The complexities of defining optimal sleep: empirical and theoretical considerations with a special emphasis on children

European expert guidance on management of sleep onset insomnia and melatonin use in typically developing children

Sleeping problems are prevalent among children and adolescents, often leading to frequent consultations with pediatricians. While cognitive-behavioral therapy has shown effectiveness, especially in the short term, there is a lack of globally endorsed guidelines for the use of pharmaceuticals or over-the-counter remedies in managing sleep onset insomnia. An expert panel of pediatric sleep specialists and chronobiologists met in October 2023 to develop practical recommendations for pediatricians on the management of sleep onset insomnia in typically developing children. When sleep onset insomnia is present in otherwise healthy children, the management should follow a stepwise approach. Practical sleep hygiene indications and adaptive bedtime routine, followed by behavioral therapies, must be the first step. When these measures are not effective, low-dose melatonin, administered 30-60 min before bedtime, might be helpful in children over 2 years old. Melatonin use should be monitored by pediatricians to evaluate the efficacy as well as the presence of adverse effects.    Conclusion: Low-dose melatonin is a useful strategy for managing sleep onset insomnia in healthy children who have not improved or have responded insufficiently to sleep hygiene and behavioral interventions.

Predictors for achieving optimal sleep in healthy children: Exploring sleep patterns in a sleep extension trial

STUDY OBJECTIVES

Earlier bedtimes can help some children get more sleep, but we don't know which children, or what features of their usual sleep patterns could predict success with this approach. Using data from a randomized crossover trial of sleep manipulation, we sought to determine this.

METHODS

Participants were 99 children aged 8-12years (49.5% female) with no sleep disturbances. Sleep was measured by actigraphy at baseline and over a restriction or extension week (1 hour later or earlier bedtime respectively), randomly allocated and separated by a washout week. Data were compared between baseline (week 1) and extension weeks only (week 3 or 5), using linear or logistic regression analyses as appropriate, controlling for randomization order.

RESULTS

One hour less total sleep time than average at baseline predicted 29.7 minutes (95% CI: 19.4, 40.1) of sleep gained and 3.45 (95% CI: 1.74, 6.81) times higher odds of successfully extending sleep by >30 minutes. Per standardized variable, less total sleep time and a shorter sleep period time were the strongest predictors (significant odds ratios (ORs) of 2.51 and 2.28, respectively). Later sleep offset, more variability in sleep timing and lower sleep efficiency also predicted sleep gains. The sleep period time cut-point that optimized prediction of successful sleep gains was <8 hours 28 minutes with 75% of children's baseline sleep in that range.

CONCLUSIONS

Children with a baseline sleep period time <8½ hours a night obtained the most sleep from earlier bedtimes maintained over a week, demonstrating experimentally the value of earlier bedtimes to improve sleep.

CLINICAL TRIALS REGISTRY

Australian New Zealand Clinical Trial Registry, ACTRN12618001671257, https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=367587&isReview=true.

Childhood sleep: assessments, risk factors, and potential mechanisms

BACKGROUND

Sleep problem is a highly prevalent health issue among pediatric populations across the world. In this review, we aimed to identify risk factors contributing to sleep deficiency and poor sleep hygiene in children. Potential biological, psychosocial, and environmental mechanisms as well as research gaps in the literature are also discussed.

DATA SOURCES

A comprehensive search for relevant English language full-text, peer-reviewed publications was performed focusing on pediatric sleep studies from prenatal to childhood and adolescence in a variety of indexes in PubMed, SCOPUS, and Psych Info. Both relevant data based and systematic reviews are included.

RESULTS

This paper summarizes many risk factors for childhood sleep problems, including biological (e.g., genetics, gender, age and puberty, prenatal factors, postnatal factors); nutritional (e.g., macronutrients, micronutrients, omega-3 fatty acids, obesity); environmental (e.g., heavy metals, noise, light, air pollution); interpersonal (e.g., family, exposure to violence, screen media use, physical injury); and community/socioeconomic variables (e.g., racial/ethnicity and cultural factors, neighborhood conditions and socioeconomic status, school factors, public health disasters/emergencies), to better understand the development of sleep problems in children.

CONCLUSIONS

Poor childhood sleep is a multifactorial issue affected by a wide range of prenatal and early-life biological, environmental, and psychosocial risk factors and contributors. A better understanding of these risk factors and their mechanisms is an important first step to develop future research and prevention programs focusing on pediatric sleep problems.

Sleep tight! Adolescent sleep quality across three distinct sleep ecologies

Background and objectives

Good sleep quality, associated with few arousals, no daytime sleepiness and self-satisfaction with one's sleep, is pivotal for adolescent growth, maturation, cognition and overall health. This article aims to identify what ecological factors impact adolescent sleep quality across three distinct sleep ecologies representing a gradient of dense urbanity to small, rural environments with scarce artificial lighting and no Internet.

Methodology

We analyze variation of sleep efficiency, a quantitative measure of sleep quality-defined as the ratio of total time spent asleep to total time dedicated to sleep-in two agricultural indigenous populations and one post-industrial group in Mexico (Campeche = 44, Puebla = 51, Mexico City = 50, respectively). Data collection included actigraphy, sleep diaries, questionnaires, interviews and ethnographic observations. We fit linear models to examine sleep efficiency variation within and between groups.

Results

We found that sleep efficiency varied significantly across sites, being highest in Mexico City (88%) and lowest in Campeche (75%). We found that variation in sleep efficiency was significantly associated with nightly exposure to light and social sleep practices.

Conclusions and implications

Our findings point toward contextual cost-benefits of sleep disruption in adolescence. We highlight the need to prioritize research on adolescent sleep quality across distinct developmental ecologies and its impact on health to improve adolescent wellbeing through evidence-based health practices.

Bedtime procrastination mediates the relation between anxiety and sleep problems

The prevalence of sleep problems is high in primary care patients and in anxious individuals. This study assessed whether total sleep time and bedtime procrastination mediated the association between anxiety and sleep problems. We predicted higher anxiety would be negatively associated with total sleep time and positively associated with bedtime procrastination and sleep problems, and these variables would statistically mediate the association between anxiety and sleep problems. Participants were 308 adult primary care patients, predominantly female (non-Hispanic White = 158, Latinx = 111, mean age = 33.30), who initiated behavioral health services at an integrated primary care clinic. Patients completed a questionnaire regarding psychological health and sleep behaviors. Using structural equation modeling, we found higher anxiety related to higher sleep problems, partially mediated by bedtime procrastination but not total sleep time. This study highlights related factors like anxiety and prebedtime behaviors that may be effective treatment targets for sleep challenges.

Sleep deprivation among adolescents in urban and indigenous-rural Mexican communities

Comparing the nature of adolescent sleep across urban and more isolated, rural settings through an ecological, cross-cultural perspective represents one way to inform sleep nuances and broaden our understanding of human development, wellbeing and evolution. Here we tested the Social Jetlag Hypothesis, according to which contemporary, urban lifestyles and technological advances are associated with sleep insufficiency in adolescents. We documented the adolescent sleep duration (11-16 years old; X̅ = 13.7 ± 1.21; n = 145) in two small agricultural, indigenous and one densely urban context in Mexico to investigate whether adolescents in socio-ecologically distinct locations experience sleep deprivation. Sleep data was assembled with actigraphy, sleep diaries and standardized questionnaires. We employed multilevel models to analyze how distinct biological and socio-cultural factors (i.e., pubertal maturation, chronotype, napping, gender, working/schooling, access to screen-based devices, exposure to light, and social sleep practices) shape adolescent sleep duration. Results suggest that the prevalence of adolescent short sleep quotas is similar in rural, more traditional environments compared to highly urbanized societies, and highlight the influence of social activities on the expression of human sleep. This study challenges current assumptions about natural sleep and how adolescents slept before contemporary technological changes occurred.

Insufficient Sleep Syndrome: A Blind Spot in Our Vision of Healthy Sleep

Chronic sleep deficiency (CSD) poses a threat to physical health, mental well-being, and social functioning. The concept of behaviorally induced CSD has not changed much since it was first introduced four decades ago. Behaviorally induced CSD is currently referred to as insufficient sleep syndrome (ISS). In the latest edition of the International Classification of Sleep Disorders (ICSD-3, 2014), ISS is considered a disorder of central hypersomnolence with diagnostic codes ICD-9-CM 307.44 and ICD-10-CM F51.12. In this review, we will describe the biological importance of sleep, the ramifications of CSD on the individual and society, the nosological status and diagnostic features of ISS, and the apparent lack of attention to ISS in contemporary medical practice and public health programs. The last three decades have seen a global rise in voluntary sleep curtailment such that ISS may already be the leading cause of CSD, not only in adults but also in school-aged children and adolescents. Acknowledging ISS as a public health priority is a necessary first step in our response to the global threat of CSD and CSD-related health consequences. It is only by confronting ISS directly that we can hope to develop and implement effective educational and advocacy programs, along with more responsible public health policies and regulations.

Sleep and brain evolution across the human lifespan: A mutual embrace

Sleep can be considered a window to ascertain brain wellness: it dynamically changes with brain maturation and can even indicate the occurrence of concealed pathological processes. Starting from prenatal life, brain and sleep undergo an impressive developmental journey that accompanies human life throughout all its steps. A complex mutual influence rules this fascinating course and cannot be ignored while analysing its evolution. Basic knowledge on the significance and evolution of brain and sleep ontogenesis can improve the clinical understanding of patient's wellbeing in a more holistic perspective. In this review we summarized the main notions on the intermingled relationship between sleep and brain evolutionary processes across human lifespan, with a focus on sleep microstructure dynamics.

Chronotype, sleep quality and academic performances among Mizo students

Sleep is an essential component of the daily cycle. Age and puberty-related declines in sleep duration, delays in chronotype, and an increase in social jet lag have been consistently reported. This study examined chronotype and gender-based differences in adolescents' sleep quality, depression level, and academic achievements. Eight hundred fifteen school students (372 male and 443 female) aged 14 to 20 years voluntarily participated in this study. Horne and Östberg Morningness-Eveningness Questionnaire (MEQ) was used to measure their chronotype. Sleep duration, sleep quality, and daytime sleepiness were assessed by the Pediatric Daytime Sleepiness Scale (PDSS) and Epworth Sleepiness Scale (ESS). Pittsburgh's Sleep Quality Index (PSQI) was used to evaluate sleep habits. Cleveland Adolescent Sleepiness Questionnaire (CASQ) was used to measure the sleep pattern of the students. Zung Self-Rating Depression Scale (SDS) was used to assess the level of depression for the students. Our results show neither type of students dominated the population studied but interestingly, in comparison to evening type, morning type individuals were higher among the population. Chronotype-based sleep quality and academic performances were observed, and higher depression levels, poor sleep quality, poor academic performances were observed in evening type compared to neither type and morning type. In contrast to males, females had a poor sleep pattern (CASQ) and a higher depression level (SDS). Altogether, our study shows the effect of chronotype and gender on sleep quality and depression levels among school students.

Heartbeat-Evoked Cortical Potential during Sleep and Interoceptive Sensitivity: A Matter of Hypnotizability

Individuals with different hypnotizability display different interoceptive sensitivity/awareness (IS) and accuracy (IA), likely sustained by morphofunctional differences in interoception-related brain regions and, thus, possibly also observable during sleep. We investigated the heartbeat-evoked cortical potential amplitude (HEP) during sleep, its association with IS, and the role of hypnotizability in such association. We performed a retrospective analysis of polysomnographic recordings of 39 healthy volunteers. Participants completed the Multidimensional Assessment of Interoceptive Awareness (MAIA), measuring IS and IA, and underwent hypnotic assessment via the Stanford Hypnotic Susceptibility Scale, form A. The amplitude of the early and late HEP components was computed at EEG frontal and central sites. In both regions, the early HEP component was larger in N3 than in N2 and REM, with no difference between N2 and REM. Greater HEP amplitude at frontal than at central sites was found for the late HEP component. HEP amplitudes were not influenced by the autonomic state assessed by heart rate variability in the frequency and time domains. We report for the first time a positive correlation between the central late HEP component and MAIA dimensions, which became non-significant after removing the effects of hypnotizability. Our findings indicate that hypnotizability sustains the correlation between IS and HEP amplitude during sleep.

Parenting Practices, Bedtime Routines, and Consistency: Associations with Pediatric Sleep Problems

OBJECTIVES

Investigate the direct and moderating effects of daytime parenting practices on the relationship between bedtime routines and pediatric sleep problems.

METHODS

A community sample of 407 parents with children 2-10 years old completed measures of parenting practices (i.e., laxness and over-reactivity) and bedtime routines (i.e., consistency and reactivity to changes in routines). Sleep problems (i.e., severity and signaled night waking) were assessed by a parent-report questionnaire and sleep diaries.

RESULTS

Higher parenting laxness (β = .13) and less bedtime routine consistency (β = -.34) significantly predicted sleep problem severity. Laxness moderated the relationship between bedtime reactivity and sleep problem severity: when bedtime reactivity was high, higher parental laxness was associated with more severe sleep problems.

CONCLUSIONS

Daytime parenting practices are important to consider when children are reactive to changes in bedtime routines, as permissive or inconsistent daytime parenting practices were found to be associated with more severe sleep problems. Future research should examine the effects of parenting practices and bedtime routines on problematic signaled night waking in a clinical sample of children.

Association between sleep habits/disorders and emotional/behavioral problems among Japanese children

Actual sleep status and the association between sleep habits/disorders and emotional/behavioral problems among children in the development stage have not been fully clarified. A questionnaire survey was conducted on the sleep habits/disorders (Brief Child Sleep Questionnaire; BCSQ) and emotional/behavioral problems (Strengths and Difficulties Questionnaire; SDQ) of 87,548 children enrolled in ordinary classes in nine grade levels from the first grade of elementary school to the third grade of junior high school from December 2009 to April 2010. As school grade increased, children's bedtimes were delayed and sleep duration was reduced by 2.0 h over the nine grade levels. Based on the BCSQ, 18.3% of children were judged to have some type of sleep disorder, and about 30% to 40% of children had sleep symptoms at bedtime, during sleep, and at wake time. Multiple regression analysis showed that emotional and behavioral problems were associated with presence of any sleep symptom, longer sleep latency, and longer awake time after sleep onset, whereas total sleep time was not. Sleep symptoms at wake time were most strongly associated with emotional and behavioral problems. Status of sleep habits/disorders should be considered when interpreting emotional/behavioral problems in school-age children.

Trajectories of sleep problems in childhood: associations with mental health in adolescence

STUDY OBJECTIVES

We examined initial levels (intercepts) of sleep-wake problems in childhood and changes in sleep-wake problems across late childhood (slopes) as predictors of externalizing behavior problems, depressive symptoms, and anxiety in adolescence. To ascertain the unique effects of childhood sleep problems on adolescent mental health, we controlled for both childhood mental health and adolescent sleep problems.

METHODS

Participants were 199 youth (52% boys; 65% White/European American, 35% Black/African American). Sleep-wake problems (e.g. difficulty sleeping and waking up in the morning) were assessed during three time points in late childhood (ages 9, 10, and 11) with self-reports on the well-established School Sleep Habits Survey. At age 18, multiple domains of mental health (externalizing behavior problems, depressive symptoms, and anxiety) and sleep-wake problems were assessed.

RESULTS

Latent growth curve modeling revealed that children with higher levels of sleep-wake problems at age 9 had consistently higher levels of such problems between ages 9 and 11. The initial level of sleep-wake problems at age 9 predicted externalizing behaviors, depressive symptoms, and anxiety at age 18, controlling for mental health in childhood and concurrent sleep-wake problems in adolescence. The slope of sleep-wake problems from ages 9 to 11 did not predict age 18 mental health.

CONCLUSIONS

Youth who had higher sleep-wake problems during late childhood had higher levels of mental health problems in adolescence even after controlling for childhood mental health and concurrent sleep-wake problems. Findings illustrate that childhood sleep problems may persist and predict adolescent mental health even when potentially confounding variables are rigorously controlled.

The Associations Between Media Use, Midpoint of Sleep, and Sleep Quality in German Preschoolers: A Mediation Analysis Based on the Ulm SPATZ Health Study

INTRODUCTION

The relation of electronic media use with sleep quality among preschoolers is a matter of ongoing debate. Longitudinal data are scarce and do not account for sleeping schedules.

METHODS

We used the German Children's Sleep Habits Questionnaire to measure parent-reported child's sleep quality; its score is computed by the sum of 34 items defined by a 1-3 level Likert scale (score ranging 34-102), with higher values representing lower sleep quality. A causal mediation analysis of these relations using data from the Ulm SPATZ Health Study in Germany was conducted. Repeated data on electronic media use, book reading, sleep quality, sleep duration, and midpoint of sleep were prospectively collected yearly from ages 4 to 6 years (n=563) during parent's working days and free days.

RESULTS

We observed negative correlations of sleep quality with sleep duration and midpoint of sleep at ages 4-5 (R=-0.21 to -0.10), which attenuated with age 6 years. Sleep duration and midpoint of sleep were strongly positively correlated at all ages (R=0.55-0.95). We observed significant negative associations between total electronic media use and TV/DVD watching, while book reading did neither affect the sleep quality score nor sleep duration or midpoint of sleep. We found little evidence for an indirect negative effect of media use on sleep quality via sleep duration or midpoint of sleep, indicating that media use acts independently on sleep duration, midpoint of sleep, and sleep quality. Non-statistically significant associations of sleep duration and midpoint of sleep on sleep quality indicate that these are independent aspects of sleep adequacy. Evidence for this was stronger during free days.

CONCLUSION

Media use acted on sleep quality through a direct effect in a prospective fashion. Thus, we conclude that electronic media use increases the risk for sleep impairments in German preschoolers, while book reading seems to be a safe and healthy alternative.

Effect of Interaction Between Slow Wave Sleep and Obstructive Sleep Apnea on Insulin Resistance: A Large-Scale Study

OBJECTIVE

Slow-wave sleep (SWS) and obstructive sleep apnea (OSA) have attracted recent research attention. However, their joint effects on insulin resistance (IR) remain unclear. This study explored whether SWS influences the relationship between OSA and IR.

METHODS

We enrolled potential participants in our sleep center from 2007 to 2019. We collected demographic and clinical characteristics and determined IR status. SWS was derived from polysomnography data. Logistic regression analysis was used to reveal the associations between SWS and IR.

RESULTS

In all, 6966 participants (5709 OSA and 1257 primary snoring [PS] subjects) were enrolled. Less SWS increased the risk of IR in OSA patients but not in PS patients. OSA patients with SWS <6.5% were more likely to have IR than were those with SWS >21.3%. OSA was an independent risk factor for IR after adjusting for potential confounding factors. In stratified analyses according to the percentage of SWS, OSA patients with SWS <6.5% had an odds ratio for IR of 2.461 (95% CI, 2.018-3.002) compared to the PS group after adjusting for potential confounders.

CONCLUSION

Less SWS is associated with higher odds for IR in OSA patients but not in PS patients. OSA is independently associated with IR. In addition, OSA combined with an extreme lack of SWS has a more harmful effect on the status of IR than OSA itself.

Persistent Short Sleep from Childhood to Adolescence: Child, Parent and Peer Predictors

PURPOSE

Many children have periods when they sleep too little, with widely recognized detrimental effects. Less is known about persistent short sleep during childhood. Therefore, the present study aimed to investigate the prevalence of persistent short sleep in school-aged children and identify a set of child, parent, and peer predictors thereof.

PARTICIPANTS AND METHODS

Objectively measured sleep duration (hip-held accelerometer) was biennially assessed in a community sample followed from 6 to 14 years (n=801). A latent profile analysis was applied to assess whether a subgroup of children slept consistently short across time and predictors of persistent short sleep were determined through regression analysis.

RESULTS

A subgroup of children (n=160; 20.2%) was identified as having persistent short sleep across time. Temperamental negative affectivity (β=0.08; 95% CI=0.01, 0.15; p=0.03) and low observer-assessed parental emotional availability (β=-.09; 95% CI=-.18, -.01; p=0.04) predicted membership to that group. Teacher ratings of victimization from bullying were not associated with persistent short sleep (β=0.01; 95% CI: -.10, 11; p=0.88).

CONCLUSION

High child temperamental negative affectivity and low parental emotional availability may be involved in the development of persistent short sleep through childhood.

Insomnia and poor sleep quality during peripartum: a family issue with potential long term consequences on mental health

BACKGROUND

Improving maternal's health is a worldwide priority. Sleep is a fundamental operating state of the central nervous system and it may be one of the most important psychophysiological processes for brain function and mental health. The study of maternal sleep problem including insomnia, however, implies deepening our understanding of family context. Family systems are dynamic and involve reciprocal interactions among members during day and night. So far, however, maternal and children's sleep has been rarely studied in a family perspective, and paternal sleep has often been neglected.

METHODS

The present work summarizes in a narrative review the state of the art of our current knowledge on the role of insomnia and poor quality of sleep for mental health in all family members in the peripartum period. The mother, the father, the child and the family interactive perspectives are considered.

RESULTS

Insomnia and poor sleep problems are frequent in all family members during peripartum. Poor sleep and insomnia symptoms are recognized as important risk factors for mental health in adults and children. Despite this alarming evidence, sleep is rarely assessed in clinical contexts.

CONCLUSIONS

Clinical implications include the utmost relevance of assessing sleep problems during pregnancy and early post-partum. Insomnia and poor sleep quality should be evaluated and treated in the clinical practice by using a "family perspective."

Sleep Health Promotion in the Workplace

Poor sleep and sleepiness in the workplace are associated with accidents. A workplace sleep health promotion program was implemented in an Italian police unit. Of the 242 police officers in the unit, 218 (90%) agreed to take part in the program. A crossover trial was made in which the police officers were divided into two groups that performed sleep health promotion activities in the first and second year, respectively. The first group of officers showed significant sleep improvements at the end of the first year, while the second group had similar or worse parameters than at baseline. At follow-up, a significant improvement in the quantity and quality of sleep was reported in both groups. Sleep improvements at follow-up were associated with a marked reduction in the frequency of accidents at work and near-misses. Before the intervention, sleepiness was the best predictor of injuries (aOR 1.220; CI95% 1.044–1.426) and near-misses (aOR 1.382; CI95% 1.182–1.615). At follow-up, when sleep conditions had improved, insomnia symptoms were the most significant predictors of work accidents (aOR 13.358; CI95% 2.353–75.818). Sleep health promotion can be useful in police officers.

Association between free-living sleep and memory and attention in healthy adolescents

In laboratory studies, imposed sleep restriction consistently reduces cognitive performance. However, the association between objectively measured, free-living sleep and cognitive function has not been studied in older adolescents. To address this gap, we measured one week of sleep with a wrist-worn GT3X+ actigraph in 160 adolescents (96 girls, 17.7 ± 0.3 years) followed by assessment of working memory with an n-back task and visual attention with a Posner cue-target task. Over the week, participants spent 7.1 ± 0.8 h/night in bed and slept 6.2 ± 0.8 h/night with 88.5 ± 4.8% efficiency and considerable intra-participant night-to-night variation, with a standard deviation in sleep duration of 1.2 ± 0.7 h. Sleep measures the night before cognitive testing were similar to weekly averages. Time in bed the night before cognitive testing was negatively associated with response times during the most challenging memory task (3-back; p = 0.005). However, sleep measures the night before did not correlate with performance on the attention task and weekly sleep parameters were not associated with either cognitive task. Our data suggests shorter acute free-living sleep may negatively impact difficult memory tasks, however the relationship between free-living sleep and cognitive task performance in healthy adolescents is less clear than that of laboratory findings, perhaps due to high night-to-night sleep variation.

The impact of reduced sleep on school related outcomes for typically developing children aged 11–19: A systematic review

This systematic literature review examines the relationship between restricted and reduced sleep and school performance, learning and cognitive functioning in typically developing adolescents. Correlational and experimental data were evaluated from 17 studies which included participants ranging from 11 to 19 years in studies from seven countries around the world. The review found that there is evidence that restricted and reduced sleep is negatively associated with school performance and cognitive outcomes, although the findings were mixed. Implications for psychologists working with schools are discussed. More research and evaluation is needed to establish how these factors relate to each other conclusively.

Linear and Nonlinear Associations between Sleep and Adjustment in Adolescence

BACKGROUND & OBJECTIVES

A growing body of work supports linear associations between sleep and socioemotional adjustment in adolescence. However, associations between sleep and adjustment are not necessarily linear and investigations of nonlinear effects are scarce. This study examined linear and nonlinear relations between several sleep-wake parameters and externalizing behavior and internalizing symptoms in adolescence, and assessed the role of adolescent sex as a moderator of effects.

PARTICIPANTS

Participants were high school students (N = 180; M age = 17.49, SD = .62; 59% female; 68% White/European American, 32% Black/African American) from a wide range of socio-economic backgrounds living in semirural communities and small towns in Alabama.

METHODS

Sleep-wake parameters were indexed by actigraphy-derived sleep minutes and adolescents' reports on morningness-eveningness (circadian preference), sleep-wake problems (sleep quality), and sleepiness. Adolescents completed questionnaires on externalizing behaviors and internalizing symptoms.

RESULTS

Controlling for sleep duration, a higher preference for eveningness and poor sleep quality were associated in a linear fashion with increased externalizing and internalizing symptoms. Nonlinear relations between sleepiness and internalizing symptoms emerged with pronounced sex-related effects, including somewhat delayed accelerating relations for males and rapidly accelerating associations that tended to plateau for females.

CONCLUSIONS

Results illustrate the importance of examining multiple sleep-wake and adjustment variables as well as linear and nonlinear associations.

Interaction of Sleep and Cortical Structural Maintenance From an Individual Person Microlongitudinal Perspective and Implications for Precision Medicine Research

Sleep and maintenance of brain structure are essential for the continuity of a person's cognitive/mental health. Interestingly, whether normal structural maintenance of the brain and sleep continuously interact in some way over day-week-month times has never been assessed at an individual-person level. This study used unconventional microlongitudinal sampling, structural magnetic resonance imaging, and n-of-1 analyses to assess normal interactions between fluctuations in the structural maintenance of cerebral cortical thickness and sleep duration for day, week, and multi-week intervals over a 6-month period in a healthy adult man. Correlation and time series analyses provided indications of "if-then," i.e., "if" this preceded "then" this followed, sleep-to-thickness maintenance and thickness maintenance-to-sleep bidirectional inverse interactions. Inverse interaction patterns were characterized by concepts of graded influences across nights, bilaterally positive relationships, continuity across successive weeks, and longer delayed/prolonged effects in the thickness maintenance-to-sleep than sleep-to-thickness maintenance direction. These interactions are proposed to involve normal circadian/allostatic/homeostatic mechanisms that continuously influence, and are influenced by, cortical substrate remodeling/turnover and sleep/wake cycle. Understanding interactions of individual person "-omics" is becoming a central interest in precision medicine research. The present n-of-1 findings contribute to this interest and have implications for precision medicine research use of a person's cortical structural and sleep "-omics" to optimize the continuous maintenance of that individual's cortical structure, sleep, and cognitive/mental health.

Association of hypnotizability and deep sleep: any role for interoceptive sensibility?

The aim of the study was to investigate the possible association of hypnotizability and deep sleep (N3) duration, and whether the interoceptive sensibility influences this association. This was motivated by the proneness of highly hypnotizable individuals to easily change their psychophysiological state, i.e., from wakefulness to hypnosis and sleep, and by the positive association observed between hypnotizability and interoceptive sensibility. Forty-seven healthy participants previously enrolled in a polysomnographic night sleep study completed the questionnaire for Multidimensional Assessment of Interoceptive Awareness (MAIA) and underwent hypnotic assessment through the Stanford Hypnotic Susceptibility Scale, form A (SHSS,A). Results showed that N3 duration is not linearly correlated with hypnotizability. Controlling for a few MAIA scales did not modify the relation between hypnotizability and deep sleep. A polynomial relation indicates that N3 duration and N3 percentage of the total sleep time increase with hypnotizability in the low-to-medium range of hypnotizability and decrease in the medium-to-high range. In conclusion, hypnotic assessment predicts N3 duration and their association is not modified by interoceptive awareness/sensitivity.

Nurse Health: The Influence of Chronotype and Shift Timing

Extreme chronotype and circadian disrupting work hours may increase nurse disease risks. This national, cross-sectional study of nurses (N = 527) had three hypotheses. When chronotype and shift times are incongruent, nurses will experience increased likelihood of (1) obesity, (2) cardiovascular disease/risk factors, and (3) obesity or cardiovascular disease/risk factors when theoretically linked variables exist. Chronotype mismatched nurses' (n = 206) average sleep (6.1 hours, SD = 1.2) fell below 7-9 hours/24-hours sleep recommendations. Proportion of male nurses was significantly higher chronotype mismatched (12.3%) than matched (6.3%). Analyses found no direct relationship between chronotype match/mismatch with outcome variables. Exploratory interaction analysis demonstrated nurses with mismatched chronotype and above average sleep quality had an estimated 3.51 times the adjusted odds (95% CI 1.52,8.17; p = .003) of being obese. Although mechanism is unclear, this suggests sleep quality may be intricately associated with obesity. Further research is needed to inform nurses on health risks from disrupted sleep, chronotypes, and shift work.

What does a good night's sleep mean? Nonlinear relations between sleep and children's cognitive functioning and mental health

STUDY OBJECTIVES

We attempted to identify the duration and quality of sleep associated with the optimal child outcomes in key developmental domains including cognitive functioning, academic performance, and mental health. In doing so, we examined nonlinear associations between the sleep and developmental variables. Based on racial/ethnic disparities in children's sleep, we assessed this variable as a moderator of examined relations.

METHODS

Two hundred eighty-two children participated (Mage = 9.4 years, SD = .72; 52% boys; 65% white/European American, 35% black/African American). Sleep was examined with actigraphy for seven consecutive nights and with self-reports. Actigraphy-based sleep duration (minutes) and quality (efficiency), as well as self-reported sleep quality were derived. Children reported on their mental health and were administered cognitive performance tests. Mothers and teachers reported on children's mental health; teachers also reported on academic functioning. Schools provided academic achievement data.

RESULTS

Sleep duration had an accelerating nonlinear negative association with externalizing behaviors. Nonlinear associations were also detected between both actigraphy-derived and subjective reports of sleep quality and multiple developmental domains including academic functioning and mental health and the best functioning corresponded with the highest levels of sleep quality. Emphasizing the importance of individual differences, several examined associations were moderated by race/ethnicity.

CONCLUSIONS

Sleep duration and quality emerged as nonlinear predictors of multiple domains of child development. Findings illustrate that the benefits of longer and better-quality sleep did not taper off and that assessments of nonlinear relations may enhance understanding of the nature of associations between sleep and child functioning.

Quantity versus quality of objectively measured sleep in relation to body mass index in children: cross-sectional and longitudinal analyses

BACKGROUND/OBJECTIVES

Although sleep duration is well established as a risk factor for child obesity, how measures of sleep quality relate to body size is less certain. The aim of this study was to determine how objectively measured sleep duration, sleep timing, and sleep quality were related to body mass index (BMI) cross-sectionally and longitudinally in school-aged children.

SUBJECTS/METHODS

All measures were obtained at baseline, 12 and 24 months in 823 children (51% female, 53% European, 18% Māori, 12% Pacific, 9% Asian) aged 6-10 years at baseline. Sleep duration, timing, and quality were measured using actigraphy over 7 days, height and weight were measured using standard techniques, and parents completed questionnaires on demographics (baseline only), dietary intake, and television usage. Data were analysed using imputation; mixed models, with random effects for person and age, estimated both a cross-sectional effect and a longitudinal effect on BMI z-score, adjusted for multiple confounders.

RESULTS

The estimate of the effect on BMI z-score for each additional hour of sleep was -0.22 (95% CI: -0.33, -0.11) in cross-sectional analyses and -0.05 (-0.10, -0.004) in longitudinal analyses. A greater effect was observed for weekday sleep duration than weekend sleep duration but variability in duration was not related to BMI z-score. While sleep timing (onset or midpoint of sleep) was not related to BMI, children who were awake in the night more frequently (0.19; 0.06, 0.32) or for longer periods (0.18; 0.06, 0.36) had significantly higher BMI z-scores cross-sectionally, but only the estimates for total time awake (minutes) were significant longitudinally (increase in BMI z-score of 0.04 for each additional hour awake).

CONCLUSION

The beneficial effect of a longer sleep duration on BMI was consistent in children, whereas evidence for markers of sleep quality and timing were more variable.

US acculturation and poor sleep among an intergenerational cohort of adult Latinos in Sacramento, California

Acculturation may shape the disproportionate burden of poor sleep among Latinos in the United States. Existing studies are limited by unidimensional acculturation proxies that are incapable of capturing cultural complexities across generations. Understanding how acculturation relates to sleep may lead to the identification of modifiable intervention targets. We used multivariable regression and latent class methods to examine cross-sectional associations between a validated multidimensional scale of US acculturation and self-reported poor sleep measures. We analyzed an intergenerational cohort: first-generation (GEN1) older Latinos (Sacramento Area Latino Study on Aging; N = 1,716; median age: 69.5) and second-generation (GEN2) middle-aged offspring and relatives of GEN1 (Niños Lifestyle and Diabetes Study; N = 670; median age: 54.0) in Sacramento, California. GEN1 with high US acculturation, compared with high acculturation towards another origin/ancestral country, had less restless sleep (prevalence ratio [PR] [95% confidence interval (CI)]: 0.67 [0.54, 0.84]) and a higher likelihood of being in the best sleep class than the worst (OR [95% CI]: 1.62 [1.09, 2.40]), but among nonmanual occupations, high intergenerational US acculturation was associated with more general fatigue (PR [95% CI: 1.86 [1.11, 3.10]). GEN2 with high intergenerational US acculturation reported shorter sleep (PR [95% CI]: 2.86 [1.02, 7.99]). High US acculturation shaped sleep differentially by generation, socioeconomic context, and intergenerational acculturative status. High US acculturation was associated with better sleep among older, lower socioeconomic Latinos, but with shorter sleep duration among middle-aged, higher socioeconomic Latinos; results also differed by parental acculturation status. Upon replication, future studies should incorporate prospective and intergenerational designs to uncover sociobehavioral pathways by which acculturation may shape sleep to ultimately inform intervention efforts.

Interaction Between Slow Wave Sleep and Obstructive Sleep Apnea in Prevalent Hypertension

Due to frequent abnormal breathing events and their effects on sleep architecture, patients with obstructive sleep apnea (OSA) exhibit decreased amounts of slow wave sleep (SWS). Reduced SWS has been linked to hypertension in community-based studies. We sought to investigate whether SWS percentage modifies the association between OSA and prevalent hypertension. We studied 7107 patients with OSA and 1118 primary snorers who underwent in-laboratory polysomnography. Patients were classified into quartiles of percent SWS. Hypertension was defined based either on clinic blood pressure measures or on physician diagnosis. Multivariable logistic regression model showed a significant interaction effect of OSA and SWS on prevalent hypertension (P=0.002). Decreased SWS was associated with higher odds for hypertension in OSA but not in primary snoring, with patients with OSA exhibiting <0.1% SWS (OR, 1.44 [95% CI, 1.21-1.70]; P=0.001) and those with 0.1% to 4.8% SWS (OR, 1.20 [95% CI, 1.03-1.40]; P=0.02) being more likely to have hypertension compared with those with >11.1% SWS. In analysis stratified by OSA severity, significant associations between percent SWS and blood pressure emerged only in moderate and severe OSA. Effect modifications by sex (P=0.040) and age (P=0.007) were also only evident in OSA, indicating that decreased SWS was associated with hypertension only in men and in patients <60 years old. Decreased SWS is associated with a dose-dependent increase in odds of prevalent hypertension in patients with OSA. The effects of SWS are likely to be modulated by OSA severity. SWS may be implicated in the heightened risk of cardiovascular diseases exhibited by patients with OSA.

Sleep and HbA1c in Patients With Type 2 Diabetes: Which Sleep Characteristics Matter Most?

OBJECTIVE

Poor sleep has been identified as a risk factor for poor glycemic control in individuals with type 2 diabetes (T2D). As optimal sleep can be characterized in several ways, we evaluated which sleep characteristics are most strongly associated with glycated hemoglobin A_1c (HbA_1c).

RESEARCH DESIGN AND METHODS

A total of 172 patients with T2D completed 7-day wrist-actigraphy and sleep questionnaires. Linear regression was used to evaluate associations between sleep measures (total sleep duration, variability in sleep duration, midsleep time, variability in midsleep time, sleep efficiency, subjective sleep quality, and subjective insomnia symptoms) and HbA_1c, individually and in concert.

RESULTS

Variability in sleep duration was individually most strongly associated with HbA_1c (β = 0.239; P = 0.002; R ² = 4.9%), followed by total sleep duration (U-shaped: β = 1.161/β² = 1.044; P = 0.017/0.032; R ² = 4.3%), subjective sleep quality (β = 0.191; P = 0.012; R ² = 3.6%), variability in midsleep time (β = 0.184; P = 0.016; R ² = 3.4%), and sleep efficiency (β = -0.150; R ² = 2.3%). Midsleep time and subjective insomnia symptoms were not associated with HbA_1c. In combination, variability in sleep duration, total sleep duration, and subjective sleep quality were significantly associated with HbA_1c, together explaining 10.3% of the variance in HbA_1c. Analyses adjusted for covariates provided similar results, although the strength of associations was generally decreased and showing total sleep duration and subjective sleep quality to be most strongly associated with HbA_1c, together explaining 6.0% of the variance in HbA_1c.

CONCLUSIONS

Sleep in general may be a modifiable factor of importance for patients with T2D. The prevention of sleep curtailment may serve as a primary focus in the sleep-centered management of T2D.

Cross-cultural disparities of subjective sleep parameters and their age-related trends over the first three years of human life: A systematic review and meta-analysis

Changes in nighttime sleep consolidation and daytime discontinuation have been observed in early life. Yet information about societal or cultural factors remains scant for implementing sleep recommendations. We aimed to provide pooled estimates of subjective sleep duration, number of nightwakings and sleep timing; to describe their age-related trends; and to determine potential cross-cultural disparities between predominantly-Asian (PA) and predominantly-Caucasian (PC) regions during the first three years of life. We performed this review according to the PRISMA guidelines. Overall, 102 studies with 167,886 children aged 0-3 y from 26 different countries/regions were included. Compared to PC regions, PA toddlers had shorter sleep duration and more frequent nightwakings. When PC regions were further divided into Pacific Rim and Europe, differences were much more evident between PA and Pacific Rim for all nighttime sleep parameters. Trends of nighttime sleep duration and bedtime for PC regions showed rapid changes over the first 3-6 mo before stabilizing to a plateau, whereas a different change was found for PA regions. In conclusion, an apparent cross-cultural disparity of the subjective sleep parameters already exists in early childhood. Improved operationalization of sleep parameters and more objective evidence are needed to establish cultural-sensitive recommendations this early in life.

(Re)Conceptualizing Sleep Among Children with Anxiety Disorders: Where to Next?

Children with anxiety disorders (AD) characteristically complain of sleep problems and the extent to which cognitive behavioral treatments (CBT) for childhood anxiety produce sleep-based improvements is a topic of increasing interest. The current paper reviews available evidence for subjective sleep complaints and objective sleep alterations in children and adolescents with AD, including investigations of potential changes in sleep following anxiety-focused CBT. Despite pervasive complaints of poor sleep, the empirical literature provides minimal evidence for actual sleep-wake alterations in this population of youth and evidence for sleep-based changes following treatment for anxiety is minimal. In line with calls for more comprehensive models of the role of sleep in developmental psychopathology, several fundamental gaps in understanding are described and highlighted as essential avenues for clarifying the nature and consequences of poor quality sleep among youth with clinical levels of anxiety. In a second section of the paper, an emerging body of novel, translational research investigating more intricate sleep-anxiety relationships is introduced with potential implications for both etiological models and treatment design and delivery.

Individual Differences in Optimum Sleep for Daily Mood During Adolescence

Efforts to establish an empirical basis for recommended sleep durations during adolescence need to take into account individual differences in optimum sleep, defined as the amount of sleep at which peak functioning is observed. A total of 419 adolescents (Mage = 15.03 years) with Mexican American backgrounds reported their nightly sleep duration and daily mood for a 2-week period at 1 or 2 waves of data collection, 1 year apart. Adolescents also completed an established measure of symptomatology. Multilevel modeling revealed a nonlinear association between sleep duration and next-day mood, whereby both too little and too much sleep were associated with elevated levels of daily distress. Significant individual differences in optimum sleep were observed such that younger adolescents and those with elevated levels of internalizing and total symptomatology evidenced greater sleep durations on nights before they reported their lowest levels of daily distress. Younger adolescents and those with higher internalizing and total symptomatology may need more sleep to reach their peak functioning the next day, at least in terms of daily mood.

Prenatal particulate air pollution exposure and sleep disruption in preschoolers: Windows of susceptibility

BACKGROUND

The programming of sleep architecture begins in pregnancy and depends upon optimal in utero formation and maturation of the neural connectivity of the brain. Particulate air pollution exposure can disrupt fetal brain development but associations between fine particulate matter (PM_2.5) exposure during pregnancy and child sleep outcomes have not been previously explored.

METHODS

Analyses included 397 mother-child pairs enrolled in a pregnancy cohort in Mexico City. Daily ambient prenatal PM_2.5 exposure was estimated using a validated satellite-based spatio-temporally resolved prediction model. Child sleep periods were estimated objectively using wrist-worn, continuous actigraphy over a 1-week period at age 4-5 years. Data-driven advanced statistical methods (distributed lag models (DLMs)) were employed to identify sensitive windows whereby PM_2.5 exposure during gestation was significantly associated with changes in sleep duration or efficiency. Models were adjusted for maternal education, season, child's age, sex, and BMI z-score.

RESULTS

Mother's average age was 27.7 years, with 59% having at least a high school education. Children slept an average of 7.7 h at night, with mean 80.1% efficiency. The adjusted DLM identified windows of PM_2.5 exposure between 31 and 35 weeks gestation that were significantly associated with decreased sleep duration in children. In addition, increased PM_2.5 during weeks 1-8 was associated with decreased sleep efficiency. In other exposure windows (weeks 39-40), PM_2.5 was associated with increased sleep duration.

CONCLUSION

Prenatal PM_2.5 exposure is associated with altered sleep in preschool-aged children in Mexico City. Pollutant exposure during sensitive windows of pregnancy may have critical influence upon sleep programming.

Mind-wandering, or the allocation of attentional resources, is sleep-driven across childhood

Mind-wandering or the spontaneous, uncontrolled changes in the allocation of attention resources (lapses) may cause variability in performance. In childhood, the relationship between the activation state of the brain, such as in attentional performance, and sleep has not been explored in detail. We investigated the role of sleep in attentional performance, and explored the most important parameters of their relationship. We objectively measured momentary lapses of attention of 522 children and correlated them with sleep schedules. In the subgroup of young children (age 7.1 ± 0.6 years; 60.8% girls), increasing age, long sleep duration and assessment closer to the previous night’s sleep period was associated with impaired performance speed and consistency. From pre-adolescence (age 9.4 ± 0.8 years; 50.5% girls) onwards somno-typologies may develop. As a result, in adolescence (age 13.4 ± 1.2 years; 51.3% girls) not only sleep duration but also sleep midpoint and sleep regularity influence the individual speed and stability of attention. Across development, regularity of sleep, individual sleep midpoint and bedtime become increasingly important for optimal performance throughout the day. Attentional performance and sleep shared almost half of their variance, and performance was sleep-driven across childhood. Future studies should focus on intra- and inter-individual differences in sleep-wake behavior to improve performance or decrease mind-wandering in youth by targeting sleep habits.

Time of day effects on the relationship between daily sleep and anxiety: An ecological momentary assessment approach

Previous research has linked sleep disturbance to anxiety. However, evidence for this relation has been inconsistent, largely limited to retrospective reports that do not account for daily variability, and silent on when the association is most pronounced. Thus, the present study utilized ecological momentary assessment (EMA) to examine the effects of daily deviations in total sleep time (TST) and person-average TST on anxiety and whether these effects varied as a function of time of day in a sample of unselected adults (N = 138). Results indicate that the amount of TST on a given night, relative to personal average TST, negatively predicted anxiety, and this relation was significant in the morning and afternoon, but not evening. In contrast, person-average TST was unrelated to average anxiety. Relations between TST and anxiety did not differ across objective (e.g., actigraphy) and subjective (e.g., sleep diary) measures. Furthermore, the pattern of results remained the same when controlling for previous day's anxiety and were not bidirectional. These findings suggest that getting less sleep than is typical for the individual predicts subsequent anxiety, and this effect is particularly strong in the morning. Average sleep duration may be less important to the experience of anxiety than deviations from that average. These findings highlight the importance of EMA to examine how and when variability in sleep confers vulnerability for anxiety symptoms.

Practical non-pharmacological intervention approaches for sleep problems among older adults

Poor sleep is common among older adults, often caused by multiple underlying factors such as chronic stress. Poor sleep is subsequently associated with negative health outcomes including higher morbidity and mortality. Our primary purpose is to explore practical non-pharmacological intervention approaches integrating stress management to improve sleep quality among older adults. In doing so, we highlight approaches that appear to hold promise in real-world settings with older individuals. We conducted a tailored literature review specifically on approaches to improve sleep quality among older adults, with emphasis on those integrating stress management. Online search engines were reviewed to identify research in these areas. Various non-pharmacological intervention approaches, such as mindfulness and cognitive behavioral therapy, have shown promise in improving sleep quality and health outcomes within this population. Those integrating chronic stress management appear to be particularly successful. Thus further development of multidimensional sleep interventions integrating stress management with seniors is warranted.

Cardiac Vagal Control and Depressive Symptoms: The Moderating Role of Sleep Quality

Lower cardiac vagal control (CVC) has been linked to greater depression. However, this link has not been consistently demonstrated, suggesting the presence of key moderators. Sleep plausibly is one such factor. Therefore, we investigated whether sleep quality moderates the link between CVC (quantified by high-frequency heart rate variability, HF-HRV) and depressive symptoms (assessed using established questionnaires) in 29 healthy women. Results revealed a significant interaction between HF-HRV and sleep quality in predicting depressive symptoms: participants with lower HF-HRV reported elevated depressive symptoms only when sleep quality was also low. In contrast, HF-HRV was not associated with depressive symptoms when sleep quality was high, suggesting a protective function of high sleep quality in the context of lower CVC.

Restoration of Sleep Architecture after Maxillomandibular Advancement: Success Beyond the Apnea-Hypopnea Index

While effects of maxillomandibular advancement (MMA) on respiratory parameters for patients with obstructive sleep apnea (OSA) are well described, effects on sleep architecture before and after MMA are not. A retrospective cohort analysis on sleep architecture was examined in 10 OSA patients who underwent MMA surgery between July 2013 and November 2014, and had prespecified complete polysomnography (PSG) datasets. Sleep stages were examined relative to a Western European population-based control group. All of the respiratory parameters improved significantly post MMA. Rapid eye movement (REM) latency decreased from 178.0±142.8 to 96.6±64.5min (P=0.035). %NREM (non-rapid eye movement)1 (P=0.045) and %WASO (wakefulness after sleep onset) (P=0.006) decreased, while %REM increased (P=0.002) after MMA. WASO decreased from 64.2±57min to 22.4±15.4min (P=0.017). Preoperatively, OSA subjects showed significantly lower sleep efficiency (P=0.016), sleep onset latency (P=0.015), and % REM (P<0.001) than the normative population dataset, while post MMA there was a significant decrease in %NREM1 sleep (P<0.001) and in %WASO (P<0.001). MMA results in a marked decrease in WASO and increase in REM, and to a lesser extent NREM sleep. Patients after MMA show values similar to population controls except for a lower WASO.

The combined impact of diet, physical activity, sleep and screen time on academic achievement: a prospective study of elementary school students in Nova Scotia, Canada

Background

Few studies have investigated the independent associations of lifestyle behaviors (diet, physical activity, sleep, and screen time) and body weight status with academic achievement. Even fewer have investigated the combined effect of these behaviors on academic achievement. We hypothesize that the combined effect of these behaviors will have a higher impact on academic achievement than any behavior alone, or that of body weight status.

Methods

In 2011, 4253 grade 5 (10–11 years old) students and their parents were surveyed about the child’s diet, physical activity, screen time and sleep. Students’ heights and weights were measured by research assistants. Academic achievement was measured using provincial standardized exams in mathematics, reading and writing, and was expressed as ‘meeting’ or ‘not meeting’ expectations as per standardized criterion. Exams were written 1 year following the measurement of lifestyle behaviors. Lifestyle behaviors were measured with self- and parental proxy reports and expressed as meeting recommendations (yes/no) for each behavior. Mixed effects logistic regression models adjusting for demographic confounders and caloric intake were used to determine the independent and combined associations.

Results

Meeting dietary recommendations was associated with increased likelihood of meeting academic expectations for each of math, reading and writing. Meeting recommendations for screen time and sleep was associated with meeting expectations for writing. For all three subjects, meeting additional lifestyle behavior recommendations was associated with higher likelihood of meeting expectations. Children who met 7–9 lifestyle behavior recommendations had greater than three-times the odds of meeting expectations for reading compared to those who met 0–3 recommendations (OR: 3.07, 95% CI: 2.09, 4.51), and 1.47 and 2.77 times the odds of meeting expectations in mathematics and writing, respectively. Body weight status was not associated with academic achievement.

Conclusions

We found that lifestyle behaviors, not body weight status, are strongly associated with student academic performance. Promoting compliance with established healthy lifestyle recommendations could improve both the health and educational outcomes of school-aged children. School-based health promotion initiatives that target multiple lifestyle behaviors may have a greater effect on academic achievement than those that focus on a single behavior.

Electronic supplementary material

The online version of this article (doi:10.1186/s12966-017-0476-0) contains supplementary material, which is available to authorized users.

Sleep Regulation, Physiology and Development, Sleep Duration and Patterns, and Sleep Hygiene in Infants, Toddlers, and Preschool-Age Children

Sleep problems are common, reported by a quarter of parents with children under the age of 5 years, and have been associated with poor behavior, worse school performance, and obesity, in addition to negative secondary effects on maternal and family well-being. Yet, it has been shown that pediatricians do not adequately address sleep in routine well-child visits, and underdiagnose sleep issues. Pediatricians receive little formal training in medical school or in residency regarding sleep medicine. An understanding of the physiology of sleep is critical to a pediatrician׳s ability to effectively and confidently counsel patients about sleep. The biological rhythm of sleep and waking is regulated through both circadian and homeostatic processes. Sleep also has an internal rhythmic organization, or sleep architecture, which includes sleep cycles of REM and NREM sleep. Arousal and sleep (REM and NREM) are active and complex neurophysiologic processes, involving both neural pathway activation and suppression. These physiologic processes change over the life course, especially in the first 5 years. Adequate sleep is often difficult to achieve, yet is considered very important to optimal daily function and behavior in children; thus, understanding optimal sleep duration and patterns is critical for pediatricians. There is little experimental evidence that guides sleep recommendations, rather normative data and expert recommendations. Effective counseling on child sleep must account for the child and parent factors (child temperament, parent-child interaction, and parental affect) and the environmental factors (cultural, geographic, and home environment, especially media exposure) that influence sleep. To promote health and to prevent and manage sleep problems, the American Academy of Pediatrics (AAP) recommends that parents start promoting good sleep hygiene, with a sleep-promoting environment and a bedtime routine in infancy, and throughout childhood. Thus, counseling families on sleep requires an understanding of sleep regulation, physiology, developmental patterns, optimal sleep duration recommendations, and the many factors that influence sleep and sleep hygiene.

Adolescent Sleep Duration, Variability, and Peak Levels of Achievement and Mental Health

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 underappreciated 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 2 weeks; approximately 80% repeated the same protocol 1 year later. Multilevel modeling indicated that the amount of sleep associated with the lowest levels of internalizing and externalizing symptoms was more than 1 hr 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.

Impact of different recommendations on adequacy rate for sleep duration in children

A huge amount of literature in the last decades showed that sleep is essential for children’s health and well-being and that short sleep duration is associated with several negative health outcomes. Many developmental phases in infancy and childhood are in strict relationship with an healthy sleep.

In the last years some specific recommendations made for how much sleep children need have been published. The empirical evidences for contemporary sleep recommendations has changed and the new recommendations are clearly different from the previous ones and reflect clearly the changes in the sleep need of the children and adolescents in the last decades although seem still to be largely unfitting for preadolescence and adolescence.

If sleep is to be treated as a therapeutic intervention, then consensus guidelines, statements, and evidence-based best-practice documents are needed to underpin sleep recommendations for children.

Sleep recommendations for children play an important role for public policies and interventions, and to advertise parents and children of the negative consequences of sleep deprivation/reduction.

Impulsive personality traits and alcohol use: Does sleeping help with thinking?

Both impulsivity and sleep disturbance have been associated with heavy alcohol use among young adults; yet studies to date have not examined their interactive effects. The current study aimed to determine if adequate sleep moderates the association between impulsive personality traits and alcohol use among young adults. College students (N = 568) who had been mandated to alcohol treatment following violation of campus alcohol policy provided information regarding alcohol use and related consequences, impulsive personality traits (measured using the UPPS Impulsive Behavior Scale), and perception of sleep adequacy as part of a larger intervention trial. Higher urgency, lower premeditation, and higher sensation-seeking predicted greater levels of alcohol consumption, while higher urgency predicted more alcohol-related consequences. As hypothesized, there was a significant interaction between premeditation and sleep adequacy in the prediction of drinks per week; in contrast to hypotheses, however, premeditation was associated with drinking only among those reporting adequate (rather than inadequate) sleep. Specifically, the tendency to premeditate was associated with less drinking among those who reported adequate sleep and was not associated with drinking among those reporting inadequate sleep. Sensation-seeking and urgency are associated with greater alcohol involvement among young adults, regardless of sleep adequacy. Conversely, the ability to plan ahead and anticipate the consequences of one's behaviors (premeditation) is only protective against heavy drinking among individuals receiving adequate sleep. With replication, these findings may inform alcohol prevention and intervention efforts. (PsycINFO Database Record

Adequate sleep moderates the prospective association between alcohol use and consequences

OBJECTIVE

Inadequate sleep and heavy alcohol use have been associated with negative outcomes among college students; however, few studies have examined the interactive effects of sleep and drinking quantity in predicting alcohol-related consequences. This study aimed to determine if adequate sleep moderates the prospective association between weekly drinking quantity and consequences.

METHOD

College students (N=568) who were mandated to an alcohol prevention intervention reported drinks consumed per week, typical sleep quantity (calculated from sleep/wake times), and perceptions of sleep adequacy as part of a larger research trial. Assessments were completed at baseline and one-, three-, and five-month follow-ups.

RESULTS

Higher baseline quantities of weekly drinking and inadequate sleep predicted alcohol-related consequences at baseline and one-month follow-up. Significant interactions emerged between baseline weekly drinking quantity and adequate sleep in the prediction of alcohol-related consequences at baseline, one-, three-, and five-month assessments. Simple slopes analyses revealed that weekly drinking quantity was positively associated with alcohol-related consequences for those reporting both adequate and inadequate sleep, but this association was consistently stronger among those who reported inadequate sleep.

CONCLUSION

Subjective evaluation of sleep adequacy moderates both the concurrent and prospective associations between weekly drinking quantity and consequences, such that heavy-drinking college students reporting inadequate sleep experience more consequences as a result of drinking. Research needs to examine the mechanism(s) by which inadequate sleep affects alcohol risk among young adults.