Day type and the relationship between weight status and sleep duration in children and adolescents

Chronic reduced quality and duration of sleep have been associated with a range of physical and psychosocial disturbances in both adults and children, including: impaired attention, memory, creativity, learning and academic performance;1 motor skill deficits; 2 greater emotional lability, increased impulsivity, aggression and hyperactivity; 3 and increased potential for alcohol and drug abuse in adulthood.

The relationships between sex, age, geography and time in bed in adolescents : a meta-analysis of data from 23 countries

Objectives: To quantify the relationships between age, sex and country of residence and sleep time (time in bed) in young people aged 9–18 years

Normative data on the sleep habits of Australian children and adolescents

Study objective: To provide normative sleep data on 9-18 year old Australians. Design: Cohort study. Setting: Participants' homes. Participants: 4032 Australians aged 9-18 years. Interventions: N/A. Measurements and results: Participants completed a 48h use of time recall, comprising sleep data for one complete night. Sleep duration, bedtime and wake time were compared across age groups, between genders, and between school and non-school days using ANOVA. Sleep duration declined with age (P<0.0001) at the rate of 12 min/ night per year of age on school days, and 4 min on non-school days. Girls slept slightly longer than boys (5 min/ night, P=0.03). Non-school day sleep was 16 min longer than school day sleep (P<0.0001), with the difference increasing with age. Betimes got later with age (P<0.0001), however there were no differences in bedtimes between boys and girls. Bedtimes occurred 34 min later on non-school days (P<0.0001). Wake times were very similar across age groups on school days, but increased at the rate of 10 min/ year of age on non-school days. Wake times were similar for boys and girls, and occurred on average 82 min later on non-school days (P<0.0001). Overall, 17% of school days and 20% of non-school days failed to meet the American Centers for Disease Control and Prevention sleep duration guidelines. Conclusions: Normative sleep data will provide a valuable yardstick for health and education professionals when dealing with sleep-related issues

Not all sedentary behaviour is equal: Children's adiposity and sedentary behaviour volumes, patterns and types

OBJECTIVE: The importance of different constructs of sedentary behaviours in relation to childhood obesity is uncertain. Thus, this study aimed to investigate relationships between volume, patterns and types of sedentary behaviour and adiposity in children. METHODS: A case-control study was undertaken involving 234 children aged 10-13 years who were either of a healthy-weight (74 boys, 56 girls) or classified as obese (56 boys, 48 girls). Percent body fat (by dual-energy X-ray absorptiometry) and waist-to-height ratio were assessed. Time, type (television, videogame, computer, eating, passive transport) and bout length of sedentary behaviours were measured using accelerometry and the Multimedia Activity Recall for Children and Adolescents. Time use (total daily energy expenditure, sleep, physical activity), age, household income and Tanner stage were covariates in sex-stratified partial least squares analyses. RESULTS: Daily energy expenditure and income were negatively associated with adiposity for both sexes. Television time was consistently positively associated with adiposity. In boys only, prolonged bouts of sedentary behaviour and time spent playing video games/computer were positively linked with adiposity. Non-screen sedentary behaviour was negatively associated with adiposity in girls. Independent of total energy expenditure, total sedentary time was only inconsistently associated with fatness. CONCLUSIONS: These data suggest that (1) characteristics of sedentary time other than duration are associated with adiposity in children, and (2) associations may be sex-specific

Sleep education improves the sleep duration of adolescents : a randomized controlled pilot study

Purpose: To determine the feasibility and pilot a sleep education program in New Zealand high school students. Methods: A parallel, two-arm randomized controlled pilot trial was conducted. High school students (13 to 16 years) were randomly allocated to either a classroom-based sleep education program intervention (n = 15) or to a usual curriculum control group(n = 14). The sleep education program involved four 50-minute classroom-based education sessions with interactive groups. Students completed a 7-day sleep diary, a sleep questionnaire (including sleep hygiene, knowledge and problems) at baseline,post-intervention (4 weeks) and 10 weeks follow-up. Results: An overall treatment effect was observed for weekend sleep duration (F1,24 = 5.21, p = 0.03). Participants in the intervention group slept longer during weekend nights at 5 weeks (1:37 h:min, p = 0.01) and 10 weeks: (1:32h:min, p = 0.03) compared to those in the control group. No differences were found between groups for sleep duration on weekday nights. No significant differences were observed between groups for any of the secondary outcomes (sleep hygiene, sleep problems, or sleep knowledge). Conclusions: A sleep education program appears to increase weekend sleep duration in the short term. Although this program was feasible, most schools are under time and resource pressure, thus alternative methods of delivery should be assessed for feasibility and efficacy. Larger trials of longer duration are needed to confirm these findings and determine the sustained effect of sleep education on sleep behavior and its impact on health and psychosocial outcomes

Never enough sleep: a brief history of sleep recommendations for children

BACKGROUND AND OBJECTIVE: There is a common belief that children are not getting enough sleep and that children’s total sleep time has been declining. Over the century, many authors have proposed sleep recommendations. The aim of this study was to describe historical trends in recommended and actual sleep durations for children and adolescents, and to explore the rationale of sleep recommendations. METHODS: A systematic literature review was conducted to identify recommendations for children’s sleep requirements and data reporting children’s actual total sleep time. For each recommendation identified, children’s actual sleep time was determined by identifying studies reporting the sleep duration of children of the same age, gender, and country in the same years. Historical trends in ageadjusted recommended sleep times and trends in children’s actual sleep time were calculated. A thematic analysis was conducted to determine the rationale and evidence-base for recommendations. RESULTS: Thirty-two sets of recommendations were located dating from 1897 to 2009. On average, age-specific recommended sleep decreased at the rate of –0.71 minute per year. This rate of decline was almost identical to the decline in the actual sleep duration of children (–0.73 minute per year). Recommended sleep was consistently ∼37 minutes greater than actual sleep, although both declined over time. CONCLUSIONS: A lack of empirical evidence for sleep recommendations was universally acknowledged. Inadequate sleep was seen as a consequence of “modern life,” associated with technologies of the time. No matter how much sleep children are getting, it has always been assumed that they need more. Pediatrics 2012;129:548–55

Children's sleep needs : is there sufficient evidence to recommend optimal sleep for children?

It is widely recognised that sleep is important for children’s health and well-being and that short sleep duration is associated with a wide range of negative health outcomes. Recently, there has been much interest into whether or not there is sufficient data to support the specific recommendations made for how much sleep children need. In this paper we explore concepts around children’s sleep need, discuss the theory, rationale and empirical evidence for contemporary sleep recommendations and outline future research directions for sleep recommendations. 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

Research combining physical activity and sleep: A bibliometric analysis

This study used a bibliometric analysis through the Scopus database to examine papers that combined physical activity and sleep, published between 1979 and 2018. Bibliometric indicators of productivity included publication volume and citation distribution, top 10 authors, average authors per paper, single- and multicountry collaboration, collaborative index, top 10 countries, leading journals, highly cited papers and network visualization for coauthorship, international collaboration, and co-occurrence of author keywords. The initial search identified 1,509 papers, of which 607 passed through comprehensive screening and were included in the final analysis. Most of the papers were research articles (90.8%) and published in English (90.8%). Most papers (81.4%) were published within the past decade, 2009–2018. The mean number of papers published per year was 15.2, the mean number of citations per paper was 257.3, and the mean number of authors per paper was 5.5. International collaboration was evident for 21.6% of the papers, and 95.6% of papers were multiauthored. The most prolific publishing institutions and authors were from the United States, Canada, Australia, Switzerland, and Brazil. Keyword analysis suggested that almost all age groups and study designs were covered, but most papers focus on noncommunicable diseases. Although there has been a rise in scientific production on combined physical activity and sleep research in recent years, future work in this area should include researchers from developing countries. © The Author(s) 2019

Interindividual and intraindividual variability in adolescent sleep patterns across an entire school term: A pilot study

Objectives: This study aimed to investigate sleep patterns in adolescent males over a 12-week period (a 10-week school term and pre and post term holidays). Design: Intensive longitudinal design, with sleep data collected daily via actigraphy for 81 consecutive days. Setting: Five Secondary Schools in Adelaide, South Australia. Participants: Convenience sample of 47 adolescent males aged 14 to 17 years. Measurements: Daily sleep duration, bedtimes, rise times, and sleep efficiency were collected via actigraphy with all (except sleep efficiency) also measured by sleep diary. Mood was measured weekly with Depression Anxiety Stress Scale-21 (DASS-21) and weekly wellbeing with the Satisfaction with Life Scale (SWLS). Age, body mass index, self-reported mood, life satisfaction, and chronotype preference assessed at baseline (pre-term holiday week) were included as covariates. Results: Dynamic Structural Equation Modeling indicated significant but small fixed-effect and random-effect auto-regressions for all sleep variables. Collectively, these findings demonstrate day-to-day fluctuations in sleep patterns, the magnitude of which varied between individuals. Age, morningness, and mood predicted some of the temporal dynamics in sleep over time but other factors (BMI, life satisfaction) were not associated with sleep dynamics. Conclusions: Using intensive longitudinal data, this study demonstrated inter-individual and intra-individual variation in sleep patterns over 81 consecutive days. These findings provide important and novel insights into the nature of adolescent sleep and require further examination in future studies

Sleepy schoolboy blues? : Sleep and depression across the school term

Aims: Adolescents experience a change in sleep patterns, together with a later sleep onset time compared to children in younger age groups. This, in combination with early school starting times can restrict the time available for sleep. As a consequence, sleep loss can accumulate across the school week. If sleep loss is not recovered on weekends, a cumulative sleep debt may develop across weeks of the school term. Cumulative sleep loss has been linked to depression. We sought to determine whether adolescent males accumulated a sleep debt across the term, and if so, whether the loss was associated with the onset of depressive symptoms. Methods: Eleven healthy adolescent males, with a mean age of 15.29 (±0.83) years, participated in an 11-week field study. Baseline testing occurred in the pre-term holiday, prior to the term commencement. Participants wore an activity-monitoring device (Actiwatch) at all times and completed sleep diaries daily. The Depression Anxiety and Stress Scale (DASS-21) was completed weekly. Mixed-effects models examined differences in weekly sleep across the term and any associations with depressive symptoms. Results: On average, daily sleep was 18 minutes longer in the pre-term period than during the term period. Participants spent less time in bed on school nights than on weekends during the school term (p.05) because participants advanced weekly bed times and increased sleep duration on the weekends. The changes observed in sleep were not associated with depressive symptoms. Discussion: This pilot study provides insight into sleeping habits during a school term. Whilst a relationship with depression was not significant, future studies could investigate a clinical population rather than the normal population of adolescents sampled here