No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Optimal sleep and circadian habits in infants and children
Abstract
Sleep, a basic biological need, is the primary behavioral state of infants and children. Sleep is often problematic in early childhood, with about 30% of infants and children reportedly not obtaining sufficient sleep. This article discusses the concept of “optimal” sleep in infants and children by presenting theoretical models for understanding sleep behavior and the development of sleep and circadian rhythms. It also addresses the questions of “optimal sleep for whom?”, “optimal sleep for what?”, and “what environmental factors influence optimal sleep?” Overall, data suggest high individual differences in sleep behavior and that early sleep indicators are central to health and developmental outcomes.
As digital media is present in children’s daily lives, the question of the most and least beneficial moments to offer screens naturally arises among parents and healthcare providers. Researchers are trying to answer this question, and so far, there has been an outgrowing trend to recommend avoiding digital media use during sleeping and eating routines. At bedtime, arousal caused by media content and the device’s blue light can alter sleep time, resulting in fewer hours of quality rest. Media use or background TV during mealtime affects children’s eating habits, as they may not pay enough attention to what and how much they eat, which could favor unhealthy eating habits and lead to obesity. Children may also have more access to food and drink advertisements on digital media, which could impact their health and eating habits. In this chapter, we review the latest scientific evidence on the possible outcomes of media use during bedtime and mealtime for child well-being and development. We conclude with practical implications arising from these research results.
Children's vocabulary ability at school entry is highly variable and predictive of later language and literacy outcomes. Sleep is potentially useful in understanding and explaining that variability, with sleep patterns being predictive of global trajectories of language acquisition. Here, we looked to replicate and extend these findings. Data from 354 children (without English as an additional language) in the Born in Bradford study were analysed, describing the mean intercepts and linear trends in parent-reported day-time and night-time sleep duration over five time points between 6 and 36 months-of-age. The mean difference between night-time and day-time sleep was predictive of receptive vocabulary at age five, with more night-time sleep relative to day-time sleep predicting better language. An exploratory analysis suggested that socioeconomic status was predictive of vocabulary outcomes, with sleep patterns partially mediating this relationship. We suggest that the consolidation of sleep patterns acts as a driver of early language development.
Naps have been shown to benefit visuo‐spatial learning in early childhood. This benefit has been associated with sleep spindles during the nap. However, whether young children’s naps and their accompanying physiology benefit other forms of declarative learning is unknown. Using a novel storybook task, we found performance in children (N = 22, mean age = 51.23 months) was better following a nap compared to performance following an equivalent interval spent awake. Moreover, performance remained better the following day if a nap followed learning. Change in post‐nap performance was positively associated with the amount of time spent in slow wave sleep during the nap. This suggests that slow wave sleep in naps may support episodic memory consolidation in early childhood. Taken in conjunction with prior work, these results suggest that multiple features of brain physiology during naps may contribute to declarative memory processing in early childhood.
Sleep disorders and sleep insufficiency are common among preschool-aged children. Studies among school-aged children show disordered sleep is often more prevalent among racial minority groups. The primary aim of this systematic review was to critically appraise empirical data to elucidate the relationship between race and key sleep variables among children aged 2 to 5 years old. By systematically searching PubMed, Web of Science, and EBSCO databases, we identified empirical research articles conducted in the United States that investigate this relationship. We searched for variables relevant to (1) insufficient sleep duration, (2) poor sleep quality, (3) irregular timing of sleep, including sleep/wake problems and irregular bedtime onset and wake times (4) and sleep/circadian disorders. Nine studies satisfied the criteria for inclusion: five investigated nocturnal sleep duration, five investigated bedtime-related variables, four investigated daytime sleep (napping), three investigated total sleep, two investigated sleep quality, and one investigated wake times. Four studies specifically addressed racial and demographic differences in sleep variables as the primary aim, while the remaining five contained analyses addressing racial and demographic differences in sleep as secondary aims. Non-Hispanic white, white, or European-American race was used as the reference category in all studies. The results provided consistent evidence that white, non-Hispanic children were more likely to go to bed earlier and more regularly, have longer nocturnal sleep, and nap less than most racial and ethnic minorities. Combined, this literature presents a compelling narrative implicating race as an important factor in sleep patterns among a preschool age population.
The maturation of sleep regulatory systems during adolescence in combination with psychosocial and societal pressures culminate in a "Perfect Storm" of short and ill-timed sleep and the associated consequences for many youngsters. This model, first described by Carskadon in 2011, guides our current thinking of adolescent sleep behavior. Since the original description, the field has moved forward with remarkable pace, and this review aims to summarize recent progress and describe how this new work informs our understanding of sleep regulation and sleep behavior during this developmental time frame.
Although the light-induced melatonin suppression response is well characterized in adults, studies examining the dynamics of this effect in children are scarce. The purpose of this study was to quantify the magnitude of evening light-induced melatonin suppression in preschool-age children. Healthy children (n = 10; 7 females; 4.3 ± 1.1 years) participated in a 7-day protocol. On days 1–5, children followed a strict sleep schedule. On day 6, children entered a dim light environment (<15 lux) for 1-h before providing salivary samples every 20- to 30-min from the afternoon until 50-min after scheduled bedtime. On day 7, subjects remained in dim light conditions until 1-h before bedtime, at which time they were exposed to a bright light stimulus (~1000 lux) for 1-h and then re-entered dim light conditions. Saliva samples were obtained before, during, and after bright light exposure and were time anchored to samples taken the previous evening. We found robust melatonin suppression (87.6 ± 10.0%) in response to the bright light stimulus. Melatonin levels remained attenuated for 50-min after termination of the light stimulus (P < 0.008). Furthermore, melatonin levels did not return to 50% of those observed in the dim light condition 50-min after the light exposure for 7/10 children. Our findings demonstrate a robust light-induced melatonin suppression response in preschool-age children. These findings have implications for understanding the role of evening light exposure in the development of evening settling difficulties and may serve as experimental evidence to support recommendations regarding light exposure and sleep hygiene practices in early childhood.
This paper reviews the evidence regarding the efficacy of behavioral treatments for bedtime problems and night wakings in young children. It is based on a review of 52 treatment studies by a task force appointed by the American Academy of Sleep Medicine to develop practice parameters on behavioral treatments for the clinical management of bedtime problems and night wakings in young children. The findings indicate that behavioral therapies produce reliable and durable changes. Across all studies, 94% report that behavioral interventions were efficacious, with over 80% of children treated demonstrating clinically significant improvement that was maintained for 3 to 6 months. In particular, empirical evidence from controlled group studies utilizing Sackett criteria for evidence-based treatment provides strong support for unmodifi ed extinction and preventive parent education. In addition, support is provided for graduated extinction, bedtime fading/positive routines, and scheduled awakenings. Additional research is needed to examine delivery methods of treatment, longer-term efficacy, and the role of pharmacological agents. Furthermore, pediatric sleep researchers are strongly encouraged to develop standardized diagnostic criteria and more objective measures, and to come to a consensus on critical outcome variables.
Light exposure and sleep timing are two factors that influence inter-individual variability in the timing of the human circadian clock. The aim of this study was to quantify the degree to which evening light exposure predicts variance in circadian timing over and above bedtime alone in preschool children. Participants were 21 children ages 4.5–5.0 years (4.7±0.2 years; 9 females). Children followed their typical sleep schedules for 4 days during which time they wore a wrist actigraph to assess sleep timing and a pendant light meter to measure minute-by-minute illuminance levels in lux. On the 5th day, children participated in an in-home dim-light melatonin onset (DLMO) assessment. Light exposure in the 2hours before bedtime was averaged and aggregated across the 4 nights preceding the DLMO assessment. Mean DLMO and bedtime were 19:22±01:04 and 20:07±00:46, respectively. Average evening light exposure was 710.1±1418.2lx. Children with later bedtimes (lights-off time) had more delayed melatonin onset times (r=0.61, p=0.002). Evening light exposure was not independently associated with DLMO (r=0.32, p=0.08); however, a partial correlation between evening light exposure and DLMO when controlling for bedtime yielded a positive correlation (r=0.46, p=0.02). Bedtime explained 37.3% of the variance in the timing of DLMO, and evening light exposure accounted for an additional 13.3% of the variance. These findings represent an important step in understanding factors that influence circadian phase in preschool-age children and have implications for understanding a modifiable pathway that may underlie late sleep timing and the development of evening settling problems in early childhood.
The shift from a biphasic to a monophasic sleep schedule is a fundamental milestone in early childhood. This transition, however, may result in periods of acute sleep loss as children may nap on some but not all days. Although data indicating the behavioral consequences of nap deprivation in young children are accumulating, little is known about changes to sleep neurophysiology following daytime sleep loss. This study addresses this gap in knowledge by examining the effects of acute nap deprivation on subsequent nighttime sleep electroencephalographic (EEG) parameters in toddlers. Healthy children (n=25; 11 males; ages 30–36 months) followed a strict sleep schedule for ≥5 days before sleep EEG recordings performed on 2 non-consecutive days: one after 13 h of prior wakefulness and another at the same clock time but preceded by a daytime nap. Total slow-wave energy (SWE) was computed as cumulative slow-wave activity (SWA; EEG power in 0.75–4.5 Hz range) over time. Nap and subsequent night SWE were added and compared to SWE of the night after a missed nap. During the night following a missed nap, children fell asleep faster (11.9±8.7 min versus 37.3±22.1 min; d=1.6, p=0.01), slept longer (10.1±0.7 h versus 9.6±0.6 h; d=0.7, p
Objective To explore the association of sleep duration and awakening frequency with cognitive outcomes in young children. Methods Mothers of 2,800 children from the Generation R cohort reported sleep duration and awakenings at children’s age 24 months.
At age 6 years, validated Dutch measures were used to assess children’s nonverbal intelligence and language comprehension. Results We found a nonlinear association of total sleep time at 24 months with nonverbal intelligence (p = 0.03) and language comprehension (p = 0.04) at 6 years. Toddlers sleeping within the recommended 11–14 hr had more favorable cognitive development compared with
both extremes. Frequent awakenings were negatively associated with nonverbal intelligence, but not with verbal comprehension. Conclusion Sleep duration in toddlerhood has an inverted-U-shaped relation with childhood cognitive measures. Frequent awakenings are
associated with lower nonverbal intelligence. Given the marked decline in sleep duration and awakenings in toddlerhood, developmental
changes of sleep patterns might be important for cognitive development.
The timing of the internal circadian clock shows large inter-individual variability across the lifespan. Although the sleep-wakefulness pattern of most toddlers includes an afternoon nap, the association between napping and circadian phase in early childhood remains unexplored. This study examined differences in circadian phase and sleep between napping and non-napping toddlers. Data were collected on 20 toddlers (34.2±2.0 months; 12 females; 15 nappers). Children followed their habitual napping and non-napping sleep schedules (monitored with actigraphy) for 5 days before an in-home salivary dim light melatonin onset (DLMO) assessment. On average, napping children fell asleep during their nap opportunities on 3.6±1.2 of the 5 days before the DLMO assessment. For these napping children, melatonin onset time was 38 min later (p = 0.044; d = 0.93), actigraphically-estimated bedtime was 43 min later (p = 0.014; d = 1.24), sleep onset time was 59 min later (p = 0.006; d = 1.46), and sleep onset latency was 16 min longer (p = 0.030; d = 1.03) than those not napping. Midsleep and wake time did not differ by napping status. No difference was observed in the bedtime, sleep onset, or midsleep phase relationships with DLMO; however, the wake time phase difference was 47 min smaller for napping toddlers (p = 0.029; d = 1.23). On average, nappers had 69 min shorter nighttime sleep durations (p = 0.006; d = 1.47) and spent 49 min less time in bed (p = 0.019; d = 1.16) than non-nappers. Number of days napping was correlated with melatonin onset time (r = 0.49; p = 0.014). Our findings indicate that napping influences individual variability in melatonin onset time in early childhood. The delayed bedtimes of napping toddlers likely permits light exposure later in the evening, thereby delaying the timing of the clock and sleep. Whether the early developmental trajectory of circadian phase involves an advance associated with the decline in napping is a question necessitating longitudinal data as children transition from a biphasic to monophasic sleep-wakefulness pattern.
The aim of this descriptive analysis was to examine sleep timing, circadian phase, and phase angle of entrainment across adolescence in a longitudinal study design. Ninety-four adolescents participated; 38 (21 boys) were 9-10 years ("younger cohort") and 56 (30 boys) were 15-16 years ("older cohort") at the baseline assessment. Participants completed a baseline and then follow-up assessments approximately every six months for 2.5 years. At each assessment, participants wore a wrist actigraph for at least one week at home to measure self-selected sleep timing before salivary dim light melatonin onset (DLMO) phase - a marker of the circadian timing system - was measured in the laboratory. Weekday and weekend sleep onset and offset and weekend-weekday differences were derived from actigraphy. Phase angles were the time durations from DLMO to weekday sleep onset and offset times. Each cohort showed later sleep onset (weekend and weekday), later weekend sleep offset, and later DLMO with age. Weekday sleep offset shifted earlier with age in the younger cohort and later in the older cohort after age 17. Weekend-weekday sleep offset differences increased with age in the younger cohort and decreased in the older cohort after age 17. DLMO to sleep offset phase angle narrowed with age in the younger cohort and became broader in the older cohort. The older cohort had a wider sleep onset phase angle compared to the younger cohort; however, an age-related phase angle increase was seen in the younger cohort only. Individual differences were seen in these developmental trajectories. This descriptive study indicated that circadian phase and self-selected sleep delayed across adolescence, though school-day sleep offset advanced until no longer in high school, whereupon offset was later. Phase angle changes are described as an interaction of developmental changes in sleep regulation interacting with psychosocial factors (e.g., bedtime autonomy).
Circadian rhythms are near 24-h patterns of physiology and behaviour that are present independent of external cues including hormones, body temperature, mood, and sleep propensity. The term ‘circadian misalignment’ describes a variety of circumstances, such as inappropriately timed sleep and wake, misalignment of sleep/wake with feeding rhythms, or misaligned central and peripheral rhythms. The predominance of early research focused on misalignment of sleep to the biological night. However, discovery of clock genes and the presence of peripheral circadian oscillators have expanded the definitions of misalignment. Experimental studies conducted in animal models and humans have provided evidence of potential mechanisms that link misalignment to negative outcomes. These include dysregulation of feeding behaviours, changes in appetite stimulating hormones, glucose metabolism and mood. This review has two foci: (1) to describe how circadian misalignment has been defined and evaluated in laboratory and field experiments, and (2) to describe evidence linking different types of circadian misalignment to increased risk for physical (cardiovascular disease, diabetes, obesity, cancer) and psychiatric (depression, bipolar, schizophrenia, attention deficit) disorders. This review will describe the role of circadian misalignment as a risk factor for disease in the general population and in clinical populations, including circadian rhythm sleep disorders and psychiatric disorders.
Objective:
To examine the effect of experimental changes in children's sleep duration on self-reported food intake, food reinforcement, appetite-regulating hormones, and measured weight.
Methods:
Using a within-subjects, counterbalanced, crossover design, 37 children, 8 to 11 years of age (27% overweight/obese) completed a 3-week study. Children slept their typical amount at home for 1 week and were then randomized to either increase or decrease their time in bed by 1.5 hours per night for 1 week, completing the alternate schedule on the third week. Primary outcomes were dietary intake as assessed by 24-hour dietary recalls, food reinforcement (ie, points earned for a food reward), and fasting leptin and ghrelin. The secondary outcome was child weight.
Results:
Participants achieved a 2 hour, 21 minute difference in the actigraph defined sleep period time between the increase and decrease sleep conditions (P < .001). Compared with the decrease sleep condition, during the increase condition, children reported consuming an average of 134 kcal/day less (P < .05), and exhibited lower fasting morning leptin values (P < .05). Measured weights were 0.22 kg lower during the increase sleep than the decrease sleep condition (P < .001). There were no differences in food reinforcement or in fasting ghrelin.
Conclusions:
Compared with decreased sleep, increased sleep duration in school-age children resulted in lower reported food intake, lower fasting leptin levels, and lower weight. The potential role of sleep duration in pediatric obesity prevention and treatment warrants further study.
Significance
Lacking scientific understanding of the function of naps in early childhood, policy makers may curtail preschool classroom nap opportunities due to increasing curriculum demands. Here we show evidence that classroom naps support learning in preschool children by enhancing memories acquired earlier in the day as compared with equivalent intervals spent awake.
The influence of road traffic noise on the sleep of adults and 6-11 year old children was studied by using electrophysiological methods. Young adults, unaccustomed to traffic noise, were disturbed by continuous and intermittent traffic noise at 45 dB(A). No sleep disturbances were found for continuous traffic noise at 36 dB(A). Car passages with a peak noise level of 55 dB(A) caused awakenings. The equivalent sound pressure level (Leq) did not correlate with sleep disturbance effects. A better noise dose description was found in the number of vehicles per night that made most noise. Children wer about 10 dB(A) less sensitive than adults to awakening reactions, and even less sensitive with respect to disturbances of REM sleep and deep sleep. Total habituation to road traffic noise did not occur, even after at least one year of exposure. Sound reduction in the bedroom induced increased amounts of deep sleep for adults and reduced falling-asleep time for children. Road traffic noise during the first hours of a night's sleep tended to disturb sleep more than when it ocurred later in the night, the main effects being a reduction of the total amount of REM sleep during the night and an increased duration of intermittent wakefulness during the hours of exposure.
Examines the decisions of middle-class US and Highland Mayan parents regarding sleeping arrangements during their child's 1st 2 yrs and their explanations for their differing practices. All 14 Mayan children slept in their mothers' beds into toddlerhood. None of the 18 US infants slept in bed with their mothers on a regular basis as newborns, although 15 slept near their mothers until age 3–6 mo, when most were moved to a separate room. The Mayan parents explained their practices in terms of the value of closeness with infants; US parents explained their practices in terms of the value of independence for infants. US families, but not Mayan families, used bedtime routines and objects to facilitate the transition to sleep. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Sleep-related problems are highly prevalent among childhood and adolescent anxiety disorders. The objective of this review was to summarize the relevant clinical research literature as it pertains to the nature of the association between sleep-related problems and youth anxiety, developmental factors relevant to this association, and intervention efforts to target comorbid sleep challenges and anxiety. Limitations of the literature and future directions are discussed.
This article reviews the literature on mood disorders and sleep disorders among children and adolescents. Research suggests that sleep plays an important role in the development, progression, and maintenance of mood disorder symptoms among children and adolescents. Sleep problems as early as maternal perinatal insomnia may predict and predate depression among youth. Children and adolescents who develop comorbid mood disorders and sleep problems represent a particularly high-risk group with more severe mood episode symptoms, higher rates of self-harm and suicidality, and less responsivity to treatment. Treatment research supports the idea that sleep problems can be improved through behavioral interventions.
Sleep problems are common in youth with attention-deficit/hyperactivity disorder (ADHD). Externalizing and internalizing problems contribute to dysfunction in youth with ADHD and are amplified by disrupted sleep. This objective of this article is to synthesize empirical studies that examined the associations between sleep and internalizing or externalizing problems in individuals with ADHD. The main findings are that sleep problems precede, predict, and significantly contribute to the manifestation of internalizing and externalizing behavior problems among children and adolescents with ADHD. Clinicians should assess sleep and integrate sleep interventions into the management of youth with ADHD.
Research on anxiety in children and adolescents with autism spectrum disorder (ASD) has burgeoned in the past 15 years. Most of the research has focused on school‐age children, ages 6 to 18 years. Yet, recent studies suggest that anxiety can emerge in young children, under 6 years, with ASD. This scoping review synthesized the literature on anxiety in young children with ASD. Three domains of anxiety research were reviewed: (a) prevalence/severity, phenomenology, and course; (b) correlates; and (c) treatment. Four online databases were searched from the start of the database until March 2020. Keywords pertaining to anxiety, autism, and young children were entered. The search identified 44 articles for inclusion. These studies varied with respect to sample source, informants, and measures to assess anxiety. The overall prevalence of anxiety ranged from 1.6 to 62%. Sixteen of 17 studies found that young children with ASD had higher levels of anxiety compared to various control groups. A variety of DSM anxiety symptoms and disorders were present in young children with the most common symptoms being specific, social, and generalized fears. Correlates of anxiety included sensory over‐responsivity, sleep disturbance, aggression/defiance, and attention deficit/hyperactivity disorder. Three cognitive behavioral treatment studies for anxiety and one developmental intervention targeting ASD symptoms showed promise in reducing anxiety. Findings indicate an early emergence of anxiety in some children with ASD. Further research on the measurement, pathophysiology, and treatment of anxiety in early childhood is critical to improving outcomes in children with ASD.
Lay summary
This scoping review synthesizes the literature on anxiety in young children with autism spectrum disorder (ASD). Results indicate that children with ASD have higher levels of anxiety than children without ASD. Potential factors that could be contributing to anxiety include sensory, sleep, and behavioral problems. Preliminary studies show that anxiety can improve with cognitive behavioral treatment. These findings suggest that research on anxiety in young children with ASD should be prioritized to improve mental health outcomes.
Prolonged viewing of screen‐based media is associated with poor sleep in children. Previous systematic reviews have analysed the effectiveness of interventions that aim to limit children's screen use; however, none have evaluated its effect on sleep. The aim of this systematic review was to evaluate the effect of interventions that incorporate strategies to control children's screen use on screen use and sleep. The databases Pubmed, Embase, Eric, Scopus and PsycInfo were searched during October 2017 and updated in February 2019 for experimental studies with a control that assessed interventions to control screen use in children aged 2–14 years and reported both screen use and sleep outcomes. From 3,872 initial records, 11 studies (six randomized control [RCT], four cluster RCT and one cluster, quasi‐experimental) were eligible for inclusion. A total of 4,656 children aged 2–13 years were included in the studies. The mean reduction in screen time was 0.56 hr (33 min)/day (95% confidence interval [CI], 0.92, 0.20) and the mean sleep duration increased by 0.19 hr (11 min)/day (95% CI, 0.05, 0.33). Bedtime was advanced by 0.16 hr (10 min) on weekdays and by 1.0 hr at the weekend. Subgroup analyses indicated stronger intervention effects for interventions of shorter duration (<3 months), which specifically targeted screen use or sleep, and those with direct participant contact. In conclusion, small improvements in screen time and sleep duration can be achieved in children. It is not possible to determine if a reduction in screen time directly improves sleep, due to the limited number of studies, the presence of co‐interventions, issues with studies' methodological quality and heterogeneity.
Background:
Despite significant income-related disparities in pediatric sleep, few early childhood sleep interventions have been tailored for or tested with families of lower socio-economic status (SES). This qualitative study assessed caregiver and clinician perspectives to inform adaptation and implementation of evidence-based behavioral sleep interventions in urban primary care with families who are predominantly of lower SES.
Methods:
Semi-structured interviews were conducted with (a) 23 caregivers (96% mothers; 83% Black; 65% ≤125% U.S. poverty level) of toddlers and preschoolers with insomnia or insufficient sleep and (b) 22 urban primary care clinicians (physicians, nurse practitioners, social workers, and psychologists; 87% female; 73% White). Guided by the Consolidated Framework for Implementation Research, the interview guide assessed multilevel factors across five domains related to intervention implementation. Qualitative data were analyzed using an integrated approach to identify thematic patterns across participants and domains.
Results:
Patterns of convergence and divergence in stakeholder perspectives emerged across themes. Participants agreed upon the importance of child sleep and intervention barriers (family work schedules; household and neighborhood factors). Perspectives aligned on intervention (flexibility; collaborative and empowering care) and implementation (caregiver-to-caregiver support and use of technology) facilitators. Clinicians identified many family barriers to treatment engagement, but caregivers perceived few barriers. Clinicians also raised healthcare setting factors that could support (integrated care) or hinder (space and resources) implementation.
Conclusions:
Findings point to adaptations to evidence-based early childhood sleep intervention that may be necessary for effective implementation in urban primary care. Such adaptations could potentially reduce significant pediatric sleep-related health disparities.
Background
The objective of this systematic review and meta-analysis was to investigate the associations between neighborhood socioeconomic status (nSES) and sleep duration in children aged 0–18 years.
Methods
Three electronic databases were searched for relevant articles that assessed nSES and sleep duration (either subjectively or objectively). Inclusion criteria included peer-reviewed scholarly articles on the topic area that reported an association between nSES and sleep in children and adolescents.
Results
The database searched identified 6080 potentially eligible studies, of which 1210 were selected for full-text review, and 8 met the inclusion criteria. Data included 67,677 unique participants. Studies were conducted in either the United States of America or Australia. Pooled estimates suggested that poorer nSES was associated with shorter child sleep duration (odds ratio: 1.262; 95% confidence interval: 1.086–1.467). This relationship between nSES and sleep was moderated by sleep assessment type (self-report versus actigraphy), child sex/gender, and child race/ethnicity.
Conclusions
Across studies, there is an association between nSES and child sleep duration. This study adds child sleep to the growing number of child health disparities associated with nSES.
Human biology follows recurring daily rhythms that are governed by circadian cues in the environment. Here we show that human milk is a powerful form of “chrononutrition,” formulated to communicate time-of-day information to infants. However, 85% of breastfed infants in the US consume some milk that does not come directly from the breast but is pumped and stored in advance of feeding. Expressed milk is not necessarily circadian-matched (e.g., an infant might drink breastmilk pumped in the evening on the following morning). Ingesting mistimed milk may disrupt infants’ development of circadian rhythms, potentially contributing to sleep problems and decreased physiological attunement with their mothers and environments. Dysregulated circadian biology may compromise infant health and development. Despite wide-ranging public health implications, the timing of milk delivery has received little empirical study, and no major pediatric or public health organization has issued recommendations regarding the circadian-matching of milk. However, potential adverse developmental and health consequences could be ameliorated by simple, low-cost interventions to label and circadian-match stored milk. The current paper reviews evidence for human milk as chrononutrition and makes recommendations for future research, practice, and policy.
Objective/background
Sleep problems are common in young children, especially young children with autism spectrum disorder (ASD). Sleep hygiene is a set of practices, which promote good sleep. However, other than bedtime routines and schedules, sleep hygiene is not often examined in this age group, or in ASD. The aim of this study was to examine sleep problems in young children with and without ASD and their relationship to sleep hygiene practices.
Participants
Parents (N = 101) of young children aged 2–5 years (M = 47.5 mths, SD = 1.3) were surveyed. Children included 28 with ASD, 2 with global developmental delay, and 71 who were typically developing.
Methods
A survey of sleep and sleep hygiene practices and the Children’s Sleep Habits Questionnaire (CSHQ) examined via parent-report sleep problems and their relationship with thermal comfort, screen time, and diet.
Results
More than half of all children (55.4%; 78.6% of children with ASD) had a sleep problem. Children with ASD and a sleep problem slept fewer hours than other children, but they did not differ on their CSHQ score. Areas of sleep hygiene associated with poorer sleep for children with and without ASD included thermal comfort factors and screen usage.
Conclusions
These results suggest that too much screen time may be related to sleep problems for young children with and without ASD. Parents also may need advice about maintaining appropriate thermal comfort for their sleeping child. Although these findings provide preliminary relationships and require replication and specific intervention recommendations, these results are particularly important for children with ASD who are at high risk for poor sleep.
This paper presents a conceptual model and reviews the empirical evidence to support a nightly bedtime routine as a key factor in the promotion of not only healthy sleep, but also of broad development and wellbeing in early childhood. A bedtime routine embodies the characteristics of nurturing care and early child stimulation, which are deemed to be essential for positive outcomes, especially for at-risk children. Furthermore, common, adaptive components of a bedtime routine can contribute to an array of positive developmental outcomes beyond improved sleep, inclusive of language development, literacy, child emotional and behavioral regulation, parent-child attachment, and family functioning, among other outcomes. These bedtime routine components include activities in the broad domains of nutrition (e.g., feeding, healthy snack), hygiene (e.g., bathing, oral care), communication (e.g., reading, singing/lullabies) and physical contact (e.g., massage, cuddling/rocking). A bedtime routine can provide multiple benefits to child and family functioning at a time of day that many parents are present with their children. Although additional research on hypothesized routine-related child outcomes and mechanisms of action are needed, promoting a bedtime routine may be a feasible and cost-effective method to promote positive early childhood development worldwide, particularly for socioeconomically disadvantaged and other at-risk young children.
Given the pervasive use of screen-based media and the high prevalence of insufficient sleep among American youth and teenagers, this brief report summarizes the literature on electronic media and sleep and provides research recommendations. Recent systematic reviews of the literature reveal that the vast majority of studies find an adverse association between screen-based media consumption and sleep health, primarily via delayed bedtimes and reduced total sleep duration. The underlying mechanisms of these associations likely include the following: (1) time displacement (ie, time spent on screens replaces time spent sleeping and other activities); (2) psychological stimulation based on media content; and (3) the effects of light emitted from devices on circadian timing, sleep physiology, and alertness. Much of our current understanding of these processes, however, is limited by cross-sectional, observational, and self-reported data. Further experimental and observational research is needed to elucidate how the digital revolution is altering sleep and circadian rhythms across development (infancy to adulthood) as pathways to poor health, learning, and safety outcomes (eg, obesity, depression, risk-taking).
Background:
Poverty has been linked to sleep disruption, which is in turn associated with health and behavior problems. Sleep disturbance may be a key mechanism by which poverty affects child development.
Objective:
To evaluate the feasibility, appeal, and promise of a brief sleep-promoting intervention for low-income families with 4- to 8-year-old children in site-based supportive housing.
Methods:
University researchers and community partners developed a sleep-promoting intervention (family workshop and bedtime relaxation routine) that was implemented at one supportive housing site. Multiple methods were used to assess feasibility and preliminary effectiveness in 11 participating families.
Results:
Intervention and research activities were acceptable to families, but adherence to daily sleep measures was low. Most parents reported high satisfaction, and data showed trends of improvement in children's sleep, behavior, and executive function (EF).
Conclusions:
A brief sleep-promoting intervention for children in disadvantaged families showed feasibility and promise. Future studies are needed to test the efficacy of a refined version of this sleep intervention with families in similar situations, focusing on decreasing burden, tailoring interventions, and sustaining change.
Sleep is essential for optimal health, well-being, and cognitive functioning, and yet nationwide, youth are not obtaining consistent, adequate, or high-quality sleep. In fact, more than two-thirds of US adolescents are sleeping less than 8 hours nightly on school nights. Racial and ethnic minority children and adolescents are at an increased risk of having shorter sleep duration and poorer sleep quality than their white peers. In this review, we critically examined and compared results from 23 studies that have investigated racial/ethnic sleep disparities in American school-aged children and adolescents ages 6-19 years. We found that White youth generally had more sufficient sleep than minority youth, Hispanics had more than Blacks, and there was inconclusive evidence for Asians and other minorities. Recommendations for researchers include the following: (1) explore underlying causes of the disparities of these subpopulations, with a particular interest in identifying modifiable causes; (2) examine factors that may be impacted by racial/ethnic sleep disparities; (3) use a multidimensional approach to measuring sleep disparities; and (4) examine how beliefs about sleep are patterned by race/ethnicity. Understanding sleep disparities can inform interventions, policies, and educational programs to minimize sleep disparities and their impact on health, psychological, and educational outcomes.
Objectives:
To assess the effect of poor sleep quality on Overweight/Obesity (Ow/Ob) in young subjects, and explore if this association is independent of sleep duration.
Methods:
Pubmed, EMBASE, and MEDLINE databases were searched for papers on sleep quality and overweight/obesity, focusing on children, adolescents, and young adults. Studies based on subjects with medical/psychological problems or published in languages other than English were excluded. Quality effects model was used to pool studies for meta-analysis.
Results:
Findings from the systematic review suggest a link between poor sleep quality and Ow/Ob in young subjects. Pooled estimate (from 26,553 subjects) suggest a role of inadequate sleep (including both short duration and poor quality) in Ow/Ob (OR: 1.27 95% CI: 1.05-1.53). Sub-group-analyses suggest considerably higher odds of Ow/Ob (OR = 1.46, 95% CI: 1.24-1.72) in young subjects with poor sleep quality (independent of duration).
Conclusions:
Poor sleep quality seems to be associated with Ow/Ob, and some studies indicate this association to be independent of duration. Therefore, considering only sleep duration might not help in disentangling sleep-obesity association. However, this review is mostly composed of cross-sectional studies. Therefore, a causal link or the stability of the sleep quality and Ow/Ob association could not be established.
Objective:
Previous epidemiology studies have demonstrated that short sleep duration may be associated with the development of obesity, although the effects remain controversial. This study aimed to assess epidemiologic evidence systematically on the relation between sleep duration and obesity in children.
Design and methods:
We searched the Medline, Cochrane Library, EMBASE and Science Citation Index databases and reference lists of the included articles. Pooled odds ratio (OR) with 95% confidence interval (CI) was calculated using a random-effects model.
Results:
Fifty cohorts from thirteen studies were included in the pooled analysis. They included 35,540 participants from around the world. In children/adolescents the pooled OR was 1.71 (1.36-2.14; I(2)=91.3%), the positive association was consistent after omitting any of the studies. In subgroup analyses, the results indicated that the heterogeneity of effect may due to differences in geographical location, cut-off for short sleep duration and definition of obesity/overweight. The publication bias tests indicated a no evidence of publication bias.
Conclusion:
This meta-analysis provides evidence that short sleep duration in children is associated with a significantly increased risk of obesity. Enough sleep duration is potentially important for the prevention of obesity among children.
Sleep is essential for optimal health in children and adolescents. Members of the American Academy of Sleep Medicine developed consensus recommendations for the amount of sleep needed to promote optimal health in children and adolescents using a modified RAND Appropriateness Method. The recommendations are summarized here. A manuscript detailing the conference proceedings and the evidence supporting these recommendations will be published in the Journal of Clinical Sleep Medicine.
The purpose of this study was to investigate and compare sleep and skin temperature (Tsk) of preschool children with those of their mothers. The subjects included 18 pairs of preschool children and their mothers. The actigraphic measurement of sleep, Tsk, heart rate, bedroom climate, and the microclimate temperature and humidity (bed climate) were measured. Proximal and distal Tsk, the temperature gradient of distal and proximal Tsk (DPG), and bed climate temperature were significantly lower in the children. Approximately 70% of the children slept without bed covering. Heat dissipation during sleep in preschool children may primarily rely on the proximal Tsk. The lower Tsk than adults, and behavioral thermoregulation, may be important for sleep in preschoolers.
We completed a systematic review of literature related to parent knowledge of children’s sleep, to determine how much parents know about typical child sleep and symptoms related to sleep problems in childhood and how parent knowledge has been assessed. We also examined whether relationships have been reported between parent knowledge of children’s sleep, parent education, child sleep problems, sleep duration, and sleep hygiene. An extensive literature search of five electronic databases was conducted, and of 615 articles identified, eight met inclusion criteria for review: four descriptive studies and four educational interventions. These studies varied considerably in the number of items included in scales, the specific content measured, the response scales used, and the populations included, limiting the conclusions that could be drawn across studies. In general, parent knowledge of child sleep was poor. Greater accuracy was reported for items pertaining to healthy sleep practices at sleep onset and daytime symptoms, in comparison with items pertaining to child sleep problems during the night. More knowledgeable parents were more likely to report that their children exhibited healthy sleep practices; associations with sleep duration were mixed. Small interventions demonstrated an increase in parental knowledge in the short-term, but effects were not maintained at follow-up. Future work is needed to clarify relations between parental knowledge and child sleep, and to design and evaluate effective methods of promoting education about child sleep in a range of parent populations. The further development of validated tools to assess parent knowledge of child sleep will be required to underpin this work.
Objective:
To make scientifically sound and practical recommendations for daily sleep duration across the life span.
Methods:
The National Sleep Foundation convened a multidisciplinary expert panel (Panel) with broad representation from leading stakeholder organizations. The Panel evaluated the latest scientific evidence and participated in a formal consensus and voting process. Then, the RAND/UCLA Appropriateness Method was used to formulate sleep duration recommendations.
Results:
The Panel made sleep duration recommendations for 9 age groups. Sleep duration ranges, expressed as hours of sleep per day, were designated as recommended, may be appropriate, or not recommended. Recommended sleep durations are as follows: 14-17 hours for newborns, 12-15 hours for infants, 11-14 hours for toddlers, 10-13 hours for preschoolers, 9-11 hours for school-aged children, and 8-10 hours for teenagers. Seven to 9 hours is recommended for young adults and adults, and 7-8 hours of sleep is recommended for older adults. The self-designated basis for duration selection and critical discussions are also provided.
Conclusions:
Consensus for sleep duration recommendations was reached for specific age groupings. Consensus using a multidisciplinary expert Panel lends robust credibility to the results. Finally, limitations and caveats of these recommendations are discussed.
To assess the association between infant sleeping position and risk of sudden infant death syndrome (SIDS) in an ethnically diverse US population, the authors conducted a population-based case-control study in 11 counties in California from May 1997 through April 2000. The authors conducted in-person interviews with the mothers of 185 SIDS cases and 312 randomly selected race/ethnicity- and age-matched controls to collect information on sleeping positions. Infants who had last been put down to sleep in the prone or side position were at greater risk of SIDS than were infants who had last been put down on their backs (adjusted odds ratio (AOR) = 2.6 (95% confidence interval (Cl): 1.5, 4.5) and AOR = 2.0 (95% Cl: 1.2, 3.4) for the prone and side positions, respectively). The risk of SIDS was especially high for an unstable side position in which an infant was placed on its side and found prone (AOR = 8.7, 95% Cl: 3.3, 22.7). Infants who were usually placed on their backs to sleep but had last been put down in the prone or side position (an unaccustomed position) had a significantly high risk of SIDS (AOR = 8.2 (95% Cl: 2.6, 26.0) and AOR = 6.9 (95% Cl: 2.3, 20.6) for the prone and side positions, respectively). Infants placed in an unaccustomed prone or side sleeping position had a higher risk of SIDS than infants who were always placed prone or on the side.
There has been a major decrease in the incidence of sudden infant death syndrome (SIDS) since the American Academy of Pediatrics (AAP) released its recommendation in 1992 that infants be placed down for sleep in a nonprone position. Although the SIDS rate continues to fall, some of the recent decrease of the last several years may be a result of coding shifts to other causes of unexpected infant deaths. Since the AAP published its last statement on SIDS in 2000, several issues have become relevant, including the significant risk of side sleeping position; the AAP no longer recognizes side sleeping as a reasonable alternative to fully supine sleeping. The AAP also stresses the need to avoid redundant soft bedding and soft objects in the infant's sleeping environment, the hazards of adults sleeping with an infant in the same bed, the SIDS risk reduction associated with having infants sleep in the same room as adults and with using pacifiers at the time of sleep, the importance of educating secondary caregivers and neonatology practitioners on the importance of "back to sleep," and strategies to reduce the incidence of positional plagiocephaly associated with supine positioning. This statement reviews the evidence associated with these and other SIDS-related issues and proposes new recommendations for further reducing SIDS risk.
An increasing body of literature indicates that discrimination has a negative impact on health; poor sleep may be an underlying mechanism. The primary objective of this review was to examine existing studies on the relationship between discrimination and sleep to clarify (a) the potential role of discrimination in shaping population patterns of sleep and sleep disparities, and (b) the research needed to develop interventions at individual and institutional levels. We identified articles from English-language publications in PubMed and EBSCO databases from inception through July 2014. We employed a broad definition of discrimination to include any form of unfair treatment and all self-reported and objectively assessed sleep outcomes, including duration, difficulties, and sleep architecture. Seventeen studies were identified: four prospective, 12 cross-sectional, and one that utilized a daily-diary design. Fifteen of the 17 studies evaluated interpersonal discrimination as the exposure and the majority of studies included self-reported sleep as the outcome. Only four studies incorporated objective sleep assessments. All 17 studies identified at least one association between discrimination and a measure of poorer sleep, although studies with more detailed consideration of either discrimination or sleep architecture revealed some inconsistencies. Taken together, existing studies demonstrate consistent evidence that discrimination is associated with poorer sleep outcomes. This evidence base can be strengthened with additional prospective studies that incorporate objectively measured aspects of sleep. We outline important extensions for this field of inquiry that can inform the development of interventions to improve sleep outcomes, and consequently promote well-being and reduce health inequities across the life course.
Copyright © 2015 Elsevier B.V. All rights reserved.
Associations of inadequate sleep with numerous health outcomes among youth necessitate identifying its modifiable determinants. Television (TV) has been associated with sleep curtailment, but little is known about small screens (eg, smartphones), which can be used in bed and emit notifications. Therefore, we examined associations of different screens in sleep environments with sleep duration and perceived insufficient rest or sleep.
Participants included 2048 fourth- and seventh-graders participating in the Massachusetts Childhood Obesity Research Demonstration Study in 2012 to 2013. Using linear and log binomial regression, we examined cross-sectional associations of small screens and TVs in sleep environments and screen time with weekday sleep duration and perceived insufficient rest or sleep in the past week.
Children who slept near a small screen (compared with never) reported 20.6 fewer minutes of sleep (95% confidence interval [CI], -29.7 to -11.4) and had a higher prevalence of perceived insufficient rest or sleep (prevalence ratio, 1.39; 95% CI, 1.21 to 1.60). Children who slept in a room with a TV (compared with no TV) reported 18.0 fewer minutes of sleep (95% CI, -27.9 to -8.1). TV or DVD viewing and video or computer game playing were associated with both sleep outcomes (P < .01). Some associations were stronger among Hispanic, non-Hispanic black, and older children (P < .05 for heterogeneity).
Sleeping near a small screen, sleeping with a TV in the room, and more screen time were associated with shorter sleep durations. Presence of a small screen, but not a TV, in the sleep environment and screen time were associated with perceived insufficient rest or sleep. These findings caution against unrestricted screen access in children's bedrooms.
Copyright © 2015 by the American Academy of Pediatrics.
Children in families of low socioeconomic status (SES) have been found to have poor sleep, yet the reasons for this finding are unclear. Two possible mediators, presleep worries and home environment conditions, were investigated as indirect pathways between SES and children's sleep.
The participants consisted of 271 children (M (age) = 11.33 years; standard deviation (SD) = 7.74 months) from families varying in SES as indexed by the income-to-needs ratio. Sleep was assessed with actigraphy (sleep minutes, night waking duration, and variability in sleep schedule) and child self-reported sleep/wake problems (eg, oversleeping and trouble falling asleep) and sleepiness (eg, sleeping in class and falling asleep while doing homework). Presleep worries and home environment conditions were assessed with questionnaires.
Lower SES was associated with more subjective sleep/wake problems and daytime sleepiness, and increased exposure to disruptive sleep conditions and greater presleep worries were mediators of these associations. In addition, environmental conditions served as an intervening variable linking SES to variability in an actigraphy-derived sleep schedule, and, similarly, presleep worry was an intervening variable linking SES to actigraphy-based night waking duration. Across sleep parameters, the model explained 5-29% of variance.
Sleep environment and psychological factors are associated with socioeconomic disparities, which affect children's sleep.
Copyright © 2014 Elsevier B.V. All rights reserved.
Early childhood represents a time of developmental changes in both sleep and self-regulation, a construct reflecting the ability to control one's behaviour, attention and emotions when challenged. Links between sleep and self-regulation processes have been proposed, but experimental evidence with young children is lacking. In the current study, we tested the effects of acute sleep restriction (nap deprivation) on toddlers' self-regulation. Healthy children (n = 12; four males; aged 30-36 months (33.9 ± 1.7)) slept on a strict schedule (verified with actigraphy and sleep diaries) for 5 days before each of two afternoon assessments following a nap and a no-nap condition (~11-day protocol). Children were videotaped while attempting an unsolvable puzzle, and 10 mutually exclusive self-regulation strategies were later coded. On average, children lost ~90 min of sleep on the no-nap versus the nap day. Nap deprivation resulted in moderate-to-large effects on self-regulation strategies, with decreases in scepticism (d = 0.77; 7% change), negative self-appraisal (d = 0.92; 5% change) and increases in physical self-soothing (d = 0.68; 10% change), focus on the puzzle piece that would not fit (perseveration; d = 0.50; 9% change) and insistence on completing the unsolvable puzzle (d = 0.91; 10% change). Results suggest that sleep serves an important role in the way that toddlers respond to challenging events in their daily lives. After losing daytime sleep, toddlers were less able to engage effectively in a difficult task and reverted to less mature self-regulation strategies than when they were well rested. Over time, chronically missed sleep may impair young children's self-regulation abilities, resulting in risk for social-emotional, behavioural and school problems.
Background:
Establishment of a consistent bedtime routine (the activities that occur right before lights out) is often recommended as part of healthy sleep habits. However, no studies have investigated the dose-dependent association of a bedtime routine with sleep outcomes, especially in young children for whom they are particularly recommended. Thus, the aim of this study was to examine the associations of a consistent bedtime routine with sleep outcomes in young children (ages 0 through 5 y) in a large global sample and assess whether there is a dose-dependent relationship between the frequency of a bedtime routine both concurrently and retrospectively with sleep outcomes.
Participants:
Mothers of 10,085 children (Australia-New Zealand, Canada, China, Hong Kong, India, Japan, Korea, Malaysia, Philippines, Singapore, Thailand, United Kingdom, United States) completed the Brief Infant/Child Sleep Questionnaire.
Results:
A consistent bedtime routine was associated with better sleep outcomes, including earlier bedtimes, shorter sleep onset latency, reduced night wakings, and increased sleep duration. Decreased parent-perceived sleep problems and daytime behavior problems were also related to institution of a regular bedtime routine. Furthermore, there was a dose-dependent relationship, with better outcomes associated with increased "doses" of having a bedtime routine, both currently and retrospectively, and was found within both predominantly Asian and predominantly Caucasian cultural regions.
Conclusions:
These results indicate that having a regular nightly bedtime routine is associated with improved sleep in young children, and suggests that the more consistently a bedtime routine is instituted and the younger started the better.
We systematically examined and updated the scientific literature on the association between screen time (e.g., television, computers, video games, and mobile devices) and sleep outcomes among school-aged children and adolescents. We reviewed 67 studies published from 1999 to early 2014. We found that screen time is adversely associated with sleep outcomes (primarily shortened duration and delayed timing) in 90% of studies. Some of the results varied by type of screen exposure, age of participant, gender, and day of the week. While the evidence regarding the association between screen time and sleep is consistent, we discuss limitations of the current studies: 1.) causal association not confirmed; 2.) measurement error (of both screen time exposure and sleep measures); 3.) limited data on simultaneous use of multiple screens, characteristics and content of screens used. Youth should be advised to limit or reduce screen time exposure, especially before or during bedtime hours to minimize any harmful effects of screen time on sleep and well-being. Future research should better account for the methodological limitations of the extant studies, and seek to better understand the magnitude and mechanisms of the association. These steps will help the development and implementation of policies or interventions related to screen time among youth.
Study objectives:
To evaluate a novel sleep education program for low-income preschool children and their families.
Design:
Randomized trial of an educational intervention.
Setting:
Community-based.
Participants:
Head Start preschool families (n = 152) in greater Lansing and Detroit, Michigan.
Interventions:
Classrooms or Head Start sites were randomized to an intervention group (prompt intervention) versus a control group (delayed intervention). Parents attended a one-time, 45-min sleep education program and preschoolers received 2 w (320 total min) of classroom sleep curriculum.
Measurements:
Parent knowledge, attitudes, self-efficacy, and beliefs were assessed as the primary outcomes just before the 45-min sleep intervention, immediately postintervention, and approximately 1 mo postintervention. Parents reported their child's bedtimes and wake times on 7-day sleep diaries at baseline and at 1-mo follow-up. Average weeknight sleep durations and bedtimes served as secondary outcomes.
Results:
Linear mixed models showed a time × treatment effect for parents' knowledge, attitudes, and self-efficacy (each P < 0.05) but not beliefs. These improvements were found immediately postintervention but were not retained at 1-mo follow-up. Children in the intervention group improved their weeknight sleep duration at 1-mo follow-up by 30 min (11.0 ± 0.9 h vs. 10.5 ± 1.0 hours at baseline) compared to controls (10.4 ± 0.9 h versus 10.5 ± 0.9 h at baseline) (P = 0.04 for difference between groups). Children did not show statistically significant improvements in bedtime.
Conclusions:
Educational interventions in early childhood can have an effect on parents' sleep knowledge, attitudes, and self-efficacy, and on children's sleep behavior. However, repeated exposure to the new information may be important for parents as well as their children.
Context:
The sensitivity of melatonin to light suppression is expected to be higher in children because children have large pupils and pure crystal lenses. However, melatonin suppression by light in children remains unclear.
Objective:
We investigated whether light-induced melatonin suppression in children is larger than that in adults.
Methods:
Thirty-three healthy primary school children (mean age, 9.2 ± 1.5 y) and 29 healthy adults (mean age, 41.6 ± 4.7 y) participated in two experiments. In the first experiment, salivary melatonin concentrations in 13 children and 13 adults were measured at night under a dim light (<30 lux) and a moderately bright light (580 lux) in an experimental facility. Pupil diameters were also measured under dim light and bright light. In the second experiment, melatonin concentrations in 20 children and 16 adults were measured under dim light in the experimental facility and under room light at home (illuminance, 140.0 ± 82.7 lux).
Results:
In experiment 1, the melatonin concentration was significantly decreased by exposure to moderately bright light in both adults and children. Melatonin suppression was significantly larger in children (88.2%; n = 5) than in adults (46.3%; n = 6; P < .01), although the data for some participants were excluded because melatonin concentrations had not yet risen. In experiment 2, melatonin secretion was significantly suppressed by room light at home in children (n = 15; P < .05) but not in adults (n = 11).
Conclusion:
We found that the percentage of melatonin suppression by light in children was almost twice that in adults, suggesting that melatonin is more sensitive to light in children than in adults at night.
Sleep duration is commonly studied in children, but less is known about the potential impact of adverse sleep environments, particularly at preschool ages. We examined the frequency of suboptimal sleep environments and tested for associations with sleep duration or nocturnal sleep time among low-income preschool children.
Parents of Head Start preschoolers in Michigan (Detroit and greater Lansing) completed questionnaires on children's sleep schedules and sleep environments. Respondents indicated how often their children slept in a place "too bright," "too loud," "too cold," or "too hot" on a scale of 1 = never to 5 = always. A suboptimal sleep environment (SSE) was defined when one or more of these conditions were reported for ≥ 1-2 nights/week. Weeknight sleep duration or reported time that the child went to sleep was regressed on SSE as an explanatory variable, with adjustment for age, race/ethnicity, gender, maternal education, and average daily nap duration.
Among 133 preschool children, mean age was 4.1 ± 0.5 (SD), 48% were male, 39% were white, and 52% were black; 34% of parents had ≤ a high school degree. Parents reported that 26 (20%) of the children slept in a SSE ≥ 1-2 nights per week. In regression models, SSE was associated with 27 minutes shorter sleep duration (β = -0.45, SE = 0.22, p = 0.044) and 22 minutes later time child "fell asleep" (β = 0.37, SE = 0.19, p = 0.048) on weeknights.
Among these Head Start preschool children, environmental challenges to adequate sleep are not uncommon, and they may have consequences. Clinician or preschool assessment of sleep environments may open opportunities to improve sleep at early ages.
Wilson KE; Miller AL; Lumeng JC; Chervin RD. Sleep environments and sleep durations in a sample of low-income preschool children. J Clin Sleep Med 2014;10(3):299-305.
Nighttime settling difficulties (i.e., bedtime resistance, sleep-onset delay) occur in about 25% of young children and are associated with attentional, behavioral, and emotional problems. We examined whether the timing of internal (endogenous) circadian melatonin phase (i.e., dim light melatonin onset; DLMO) and its relationship with parent-selected bedtimes were related to nighttime settling behaviors. Fourteen regularly napping preschoolers (8 females; 30–36 months) participated in a 6-day protocol (parent-report of nighttime settling, actigraphic assessment of sleep onset latency, evening salivary DLMO). Average DLMO clock time was 07:40 p.m. ± 00:48 minutes, occurring 29 minutes ± 32 minutes prior to bedtime (lights-out). Children with later DLMOs had longer sleep-onset latencies (r = .62) and poorer success in falling asleep (r = −.59). Children whose bedtimes were closer to their DLMO had longer sleep-onset latencies (r = .72) and increased bedtime resistance (r = −.54). We conclude that dissonance between parent-selected bedtimes and children's circadian physiology may contribute to the development of nighttime settling difficulties in early childhood.
Circadian phase and its relation to sleep are increasingly recognized as fundamental factors influencing human physiology and behavior. Dim light melatonin onset (DLMO) is a reliable marker of the timing of the circadian clock, which has been used in experimental, clinical, and descriptive studies in the past few decades. Although DLMO and its relationship to sleep have been well documented in school-aged children, adolescents, and adults, very little is known about these processes in early childhood. The purpose of this study was 1) to describe circadian phase and phase angles of entrainment in toddlers and 2) to examine associations between DLMO and actigraphic measures of children's nighttime sleep. Participants were 45 healthy toddlers aged 30 to 36 months (33.5 ± 2.2 months; 21 females). After sleeping on a parent-selected schedule for 5 days (assessed with actigraphy and diaries), children participated in an in-home DLMO assessment involving the collection of saliva samples every 30 minutes for 6 hours. Average bedtime was 2015 ± 0036 h, average sleep onset time was 2043 ± 0043 h, average midsleep time was 0143 ± 0038 h, and average wake time was 0644 ± 0042 h. Average DLMO was 1929 ± 0051 h, with a 3.5-hour range. DLMO was normally distributed; however, the distribution of the bedtime, sleep onset time, and midsleep phase angles of entrainment were skewed. On average, DLMO occurred 47.8 ± 47.6 minutes (median = 39.4 minutes) before bedtime, 74.6 ± 48.0 minutes (median = 65.4 minutes) before sleep onset time, 6.2 ± 0.7 hours (median = 6.1 hours) before midsleep time, and 11.3 ± 0.7 hours before wake time. Toddlers with later DLMOs had later bedtimes (r = 0.46), sleep onset times (r = 0.51), midsleep times (r = 0.66), and wake times (r = 0.65) (all p < 0.001). Interindividual differences in toddlers' circadian phase are large and associated with their sleep timing. The early DLMOs of toddlers indicate a maturational delay in the circadian timing system between early childhood and adolescence. These findings are a first step in describing the fundamental properties of the circadian system in toddlers and have important implications for understanding the emergence of sleep problems and the consequences of circadian misalignment in early childhood.
in our own studies of the functional significance of temperament we have found the formulation of goodness of fit to be a most useful conceptual framework / there is goodness of fit when the person's temperament and other characteristics, such as motivations and levels of intellectual and other abilities, are adequate to master the successive demands, expectations, and opportunities of the environment
several specific examples from our longitudinal studies will illustrate our application of the goodness-of-fit concept to the analysis of the functional significance of temperament / these examples will be based on our own formulation of the definition and diagnosis of temperament / the concept of goodness of fit can be applied to other conceptualizations of temperament
diagnostic formulation of temperamental categories / sociocultural factors / goodness of fit and similarities of temperament / goodness of fit, self-awareness, and self-esteem / generalization of the goodness-of-fit model / prevention and treatment of behavior disorders (PsycINFO Database Record (c) 2012 APA, all rights reserved)