From Scalp to Ear-EEG: A Generalizable Transfer Learning Model for Automatic Sleep Scoring in Older People.

OBJECTIVE: Sleep monitoring has extensively utilized electroencephalogram (EEG) data collected from the scalp, yielding very large data repositories and well-trained analysis models. Yet, this wealth of data is lacking for emerging, less intrusive modalities, such as ear-EEG. METHODS AND PROCEDURES: The current study seeks to harness the abundance of open-source scalp EEG datasets by applying models pre-trained on data, either directly or with minimal fine-tuning; this is achieved in the context of effective sleep analysis from ear-EEG data that was recorded using a single in-ear electrode, referenced to the ipsilateral mastoid, and developed in-house as described in our previous work. Unlike previous studies, our research uniquely focuses on an older cohort (17 subjects aged 65-83, mean age 71.8 years, some with health conditions), and employs LightGBM for transfer learning, diverging from previous deep learning approaches. RESULTS: Results show that the initial accuracy of the pre-trained model on ear-EEG was 70.1%, but fine-tuning the model with ear-EEG data improved its classification accuracy to 73.7%. The fine-tuned model exhibited a statistically significant improvement (p < 0.05, dependent t-test) for 10 out of the 13 participants, as reflected by an enhanced average Cohen's kappa score (a statistical measure of inter-rater agreement for categorical items) of 0.639, indicating a stronger agreement between automated and expert classifications of sleep stages. Comparative SHAP value analysis revealed a shift in feature importance for the N3 sleep stage, underscoring the effectiveness of the fine-tuning process. CONCLUSION: Our findings underscore the potential of fine-tuning pre-trained scalp EEG models on ear-EEG data to enhance classification accuracy, particularly within an older population and using feature-based methods for transfer learning. This approach presents a promising avenue for ear-EEG analysis in sleep studies, offering new insights into the applicability of transfer learning across different populations and computational techniques. CLINICAL IMPACT: An enhanced ear-EEG method could be pivotal in remote monitoring settings, allowing for continuous, non-invasive sleep quality assessment in elderly patients with conditions like dementia or sleep apnea.

Disentangling associations between pubertal development, healthy activity behaviors, and sex in adolescent social networks.

With the onset of puberty, youth begin to choose their social environments and develop health-promoting habits, making it a vital period to study social and biological factors contextually. An important question is how pubertal development and behaviors such as physical activity and sleep may be differentially linked with youths' friendships. Cross-sectional statistical network models that account for interpersonal dependence were used to estimate associations between three measures of pubertal development and youth friendships at two large US schools drawn from the National Longitudinal Study of Adolescent to Adult Health. Whole-network models suggest that friendships are more likely between youth with similar levels of pubertal development, physical activity, and sleep. Sex-stratified models suggest that girls' friendships are more likely given a similar age at menarche. Attention to similar pubertal timing within friendship groups may offer inclusive opportunities for tailored developmental puberty education in ways that reduce stigma and improve health behaviors.

The relationship between modifiable lifestyle behaviours and self-reported health in children and adolescents in the United Kingdom.

Obesity, along with its associated health issues, is closely tied to lifestyle habits. While certain elements affecting childhood health, such as genetics and ethnicity, are beyond individuals' control, there exists modifiable lifestyle behaviours that can facilitate healthier living. This study employed multiple regression analysis to investigate the relationship between specific modifiable lifestyle behaviours and self-reported health. The independent variables considered included days of moderate to vigorous physical activity (MVPA), fruit and vegetable consumption, breakfast frequency, school night sleep duration, and non-school night sleep duration. These variables were chosen for their practical modifiability within participants' daily lives. The analysis revealed a highly significant overall model (F(13,11363) = 191.117, p < .001), explaining 17.9% of the variance in self-reported health. Notably, higher MVPA levels were associated with improved self-reported health (B = 0.136 to 0.730, p < .001). Additionally, regular breakfast consumption and increased fruit and vegetable intake exhibited positive associations with self-reported health (B = 0.113 to 0.377, p < .001), while girls reported lower self-reported health (B = -0.079, p < .001). School night sleep duration was positively linked to self-reported health (B = 0.071, p < .001). Furthermore, a dose-response relationship between MVPA, dietary habits, and health was identified. These findings hold substantial potential for public health campaigns to promote healthy behaviours and prevent chronic diseases in young individuals. It is imperative to emphasise that all the variables considered in this study are readily modifiable aspects of individuals' lives, offering a promising avenue for personal health and well-being enhancement.

A pilot randomised control study to investigate the effect of the South African Adolescence Group Sleep Intervention (SAASI) on adolescent sleep and PTSD.

Background: Trauma exposure prevalence and consequent post-traumatic stress disorder among South African adolescents are significant. Sleep disturbances are among the most frequently reported difficulties faced by those dealing with PTSD. The current study examined the feasibility and preliminary efficacy of the South African Adolescence Group Sleep Intervention on PTSD symptom severity and sleep disturbance.Method: Sixty-one adolescents with PTSD diagnoses and sleep disturbance were randomly assigned (1:1) to one individual and four group sessions of a sleep intervention (SAASI) or a control group. Participants completed the Child PTSD symptom scale for DSM5 (CPSS-5) and the Pittsburgh Sleep Quality Index (PSQI) among other sleep and psychiatric measures. The trial was registered on the Pan African Trial Registry (PACTR202208559723690).Results: There was a significant but similar decrease in PSQI scores in both groups over time indicating no overall intervention effect (Wald test = -2.18, p = .029), mean slope = -0.2 (95% CI: -0.37 to -0.02) (p = .583). On the CPSS-5, interaction between groups was also not significant (p = .291). Despite this overall finding, the mean difference in CPSS-SR-5 scores increased over time, with the difference between groups post-treatment -9.10 (95%CI: -18.00 to -0.21), p = .045 and the 1-month follow-up contrast - 11.22 (95%CI: -22.43 to -0.03), p = .049 suggesting that PTSD symptom severity decreased more in the intervention group than the control group. The dropout rate was higher than expected for both the intervention (n = 10; 32%) and control (n = 8; 26.7%) groups. Dropout were mostly school commitments or travel related.Conclusions: Early findings suggest a trend towards dual improvement in sleep quality and PTSD symptom severity in adolescents with a sleep disturbance and PTSD receiving a group sleep intervention (SAASI). Further investigation in a properly powered RCT with detailed retention planning is indicated.

A four-week group sleep intervention seems feasible in adolescents with PTSD and sleep disturbances in a low-resource South African setting.Utilising less specialised mental health resources such as nurses and counsellors in intervention delivery was feasible and effective.Preliminary results are promising and support further research to establish the efficacy of the intervention.

Sleeping and waking-state oral behaviors in TMD patients: their correlates with jaw functional limitation and psychological distress.

OBJECTIVES: This study investigated oral behaviors in various temporomandibular disorder (TMD) subtypes, assessing their frequency, extent, and associations with both jaw functional status and psychological distress. MATERIALS AND METHODS: Anonymized data from consecutive "initial-visit" TMD patients at a university-affiliated oral medicine clinic were obtained. Alongside demographic information, patients completed various questionnaires including the Diagnostic Criteria for TMD (DC/TMD) Symptom Questionnaire, Oral Behavior Checklist (OBC), Jaw Functional Limitation Scale-20 (JFLS-20), Patient Health Questionnaire-9 (PHQ-9), and General Anxiety Disorder Scale-7 (GAD-7). Patients underwent a protocolized clinical examination and received diagnoses of pain-related (PT), intra-articular (IT), or combined (CT) TMD using the DC/TMD diagnostic algorithms. Data were evaluated with Chi-square/non-parametric tests and logistic regression analyses (α = 0.05). RESULTS: The study comprised 700 patients (mean age 37.4 ± 15.7 years), with 12.6%, 15.1%, and 72.3% diagnosed with PT, IT, and CT, respectively. For all TMD subtypes, oral activities during sleep were more prevalent than those during wakefulness. While variations in total/subscale OBC scores were insignificant, substantial differences were observed in global/subscale JFLS (PT, CT > IT), depression (PT, CT > IT), and anxiety (CT > IT) scores. Near-moderate correlations (rs = 0,36-0.39) were discerned between overall/waking-state non-functional oral behaviors and depression/anxiety. Multivariate analysis indicated that the odds of different TMD subtypes were influenced by sex, age, and jaw functional status. CONCLUSIONS: For all TMD patients, sleep-related oral activities were more commonly reported than waking-state activities. Factors such as sex, age, and jaw functional limitation are associated with the likelihood of different TMD subtypes. STATEMENT OF CLINICAL RELEVANCE: Oral behaviors, in themselves, do not predict distinct TMD subtypes, in contrast to factors such as sex, age, and jaw functional status.

The existing state of knowledge about sleep health in community-dwelling older persons - a scoping review.

OBJECTIVES: It is widely known that sleep disorders are a common problem among older persons. Few reviews have described current knowledge about the holistic concept of sleep health of community-dwelling older people. AIM: This study aimed to describe the current state of knowledge and identify research gaps concerning sleep health among community-dwelling older persons. METHOD: We conducted a scoping review. Searches were conducted in three databases (Medline, CINAHL, and PsycINFO) to identify scientific articles including outcomes with all five sleep health dimensions (sleep duration, sleep continuity, timing, wakefulness/daytime sleepiness, and sleep quality) among community-dwelling older persons aged ≥65 years. Eight articles were included from a total of 1826 hits, with sample sizes between 1413 and 6485. RESULTS: The sleep health outcomes of community-dwelling older adults differed between the sexes. Older persons with at least two or more poor sleep health dimensions might have increased risk for depression, higher healthcare costs and mortality, while self-reported better sleep health might be associated with lower odds of frailty. CONCLUSION: Future research is needed to confirm the findings by investigating the multidimensional concept of sleep health in a general older population. The identified knowledge gaps are how persons ≥80 years' experience their sleep health, and how sleep medicine is prescribed to treat sleep problems in persons ≥80 years in different care contexts.

Stress in autism (STREAM): A study protocol on the role of circadian activity, sleep quality and sensory reactivity.

Mental health issues are markedly increased in individuals with autism, making it the number one research priority by stakeholders. There is a crucial need to use personalized approaches to understand the underpinnings of mental illness in autism and consequently, to address individual needs. Based on the risk factors identified in typical mental research, we propose the following themes central to mental health issues in autism: sleep difficulties and stress. Indeed, the prevalence of manifold circadian disruptions and sleep difficulties in autism, alongside stress related to sensory overload, forms an integral part of autistic symptomatology. This proof-of-concept study protocol outlines an innovative, individualised approach towards investigating the interrelationships between stress indices, sleep and circadian activation patterns, and sensory sensitivity in autism. Embracing an individualized methodology, we aim to collect 14 days of data per participant from 20 individuals with autism diagnoses and 20 without. Participants' sleep will be monitored using wearable EEG headbands and a sleep diary. Diurnal tracking of heart rate and electrodermal activity through wearables will serve as proxies of stress. Those objective data will be synchronized with subjective experience traces collected throughout the day using the Temporal Experience Tracing (TET) method. TET facilitates the quantification of relevant aspects of individual experience states, such as stress or sensory sensitivities, by providing a continuous multidimensional description of subjective experiences. Capturing the dynamics of subjective experiences phase-locked to neural and physiological proxies both between and within individuals, this approach has the potential to contribute to our understanding of critical issues in autism, including sleep problems, sensory reactivity and stress. The planned strives to provide a pathway towards developing a more nuanced and individualized approach to addressing mental health in autism.

Sleep Delta power, age, and sex effects in treatment-resistant depression.

Electroencephalographic (EEG) deficits in slow wave activity or Delta power (0.5-4 Hz) indicate disturbed sleep homeostasis and are hallmarks of depression. Sleep homeostasis is linked to restorative sleep and potential antidepressant response via non-rapid eye movement (NREM) slow wave sleep (SWS) during which neurons undergo essential repair and rejuvenation. Decreased Low Delta power (0.5-2 Hz) was previously reported in individuals with depression. This study investigated power levels in the Low Delta (0.5-<2 Hz), High Delta (2-4 Hz), and Total Delta (0.5-4 Hz) bands and their association with age, sex, and disrupted sleep in treatment-resistant depression (TRD). Mann-Whitney U tests were used to compare the nightly progressions of Total Delta, Low Delta, and High Delta in 100 individuals with TRD and 24 healthy volunteers (HVs). Polysomnographic parameters were also examined, including Total Sleep Time (TST), Sleep Efficiency (SE), and Wake after Sleep Onset (WASO). Individuals with TRD had lower Delta power during the first NREM episode (NREM1) than HVs. The deficiency was observed in the Low Delta band versus High Delta. Females with TRD had higher Delta power than males during the first NREM1 episode, with the most noticeable sex difference observed in Low Delta. In individuals with TRD, Low Delta power correlated with WASO and SE, and High Delta correlated with WASO. Low Delta power deficits in NREM1 were observed in older males with TRD, but not females. These results provide compelling evidence for a link between age, sex, Low Delta power, sleep homeostasis, and non-restorative sleep in TRD.

Consciousness and sleep.

Sleep is a universal, essential biological process. It is also an invaluable window on consciousness. It tells us that consciousness can be lost but also that it can be regained, in all its richness, when we are disconnected from the environment and unable to reflect. By considering the neurophysiological differences between dreaming and dreamless sleep, we can learn about the substrate of consciousness and understand why it vanishes. We also learn that the ongoing state of the substrate of consciousness determines the way each experience feels regardless of how it is triggered-endogenously or exogenously. Dreaming consciousness is also a window on sleep and its functions. Dreams tell us that the sleeping brain is remarkably lively, recombining intrinsic activation patterns from a vast repertoire, freed from the requirements of ongoing behavior and cognitive control.

Association between nocturnal sleep duration and midday napping and the incidence of sarcopenia in middle-aged and older adults: a 4-year longitudinal study.

BACKGROUND: Identifying treatment targets for sarcopenia is a public health concern. This study aimed to examine the association of nocturnal sleep duration and midday napping with the presence of sarcopenia in middle-aged and older adults, utilizing data from the China Health and Retirement Longitudinal Study in 2011 and 2015. METHODS: A sum of 7,926 individuals (≥40 years) took part in this study. Sarcopenia was diagnosed according to the Asian Working Group for Sarcopenia. A self-reported questionnaire was used to collect data on nocturnal sleep duration and midday napping. Nocturnal sleep duration was categorized into three groups: short sleepers (<6 h), normal sleepers (6-8 h), and long sleepers (>8 h). Midday napping was coded as a dichotomous outcome (yes/no). RESULTS: The incidence of sarcopenia was 5.3% during the 4-year follow-up. Short sleep duration (<6 h) was substantially linked to an increased incidence of sarcopenia (OR: 1.50, 95% CI: 1.21-1.87) as compared to nocturnal sleep length (6-8 h). Adults with midday napping had a lower risk of developing sarcopenia than non-nappers (OR: 0.78, 95% CI: 0.63-0.95). We further found that short sleepers with midday napping did not have a significantly higher risk of subsequent diagnosis of sarcopenia compared to normal sleepers without midday napping. CONCLUSION: These findings imply that short sleep duration in middle-aged and older persons is related to an increased incidence of sarcopenia. However, the adverse effect of short sleep duration on sarcopenia can be compensated by midday napping.

"The worst thing is lying in bed thinking 'I want a cigarette'" a qualitative exploration of smoker's and ex-smoker's perceptions of sleep during a quit attempt and the use of cognitive behavioural therapy for insomnia to aid cessation.

Smokers report poorer sleep quality than non-smokers and sleep quality deteriorates further during cessation, increasing risk of smoking relapse. Despite the use of cognitive behavioural therapy for insomnia (CBT-I) to aid quit attempts emerging in the area, little is known about smokers and ex smoker's experiences of sleep during a quit attempt or their perceptions of CBT-I. This study addresses this gap by exploring smoker's and ex-smoker's experiences of the link between smoking and sleep and how this may change as a function of smoking/smoking abstinence. It also explores views of traditional CBT-I components (i.e., perceived feasibility, effectiveness, barriers of use). We conducted semi-structured interviews with current and recently quit smokers (n = 17) between January and September 2022. The framework method was used for analysis. Four themes addressing research questions were described. These included: 1) A viscous cycle; poor sleep quality and negative psychological state during cessation; 2) Perceived engagement and effectiveness; the importance of feasibility, experience, value, identity and psychological state in assessing CBT-I as a cessation tool; 3) Striking a balance; tailoring CBT-I to reduce psychological overload in a time of lifestyle transition; and 4) Personalisation and digital delivery helping overcome psychological barriers during cessation. The analysis suggested during quit attempts smokers experienced a range of sleep problems that could increase risk of relapse due to a negative impact on psychological state. It also revealed participants thought that CBT-I is something they would use during a quit attempt but suggested changes and additions that would improve engagement and be better tailored to quitting smokers. Key additions included the integration of smoking-based cognitive restructuring, starting the intervention prior to a quit attempt, and the need for personalisation and tailoring.

The 24-h movement behaviours composition is associated with parasympathetic modulation in preschoolers.

AIM: To investigate the associations between 24-h movement behaviours and heart rate variability (HRV) in preschool children. METHODS: A total of 123 preschoolers (4.52 ± 0.25 years old; 62 girls) were assessed for physical activity (PA) and sedentary behaviour (SB) using an accelerometer (Actigraph WGT3x). Sleep duration (SD) was parent-reported. Children were laid down in a supine position for 10 min to assess HRV data. The R-R intervals recorded during the last 5 min of this period were analysed. We conducted compositional analysis in R studio, and the significance level was 95%. All ethical procedures were followed, and the study had the approval of the local ethical board. RESULTS: When considered as a composition, adjusted for age, body mass index and sex, the 24-h movement composition (PA, SB and SD) significantly predicted better parasympathetic modulation (Root mean square of the successive differences [RMSSD] [p = 0.04; r2 = 0.13]), but not high frequency (HF) (nu) (p = 0.51, r2 = 0.01), low frequency (nu) (p = 0.52, r2 = 0.02),or standard deviation (standard deviation of normal-to-normal intervals) (p = 0.55, r2 = 0.02), respectively. CONCLUSION: These results suggest the 24-h movement composition predicted the RMSSD time-domain index related to parasympathetic activity.

Stressors in Atopic Dermatitis.

As with other inflammatory skin disorders, atopic dermatitis has a tendency to cause stress and also be exacerbated by it. Patients with atopic dermatitis have several disease-associated stressors, some of which include physical discomfort due to itching and altered appearance due to flare-ups. These stressors have been shown to effect patients psychosocially by altering sleep patterns, decreasing self-esteem, and interfering with interpersonal relationships. In combination with its direct effect on patients, atopic dermatitis also causes stress for parents and caregivers. Studies suggest that atopic dermatitis is strongly correlated with co-sleeping habits, which can negatively impact the health and mood of parents or caregivers. It has also been reported to interfere with the formation of a strong mother-child relationship. In order to optimize treatment for patients with atopic dermatitis, it is important to note the impact that it has on quality of life. By implementing patient counseling, sleep-targeted therapies, and the use of quality of life (QoL) indices, atopic dermatitis patients and caregivers have the potential to experience greater satisfaction with treatment.

Association of genetically determined chronotype with circulating testosterone: a Mendelian randomization study.

Low testosterone levels in men have been linked to decreased physical and mental function, as well as a reduced quality of life. Previous prospective observational studies have suggested an association between testosterone and sleep traits, but the causality of this relationship remains unclear. We aimed to explore the potential causal link between genetically determined sleep traits and testosterone levels in men using Mendelian randomization (MR) analysis from the UK Biobank dataset. Our exposures were genetic variants associated with sleep traits (chronotype and sleep duration), whereas our outcomes were traits of sex steroid hormones (total testosterone, TT; bioavailable testosterone, BAT; and sex hormone-binding globulin, SHBG). We employed inverse variance weighted (IVW) and weighted median (WM) methods to assess the causal associations. The IVW method offers a robust estimate of causality, whereas the WM method provides reliable results even when some genetic variants are invalid instruments. Our main analysis involving sex steroid hormones and chronotype identified 155 chronotype-related variants. The primary findings from the analysis, which used chronotype as the exposure and sex steroid hormones as the outcomes, showed that a genetically predicted chronotype score was significantly associated with an increased levels of TT (association coefficient ß, 0.08; 95% confidence interval [CI], 0.02-0.14; P = 0.008) and BAT (ß, 0.08; 95% CI, 0.02-0.14; P = 0.007), whereas there was no significant association with SHBG (ß, 0.01; 95% CI, -0.02-0.03; P = 0.64). Meanwhile, MR analysis of sex steroid hormones and sleep duration was performed, and 69 variants associated with sleep duration were extracted. There were no significant association between sleep duration and sex steroid hormones (TT, P = 0.91; BAT, P = 0.82; and SHBG, P = 0.95). Our data support a causal association between chronotype and circulating testosterone levels in men. These findings underscore a potential causal relationship between chronotype and testosterone levels in men, suggesting that lifestyle adjustments are crucial for men's health. Recognizing factors that influence testosterone is essential. One limitation of this study is the use of one-sample MR, which can introduce potential bias due to non-independence of genetic associations for exposure and outcome. In conclusion, our findings indicate that a morning preference is correlated with circulating testosterone levels, emphasizing the potential impact of lifestyle habits on testosterone levels in men.

Sleeping more than 8 h: a silent factor contributing to decreased muscle mass in Chinese community-dwelling older adults.

BACKGROUND: Muscle mass loss is an age-related process that can be exacerbated by lifestyle, environmental and other factors, but can be mitigated by good sleep. The objective of this study was to investigate the correlation between varying time lags of sleep duration and the decline in muscle mass among individuals aged 60 years or older by using real-world health monitoring data obtained from wearable devices and smart home health monitoring devices. METHODS: This study included 86,037 observations from 2,869 participants in the Mobile Support System database. Missing data were supplemented by multiple imputation. The investigation utilized generalized estimating equations and restricted cubic spline curve to examine the relationship between sleep duration and low muscle mass. Various lag structures, including 0, 1, 2, 0-1, 0-2, and 1-2 months, were fitted, and the interaction effect of observation time with sleep duration was estimated for each lag structure. Additionally, subgroup analyses were conducted. The models were adjusted for various covariates, including gender, age, body mass index, footsteps, smoking status, drinking status, marital status, number of chronic diseases, number of medications, diabetes mellitus, hyperlipidemia, coronary artery disease, respiratory disease, and musculoskeletal disease and an interaction term between time and sleep duration. RESULTS: The results of the generalized estimating equation showed a significant correlation (p < 0.001) between sleep duration of 8 h or more and low muscle mass in older adults, using 6-7 h of sleep as a reference. This effect was seen over time and prolonged sleep accumulated over multiple months had a greater effect on muscle mass loss than a single month. The effect of long sleep duration on muscle mass loss was significantly greater in females than in males and greater in the over-75 than in the under-75 age group. Restricted cubic spline plots showed a non-linear relationship between sleep duration and low muscle mass (p < 0.001). CONCLUSIONS: This study found an association between sustained nighttime sleep of more than eight hours and decreased muscle mass in older adults, especially older women.

Relationships among Sleep Time, Physical Activity Time, Screen Time, and Nutrition Literacy of Adolescents: A Cross-Sectional Study in Chongqing, China.

Background: Unhealthy lifestyles among adolescents are reaching alarming levels and have become a major public health problem. This study aimed to assess the relationship between sleep time, physical activity (PA) time, screen time (ST), and nutritional literacy (NL). Methods: This cross-sectional online study involving adolescents aged 10-18 years was conducted in September 2020 in 239 schools in Chongqing, China. NL was measured using the "Nutrition Literacy Scale for middle school students in Chongqing (CM-NLS)". According to the recommended by the Chinese dietary guidelines (2022), we divided the sleep time of junior high school students into <9 h and ≥9 h, high school students into <8 h and ≥8 h, divided the workdays into weekend PA time < 1 h and ≥1 h, and divided the workdays into weekend ST < 2 h and ≥2 h. The multinomial logistic regression model was used to examine the association. Results: A total of 18,660 adolescents (50.2% males) were included. The proportion of participants that were junior high school students and attended boarding schools was 57.2% and 65.3%, respectively. Compared with senior high school students, junior high school students had a higher level of NL. Whether on workdays or weekends, participants with sleep time ≥ 8/9 h, PA time ≥ 1 h, and ST < 2 h per day had higher levels of NL. On weekdays, participants who met the sleep time ≥ 8 h/9 h (OR = 1.48, 95% CI: 1.36, 1.62) and PA time ≥ 1 h (OR = 1.69, 95% CI: 1.59, 1.81) had higher reporting of NL levels. Conclusions: Sleep time, PA time, and ST were positively correlated with NL among adolescents, especially junior high school students.

Classification of Sleep Quality and Aging as a Function of Brain Complexity: A Multiband Non-Linear EEG Analysis.

Understanding and classifying brain states as a function of sleep quality and age has important implications for developing lifestyle-based interventions involving sleep hygiene. Current studies use an algorithm that captures non-linear features of brain complexity to differentiate awake electroencephalography (EEG) states, as a function of age and sleep quality. Fifty-eight participants were assessed using the Pittsburgh Sleep Quality Inventory (PSQI) and awake resting state EEG. Groups were formed based on age and sleep quality (younger adults n = 24, mean age = 24.7 years, SD = 3.43, good sleepers n = 11; older adults n = 34, mean age = 72.87; SD = 4.18, good sleepers n = 9). Ten non-linear features were extracted from multiband EEG analysis to feed several classifiers followed by a leave-one-out cross-validation. Brain state complexity accurately predicted (i) age in good sleepers, with 75% mean accuracy (across all channels) for lower frequencies (alpha, theta, and delta) and 95% accuracy at specific channels (temporal, parietal); and (ii) sleep quality in older groups with moderate accuracy (70 and 72%) across sub-bands with some regions showing greater differences. It also differentiated younger good sleepers from older poor sleepers with 85% mean accuracy across all sub-bands, and 92% at specific channels. Lower accuracy levels (<50%) were achieved in predicting sleep quality in younger adults. The algorithm discriminated older vs. younger groups excellently and could be used to explore intragroup differences in older adults to predict sleep intervention efficiency depending on their brain complexity.

The association between sleep duration and cardiometabolic risk among children and adolescents in the United States (US): A NHANES study.

PURPOSE: This work aims to assess the association of sleep duration with cardiometabolic risk (adiposity, blood pressure, lipids, albuminuria and A1C) and to investigate lifestyle factors (physical activity, light exposure, caffeine consumption and sugar consumption) associated with sleep duration in children. METHODS: A nationally representative sample of 3907 children ages 6-17 years enrolled in NHANES from 2011 to 2014 was included in this cross-sectional study. Sleep duration was defined as the daily average time spent sleeping over 7 days as measured by a physical activity monitor (PAM). Participants without valid sleep data for ≥95% of the study were excluded. Regression models were adjusted for age, sex, race, body mass index (BMI) Z score, physical activity and light exposure. RESULTS: In adjusted regression models, longer sleep duration was associated with lower systolic blood pressure index (ß = -3.63 * 10-5, 95% CI -6.99 * 10-5, -2.78 * 10-6, p = 0.035) and BMI Z score (ß = -0.001, 95% CI -0.001, 0.000, p = 0.002). In logistic regression models, longer sleep duration was associated with lower odds of obesity (OR = 0.998, 95% CI 0.997, 0.999, p < 0.001) and overweight status (OR = 0.998, 95% CI 0.997, 0.999, p = 0.004). Greater light exposure (ß = 6.64 * 10-5, 95% CI 3.50 * 10-5, 9.69 * 10-5, p < 0.001) and physical activity (ß = 0.005, 95% CI 0.004, 0.006, p < 0.001) were associated with longer sleep. CONCLUSION: Longer sleep duration was associated with lower blood pressure and adiposity measures in children. Improving sleep quality by increasing physical activity and light exposure in childhood may decrease the lifetime risk of cardiometabolic disease.