Wake Episodes Research Articles

Deep behavioural representation learning reveals risk profiles for malignant ventricular arrhythmias

We aimed to identify and characterise behavioural profiles in patients at high risk of SCD, by using deep representation learning of day-to-day behavioural recordings. We present a pipeline that employed unsupervised clustering on low-dimensional representations of behavioural time-series data learned by a convolutional residual variational neural network (ResNet-VAE). Data from the prospective, observational SafeHeart study conducted at two large tertiary university centers in the Netherlands and Denmark were used. Patients received an implantable cardioverter-defibrillator (ICD) between May 2021 and September 2022 and wore wearable devices using accelerometer technology during 180 consecutive days. A total of 272 patients (mean age of 63.1 ± 10.2 years, 81% male) were eligible with a total sampling of 37,478 days of behavioural data (138 ± 47 days per patient). Deep representation learning identified five distinct behavioural profiles: Cluster A (n = 46) had very low physical activity levels and a disturbed sleep pattern. Cluster B (n = 70) had high activity levels, mainly at light-to-moderate intensity. Cluster C (n = 63) exhibited a high-intensity activity profile. Cluster D (n = 51) showed above-average sleep efficiency. Cluster E (n = 42) had frequent waking episodes and poor sleep. Annual risks of malignant ventricular arrhythmias ranged from 30.4% in Cluster A to 9.8% and 9.5% for Clusters D-E, respectively. Compared to low-risk profiles (D-E), Cluster A demonstrated a three-to-four fold increased risk of malignant ventricular arrhythmias adjusted for clinical covariates (adjusted HR 3.63, 95% CI 1.54–8.53, p < 0.001). These behavioural profiles may guide more personalised approaches to ventricular arrhythmia and SCD prevention.

Melinjo (Gnetum gnemon L.) seed extract for treatment of sleep/wake fragmentation in diet-induced obese mice.

Dietary supplementation with melinjo (Gnetum gnemon L.) seed extract (MSE) has been an integral part of an anti-obesity therapeutic regimen. To examine the relationship between anti-obesity and sleep, we explored the effect of MSE on sleep structure in high-fat diet (HFD)-induced obese mice. Although HFD did not alter the total amount of daily sleep, it significantly reduced the average duration of non-rapid eye movement (NREM) sleep and wakefulness episodes and significantly increased the number of these episodes. These findings indicate fragmented NREM sleep due to repeated brief awakenings in the HFD-fed mice. When 1% (w/v) MSE was given to HFD-fed mice, their weight or sleep structure were comparable to those of ND-fed mice, proving that dietary MSE completely hindered HFD-induced weight gain and sleep/wake fragmentation. Our data provide compelling evidence that MSE is a novel and promising dietary supplement that restores obesity-induced sleep architecture changes in mice.

Abstract P174: The endogenous circadian system modulates blood pressure reduction after an aerobic exercise session in healthy adults

Objective: To determine the role of the circadian system on blood pressure (BP) reduction promoted by exercise. Methods: Nine (4 male/5 female) healthy adults (aged 23±2 y) completed a 30-hour circadian protocol in a dim light laboratory (&lt;8 lux), where all behaviors and measurements were evenly distributed across the 24-hour cycle. Participants underwent five recurring 6-hour day-cycles of 2-hour sleep opportunities and 4-hour standardized wake episodes. Systolic, diastolic, and mean BPs, cardiac output (CO), and stroke volume were derived from beat-to-beat BP waveform (plethysmography). Heart rate (HR) was determined from an electrocardiogram (ECG), and systemic vascular resistance (SVR) was calculated (SVR = Mean BP/CO). Data were recorded for 10 minutes in supine at rest, before and after 30 minutes of moderate aerobic exercise (cycle ergometer, 30 min, 40% HR reserve). Circadian phases were calculated based on individual dim-light melatonin onsets. Mixed-model cosinor analyses tested if changes between before and postexercise had systematic rhythmicity with an underlying sinusoidal profile. Results: Systolic and mean BP change had a circadian rhythm (p&lt;0.05) with the greatest decrease (-12 and -9 mmHg) at ~1pm and an amplitude of 11 and 8 mmHg, respectively, from its blunted response at ~1am. SVR change had a circadian rhythm with a greater decrease ~10am (see figure). No other variables displayed a circadian variation. Conclusion: In young healthy adults, the circadian system potentiates the hypotensive effect of exercise in the afternoon. However, the absence of this ability during the night may represent cardiovascular vulnerability in those who stay awake at that time (e.g., shift workers).

Exposure to parental interpartner conflict in adolescence predicts sleep problems in emerging adulthood

ObjectivesParental interpartner conflict is a highly prevalent form of family risk that is stressful for adolescents with ramifications for their sleep. Multiple studies have demonstrated that adolescents from high-conflict homes are at risk for sleep problems. Building on this literature, we conducted novel analyses and investigated whether exposure to interpartner conflict in adolescence predicts sleep problems in the subsequent developmental period of emerging adulthood. MethodsWe used a rigorous four-wave design spanning 8years (collected between 2012-2020). At wave 1, participants were 245 adolescents from diverse backgrounds (M age=15.74years; 67% White/European American, 33% Black/African American; 52% girls). Individuals participated again in their adolescence at wave 2 (M age=16.77) and wave 3 (M age=17.69). Participants returned for wave 4 in emerging adulthood (M age=22.97). Adolescents reported on their parents’ interpartner conflict (intense and frequent conflict). Sleep duration (minutes) and quality (efficiency, long wake episodes) were measured using actigraphy. ResultsAfter controlling for autoregressive effects and several covariates, findings from a structural equation model revealed that greater exposure to parental interpartner conflict in adolescence predicted reduced sleep efficiency and more long wake episodes in emerging adulthood. ConclusionsResults build on the literature to consider sleep in the family context and are among the first to illustrate that exposure to parental interpartner conflict in adolescence predicts sleep problems in emerging adulthood. Continued investigations into the antecedents of sleep problems in emerging adulthood may benefit from considering past exposure to family risk.

Role of the oral health professional in obstructive sleep apnea

American Academy of Sleep Medicine (AASM) describes obstructive sleep apnea (OSA) as a sleep-related breathing disorder that involves a decrease or complete halt in airflow despite an ongoing effort to breathe. This causes multiple episodes of hyperarousal or wakefulness from sleep, which leads to a decrease in the quality of sleep, leading to daytime sleepiness, increased affinity to accidents, and cardiovascular diseases such as myocardial infarction, congestive heart failure, and stroke. It is measured using the apnea-hypopnea index, that is, the number of sleep arousals in a given night. Possible risk factors for the disease include obesity (body mass index of ≥30), older age, Down’s syndrome, family history of OSA, and abnormal craniofacial features. Treatment options include continuous positive airway pressure, weight loss, oral devices, surgeries of the soft palate and/or genioglossus muscle, and maxilla-mandibular advancements. This review aims to address the oral diagnosis and dental treatment of OSA.

Deep embedded clustering of physical behaviour in patients with an implanted cardioverter-defibrillator identifies high and low risk profiles

Abstract Introduction Patients at high risk of sudden cardiac death are treated with an implantable cardioverter-defibrillator (ICD). Patterns in physical behaviour may be prognostic for clinical deterioration. Deep embedded clustering (DEC) employs deep neural networks to learn compact and meaningful representations from high-dimensional data, on which an unsupervised clustering then operates. Purpose The objectives of this study were to use DEC to identify and describe behavioural profiles in a prospective ICD cohort and assess their risk of clinical outcomes. Methods Data from the multicenter, prospective SafeHeart study conducted at our 2 centers, was used. Patients received an implantable cardioverter defibrillator (ICD) between May 2021 and September 2022, who then wore wearable devices during 6 months that capture physical behaviour. Latent representations were extracted from the time-series behavioural data using a variational autoencoder, and used as input to an unsupervised machine learning algorithm (Figure 1). Kaplan-Meier survival curves were used to visualise the annual risk of appropriate ICD-therapy, and the composite of all ICD-therapy and death. Results A total of 272 patients (mean age of 63.1 ±10.2 years, 81% male) were eligible, with a total of 37478 days of behavioural data (138 ±47 days per patient). DEC identified five distinct behavioural profiles: Cluster A (n=70) had high activity levels, mainly at light-to-moderate intensity. Cluster B (n=51) showed above-average sleep efficiency. Cluster C (n=63) exhibited a high-intensity activity profile. Cluster D (n=42) had frequent waking episodes and poor sleep. Cluster E (n=46) had very low physical activity levels and an impaired sleep architecture. Significantly differences were observed between clusters A-E in ICD-therapy and mortality (log-rank p-value 0.04) (Figure 2). Clusters B and D exhibited a threefold decrease in the annual risk of appropriate ICD therapy compared to cluster E. Conclusion DEC reveals distinct behavioural profiles in a prospective ICD cohort, with their inherent risk on outcomes. Wearable accelerometer devices enable behavioural monitoring that may provide opportunities for improved personalised risk prediction in a notoriously heterogeneous high-risk patient population.Deep embedded clustering of behaviourEvent rates stratified for clusters

Routine, Routine, Routine: Sleep Regularity and its Association with Sleep Metrics in Professional Rugby Union Athletes

BackgroundMaintaining a consistent sleep and wake time is often reported as a key component of circadian rhythmicity and quality sleep. However, the impact of sleep onset and offset time variability on overall sleep outcomes are underreported in elite athlete populations. This study investigated the relationship between sleep onset and offset time variability using the sleep regularity index (SRI) and measures of sleep and well-being in professional rugby union athletes. Twenty-three professional male rugby union athletes (mean ± SD, age: 23 ± 3 y) underwent sleep monitoring via wrist actigraphy for three weeks during a pre-season phase of training and completed a daily wellness questionnaire. Median SRI was calculated and used to stratify the trainees into two quantile groups: >76.4 SRI (Regular, n = 11) and < 76.4 SRI (Irregular, n = 12).ResultsThe regular sleep group showed significantly longer total sleep duration (p = 0.02, d = 0.97) compared to the irregular group (7:42 ± 0:29 vs. 7:18 ± 0:20 h: min per night, respectively). Furthermore, while not statistically significant, the regular sleep group showed greater sleep efficiency and less wake episodes compared to irregular sleepers, as demonstrated by moderate effect sizes (d = 0.71 and 0.69, respectively).ConclusionsThe results from this study indicate that minimizing variability in sleep onset and offset time is beneficial for increasing sleep duration and may improve sleep efficiency during pre-season training in elite male rugby union athletes. This study provides evidence for the importance of including sleep-wake routines as a key component of sleep education interventions.

Association of Visual-Based Signals with Electroencephalography Patterns in Enhancing the Drowsiness Detection in Drivers with Obstructive Sleep Apnea.

Individuals with obstructive sleep apnea (OSA) face increased accident risks due to excessive daytime sleepiness. PERCLOS, a recognized drowsiness detection method, encounters challenges from image quality, eyewear interference, and lighting variations, impacting its performance, and requiring validation through physiological signals. We propose visual-based scoring using adaptive thresholding for eye aspect ratio with OpenCV for face detection and Dlib for eye detection from video recordings. This technique identified 453 drowsiness (PERCLOS ≥ 0.3 || CLOSDUR ≥ 2 s) and 474 wakefulness episodes (PERCLOS < 0.3 and CLOSDUR < 2 s) among fifty OSA drivers in a 50 min driving simulation while wearing six-channel EEG electrodes. Applying discrete wavelet transform, we derived ten EEG features, correlated them with visual-based episodes using various criteria, and assessed the sensitivity of brain regions and individual EEG channels. Among these features, theta-alpha-ratio exhibited robust mapping (94.7%) with visual-based scoring, followed by delta-alpha-ratio (87.2%) and delta-theta-ratio (86.7%). Frontal area (86.4%) and channel F4 (75.4%) aligned most episodes with theta-alpha-ratio, while frontal, and occipital regions, particularly channels F4 and O2, displayed superior alignment across multiple features. Adding frontal or occipital channels could correlate all episodes with EEG patterns, reducing hardware needs. Our work could potentially enhance real-time drowsiness detection reliability and assess fitness to drive in OSA drivers.

Analysis of definite awake bruxism using a portable electromyography device.

This study aimed to compare awake bruxism events between subjective and objective evaluations using a questionnaire survey and a modified portable electromyography (EMG) device, and to examine correlations between sleep quality and awake bruxism. The Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI), and awareness of awake bruxism as clarified via interviews were conducted on 34 participants as subjective evaluations. The EMG device was used to record left temporal muscle activity for 6.5 h (from 09:00 to 15:30) and the number of awake bruxism episodes per hour. The participants were then classified into "bruxer" and "non-bruxer" groups based on the number of awake bruxism episodes. The mean number of awake bruxism episodes per hour was 33.6 ± 21.4, and 23% of the participants who reported having no awareness of awake bruxism in the interviews were defined as "bruxers" in the objective evaluations. In the bruxer group, positive correlations were found between the number of awake bruxism episodes and both ESS and PSQI scores. These findings suggest that objective measurements using a portable EMG device can increase the diagnostic accuracy for awake bruxism, and that sleep quality is a major risk factor for awake bruxism.

A Novel Approach to Quantify Microsleep in Drivers With Obstructive Sleep Apnea by Concurrent Analysis of EEG Patterns and Driving Attributes.

Accurate quantification of microsleep (MS) in drivers is crucial for preventing real-time accidents. We propose one-to-one correlation between events of high-fidelity driving simulator (DS) and corresponding brain patterns, unlike previous studies focusing general impact of MS on driving performance. Fifty professional drivers with obstructive sleep apnea (OSA) participated in a 50-minute driving simulation, wearing six-channel Electroencephalography (EEG) electrodes. 970 out-of-road OOR (microsleep) events (wheel and boundary contact ≥1 s), and 1020 on-road OR (wakefulness) events (wheel and boundary disconnection ≥1 s), were recorded. Power spectrum density, computed using discrete wavelet transform, analyzed power in different frequency bands and theta/alpha ratios were calculated for each event. We classified OOR (microsleep) events with higher theta/alpha ratio compared to neighboring OR (wakefulness) episodes as true MS and those with lower ratio as false MS. Comparative analysis, focusing on frontal brain, matched 791 of 970 OOR (microsleep) events with true MS episodes, outperforming other brain regions, and suggested that some unmatched instances were due to driving performance, not sleepiness. Combining frontal channels F3 and F4 yielded increased sensitivity in detecting MS, achieving 83.7% combined mean identification rate (CMIR), surpassing individual channel's MIR, highlighting potential for further improvement with additional frontal channels. We quantified MS duration, with 95% of total episodes lasting between 1 to 15 seconds, and pioneered a robust correlation (r = 0.8913, p<0.001) between maximum drowsiness level and MS density. Validating simulator's signals with EEG patterns by establishing a direct correlation improves reliability of MS identification for assessing fitness-to-drive of OSA-afflicted adults.

Microglia modulate sleep/wakefulness under baseline conditions and under acute social defeat stress in adult mice

Although sleep is tightly regulated by multiple neuronal circuits in the brain, nonneuronal cells such as glial cells have been increasingly recognized as crucial sleep regulators. Recent studies have shown that microglia may act to maintain wakefulness. Here, we investigated the possible involvement of microglia in the regulation of sleep quantity and quality under baseline and stress conditions through electroencephalography (EEG)/electromyography (EMG) recordings, and by employing pharmacological methods to eliminate microglial cells in the adult mouse brain. We found that severe microglial depletion induced by the colony-stimulating factor 1 receptor (CSF1R) antagonist PLX5622 (PLX) reversibly decreased the total wake time and the wake episode duration and increased the EEG slow-wave power during wakefulness under baseline conditions. To examine the role of microglia in sleep/wake regulation under mental stress, we used the acute social defeat stress (ASDS) paradigm, an ethological model for psychosocial stress. Sleep analysis under ASDS revealed that microglial depletion exacerbated the stress-induced decrease in the total wake time and increase in anxiety-like behaviors in the open field test. These results demonstrate that microglia actively modulate sleep quantity and architecture under both baseline and stress conditions. Our findings suggest that microglia may potentially provide resilience against acute psychosocial stress by regulating restorative sleep.

Entrainment to gradual vs. immediate 8-hour phase advance shifts with and without short-wavelength enriched polychromatic green light

ObjectivesFor optimal health and well-being the sleep episode and the circadian timing system should be properly aligned. We evaluated the effectiveness of different dynamic light and sleep/wake shift schedules for rapid circadian entrainment following an 8-hour advance of sleep. MethodsForty-three healthy participants completed an 8-day inpatient protocol in which the 8-hour sleep episode was advanced by 8 hours. Participants were assigned to one of five conditions: (1) dim ambient WHITE light and GRADUAL shift in which the sleep episode was incrementally advanced over 5days; (2) dim GREEN, short-wavelength (∼504 nm) polychromatic light and GRADUAL shift; (3) dim WHITE light and SLAM shift, including an abrupt 8-hour advance on day 3 following an extended 32-hour wake episode; (4) GREEN light and SLAM shift; or (5) COMBINED (higher illuminance WHITE plus GREEN) light and modified SLAM shift with 2 short naps scheduled on the day prior to the abrupt advance. Phase shifts of the plasma dim light melatonin onset and sleep measures were compared to examine effects of protocol condition. ResultsAfter 5days, the COMBINED light/modified SLAM shift condition showed larger phase advances of dim light melatonin onset (4.02 ± 1.13 hours) compared to the other 4 conditions (range 1.50 ± 0.96-2.83 ± 2.23 hours; p < .05) and resulted in increased REM sleep duration and fewer sleep disruptions. ConclusionsConsideration of the type of shift and the illuminance and wavelength of light may assist in designing lighting countermeasures to sleep and circadian disruption, which has implications for jetlag, shiftwork, and circadian rhythm sleep disorders.

Sleep/Wake Regularity and Cognition in College Students using Antidepressants

The current project examined sleep, sleep/wake regularity, and cognition in college students diagnosed with depression and using serotonergic antidepressants and in those without a depression diagnosis. Forty participants either using antidepressants (n = 20, 24.75 ± 6.82 years) or without a depression diagnosis (n = 20, 21.70 ± 2.74 years) wore actigraphs for two consecutive weeks (14 days). Cognitive tasks were completed on day 1 (along with demographic surveys) and day 14. Effect sizes indicated that compared to non-clinically depressed peers, participants using antidepressants exhibited slightly greater wake after sleep onset (d = .36) and lower sleep efficiency (d = .40); however, these differences were likely not noticed by the sleeper. No sleep regularity or cognitive differences were present between groups. Within the antidepressant group, higher dosage predicted greater time in bed (R2 = .77), but less total sleep time (R2 = .86). The time of day that participants took their antidepressant exhibited differential effects on certain cognitive parameters, such as procedural reaction time and spatial processing, and interactions with years of antidepressant use were found. Self-reported wake episodes also predicted better reaction time and inhibition in the antidepressant group. This study is the first to demonstrate that sleep/wake regularity is comparable between people using antidepressants and non-clinically depressed human samples. For individuals using antidepressants, years of use, dosage, and time of day of use have predictive qualities for reaction times, spatial processing, and inhibition.

Family income as a moderator of relations between sleep and physical health during adolescence

ObjectivesSleep duration, quality, and consistency are associated with overall physical health in adolescence, yet the effects of sleep on development may be not uniform because both sleep and physical health vary systematically along gradients of family income. To understand “for whom” sleep may be particularly beneficial, the present study tested family income as a moderator of relations between youth sleep and physical health. MethodsThree hundred twenty-three youth (M age=17.39years; 53% female; 41% Black, 59% White) wore wrist actigraphs for 1week at home. Four well-recognized sleep parameters were derived: minutes, efficiency, long wake episodes, and variability in minutes across the week. Parents reported family income, and mothers rated adolescents’ physical health. In independent path models, physical health was regressed onto each indicator of sleep, family income, and Sleep × Family Income interactions to test potential moderation effects. ResultsAssociations between sleep and physical health were moderated by family income. Lower sleep efficiency, more long wake episodes, and more variability in sleep minutes were associated with poorer physical health among adolescents from lower-income families. At optimal levels of all sleep variables, income-based differences in physical health were mitigated. Youth from higher-income families tended to have better physical health regardless of their sleep. ConclusionsFindings build evidence that sleep has relations with physical health for low-income youth in particular. Clinicians and other service providers working with youth might benefit from considering the role of sleep in prevention and interventions programs geared toward improving health.

Polysomnographic characteristics of sleep in adults with and without physician-diagnosed atopic dermatitis: results from the Study of Health in Pomerania

PurposeTo analyze sleep characteristics as measured with polysomnography (PSG) in adults from the general population with and without physician-diagnosed atopic dermatitis (AD).MethodsWe analyzed data from participants from the German population-based Study of Health in Pomerania (SHIP) TREND-0. AD was diagnosed in a standardized skin examination. The following polysomnographic parameters were measured: total sleep duration (min), sleep latency (min), wake after sleep onset (WASO; min), rapid eye movement (REM) latency (min), sleep efficiency (%), total number of wakefulness and movement episodes, stages of sleep (%), and apnea-hypopnea index (AHI). Additionally, the subjective sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). We compared sleep characteristics of participants with and without AD.ResultsAmong 1187 participants, 47 (4.0%) had AD. We found no differences between participants with and without AD in any of the analyzed PSG parameters except for the total number of wakefulness and movement episodes and the percentage of REM sleep. Participants with AD had a higher number of wakefulness and movement episodes, and a lower proportion of REM sleep compared to those without AD. Regarding subjective sleep parameters, no significant differences were found between participants with and without AD.ConclusionOur data do not provide evidence for poor sleep quality in individuals with AD. Major limitations of the study include the unavailability of data on AD severity and the small number of participants with AD. Larger-scaled longitudinal studies considering disease severity and specific AD symptoms with an effect on sleep are required.

FRI008 Impact Of Sleep Fragmentation And Estradiol Suppression On Leptin, Ghrelin, Satiety And Hunger In Women: An Experimental Menopause Model To Understand Menopause-related Body Fat Gain

Abstract Disclosure: S.A. Rahman: Consulting Fee; Self; Sultan &amp; Knight Limited, Bambu Vault LLC, Lucidity Lighting Inc. Grant Recipient; Self; Seoul Semiconductor Co. Ltd, Biological Innovation and Optimization Systems, LLC, Merck &amp; Co, Inc, Pfizer Inc, Vanda Pharmaceuticals Inc, Lighting Science Group. Speaker; Self; Starry Skies Lake Superior, University of Minnesota Medical School, PennWell Corp, and Seoul Semiconductor Co. Ltd. Stock Owner; Self; Melcort Inc. L.K. Grant: None. A. Cohn: None. M.D. Nathan: None. J. Harder: Consulting Fee; Self; Atman Health; O’Rourke &amp; Hawk, LLP. Grant Recipient; Self; Brigham and Women’s Hospital; President and Fellows of Harvard College. Owner/Co-Owner; Self; Jessica Harder, MD. Stock Owner; Self; Atman Health. Other; Self; Centerfield Media Holding Company. I. Gonsalvez: None. F.A. Scheer: Consulting Fee; Self; University of Alabama at Birmingham. Other; Self; Board of Directors for the Sleep Research Society. E.B. Klerman: Consulting Fee; Self; Circadian Therapeutics, The National Sleep Foundation, Sanofi-Genzynel. Other; Self; Travel support from the Sleep Research Society. S. Crawford: None. T. Luo: None. E. Menezes: None. A. Roy: None. A. Joseph: None. A. Wiley: None. U.B. Kaiser: None. H. Joffe: Consulting Fee; Self; Bayer, Hello Therapeutics. Grant Recipient; Self; National Institutes of Health, Merck, Pfizer. Body fat increases during the menopause transition. In addition to menopause-related estradiol (E2) decline, sleep fragmentation (wake episodes interrupting sleep) due to hot flashes, without a reduction in total sleep time, is common. We examined whether E2 decline and sleep fragmentation decrease the satiety hormone, leptin, increase the orexigenic hormone, ghrelin, and their behavioral correlates satiety and hunger, which would promote positive energy balance and body fat gain. We studied 38 healthy premenopausal female volunteers (mean age [±SD] 29.7±6.7 years) in a 5-night inpatient study under eucaloric conditions, once in the mid-to-late follicular phase (high-E2) and again after gonadotropin-releasing hormone agonist-induced E2-suppression (hypo-E2) in a subset (n=27). Each inpatient study involved 2 nights of unfragmented sleep followed by 3 nights of experimentally induced sleep fragmentation to achieve ∼1hr of wake after sleep-onset without reducing total sleep time. Serum for leptin and acetylated ghrelin assays and self-reported satiety and hunger via visual analog scales were collected fasting ∼1hr after waking each morning. Values were normalized relative to each individual’s baseline (high-E2, unfragmented sleep) and then compared between conditions using generalized linear mixed models. Mean (±SD) levels of leptin and ghrelin at baseline were 38.5±21.2 ng/mL and 640.9±362.0 pg/mL, respectively. Compared to the high-E2 state, omnibus analysis of E2 suppression during both unfragmented and fragmented sleep showed significant reduction from the high-E2 to hypo-E2 state in satiety-promoting leptin levels (least squares mean % of baseline [±SE]: 101.0±1.1% vs. 90.0±3.0%, p=0.001), but unchanged self-rated satiety (109.3±7.8% vs. 102.6±15.6%, p=0.58). E2 suppression also did not change hunger-promoting ghrelin levels (101.0±3.1% vs. 97.0±1.4%, p=0.13) or self-rated hunger (103.3±6.6% vs. 133.2±30.5%, p=0.28). Omnibus analysis of sleep fragmentation during both high-E2 and hypo-E2 states showed that, relative to unfragmented sleep, leptin levels were unchanged (94.0±1.5% vs. 96.7±2.5%, p=0.22), but self-rated satiety was significantly lower (113.1±11.0% vs. 99.2±11.9%, p=0.048) after sleep fragmentation. There was a trend towards the lowest satiety in the hypo-E2 sleep fragmented state (interaction p=0.052). Sleep fragmentation did not change ghrelin levels (100.7±1.8% vs. 97.3±2.7%, p=0.13) or self-rated hunger (103.0±6.2% vs. 133.6±30.0%, p=0.25). These results demonstrate significant adverse changes in leptin and satiety in women induced, respectively, by E2 suppression and sleep fragmentation, independent of aging. Findings support likely independent contributions of E2 decline and sleep fragmentation during the menopause transition toward positive energy balance and body fat gain. Funding: NIH R01AG053838 (PI: H Joffe). Presentation: Friday, June 16, 2023

Spontaneous attentional failures reflect multiplicative interactions of chronic sleep loss with acute sleep loss and circadian misalignment

ObjectivesAcute and chronic sleep loss and circadian timing interact such that, depending on their combination, small or very large performance decrements are observed in tasks of attention. Here, we tested whether such nonlinear interactions extend to a physiological measure of spontaneous visual attentional failures, indicating a fundamental principle of sleep-wake regulation. MethodsNine healthy volunteers completed an in-laboratory 3-week forced desynchrony protocol consisting of 12 consecutive 42.85-hour cycles with a sleep-wake ratio of 1:3.3. The protocol induced increasing chronic sleep loss, while extended wake (32.85 hours) and sleep episodes (10 hours) occurred at multiple circadian phases. Attentional failure rate was quantified from continuous electrooculograms (number of 30-second epochs with slow eye movements/h of wakefulness) as a function of time since scheduled wake (acute sleep loss), week of study (chronic sleep loss), and circadian (melatonin) phase. ResultsDuring the first ∼8 hours awake, attentional failure rate was low, irrespective of the week. During the following wake hours, attentional failure rate increased steadily but at a faster rate in weeks 2 and 3 compared to week 1. The effects of acute and chronic sleep loss on attentional failure rate were magnified during the biological night compared to the biological day. ConclusionsA single extended sleep episode can only temporarily reverse attentional impairment associated with chronic sleep loss. Multiplicative effects of acute and chronic sleep loss—further amplified during the biological night—substantiate the interaction of 2 homeostatic response mechanisms and caution against underestimating their disproportionate combined impact on performance, health, and safety.

Unsupervised Multitaper Spectral Method for Identifying REM Sleep in Intracranial EEG Recordings Lacking EOG/EMG Data.

A large number of human intracranial EEG (iEEG) recordings have been collected for clinical purposes, in institutions all over the world, but the vast majority of these are unaccompanied by EOG and EMG recordings which are required to separate Wake episodes from REM sleep using accepted methods. In order to make full use of this extremely valuable data, an accurate method of classifying sleep from iEEG recordings alone is required. Existing methods of sleep scoring using only iEEG recordings accurately classify all stages of sleep, with the exception that wake (W) and rapid-eye movement (REM) sleep are not well distinguished. A novel multitaper (Wake vs. REM) alpha-rhythm classifier is developed by generalizing K-means clustering for use with multitaper spectral eigencoefficients. The performance of this unsupervised method is assessed on eight subjects exhibiting normal sleep architecture in a hold-out analysis and is compared against a classical power detector. The proposed multitaper classifier correctly identifies 36±6 min of REM in one night of recorded sleep, while incorrectly labeling less than 10% of all labeled 30 s epochs for all but one subject (human rater reliability is estimated to be near 80%), and outperforms the equivalent statistical-power classical test. Hold-out analysis indicates that when using one night's worth of data, an accurate generalization of the method on new data is likely. For the purpose of studying sleep, the introduced multitaper alpha-rhythm classifier further paves the way to making available a large quantity of otherwise unusable IEEG data.

Interactions between insomnia, sleep duration and emotional processes: An ecological momentary assessment of longitudinal influences combining self-report and physiological measures.

Previous studies indicated that further investigation is needed to understand how insomnia disorder interacts with emotional processes. The present study is an ecological momentary assessment evaluating the link between emotional and sleep alterations in patients with insomnia. Physiological (heart rate and heart rate variability) and subjective (sleep and emotions) indices were observed for 5 days in patients with insomnia disorder (n = 97), good sleepers under self-imposed sleep restriction (n = 41), and good sleepers with usual amount of sleep (n = 45). We evaluated differences in emotion regulation strategies and in valence and variability of emotional experiences. Over 5 days, patients with insomnia showed increased sleep and emotional difficulties compared with both control groups. Independent from group allocation, days with more negative emotions were associated with higher sleep alterations. Longer wake episodes at night and higher diurnal heart rate were associated with increased variations in emotion experienced during the day. Only in patients with insomnia, use of adaptive emotion regulation strategies was associated with higher sleep efficiency. Our data showed that alterations in sleep and emotional processes are closely linked. A combination of strategies targeting both sleep and emotional processes appears promising in the prevention and treatment of insomnia disorder.

Neighborhood environment and adolescent sleep: The role of family socioeconomic status

ObjectivesSocioeconomic status (SES) and neighborhood context are influential predictors of adolescent sleep, yet little is known about how they may interact to influence sleep. We examined multiple dimensions of family SES as moderators of associations between neighborhood risk and multiple sleep parameters. MethodsParticipants were 323 adolescents (Mage = 17.4 years, SD = 0.86; 48% male; 60% White/European American, 40% Black/African American). Sleep was assessed using 7 nights of actigraphy from which sleep duration (minutes from onset to wake time), efficiency, long wake episodes, and variability in minutes over the week were derived. Youth reported on their sleep/wake problems and sleepiness, as well as their perceptions of safety and violence in their neighborhoods. Parents reported on SES indices, including income-to-needs ratio and perceived financial stability. ResultsLower SES (income-to-needs, perceived financial stability) was associated with lower sleep efficiency and more frequent long wake episodes. Lower neighborhood safety and greater community violence concerns were related to greater subjective sleep problems. Moderation effects illustrated two general patterns. For actigraphy-derived sleep variables, lower neighborhood safety was associated with poor sleep only among youth from lower-income families. For subjective sleep/wake problems and daytime sleepiness, associations between neighborhood risk and sleep difficulties were pronounced for higher SES youth, while lower SES youth had greater sleep problems regardless of neighborhood factors. ConclusionsFindings suggest that several dimensions of SES and neighborhood risk may be consequential for adolescents' sleep. Moderation effects highlight the significance of considering multiple contextual influences towards a better understanding of adolescents’ sleep.