints de TCSP.

This literature review explores the impact of screen media consumption on the quality, quantity, regularity, and structure of sleep among children ages 0–5 years. Thirty-one studies were included for review. Screen media use was found to negatively impact young children’s sleep. Greater consumption of, access and exposure to, and engagement with screen media was associated with shorter nightly and total daily sleep duration, poorer sleep quality, later bed times and wake times, and longer sleep onset. Day time nap duration was inversely associated with screen media use, an outcome suggestive of delays in sleep consolidation. Extant research has established problematic relations between the young children’s screen media use and sleep behavior. Future research must work to better understand the impact of young children’s screen media’s use practices on their sleep and identify the mechanisms underpinning screen media’s relations to nap and sleep consolidation.

Sleep is nearly universal among animals, yet remains poorly understood. Recent work has leveraged simple model organisms, such as Caenorhabditis elegans and Drosophila melanogaster larvae, to investigate the genetic and neural bases of sleep. However, manual methods of recording sleep behavior in these systems are labor intensive and low in throughput. To address these limitations, we developed methods for quantitative imaging of individual animals cultivated in custom microfabricated multi-well substrates and used them to elucidate molecular mechanisms underlying sleep. Here we describe the steps necessary to design, produce, and image these plates, and analyze the resulting behavioral data. We also describe approaches for experimentally manipulating sleep. Following these procedures, after approximately 2 hours of experimental preparation, we are able to simultaneously image 24 C. elegans from the second larval stage to adult stages or 20 Drosophila larvae during the second instar life stage at a spatial resolution of 10 μm or 27 μm, respectively. While this system has been optimized to measure activity and quiescence in Caenorhabditis larvae and adults and in Drosophila larvae, it can also be used to assess other behaviors over short or long periods. Moreover, with minor modifications, it can be adapted for the behavioral monitoring of a wide range of small animals.

Previous studies have reported a shift in the timing of sleep during adolescence toward a later time. To date, it is unclear whether hormonal changes during puberty might contribute to this change in sleeping behavior. We systematically assessed pubertal development and sleep timing in a cross-sectional case-control study in girls with precocious (n = 42) and boys with delayed pubertal development (n = 19). We used the Munich ChronoType Questionnaire and the Children&rsquo, s ChronoType Questionnaire to assess sleep timing in patients and age- and sex-matched controls (n = 309) and used the midpoint of sleep on free days, corrected for potential sleep debt accumulated during the school week, as a marker for sleep timing. Compared to the controls, girls with central precocious puberty showed a delay in sleep timing of 54 min, and girls with premature pubarche slept on average 30 min later. Male adolescents with delayed pubertal development showed an average sleep midpoint that was 40 min earlier compared to the control group. The results of this pilot study suggest an association between pubertal onset and shifts in sleep timing, which is a novel finding in human sleep behavior. Prospective studies in larger cohorts will be needed to examine the robustness and generalizability of the findings.

Recent studies have shown that the reduction of sperm count is associated with sleep behaviors, including restricted/excessive sleep duration, late sleep time midpoint, and shift of sleep midpoint time (social jetlag). Chronotype is suggested to regulate sleep behaviors; however, the relationship between chronotype and human sperm count is unknown. The relationship between sleep behaviors and human sperm count, when sleep behaviors as well as chronotype are controlled is also unclear. We performed a path analysis of the data obtained from 667 Chinese men recruited into the MARHCS (Male Reproductive Health in Chongqing College Students) study. Chronotype, sleep duration, sleep time midpoint, and social jetlag were estimated by the Munich Chronotype Questionnaire. Sperm count was measured by computer-aided sperm analysis. The comprehensive relationship between chronotype, all sleep behaviors, and sperm count was tested by path analysis, in which the standardized residual of sperm count was used for adjustment of age, abstinence period, body mass index, tobacco smoking, alcohol drinking, and intake of tea, cola, and coffee. Our major findings are: (1) Chronotype negatively correlated with sleep duration (correlation coefficient (R) = ���0.32, P P P P = .005), sleep midpoint (R = ���0.09, P = .021), and social jetlag (R = ���0.12, P = .001), respectively, correlated with sperm count in univariate analysis. The relationship between sleep midpoint and sperm count disappeared when social jetlag was controlled. (3) Path analysis showed that chronotype is connected with sperm count through two pathways: via sleep duration (standardized path coefficient = ���0.09, 95% CI: ���0.17 to ���0.01, P = .030) and via social jetlag (standardized path coefficient = ���0.09, 95% CI: ���0.17 to ���0.01, P = .031). For men of earlier, intermediate, and later tertile of chronotype, the sleep-duration-related decrease of sperm count was separately estimated to be 16.3%, 12.8%, and 11.6%, while the social-jetlag-related decrease of sperm count was estimated to be 9.3%, 12.8%, and 19.2%. The total effect of sleep behaviors on sperm count was estimated to be 25.7%, 25.6%, and 30.7%, with an average of 27.4% for men of different chronotypes. The present study showed that men of earlier chronotype were prone to restricted/excessive sleep duration, while men of later chronotype were prone to social jetlag, both of which correlated with reduced sperm count, suggesting that chronotype may modulate the sleep behaviors and exert dual effects on sperm count via different sleep behaviors, leading to a ubiquitous sperm decline. Men of different chronotypes should take care to avoid different types of improper sleep behaviors, so as to prevent such deleterious effect on sperm count.

Upon a drastic decline of the giraffe population in the wild, conservation efforts and therefore the role of zoos have become more important than ever. With their unique opportunities, zoos provide excellent conditions to study animal behavior, expanding the knowledge about the giraffe's behavior repertoire and their ability to adapt. This study therefore examined the nocturnal behavior of 63 giraffe living in 13 different EAZA zoos across Germany and the Netherlands. Giraffe were observed and videos recorded via infrared sensitive cameras during the winter seasons 2015-2018. The observation period spanned nightly from 17:00 to 7:00. Thus, 198 nights, with a total of 2772 h were recorded and analyzed. Linear mixed models were then used to assess potential biological and environmental factors influencing behavior during the dark phase. Results show that individual variables such as age, subspecies and motherhood determined nocturnal activity and sleep behavior most. Among the variables studied, husbandry conditions and environmental factors complying with EAZA standards had no influence on the giraffe's nocturnal behavior. By combining nocturnal activity analyses and an assessment of potential influencing factors, our findings present a holistic approach to a better understanding of captive giraffe behavior and allow for management implications.

Objective: To verify the relationship between sleep characteristics and motor development in low-birth-weight preterm infants during infancy and preschool years. Method: Forty-one healthy preterm infants (

Rapid‐eye movement (REM) sleep, or paradoxical sleep, accounts for 20–25% of total night‐time sleep in healthy adults and may be related, in pathological cases, to parasomnias. A large percentage of Parkinson's disease patients suffer from sleep disorders, including REM sleep behaviour disorder and hypokinesia; monitoring their sleep cycle and related activities would help to improve their quality of life. There is a need to accurately classify REM and the other stages of sleep in order to properly identify and monitor parasomnias. This study proposes a method for the identification of REM sleep from raw single‐channel electroencephalogram data, employing novel features based on REM microstructures. Sleep stage classification was performed by means of random forest (RF) classifier, K‐nearest neighbour (K‐NN) classifier and random Under sampling boosted trees (RUSBoost); the classifiers were trained using a set of published and novel features. REM detection accuracy ranges from 89% to 92.7%, and the classifiers achieved a F‐1 score (REM class) of about 0.83 (RF), 0.80 (K‐NN), and 0.70 (RUSBoost). These methods provide encouraging outcomes in automatic sleep scoring and REM detection based on raw single‐channel electroencephalogram, assessing the feasibility of a home sleep monitoring device with fewer channels.

Prolonged ocean voyages constrain the regular physical activity and sleep patterns of seafarers. However, there is a lack of information on seafarers&rsquo, physical activity and sleep behavior. The purpose of this study was to systematically examine physical activity and sleep patterns among seafarers using a single wrist-worn accelerometer. Fifty-one senior maritime students (mean age = 22.8 years, 80.0% male) in a university navigation department participated in the study. Data were collected from participants on three sea voyages in the Asia-Pacific region. Indicators of moderate to vigorous intensity physical activity (MVPA) and sleep patterns were compared between several conditions: (1) moored versus sailing, (2) on-navigation duty and off- navigation duty, and (3) day versus night navigation duty. Regardless of conditions, low levels of physical activity and short sleep durations were observed. Independent sample t-tests revealed that time spent doing MVPA was significantly higher when participants were off-duty than when they were on-duty (p &lt, 0.001). Physical activity did not significantly differ between the other two conditions. While total sleep duration was not significantly different between mooring and sailing, the results showed that participants awakened more frequently (p = 0.007) and their sleep was more restless (p &lt, 0.001) while sailing. The results demonstrated that developing effective programs to promote physical activity should be a public health priority for the seafaring population, and serious consideration is required to mitigate sleep disruption during sailing.

Since the beginning of the pandemic, the population has been exposed to a substantial period of social isolation, which leads to anxiety, fear, and metabolic and immune impairments. Purpose Considering that sleep restriction influences eating behavior, we highlight that changes in it may occur during the COVID-19 quarantine. Alterations in feeding time can uncouple the body clocks, leading to circadian misalignment and consequently to a disruption in homeostasis and disturbances in many metabolic functions. Method Narrative review. Results Do not apply. Conclusion The increase of body weight is related to increased food intake in response to mental stress and more time spent at home, increased opportunity to feed, and increased visual and olfactory stimulation to eat, which represents a potential risk of overfeeding nowadays. In this article, we postulate that the unusual lifestyle imposed by the COVID-19 quarantine may induce a circadian misalignment, which is capable to induce alterations on eating and sleep behaviors.

Background Adolescents' sleep behavior has deteriorated over the last decades. However, little research has been conducted into possible psychosocial factors related to this behavior, which is an important prerequisite to develop effective sleep behavior interventions. In addition, previous research showed that actively involving adolescents in the development of interventions increases the chance of effectivity and sustainability. This study examined psychosocial factors related to sleep behavior in adolescents and investigated adolescents' willingness to participate in the development of a sleep behavior intervention. Methods Nine focus group interviews were conducted with seventy-two students (63,9% girls, 14.8 (±1.0) years) using a standardized interview guide. Interviews were audio-recorded and thematic content analysis was performed using Nvivo 11. Results Adolescents had adequate knowledge of sleep hygiene and short-term consequences of sleep deficiency, but limited knowledge of sleep norms and long-term consequences. Positive attitudes towards sleep were outweighed by positive attitudes towards other behaviours such as screen time. Leisure activities, smartphones, television, schoolwork, early school time and worrying were mentioned as barriers for healthy sleep. Adolescents showed low self-efficacy towards changing their sleep behaviors and perceived a negative social norm towards sleep. Although some adolescents indicated parental rules to have a positive influence on their sleep, others indicated these sometimes provoked frustration. Finally, adolescents emphasized the importance of their participation in the development of a sleep behavior intervention at school, although adult guiding would be needed. Conclusions Future interventions promoting heathy sleep in adolescents could focus on psychosocial factors such as knowledge, attitudes, barriers, self-efficacy and social perceived norm and could involve adolescents in intervention development. Key messages Future interventions promoting heathy sleep in adolescents should in addition to knowledge, also focus on psychosocial factors such as attitudes, self-efficacy and perceived social norms. Adolescents emphasize the importance of their participation in the development of a sleep behavior intervention. This approach could be worth trying in future research.

Detection of REM sleep behavior disorder (RBD) with polysomnography (PSG) is relevant for the diagnosis of α-synucleinopathies. However, some patients referred for suspicion of RBD do not present REM sleep at PSG (NoREMSusRBD), rendering the study inconclusive. Our objective was to investigate disorders possibility associated with REM sleep absence in patients referred to PSG for investigation of RBD, in particular α-synucleinopathies. A sleep-lab database was revised to select NoREMSusRBD (n = 15) and patients: with no REM sleep referred for suspicion of other sleep disorder (NoREMSusOther, n = 28); referred for RBD suspicion with negative PSG (NegativeRBD, n = 24); α-synucleinopathies with no REM sleep (NoREMα, n = 23) and idiopathic RBD (iRBD, n = 26). NoREMSusRBD patients were compared with the other groups regarding PSG data and the emergence of prodromal features or established criteria for α-synucleinopathy. Severe Obstructive Sleep Apnea (OSA) was significantly more frequent in the NoREMsusRBD compared to the NoREMα and iRBD groups. No patient in the NoREMSusRBD developed a α-synucleinopathy (2 cases on the iRBD group). The prevalence of prodromal features in NoREMSusRBD (n = 7, 46.7%) was similar to that of iRBD (n = 18, 69.2%) and significantly higher than in the other groups. Apnea–Hypopnea Indices (AHI) were significantly higher in the NoREMSusRBD compared with iRBD and NoREMα. Our study suggests that the absence of REM sleep in NoREMSusRBD could be caused by OSA but does not exclude the possibility of underlying α- synucleinopathy, suggested by an increased prevalence of prodromal features. These data support the need for excluding OSA in patients suspected for RBD and recommends follow-up of NoREMSusRBD patients to uncover a possible α- synucleinopathy.

In mammals including humans, the convention defining rapid-eye-movement (REM) sleep — also called paradoxical sleep — states that it is mainly characterized by a low voltage fast electrocortical rhythms, rapid eye movements and a muscle atonia occasionally accompanied by brief distal twitches. When facing sleep pathologies, all these criteria are not always met and identifying REM sleep becomes thus a challenge. Here we review such criteria and report the adjustments proposed to identify and measure REM sleep in animal models of sleep pathologies such as REM sleep Behaviour Disorder and narcolepsy type 1. We also argue that video-recordings synchronized to multi-parametric polysomnography are mandatory to recognize REM sleep and differentiate it from dissociated states in animal models of sleep disorders.

Objective: To examine sleep behaviors and their associations with health characteristics in a cohort of adolescents with severe obesity undergoing bariatric surgery at Children’s Hospital Colorado. Methods: A retrospective chart review of electronic medical records was performed. All patients receiving care at the Children’s Hospital Colorado (CHCO) Bariatric Surgery Center between 06/17-08/19 were included. Demographic, medical and family history, self-reported sleep behaviors, and laboratory measures were abstracted, including medical problem list (e.g., type 2 diabetes (T2D), hypertension) and body mass index (BMI). A sleep behavior risk score (SBRS) was developed using five criteria (short sleep defined as Results: Data from 78 patients, aged 16.82.1, were reviewed. The majority of patients were female (71%), Hispanic (52%) and in 10-12 th grade in school (64%). Prior to surgery, 24% of the patients were diagnosed with hypertension and 20% with type 2 diabetes. The majority of patients (60%) had a high SBRS at baseline. High SBRS was significantly associated with higher baseline BMI (49.2 vs 45.0; p=0.03). SBRS score was not significantly associated with diagnosis of hypertension, type 2 diabetes, hyperlipidemia, or obstructive sleep apnea. Conclusions: In a population of adolescents seen in the Bariatric Surgery Center at CHCO, a majority of patients met criteria for high risk sleep behaviors, and worse sleep behaviors preoperatively were related to higher baseline BMI. A high SBRS may adversely impact adolescents’ overall health prior to surgery, which may have implications for weight loss success post-surgery. The evaluation for sleep health should be more rigorously evaluated and standardized as part of efforts to improve health outcomes in patients undergoing bariatric surgery.

Parasomnias are unwanted physical events, experiences, and autonomic nervous system activity that occur during sleep or during sleep-wake transitions. Rapid Eye Movement (REM) Sleep Behavior Disorder (RBD) is a parasomnia where the normal REM atonia is diminished or absent, with release of dream enactment behavior. RBD is more common in men, however it is not rare in women and needs to be considered in cases of sleep related injury. It is important to recognize the unique features of RBD and the relationships to neurodegenerative disorders. Finally, REM parasomnias are treatable with the proper identification and treatment of underlying co-morbid sleep disorders, the discontinuation of inducing agents, as well as the judicious use of pharmacotherapy and environmental modification.

Adolescence is a period of significant brain maturation, and cognitive and emotional development. Interacting with and reflecting these processes is sleep. In this review we synthesize the current and emerging literature on the role of adolescent sleep in brain maturation. On the one hand, studies in animals and humans suggest that sleep actively supports neurodevelopment during the adolescent period. On the other hand, over the last decade the value of sleep as a time to measure brain activity and study the brain maturational process has been appreciated. The transition from childhood to adolescence also heralds changes to sleep behavior, with sleep duration shortening across the adolescent period. This decline has important implications for adolescent cognitive and mental health, although the long-term consequences of chronic sleep restriction on adolescent brain maturation remain unknown.

While it is recognized that ensuring adequate sleep is vital in childhood development, typical activities, such television and other electronic media, early school start times, and extracurricular activities, can intrude on sleep time. Parents are faced with the responsibility of either limiting distractions and activities which interfere with sleep, or dealing with the complications of a child who does not receive adequate sleep. Some parents are not equipped with the knowledge of the amount of sleep children require. Certain parents also do not have discipline abilities to effectively manage their child's behavior to encourage sleep. Effective treatments are available for sleep disturbances in children, but often depend on a parent's ability to manage sleep behavior in their children. The following paper provides an overview of the significant literature published on sleep disturbances in children (early childhood through adolescence), along with the interrelationship between sleep and the family.

The aim of this study was to gain insight into the sleep quality of college students and related factors from a new perspective by using Latent Class Analysis (LCA). A total of 1,288 college students from four universities in Wuhu city participated in the study. LCA was used to identify the classes of sleep behaviors. Differences in class membership related to selected research factors were examined using multinomial logistic regression analysis.Four distinct classes of behaviors were identified: (1) good sleep (Class 1, 31.8%), (2) prolonged sleep latency (Class 2, 49.1%), (3) sleep disturbances and daytime dysfunction (Class 3, 6.8%), (4) multiple poor sleep behavior (Class 4, 12.3%). The latent classes of sleep behavior were correlated with the DBAS-16 total score (

Lairun Jin,1 Jun Zhou,1 Hui Peng,2 Shushu Ding,1 Hui Yuan1 1School of Public Health, Wannan Medical College, Wuhu, Anhui, People’s Republic of China; 2Department of Hospital Infection Management, Yijishan Hospital of Wannan Medical College, Wuhu, Anhui, People’s Republic of China Objective: The aims of this study were to evaluate a subset of sleep-related cognitions and to examine whether dysfunctional beliefs and attitudes about sleep were associated with sleep quality in college students. Patients and methods: A total of 1,333 college students were enrolled in this study by randomized cluster sampling. A brief version of Dysfunctional Beliefs and Attitudes about Sleep Scale (DBAS-16) was administered to college students at several colleges. Sleep quality was also assessed using the Pittsburgh Sleep Quality Index (PSQI). The DBAS-16 scores were analyzed across different demographic variables, corresponding subscales of 7-item PSQI, and relevant sleep behavior variables. Results: A total of 343 participants were poor sleepers, while 990 were good sleepers, as defined by PSQI. The DBAS-16 scores were lower in poor sleepers than in good sleepers (46.32 ± 7.851 vs 49.87 ± 8.349, p < 0.001), and DBAS-16 scores were lower in females and nonmedical students when compared with those in males and medical students, respectively (48.20 ± 8.711 vs 49.73 ± 7.923, p = 0.001; 48.56 ± 8.406 vs 49.88 ± 8.208, p = 0.009, respectively). The total score for sleep quality, as measured by PSQI, was negatively correlated with the DBAS-16 total score (r = −0.197, p < 0.01). There were significant differences in PSQI scores between individuals with attitudes and those without attitudes about sleep with respect to good sleep habits (p < 0.001), self-relaxation (p = 0.001), physical exercise (p < 0.001), taking sleeping pills (p = 0.004), and taking no action (p < 0.001). Conclusion: Dysfunctional beliefs about sleep are associated with sleep quality and should be discouraged, especially for females and nonmedical college students. Keywords: sleep, dysfunctional beliefs, college students, sleep quality, cognition

PURPOSE OF REVIEW: This paper describes a newly proposed sleep disorder, trauma-associated sleep disorder (TSD). Whether or not this represents a truly unique condition is controversial. In this paper, we describe the overlapping features and differences between TSD, post-traumatic stress disorder (PTSD) and Rapid Eye Movement (REM) sleep behavior disorder (RBD). RECENT FINDINGS: While REM sleep without atonia (RWA) and dream enactment are part of the diagnostic criteria for both RBD and TSD, only TSD features nightmares that occur both in non-REM and REM. A key difference between TSD and PTSD is the presence of symptoms during wakefulness in the latter, though the relationship between the two disorders is, as of yet, unclear. It is unknown whether or not a relationship exists between TSD and neurodegeneration, thus this needs to be explored further. SUMMARY: Additional research, such as application of TSD diagnostic criteria to more diverse population, would help to determine whether or not TSD is a distinct clinical entity, its relationships to PTSD, as well as the association of this condition with the development of neurodegeneration.

This study investigated whether trait anger linked to actual sleep behavior and what anger tendencies play the most important role for particular aspects of sleep. Data from 436 adults in Midlife of the United States Study were used to link anger tendencies to both objectively (actigraphy) and subjectively (daily diary) assessed sleep across a week. Overall, individuals who had poor anger control also had worse objectively and subjectively measured sleep and these relations were robust to effects of gender, age, race, socioeconomic status, and stress. The findings tie actual sleep behavior to individual differences in anger, suggesting poor anger control plays the most important role, and add to the growing evidence that anger and sleep depend on each other.

In Drosophila, well-delineated circuits control circadian rhythms, but the electrophysiological patterns that occur within these circuits are not well understood. In this issue, Tabuchi et al. clarify the temporal coding within a circuit, linking patterns of neural activity to sleep behavior.

The comparison between athletes and non-athletes for sleep, sedentary time or incidental daily activity is yet to be examined in a student population. Therefore, the purpose of the current study was to measure sleep and activity levels using accelerometry in athlete and non-athlete university students. 19 students on university athletic scholarships (11 female/8 male, age 20 ± 2, body mass index 24 ± 3) and 21 student non-athletes (11 female/10 male, age 21 ± 3, body mass index 25 ± 4) volunteered to wear an activity monitor over a 7-day period to measure general daily activity levels and sleep. All general daily activity, excluding time spent exercise training, was monitored and minutes spent at different activity zones as well as step count, distance covered and calories burnt were used for analysis between groups. Measures of sleep quality and quantity were also compared between groups. Significant differences were found between groups for step count and distance covered (p

We examined associations between the Children’s Sleep Habits Questionnaire (CSHQ) and sleep parameters assessed via actigraphy in a community sample of 111 children. Hypothesized correlations between CSHQ subscales and actigraphy data were not statistically significant, except for the association between CSHQ daytime sleepiness and actigraphy minutes asleep (r = −0.25, p

In the current study we set out to determine the effects of morpholino oligonucleotide (MO) knock-down of kcna2 on sleep-wake cycles in zebrafish. The results were compared to a non-overlapping MO injection, Dec2, who's mutant is also linked with a short sleep phenotype. Four groups of fish were used in the experiment: naïve fish, and fish injected with either control, kcna2, or Dec2 MO. All groups underwent 24-h behavioral monitoring of sleep-wake cycles at four and seven days-post-fertilization (dpf). First, we established an immobility dependent, sleep related, increase in arousal thresholds at both 4 and 7 dpf. Secondly, we show that kcna2 MO injected fish exhibit significantly less sleep behavior than controls and naïve fish, whereas Dec2 MO injections had similar but less severe effects. Finally, using kcna2 MO injected fish only, we turn to local field recordings at the level of the telencephalon and tectum opticum and rule out that the knock-down resulted in a non-specific increase in neural excitability that would mask sleep behavior.

To inform public health recommendations for adolescent sleep, the amounts of sleep associated with the highest levels of academic achievement and mental health were examined. The degree to which daily variability in sleep duration represents an under-appreciated but functionally-significant sleep behavior also was tested. A total of 421 adolescents (M(age) = 15.03 years) with Mexican American backgrounds reported nightly sleep times for two-weeks; approximately 80% repeated the same protocol one year later. Multilevel modeling indicated that the amount of sleep associated with the lowest levels of internalizing and externalizing symptoms was more than one hour greater than the amount associated with the highest levels of academic performance. Greater daily variability in sleep duration predicted greater symptomatology and mixed academic outcomes.

The purpose of this article was to use the multitheory model of health behavior change in predicting adequate sleep behavior in college students. A valid and reliable survey was administered in a cross-sectional design (n = 151). For initiation of adequate sleep behavior, the construct of behavioral confidence (P < .001) was found to be significant and accounted for 24.4% of the variance. For sustenance of adequate sleep behavior, changes in social environment (P < .02), emotional transformation (P < .001), and practice for change (P < .001) were significant and accounted for 34.2% of the variance.

Sleep is frequently interrupted in newborns and their mothers. Massage therapy is noted to facilitate sleep in adults and infants. Infant massage has also been more effective with oil versus no oil. In this study 76 mothers of newborns were randomly assigned to a massage with lotion versus a massage without lotion group and a non-massage control group. The mothers were then taught a simple newborn massage and were asked to massage their newborns daily for 15min at bedtime for one month. The Brief Infant Sleep Questionnaire was adapted for newborns and for mothers, and the mothers completed the questionnaires on their newborns' and their own sleep behaviors (the same behaviors for both mothers and newborns). The 3 groups were compared on the mothers' and their newborns' sleep behavior changes from birth to one month. By the last day of the study, the lotion massage group versus the other two groups showed a shorter latency to sleep and longer sleep for the mothers and fewer nightwakings and longer sleep for their infants. This may relate to the lotion group mothers massaging their infants more frequently as the number of massages was correlated with the total time sleeping and negatively correlated with nightwakings for both the mothers and the infants on the last day of the study. And, the mothers' and the infants' sleep behaviors were significantly correlated.

Humans need about 7 to 9 hours of sleep per night. Sleep habits are heritable, associated with brain function and structure, and intrinsically related to well-being, mental and physical health. This raises the question whether associations between sleep, mental and physical health can be attributed to a shared macroscale neurobiology.Combining neuroimaging and behavioral genetic approaches in two independent large-scale datasets (n=1887) we demonstrate phenotypic and genetic correspondence between sleep, intelligence, and BMI. Sleep was associated with local thickness variation in frontal, temporal, and occipital cortices. Using a comprehensive multivariate approach, we identified two robust latent components highlighting the interdigitation of sleep, intelligence, BMI, and depression and their shared relation to regions in unimodal and heteromodal association cortices. Latent relationships were heritable and driven by shared additive genetic factors. These observations provide a system-level perspective on the interrelation of sleep, mental, and physical conditions, anchored in grey-matter neuroanatomy.

Objective: To Determine whether possible sleep bruxism (PSB) is associated with daytime oral habits and sleep behavior in schoolchildren.Methods: A cross-sectional study was conducted with a representative sample of 8-to-10-year-old children (n = 544). The Sleep Behavior Questionnaire (SBQ) was administered to evaluate sleep behavior. Daytime oral habits were evaluated using the Nordic Orofacial Test-Screening.Results: The prevalence of PSB was 21% and was significantly higher in children with reports of awake bruxism (p < .001; PR = 2.76; 95% CI: 2.01-3.79), snoring (p < .001; PR = 1.93; 95% CI: 1.41-2.65), and sucking/biting the lips daily (p = .034; PR = 1.73; 95% CI: 1.08-2.78). No socioeconomic characteristics were associated with PSB in the final model.Conclusion: Possible sleep bruxism in schoolchildren is associated with possible awake bruxism, snoring, sleep fragmentation, and daytime sleepiness.

Background We aimed to investigate the association of mother's perceived levels of depression and happiness across all trimesters of pregnancy and after delivery on their children's sleep problems, as well as examine the possible mediating effect of children's behavioral problems. Methods Participants included 1257 children (54% boys, mean age = 5.74 ± 0.48 years). Pre- and postnatal maternal emotions were self-reported using a 5-point scale for happiness and a 3-point scale for depressive emotions. Children reported sleep and behavioral problems using the Child Behavior Checklist. Results Adjusted models showed that children of women reporting depressive emotions during either the postnatal period (β = 3.07, p = 0.01) or both prenatal and postnatal periods (β = 2.91, p = 0.01) were more likely to report sleep disturbances. By contrast, children of women reporting higher levels of happiness in the second (β = -1.91, p = 0.04) and third (β = -2.27, p = 0.001) trimesters were less likely to report sleep problems. Limitations Differences in maternal-report of children's behaviors could reflect memory and recall bias, and maternal emotions were assessed by researcher-designed single item measures. All measures were completed by a single reporter. Other associated factors should be considered in clarifying the complex associations. Conclusions Maternal depressive emotions during pre- and postnatal periods were associated with an increase in children's sleep problems, while increased happiness during pregnancy was associated with a decrease in children's sleep problems. Children's behavioral problems significantly mediated these relationships. To our knowledge, this is the first study to examine the relationship between maternal pre- and postnatal emotions and children's sleep behavior in an Asian sample.

This study aims to develop automated diagnostic tools to aid in the identification of rapid-eye-movement (REM) sleep behaviour disorder (RBD). Those diagnosed with RBD enact their dreams and therefore present an abnormal characteristic of movement during REM sleep. Several methods have been proposed for RBD detection that use electromyogram (EMG) recordings and manually annotated sleep stages to objectively quantify abnormal REM movement. In this work we further develop these proven techniques with additional features that incorporate the relationship of muscle movement between sleep stages and general sleep architecture. Performance is evaluated using polysomnography (PSG) recordings from 43 aged-matched healthy controls and subjects diagnosed with RBD obtained from multiple institutions and publicly available resources. Using a random forest classifier with established and additional features, the performance of RBD detection was shown to improve upon established metrics (achieving 88% accuracy, 91% sensitivity, and 86% specificity).

Objectives Chronic sleep loss among youth is a worldwide health problem. Since research on its predictors is often limited to high-income countries, it is unclear if these findings are generalizable to all populations. To address this gap from an ecological perspective, we evaluated the associations between adolescents' sleep behaviors and several factors at the community, household, and individual levels in a middle-income country. Methods This was a cross-sectional study of 73 girls (mean age = 14.5 y; range = 11-18 y) in rural and urban communities in Guyana. Sleep behaviors (nap-duration, bedtime, rise-time, night-bed-duration, and sleep-duration) were assessed with interviews and monitored up to 7 consecutive days using waist-worn accelerometers. Results Similar to other settings, Guyanese urban youth reported significantly later bedtimes than rural youth, and increasing age was associated with later bedtime and shorter night-bed-duration. In contrast to the association observed in high-income countries, increasing household poverty scores in Guyana were associated with longer night-bed-duration. Conclusions Although the relationships between locale, age, and sleep in Guyana paralleled patterns seen in high-income countries, the positive relationship between poverty and sleep diverges from previous reports. These findings suggest that predictors of chronic sleep loss seen in high-income countries are likely to differ from those in middle- and low-income countries. More sleep studies in underrepresented populations are needed to gain a comprehensive understanding of adolescent sleep behavior and its correlates.