Trends in the duration of school-day sleep among 10- to 15-year-old South Australians between 1985 and 2004

Secular trends in sleep and circadian problems among adolescents in Hong Kong: From 2011-2012 to 2017-2019

OBJECTIVE

The study aimed to investigate secular trends in sleep and circadian problems in Hong Kong Chinese adolescents.

METHODS

This study analyzed cross-sectional data from two large-scale school-based sleep surveys conducted in 2011-2012 and 2017-2019. Sleep and circadian problems, including sleep-wake pattern, insomnia, chronotype, social jetlag, daytime sleepiness, and other sleep-related factors, were compared between two survey years.

RESULTS

A total of 8082 adolescents (5639 students in 2011-2012 [Mean age: 14.4 years, 50.9% boys] and 2443 students in 2017-2019 [Mean age: 14.7 years, 54.0% boys]) were included in this 7-year study. The average time in bed of Hong Kong adolescents decreased from 8.38 hours to 8.08 hours from 2011-2012 to 2017-2019. There was a 0.28-hour delay in weekday bedtime, 0.54-hour advance in weekend wake-up time, and a 0.36-hour decline in average time in bed, resulting in increased trends of sleep loss (Time in bed <8h: OR = 2.06, 95%CI: 1.44-2.93, p < 0.01; Time in bed <7h: OR = 2.73, 95%CI: 1.92-3.89, p < 0.01), daytime sleepiness (OR = 1.70, 95%CI: 1.34-2.16, p < 0.01), and evening chronotype (OR = 1.26, 95%CI: 1.08-1.48, p < 0.01). The increased trend in insomnia disorder, however, was insignificant when covariates were adjusted.

CONCLUSION

A secular trend of reduced time in bed, delay in weekday bedtime, advance in weekend wake-up time, increase in evening chronotype and daytime sleepiness from 2011-2012 to 2017-2019 were observed. There is a timely need for systematic intervention to promote sleep health in adolescents.

From early birds to night owls: a longitudinal study of actigraphy-assessed sleep trajectories during the transition from pre- to early adolescence

STUDY OBJECTIVES

Pre- and early adolescence are believed to constitute periods of important age-related changes in sleep. However, much of the research on these presumed developmental changes has used cross-sectional data or subjective measures of sleep, limiting the quality of the evidence. In addition, little is known about the development of certain features of the sleep-wake cycle pertaining to regularity (e.g. weekend-weekday differences and intra-individual variability) or circadian rhythms (e.g. sleep midpoint).

METHODS

This study examined the sleep trajectories of 128 typically developing youth (69 girls) from ages 8 to 12 years on four sleep characteristics: sleep onset, sleep offset, total sleep time (TST), and sleep midpoint. For each of these characteristics, actigraphy-derived estimates of typical (i.e. mean) sleep and sleep regularity were obtained at each time point. Multilevel growth curves were modeled.

RESULTS

Overall, the sleep-wake cycle significantly changed between 8 and 12 years. Mean sleep onset, offset and midpoint exhibited an ascending curvilinear growth pattern that shifted later with age, while mean TST decreased linearly. Weekend-weekday differences (social jetlag) for sleep offset and midpoint became more pronounced each year. Weekday TST was longer than weekend TST, though this difference became smaller over time. Finally, intra-individual variability increased over time for all sleep characteristics, with variability in TST ascending curvilinearly. Important between-person and sex differences were also observed.

CONCLUSION

This study reveals the marked changes that occur in the sleep of typically developing pre- and early adolescents. We discuss the potential implications of these trajectories.

Branched-chain amino acids and sleep: a population-derived study of Australian children aged 11-12 years and their parents

Micronutrients, particularly amino acids, are thought to play an important role in sleep regulation and maintenance. While tryptophan is a known predictor of sleep, less is known about branched-chain amino acids (BCAAs), which compete with tryptophan for transport across the blood-brain barrier. The aim of this study was to determine the association between BCAAs and actigraphy-derived sleep duration, timing and efficiency, and self-reported trouble sleeping. This study examined data on children and adults collected as part of the Child Health CheckPoint study. Linear mixed models, adjusted for geographic clustering, were used to determine the association between BCAAs and sleep characteristics. Complete-case analysis was conducted for 741 children aged 11-12 years old (51% females) and 941parents (87% mothers). While BCAAs were significantly associated with children's sleep duration, timing and self-reported trouble sleeping, no associations were observed in adults, in fully adjusted models. In children, higher levels of BCAAs are associated with shorter sleep duration, delayed sleep timing, and more frequent reports of trouble sleeping.

Longitudinal Trends in Sleep and Related Factors Among South Korean Adults From 2009 to 2018

BACKGROUND AND PURPOSE

Excess or insufficient sleep, irregular sleep-wake patterns, and an extreme early or late chronotypes adversely impact physical and mental health. Changes in sleep characteristics should therefore be tracked, and factors that contribute to poor sleep should be identified. We investigated the changes in sleep patterns among South Korean adults during 2009-2018.

METHODS

Using data of a representative sample of South Korean adults from the 2009 (n=2,658, 48.5% males; age=44.5±15.0 years old [mean±standard deviation], age range=19-86 years) and 2018 (n=2,389, 49.1% males; age=47.9±16.3 years, age range=19-92 years) Korean Headache-Sleep Study, we explored changes in sleep timing, sleep duration, chronotype, and social jetlag (SJL). Logistic regression analysis was used to examine the association between average sleep duration and depression.

RESULTS

From 2009 to 2018, bedtimes were advanced by 10 and 25 min on workdays and free days, respectively. Meanwhile, wake-up times were advanced by 13 min and delayed by 12 min on workdays and free days, respectively. The average sleep duration significantly decreased from 7.45 h to 7.13 h. The prevalence of short sleep duration (<7 h) increased, whereas that of long sleep duration (≥8 h) decreased. A circadian preference toward eveningness and SJL increased. The prevalence of depression increased from 4.6% to 8.4%, and there were significant reverse J-shaped and U-shaped associations between average sleep duration and depression in 2009 and 2018, respectively.

CONCLUSIONS

Changes in sleep patterns and the association between sleep duration and depressive mood were determined from a representative sample of the South Korean adult population. Interventions to modify sleep behaviors might improve public health.

Santos I, Matijasevich A, Tovo-Rodrigues L. Sleep Duration in Adolescence and Its Prenatal, Perinatal, and Health Determinants in a Large Population-based Cohort Followed from Birth

Objective  To investigate sleep duration and its associated factors in adolescents aged 11 years from the 2004 Pelotas (Brazil) Birth Cohort Study. Methods  Sleep duration was assessed using a self-report sleep habits. Independent variables included perinatal, sociodemographic, behavioral, and health characteristics. The associations were estimated using multiple linear regression. Results  The mean sleep duration of 3,179 adolescents was 9.3 hour (SD =1.7 hour). Longer sleep duration was associated with lower socioeconomic status at birth (β: 0.37, 95% CI: 0.12; 0.61), lower mother's education level ( p  < 0.001), and being female (β: 0.19, 95% CI: 0.06; 0.33). Shorter sleep duration was associated with cesarean section delivery (β: -0.16, 95% CI: -0.31; -0.02); having classes in the morning shift (β: -1.38, 95% CI: -1.51; -1.26), and lower terciles of physical activity ( p  = 0.04). Conclusions  The mean sleep duration observed in this study was consistent with the international recommendations for this age range. Adolescents from lower income families, who are more active, study in shifts other than morning, girls, and those born through vaginal delivery presented higher sleep duration than their counterparts.

Multidimensional Sleep and Cardiometabolic Risk Factors for Type 2 Diabetes: Examining Self-Report and Objective Dimensions of Sleep

Purpose:

The purpose of the study was to determine the association between objective and self-report measures of sleep and cardiometabolic risk factors for type 2 diabetes.

Methods:

This study examines data on Australian adults, collected as part of the Child Health CheckPoint study. Sleep was examined in terms of actigraphy-derived sleep duration, timing, efficiency and variability; and self-report trouble sleeping. Cardiometabolic risk factors for type 2 diabetes were examined in terms of body mass index and biomarkers of inflammation and dyslipidemia. Generalized estimating equations, adjusted for geographic clustering, were used to determine the association between measures of sleep and cardiometabolic risk factors.

Results:

Complete case analysis was conducted for 1017 parents (87% mothers). Both objective and self-report measures of sleep were significantly but weakly associated with cardiometabolic risk factors.

Conclusion:

Both objective and self-report measures of sleep are significantly associated with cardiometabolic risk factors for type 2 diabetes. Self-report troubled sleep is associated with poorer cardiometabolic health, independent of actigraphy-derived sleep parameters.

Do both timing and duration of screen use affect sleep patterns in adolescents?

BACKGROUND

Sleep duration has declined in adolescents over the last 30 years and screen use has been identified as a risk factor. Studies have examined the duration of screen use and screen-based activities but have not differentiated between evening and night-time use.

METHODS

Cross sectional questionnaire survey of adolescents recruited in schools. Sleep habits on school nights and weekends, symptoms of insomnia and daytime repercussions were recorded using an online questionnaire administered in the classroom setting. Sleep deprivation (<7 hours in bed /night), school night sleep restriction (≥2 hours difference in sleep duration on school nights vs weekends), excessive sleepiness (score >6 on a visual analogue scale), duration of screen use and timing of screen use (evening vs after bedtime) were determined.

RESULTS

2513 students (53.4% female, median age 15 years) were included. 20% were sleep deprived and 41% sleep restricted. A clear dose effect relationship in a model controlling for age, sex, school level and sociodemographic class was seen with all levels of night-time screen use on sleep deprivation and sleep restriction (>2 hours use sleep deprivation OR 5.23[3.03-9.00]. sleep restriction OR 2.05[1.23-3.42]) and > 2 hours evening use (>2 hours use sleep deprivation OR 2.72[2.15-3.44] sleep restriction OR 1.69[1.36-2.11]) but not moderate evening use. All night-time use and > 2 hours evening use increased the risk of insomnia, non refreshing sleep, and affected daytime function (daytime sleepiness, lack of energy and irritability).

CONCLUSIONS

Both duration of screen use and timing are associated with adverse effects on sleep and daytime functioning in adolescents. More than 2 hours evening use and all night-time use should be avoided.

Early-Life Sleep Deprivation Enhanced Alcohol Consumption in Adolescent Rats

Evidence in the literature suggests that sleep deprivation during early-life developmental stages, by impacting important processes such as the reward circuit maturation, may increase the vulnerability for alcohol and substance use. The mechanisms involved are not fully understood. In this study, utilizing our previously established model, we examined the impact of early-life sleep deprivation on alcohol consumption in adolescent rats. Male Sprague Dawley rats served as either the control (CON) or sleep-deprived (SD) group. Sleep deprivation was induced using a Pinnacle automated sleep deprivation apparatus. The SD group of rats was sleep deprived for 6–8 h/day for 14 days from postnatal day (PND)19 to PND32. At PND33, anxiety- and depression-like behaviors were assessed in rats using elevated plus maze and sucrose splash test, respectively. At PND39, alcohol consumption was assessed in rats for five consecutive days using the two-bottle choice paradigm, water versus 5% ethanol. SD rats exhibited significant anxiety- and depression-like behaviors as compared to CON rats. Interestingly, SD rats consumed a larger volume of alcohol when compared to CON rats, which was significantly higher at day 5 (mean of alcohol consumption (ml) ± SD; CON = 6.67 ± 3.42; SD = 19.00 ± 6.05, p = 0.0126). SD rats also showed high preference for alcohol over water, which was significantly higher at day 5 (mean of alcohol preference (%) ± SD; CON = 26.85 ± 14.97; SD = 57.69 ± 5.61, p = 0.014). Our data suggest that early-life sleep deprivation enhanced alcohol consumption in adolescent rats.

The Effects of COVID-19 Pandemic on Italian School-Aged Children: Sleep-Related Difficulties and Trauma Reactions

PURPOSE

The COVID-19 pandemic has affected the mental and physical health of the world population. This study aims to investigate incidence of sleep-related difficulties and post-traumatic stress disorder in the school-aged children after 1 year of the pandemic.

METHODS

A sample of Italian children (6-12 years) was queried about their sleep behaviors after 1 year of the pandemic, answering the Children's Sleep Habits Questionnaire (CSHQ). We also evaluated trauma symptoms with the Children's Impact of Event Scale (CRIES-8).

RESULTS

Among 205 participants, 184 (89.8%) presented sleep-related difficulties. Out of all, 99 (48.3%) had a high risk to develop post-traumatic stress disorder. Ninety-five (51.6%) children with sleep-related difficulties also presented an abnormal CRIES-8 total score. A correlation was found between the CSHQ total score and the CRIES-8 total score (r = 0.354, P < .01).

CONCLUSIONS

The sleep-related difficulties occurring during COVID-19 outbreak may compound to increase the risk to develop post-traumatic stress disorder among Italian children.

The multidimensionality of sleep in population‐based samples: a narrative review

The identification of optimal sleep duration recommendations for the general population has long been an important goal on the public health agenda, as both short and long sleep duration have been linked to unfavourable health outcomes. Yet, sleep is more than duration alone and can be described across multiple domains, such as timing, regularity, satisfaction, alertness, and efficiency. We reviewed observational population‐based studies that examined differences in age, sex, and origin across multiple dimensions of sleep. Reviewed literature suggests an increasing prevalence of insomnia symptoms, shorter and less deep sleep in old age. Overall, women report poorer sleep quality than men despite objective measures revealing shorter and more fragmented sleep in men. Minorities generally have poorer quantity and quality of sleep, but multi‐ethnic studies have reported mixed results regarding the subjective experience of sleep. In sum, effects of age, sex and origin differ across sleep dimensions, thereby suggesting that the multidimensionality of sleep and how these different aspects interact should be studied across individuals. Studies should include both self‐reported measures and objective assessments in diverse population‐based samples, as both aspects are important to understand sleep health in the general population. Data‐driven descriptions could provide researchers and clinicians with insights into how well individuals are sleeping and offer concrete targets for promotion of sleep health across the population.

Neural correlates of sleep quality in children: Sex-specific associations shown by brain diffusion tractography

BACKGROUND AND PURPOSE

Sleep quality is important for healthy growth and development of children. We aimed to identify associations between sleep disturbances in healthy children without clinical diagnosis of sleep disorders and brain white matter (WM) microstructure using an advanced diffusion-weighted magnetic resonance imaging (DW-MRI) based tractography analysis, and to explore whether there are sex differences in these associations.

METHODS

Brain DW-MRI data were collected from sixty-two 8-year-old children (28 boys, 34 girls) whose parents also completed Children's Sleep Habits Questionnaire (CSHQ). Track-weighted imaging (TWI) measures were computed from the DW-MRI data for 37 WM tracts in each subject. Sex-specific partial correlation analyses were performed to evaluate correlations between TWI measures and a set of sleep disturbance scores derived from the CSHQ.

RESULTS

Significant correlations (P < .05, FDR-corrected; r: .48-.67) were identified in 13 WM tracts between TWI and sleep disturbance scores. Sexually dimorphic differences in correlations between sleep disturbance scores and WM microstructure measurements were observed. Specifically, in boys, daytime sleepiness positively correlated with track-weighted mean or radial diffusivity in 10 WM tracts (bilateral arcuate fasciculus, left cingulum, right middle longitudinal fasciculus, and three bilateral segments of superior longitudinal fasciculus). In girls, total CSHQ score, night walking, or sleep onset delay negatively correlated with track-weighted fractional anisotropy or axial diffusivity in 4 WM tracts (bilateral inferior longitudinal fasciculus and uncinate fasciculus).

CONCLUSIONS

The findings suggest that sleep disturbances without clinical diagnosis of sleep disorders are associated with lower WM microstructural integrity in children. Additionally, the associations possess unique patterns in boys and girls.

The association between internet usage and sleep problems among Japanese adolescents: three repeated cross-sectional studies

STUDY OBJECTIVES

Sleep problems and problematic internet use have important implications for adolescent health; however, there have been no large-scale surveys using comprehensive measures. We examined the association between internet use duration and sleep problems among Japanese adolescents.

METHODS

We used data from the Lifestyle Survey of Adolescents collected in 2012, 2014, and 2017. We calculated the change in sleep status (insomnia, sleep duration, bedtime, and sleep quality) and internet usage (screen time and services such as internet surfing, social media use, streaming such as YouTube, and online gaming). A binary logistic model was estimated for insomnia. Generalized ordered logit models were employed for the ordinal outcomes (sleep duration, bedtime, sleep quality, and multidimensional sleep health). Sampling weights were constructed based on participation rate on survey years and selection rates from population statistics.

RESULTS

We analyzed data from 248,983 adolescents. Sleep status was unchanged; however, many adolescents used more internet services and for longer durations. The odds ratio of internet screen time for all sleep problems (insomnia, shorter sleep duration, later bedtime, and worse sleep quality) gradually declined. Longer internet screen time (> 5 hours) was strongly associated with all sleep problems. Internet services were also associated with sleep problems; particularly, social media use and online gaming were linked to later bedtimes.

CONCLUSIONS

Despite the decreased strength in the association between internet usage and sleep problems, longer internet time was strongly associated with sleep problems. Public health interventions should consider internet use as an intervention target to improve adolescents' health.

Neighborhood environments and sleep among children and adolescents: A systematic review

Understanding salient environmental determinants of pediatric sleep is essential for informing interventions and public health initiatives. Emerging evidence suggests that the neighborhood environment can impact pediatric sleep, but this evidence has not yet been systematically reviewed. We conducted a systematic review of the scientific literature on associations between neighborhood environments and sleep in young children (0-5 y), school-aged children (6-12 y) and adolescents (13-18 y). We reviewed 85 articles published between 2003 and 2020. The most commonly examined neighborhood exposure was low socioeconomic status (40 studies), which was associated with sleep outcomes in 58% of studies (primarily shorter sleep duration, later sleep timing, or obstructive sleep apnea). Evidence was stronger for neighborhood safety/crime/violence (21 studies), with 86% of studies reporting associations with sleep outcomes (primarily self- or caregiver-reported sleep problems). Fewer studies examined associations of neighborhood physical environment exposures, including noise (15 studies), the built environment (seven studies), and air pollution (six studies). Limitations of the current body of evidence include 1) limited examination of neighborhood exposures other than socioeconomic status or safety, 2) use of primarily cross-sectional observational study designs, 3) lack of objective sleep outcome assessment, and 4) limits of current exposure assessment methods.

Contextual and Parenting Factors Contribute to Shorter Sleep Among Hispanic/Latinx Compared to Non-Hispanic White Infants

BACKGROUND

Sleep is an important aspect of child development and health. Disparities in childhood sleep have been observed as early as infancy, but little is known about the factors contributing to them.

PURPOSE

The objective of this study was to examine whether intrinsic, contextual, and parenting factors contribute to differences in sleep duration between Hispanic/Latinx and non-Hispanic white infants at 6 months of age.

METHODS

We analyzed data of 119 Hispanic/Latinx and 146 non-Hispanic white infants in Rise & SHINE, a prospective birth cohort study of mother-infant dyads. Mothers reported their infant's sleep patterns using the Brief Infant Sleep Questionnaire at 6 months. Mothers also completed surveys measuring intrinsic (sex, gestational length, and birth weight), contextual (cultural, environmental, and familial), and parenting (behaviors and practices) factors. We used multivariable linear and logistic regression analyses to examine the contributing effects of these clusters of variables on the association between racial/ethnic background and infant sleep duration.

RESULTS

Hispanic/Latinx infants slept 38 min less than white infants at 6 months (β: -0.63 [95% confidence interval: -1.07, -0.19]) and were nearly three times more likely to not meet the minimum sleep recommendation. The differences persisted after adjustment for intrinsic factors but were attenuated after additional adjustment for contextual and parenting factors, especially having a foreign-born mother and later bedtime.

CONCLUSIONS

The results of this study demonstrate that differences in sleep duration among Hispanic/Latinx infants compared to their white counterparts are present as early as 6 months of age and that context and parenting matter.

Trends in sleep problems and patterns among Japanese adolescents: 2004 to 2017

BACKGROUND

Sleep problems in adolescence, such as insomnia and short sleep duration, are associated with physical and mental health problems. However, little is known about the recent trends in sleep problems among adolescents. Therefore, this study examined trends in sleep problems among Japanese adolescents.

METHODS

Using data from the Lifestyle Survey of Adolescents collected in 2004 (n = 102,451), 2008 (n = 95,680), 2010 (n = 98,867), 2012 (n = 101,134), 2014 (n = 85,931), and 2017 (n = 64,417), we calculated the trends of insomnia, shorter sleep duration, late bedtimes, and poor sleep quality. Multivariable logistic regression analysis models were used to examine the association of each sleep problem and survey years.

FINDINGS

We analyzed data from 545,285 Japanese adolescents. Results indicated that, since 2004, the odds ratio for insomnia have decreased (Adjusted odds ratio [AOR] 0•85, 95% CI 0•82-0•87), as have the odds ratio for poor sleep quality (AOR 0•92, 95% CI 0•88-0•95). However, the odds ratio for shorter sleep duration (AOR 1•13, 95% CI 1•10-1•17) and late bedtimes tended to increase (AOR 1•06, 95% CI 1•03-1•08) during this period.

INTERPRETATION

The prevalence of insomnia symptoms and poor sleep quality among adolescents decreased from 2004 to 2017. However, there were increasing trends toward shorter sleep duration and late bedtimes. These changes are both relieving and concerning. Teachers, parents, and health professionals should consider educating adolescents regarding sleep hygiene, adjusting schedules of extracurricular activities, and enhancing time management to improve their sleep quantity.

FUNDING

This study received funding from Japan's Ministry of Health, Labour and Welfare.

Can We Reverse this Trend? Exploring Health and Risk Behaviours of Grade 12 Cohorts of Ontario Students from 2013-2019

Adolescents engage in multiple health risk behaviours that put them at risk of future chronic disease. By the time students graduate from secondary school, they may be engaging in behaviours that set them on a particular health trajectory. It is important to monitor the co-occurrence of health risk behaviours of cohorts of grade 12 students over time to highlight important areas for intervention. The purpose of this study was to examine trends in health and risk behaviours over six waves among subsequent cohorts of grade twelve students from Ontario, Canada. A total of 44,740 grade 12 students participated in the COMPASS study across the six waves (2013/14 to 2018/19), and self-reported movement (physical activity, screen time, sleep), dietary (fruit and vegetables, breakfast), and substance use (smoking, vaping, binge drinking, and cannabis use) behaviours. Over 91.0% of students reported engaging in three or more health risk behaviours, with increases in the number of students reporting inadequate sleep, not eating breakfast on every school day, and vaping over time. Although modest, the wave 6 cohort reported slightly more risk behaviours compared with the wave 1 cohort, highlighting the importance of multidimensional health promotion strategies across multiple settings.

Sleep-related difficulties in healthy children and adolescents

BACKGROUND

As sleep-related difficulties are a growing public health concern, it is important to gain an overview of the specific difficulty areas of the most vulnerable individuals: children. The current descriptive study presents the prevalence of sleep-related difficulties in two large samples of healthy children and adolescents and outlines the effects of age, gender, and socioeconomic status (SES) on various sleep-related difficulties.

METHODS

Participants were 855 4-9 year-old children (child sample) and 1,047 10-17 year-old adolescents (adolescent sample) participating 2011-2015 in the LIFE Child study, a population-based cohort study in Germany. Parents of the child participants completed the Children's Sleep Habits Questionnaire (CSHQ), whereas adolescents self-administered the Sleep Self Report (SSR). Familial SES was determined by a composite score considering parental education, occupational status, and income. Multiple regression analyses were carried out to address the research question.

RESULTS

Among 4-9 year-old children, the mean bedtime was reported to be 8 p.m., the mean wake-up time 7 a.m., and sleep duration decreased by 14 min/year of age. 22.6 % of the children and 20.0 % of the adolescents showed problematic amounts of sleep-related difficulties. In the child sample, bedtime resistance, sleep onset delay, sleep-related anxiety, night waking, and parasomnia were more frequent in younger than older children. In the adolescent sample, difficulties at bedtime were more frequent among the younger adolescents, whereas daytime sleepiness was more prominent in the older than the younger adolescents. Considering gender differences, sleep-related difficulties were more frequent among boys in the child sample and among girls in the adolescent sample. Lower SES was associated with increased sleep-related difficulties in the adolescent, but not the child sample.

CONCLUSIONS

The present results report sleep-related difficulties throughout both childhood and adolescence. Gender differences can already be observed in early childhood, while effects of SES emerge only later in adolescence. The awareness for this circumstance is of great importance for pediatric clinicians who ought to early identify sleep-related difficulties in particularly vulnerable individuals.

Chronic Sleep Reduction in Childhood and Adolescence

BACKGROUND

Habitually shortened nighttime sleep is a common phenomenon in childhood and adolescence, sometimes associated with chronic sleep reduction (CSR). CSR is associated with impairments of performance ability and emotional well-being. The extent to which children and adolescents in Germany suffer from CSR is unclear; it is also unclear what factors are predictive of CSR.

METHODS

In the present study, we carried out a telephone survey in a representative sample of 998 children and adolescents aged 12 to 17, asking them about their sleep behavior, sleep disturbances, and mental well-being. A standardized method was used.

RESULTS

The point prevalence of CSR was found to be 12.5% (95% confidence interval, [10.5; 14.6]). Children and adolescents affected by CSR reported a significantly higher frequency of insomnia, delayed sleep-phase syndrome, restless legs syndrome, and obstructive sleep apnea. Female sex, pro - longed absence from school or vocational training, emotional and behavioral disturbances, age over 15 years, bedtimes after 10:38 pm on nights before school (or vocational training), getting up after 10:04 on days off, and reported insomnia were all associated with CSR, with odds ratios (OR) ranging from 2.2 to 21.1 (R2 = 0.32 in a logistic regression model).

CONCLUSION

One in eight persons aged 12 to 17 in Germany, particularly girls, meets the criteria for CSR. CSR is associated with sleep disturbances and significantly impaired mental health and should, therefore, always be kept in mind in routine clinical practice. We provide a set of indicators for possible CSR that patients can easily be asked about.

The relationship between sleep habits, lifestyle factors, and achieving guideline-recommended physical activity levels in ten-to-fourteen-year-old Japanese children: A cross-sectional study

The current focus of meeting the physical activity guidelines for children and young people include preventing conditions such as high blood cholesterol, high blood pressure, metabolic syndrome, obesity, low bone density, depression, and injuries. However, the relationship between sleep habits and meeting physical activity guidelines is still unclear. This study aimed to assess this relationship among fifth- to eighth-grade (ages 10-14) Japanese children. This cross-sectional study included 3,123 children (boys: 1,558, girls: 1,565, mean age: 12.5 ± 1.2 years). Questionnaires were used to assess parameters such as moderate-to-vigorous physical activity per day, school and weekend night sleep durations, social jetlag, daytime sleepiness, napping, screen time, and breakfast intake. Participants were divided into an achievement and a non-achievement group depending on their physical activity guideline achievement status (i.e., whether they met the children's physical activity guideline of 60 min or more of moderate-to-vigorous physical activity per day). Then, to determine the sleep habits in relation to the children's achievement of guideline-recommended physical activity levels, multivariate logistic regression analyses were conducted. In fifth- and sixth-grade (ages 10-12) boys, an inverse association was observed between physical activity guideline achievement and daytime sleepiness. In seventh- and eighth-grade (ages 12-14) boys, physical activity guideline achievement was inversely associated with social jetlag and skipping breakfast. Additionally, in seventh- and eighth-grade girls, physical activity guideline achievement was inversely associated with inappropriate sleep duration on weekends and screen time. These results suggest that meeting the physical activity guideline is related to favorable sleep habits in Japanese children. However, their relevance may differ by school type and gender.

Association of sleep duration and snack consumption in children and adolescents: The CASPIAN-V study

OBJECTIVES

The relationship between sleep deprivation and the risk of overweight and obesity is somewhat known in children and adolescents. This study aimed to investigate the relationship between sleep duration and eating snacks in a national sample of children and adolescents aged 6-18 years old.

METHODS

This cross-sectional study was carried out on the data of the fifth survey of the national school-based surveillance system entitled the "Childhood and Adolescence Surveillance and PreventIon of Adult Non-communicable Disease" (CASPIAN-V) study. Short sleeping duration was defined 10 hr per day for children under 10 years and 9 hr per day for children ≥ 10 years. To assess food habits, the consumption frequency of some food groups including sweets, salty snacks, carbonated beverages, diet soft drinks, soft beer, fresh fruits, dried fruits, fresh juices, vegetables, packed juices, dairy products (milk, yogurt, and cheese), fast foods, tea, sugar along with tea, and coffee was asked using Likert scale ( never, rarely, weekly, and daily).

RESULTS

In multivariate model, short sleep versus long sleep in students was associated with increased chance of eating salty snacks (OR = 1.49 [95% CI: 1.38-1.61]; p = .001), soft drinks (OR = 1.12 [95% CI: 1.04-1.20]; p = .002), fast foods (OR = 1.66 [95% CI: 1.54-1.79]; p < .001), tea (OR = 1.49 [95% CI: 1.39-1.61]; p < .001), and tea with sugar (OR = 1.13 [95% CI: 1.05-1.22]; p < .001). In addition, short sleep in students was associated with a decreased odds of daily intake of soft drinks without sugars (OR = 0.64 [95% CI: 0.58-0.70]; p < .001), soft beer (OR = 0.92 [95% CI: 0.85-0.99]; p < .001), fresh fruit (OR = 0.83 [95% CI: 0.76-0.90]; p < .001), dried fruit (OR = 0.43 [95% CI: 0.39-0.46]; p < .001), fresh fruit juice (OR = 0.66 [95% CI: 0.62-0.72]; p < .001), packed juice (OR = 0.91 [95% CI: 0.84-0.98]; p < .009), milk (OR = 0.51 [95% CI: 0.47-0.55]; p < .001), yogurt (OR = 0.86 [95% CI: 0.79-0.93]; p ≤ .001), and coffee (OR = 0.82 [95% CI: 0.76-0.89]; p ≤ .001).

CONCLUSIONS

The findings of this study indicate a significant relationship between sleep duration and unhealthy food habits. Therefore, increasing awareness of families in this area may reduce obesity and its complications.

Disparities in Sleep Health among Adolescents: The Role of Sex, Age, and Migration

Background. Disparities in sleep disturbances have been described in adults; nevertheless, among adolescents, data have yielded conflicting results. Therefore, analyses of our cohort study of 500 urban, normally developed Hispanic adolescents (10–18 years), aim to determine if rates of sleep debt differ between: (a) male and female adolescents, (b) US-born Hispanics and first-generation immigrant ethnic counterparts, and (c) specific activities that these teens trade for sleep. Participants’ weekday and weekend sleep patterns, along with the reasons for sleeping less than the recommended hours were recorded. Standardized surveys were used to gather information regarding sociodemographics, migration, acculturation, and medical history. Using the criteria set forth by the National Sleep Foundation, analyses indicated that sleep deprivation is a pervasive problem, with 75% in the preadolescents and 45% of the late adolescents exhibiting sleep problems. Females slept on average at least one hour less per day than their male counterparts (7 vs. 8 hours). The sleep problems were rooted in several overlapping causes, including use of technology, video games, studying, and employment. Nevertheless, reasons for sleep loss differed by gender and by immigrant status. Multivariable adjusted logistic regression analyses showed that females, US-born teens, and preadolescents had higher odds of being sleep deprived. Pediatricians and sleep experts should be aware of gender-specific causes and responses of sleep problems. Cultural ecological frameworks need to be considered, and clearly indicate that findings may not generalize to youth from other cultural backgrounds.

Sleep quality is associated with psychosocial functioning and health-related quality of life in pediatric transplant recipients

This study examined patient-reported sleep quality in a single-center cross-sectional sample of adolescents with solid organ transplants and evaluated associations between sleep quality, psychosocial functioning (ie, depression/anxiety symptoms), and HRQOL. Health disparities associated with minority race/ethnicity and socioeconomic variables were also examined. Sixty-nine adolescents (M = 16.51 years; SD = 1.63) who received a solid organ transplant (kidney: n = 25; liver: n = 24; heart: n = 20) completed self-report measures of sleep quality, psychosocial functioning, and HRQOL. Adolescent transplant recipients endorsed significantly lower levels of sleep quality (ie, falling asleep) compared with previously published norms of healthy peers (t = -3.60; P ≤ .001). Higher sleep quality was significantly associated with fewer anxiety and depressive symptoms (r = -.31 to -.40), and higher physical and psychosocial HRQOL (r = .33-.43). Adolescents from minority backgrounds had significantly worse sleep quality compared with non-Hispanic Whites. Adolescent transplant recipients, particularly those from minority backgrounds, may be at increased risk for experiencing poor sleep quality. Suboptimal sleep is a risk factor for higher levels of anxiety and depressive symptoms, as well as lower levels of physical and psychosocial HRQOL. Sleep is an important modifiable factor that, if improved, may contribute to lower anxiety/depressive symptoms and better HRQOL in adolescent transplant recipients.

Difficulties falling asleep among adolescents: Social inequality and time trends 1991-2018

Sleep problems in adolescence are increasingly common, and associated with adverse health and psychological outcomes. Adolescents' sleep problems may be related to the family's socioeconomic status, but studies are few and no study has examined whether social inequality in sleep problems changes as sleep problems become increasingly common. This study examined trends in difficulties falling asleep among adolescents in Denmark, whether this sleep problem was associated with socioeconomic status, and whether this association changed from 1991 to 2018. The study applied data from eight comparable surveys among 11-15 year olds in Denmark 1991-2018, the Danish arm of the international Health Behaviour in School-aged Children study, N = 30,002. The prevalence of daily difficulties falling asleep increased from 7.0% to 13.4% in 1991-2018 with higher frequencies among girls and younger adolescents. The odds ratio (95% confidence interval) for daily difficulties was 1.14 (1.05-1.24) in middle and 1.52 (1.37-1.69) in low compared with high socioeconomic status. The absolute social inequality in difficulties falling asleep was persistent in 1991-2018 whereas the relative social inequality may have decreased. The increasing prevalence and the social inequality in difficulties falling asleep among adolescents is a serious public health concern that calls for more attention and efforts.

Socio-demographic and maternal predictors of adherence to 24-hour movement guidelines in Singaporean children

PURPOSE

Integrated 24-Hour Movement Guidelines provide specific recommendations on screen viewing (SV), moderate-to-vigorous physical activity (MVPA) and sleep to improve health of children and youth. However, few studies have examined whether these guidelines are met in young children, particularly in Asia. We evaluated adherence to integrated and individual guidelines and its predictors in 5.5-year-old Singaporean children.

METHODS

Growing Up in Singapore towards Healthy Outcomes (GUSTO) is a mother-offspring birth cohort study. At age 5.5 years, child SV was reported by parents. Movement behaviours (MBs) were measured continuously using wrist-worn accelerometers over 7 consecutive days and nights. For accelerometer data including ≥3 days with ≥16 h/day we estimated mean (±SD) daily MVPA, SV and nighttime sleep duration across the week. Adherence to integrated (Canadian/Australian) guidelines was defined as meeting all individual guidelines: ≥60 min of MVPA/day, ≤2 h of screen time/day, and 9-11 h of sleep/night. Socio-demographic and maternal predictors collected at pregnancy enrolment and at 26-28 weeks' gestation were examined by multivariable logistic regression.

RESULTS

Of 864 children followed up age 5.5 years, 547 (63.3%) had both valid ActiGraph and questionnaire data (51.7% boys and 58.3% Chinese ethnicity). Children averaged 101.9 (± 88.7) min/day SV, 67.3 (± 23.7) min/day MVPA and 480.6 (± 57.2) min/night sleep. Few children met integrated guidelines. Specifically, the proportions of children who met none, SV, MVPA, sleep and integrated guidelines were 11.2, 70.2, 59.6, 13.7 and 5.5%, respectively. Multivariable analysis showed that maternal activity and television (TV) viewing were associated with meeting integrated guidelines (insufficiently vs. highly active (OR [95% CI]): 0.11 [0.01, 0.95]; 2-3 vs. ≥ 3 h TV: 3.52 [1.02, 12.22]). Examining higher adherence to individual guidelines, Chinese ethnicity, younger maternal age and lower maternal TV and sleep time were associated with greater SV; male sex, Malay ethnicity, higher birth order and higher maternal activity level were associated with greater MVPA; and older maternal age was associated with adherence to sleep guideline.

CONCLUSIONS

Beyond individual behaviours, consideration of the full spectrum of MBs may be important to improve children's health. However, few Singaporean children adhere to integrated 24-h movement guidelines. Maternal behaviours as early as during pregnancy could be important targets for future interventions aiming to promote these MBs in children.

Emergence of racial/ethnic differences in infant sleep duration in the first six months of life

Objective

Examine the emergence of differences in sleep duration between infants from different racial/ethnic backgrounds and extent to which differences are explained by socioeconomic status (SES) and sleep continuity.

Methods

Sleep duration and continuity (number of night wakings and longest nighttime stretch of sleep) were assessed for 394 infants in the Rise & Sleep Health in Infancy & Early Childhood (SHINE) birth cohort at one- and six-months using the Brief Infant Sleep Questionnaire (BISQ). Multivariable regression was used to estimate associations of race/ethnicity with sleep duration adjusting for individual-level covariates, SES, and sleep continuity.

Results

The sample was 40% non-Hispanic white, 33% Hispanic, 11% Black, and 15% Asian. Mean (SD) durations for daytime, nighttime, and total sleep at one-month were 6.3 (2.0), 8.9 (1.5), and 15.2 (2.7) hours, respectively. Corresponding durations at six-months were 3.0 (1.4), 9.9 (1.3), and 13.0 (1.9) hours. At one-month, Hispanic infants had shorter nighttime sleep than white infants [β: −0.44 h (95% CI: −0.80, −0.08)]. At six-months, Hispanic [β: −0.96 h (−1.28, −0.63)] and Black [β: −0.60 h (−1.07, −0.12)] infants had shorter nighttime sleep than white infants. The near 1-h differential in night sleep among Hispanics resulted in shorter total sleep [β: −0.66 h (−1.16, −0.15)]. Associations across all racial/ethnic groups were attenuated after adjustment for SES at one- and six months. Sleep continuity attenuated associations with nighttime and total sleep duration by 20–60% for Hispanic infants at six-months.

Conclusions

Differences in sleep duration emerge early in life among racial/ethnic groups and are in part explained by SES and sleep continuity.

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At one-month, Hispanic infants slept significantly less at night than white infants.

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At six-months, Hispanic and Black infants slept less at night than white infants.

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The near 1-h differential among Hispanics resulted in shorter total sleep.

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Adjusting for SES attenuated associations across all racial/ethnic groups.

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Sleep continuity attenuated associations for Hispanic infants at six-months.

Comparison of Sleep Characteristics, Patterns, and Problems in Young Children Within the Southeast Asian Region

BACKGROUND AND OBJECTIVES

Optimal sleeping habits are important for health development of infants. The role of culture in sleep habits cannot be underestimated. We aimed to characterize sleep patterns, sleep practices, and sleep problems; and assess the sleep settings and parental perceptions of sleep problems in children from birth to 36 months in countries in the Southeast Asian (SEA) region.

PARTICIPANTS

Parents and caregivers of infants and toddlers (birth to 36 months old) from countries in Southeast Asia participated in this study.

METHODS

Data was collected using the Brief Infant Sleep Questionnaire for a total of 5,987 children from 6 countries in the SEA region (967 Indonesia/ID, 997 Malaysia/MY, 1,034 Philippines/PH, 1,001 Singapore/SG, 988 Thailand/TH, and 1,000 Vietnam/VN).

RESULTS

The sleep variables varied among SEA children studied. Bedtimes and nighttime sleep varied across the region by as much as 1 hr 34 min and 1 hr 15 min respectively.

CONCLUSIONS

Despite being geographically very close together and having some common sociocultural characteristics, sleep variables in the young child within the SEA region do differ in significant ways.

Prevalence of childhood obstructive sleep apnea syndrome and its role in daytime sleepiness

Objectives

To investigate childhood obstructive sleep apnea syndrome (OSAS) and its role in daytime sleepiness among school-age children.

Methods

A questionnaire survey was conducted with 25,211 children aged 6–15 (mean, 10.39) years attending 148 elementary and 71 middle schools in 10 prefectures across Japan and their parents. Questions concerned 4 sleep habit items (bedtime, sleep onset latency, wake time after sleep onset, wake-up time) and 4 sleep disorder items (loud snoring, snorts/gasps, breathing pauses, seems very sleepy in the daytime). Total sleep time (TST) was calculated with sleep habits. Severe possible OSAS (p-OSAS) was defined as having loud snoring, snorts and gasps, or breathing pauses “frequently” (≥ 5 times per week), and mild p-OSAS was rated as having any of these “sometimes” (2–4 times per week). Severe daytime sleepiness was defined as seeming very sleepy “frequently” and mild daytime sleepiness as seeming very sleepy “sometimes”.

Results

Mean prevalence of mild to severe p-OSAS and severe p-OSAS in children across all grade levels was 9.5% and 1.6%, respectively. p-OSAS was particularly prevalent in children at lower elementary levels, decreasing with advancing grade levels. Prevalence of mild and severe daytime sleepiness was 6.1% and 0.9%, respectively, among all children (7.0%). Prevalence of daytime sleepiness increased with advancing grade levels, particularly in middle-school level. Average TST was 8.4 ± 2.2 h in both elementary and middle-school levels, and decreased as grades advanced, particularly in middle-school levels. Multivariate logistic regression analysis showed that middle-school level, TST < 8 h, and p-OSAS were independent factors for daytime sleepiness. Strong correlations were found between severe daytime sleepiness and severe p-OSAS or TST < 6 h, and between daytime sleepiness and loud snoring or breathing pauses.

Conclusion

p-OSAS may be an independent factor influencing daytime sleepiness in school-age children. Loud snoring and breathing pauses could be clinical markers for children with severe daytime sleepiness.

Modifiable predictors of insufficient sleep durations: A longitudinal analysis of youth in the COMPASS study

The purpose of the current study was to simultaneously examine commonly proposed risk and protective factors for sleep deprivation over time among a large cohort of Ontario and Alberta secondary school students. Using 4-year linked longitudinal data from youth in years 1 through 4 (Y₁[2012/2013], Y₂[2013/2014], Y₃[2014/2015], Y₄[2015/2016]) of the COMPASS study (n=26,205), the likelihood of students meeting contemporary sleep recommendations was tested based on their self-reported substance use, bullying victimization, physical activity, and homework and screen time. Models controlled for the effect of student-reported gender, race/ethnicity, grade, school clustering, and all other predictor variables. Relative to baseline, students became less likely to meet the sleep recommendations if at follow-up they had initiated binge drinking, experienced cyber bullying victimization, or were spending more time doing homework, with other factors held constant. The likelihood of reporting sufficient sleep increased if students had begun engaging in resistance training at least three times a week. No longitudinal effect was observed when students increased their caffeine consumption (energy drinks, coffee/tea), initiated cannabis or tobacco use, experienced other forms of bullying victimization (physical, verbal, or belongings), engaged in more moderate-vigorous physical activity, or increased their screen use of any type. Few of the commonly purported modifiable risk and protective factors for youth sleep deprivation held in multinomial longitudinal analyses. Causal conclusions appear premature, with further research required to confirm the targets likely to be most effective in assisting more youth in meeting the sleep recommendations.

Past, present, and future: trends in sleep duration and implications for public health

Sleep is important for the physical, social and mental well-being of both children and adults. Over the years, there has been a general presumption that sleep will inevitably decline with the increase in technology and a busy 24-hour modern lifestyle. This narrative review discusses the empirical evidence for secular trends in sleep duration and the implications of these trends.

Secular trends in Australian school children's sleep and perceived importance of sleep between 1985 and 2013

AIM

To examine secular trends in Australian children's actual sleep time as well as the perceived importance of sleep between 1985, 2004 and 2013.

METHODS

Secular trends in children's sleep and their perception of the importance of sleep across three time points 1985 (N = 401), 2004 (N = 450) and 2013 (N = 395) were examined according to socio-economic status (SES), age and sex. The children self-reported their bedtime, wake-up time and their perceived importance of sleep, among other questions.

RESULTS

There were no significant differences in sleep duration between boys and girls in any of the survey years, nor were there differences in sleep duration between SES categories at any time point. Independent of survey year, age, sex and SES, there was a graded difference in sleep duration (minutes) across response categories for perceived importance of sleep. Overall, trends in the perceived importance of sleep appeared to match trends in actual sleep time, but not for all subgroups.

CONCLUSION

This study indicates that the sleep duration of high SES Australian school children is returning to, or near to, baseline sleep duration observed in 1985, while the sleep duration of low SES Australian children has remained at low levels.

Sleep duration trends and trajectories among youth in the COMPASS study

OBJECTIVES

Limited Canadian studies have examined youth sleep over time. This study explored sleep duration over recent years among youth, patterns over the course of secondary school, and subgroups at greater risk of sleep deprivation and problematic trajectories.

DESIGN

Longitudinal survey.

PARTICIPANTS/SETTING

Secondary school students in Ontario and Alberta, Canada.

MEASURES AND ANALYSES

In cross-sectional analyses, student-reported sleep duration was analyzed in three waves of the COMPASS study (Y₂: 2013/2014, Y₃: 2014/2015, Y₄: 2015/2016), and differences by student-level (race/ethnicity, grade, sex) and school-level (urbanicity, median household income) variables were tested in the most recent wave. For the longitudinal analyses, group-based trajectory modeling was conducted using 3-year linked data, adding risk factors as predictors of problematic trajectories.

RESULTS

Average sleep durations declined over the 3 study waves, resulting in less than half of youth meeting the guideline of 8-10 hours per night. Four trajectory groups comprised almost 90% of participants, with 8.8% of students classified as long sleepers, whereas more than one-third of students belonged to 2 sleep-deprived trajectory groups (short [9.3%] and low-normal [26.7%]). In both the cross-sectional and longitudinal analyses, longer sleep durations were more likely among students who identified as male, White, in earlier grades, and attending schools in areas with higher median household income and classified as rural/small urban, relative to their counterparts.

CONCLUSIONS

Results support the necessity of continued surveillance and interventions to monitor and counteract what appears to be an ongoing trend of diminishing sleep and a growing number of sleep-deprived adolescents. Targeted efforts in less affluent and more metropolitan areas warrant consideration.

Relationship between Mobile Phone Addiction and the Incidence of Poor and Short Sleep among Korean Adolescents: a Longitudinal Study of the Korean Children & Youth Panel Survey

Three of ten teenagers in Korea are addicted to mobile phones. The aim of this study was to examine the relationship between mobile phone addiction and the incidence of poor sleep quality and short sleep duration in adolescents. We used longitudinal data from the Korean Children & Youth Panel Survey conducted by the National Youth Policy Institute in Korea (2011-2013). A total of 1,125 students at baseline were included in this study after excluding those who already had poor sleep quality or short sleep duration in the previous year. A generalized estimating equation was used to analyze the data. High mobile phone addiction (mobile phone addiction score > 20) increased the risk of poor sleep quality but not short sleep duration. We suggest that consistent monitoring and effective intervention programs are required to prevent mobile phone addiction and improve adolescents' sleep quality.

Effect of socio-economic status on sleep

AIM

Sufficient sleep is an important factor in physical and mental health. Sleep duration can be affected by socio-economic status (SES). This study aimed to examine the association between sleep duration and SES in Korean adolescents.

METHODS

This study was conducted with 1608 adolescents aged 12-18 years, based on data from the 2010 to 2012 Korean National Health and Nutrition Examination Survey (KNHANES). Sleep duration was self-reported in hours and three SES indicators were used: household income, basic livelihood security programmes and type of health insurance. Confounding factors in this study were age, mental health and physical activity.

RESULTS

Participants' average age was 15.6 ± 0.05 years and average sleep duration was 7.04 ± 0.05 h. There was a strong association between sleep duration and household income (P < 0.05) rather than other socio-economic indicators. In addition, it showed that sleep duration was significantly associated with age, body mass index (P < 0.05) and low mood is associated with short sleep and long sleep (>9 h/night). We found similar results in both genders, that is, that the highest income group had shorter sleep duration than the lowest income group.

CONCLUSIONS

This study shows that the SES, particularly household income, is an important factor in short sleep duration in Korean adolescents. Our findings suggest that, in future investigations of the adolescent's sleep problem, attention should be paid to household income.

Developmental Trajectories of Sleep Problems from Childhood to Adolescence Both Predict and Are Predicted by Emotional and Behavioral Problems

Although the prevalence rates of sleep disorders at different stages of childhood and adolescence have been well established, little is known about the developmental course of general sleep problems. This also holds true for the bidirectional relationship between sleep problems and emotional as well as behavioral difficulties. This longitudinal study investigated the general pattern and the latent trajectory classes of general sleep problems from a large community sample aged 5–14 years. In addition, this study examined the predictive value of emotional/behavioral difficulties (i.e., anxiety/depression, attention problems, and aggressive behavior) on sleep problems latent trajectory classes, and vice-versa. Participants (N = 1993) were drawn from a birth cohort of Western Australian children born between 1989 and 1991 who were followed until 14 years of age. Sleep problems were assessed at ages 5, 8, 10, and 14, respectively, whereas anxiety/depression, attention problems, and aggressive behavior were assessed at ages 5 and 17 years. Latent growth curve modeling revealed a decline in an overall pattern of sleep problems during the observed 10-year period. Anxiety/depression was the only baseline factor that predicted the longitudinal course of sleep problems from ages 5 to 14 years, with anxious and depressed participants showing faster decreasing patterns of sleep problems over time than those without anxiety or depression. Growth mixture modeling identified two classes of sleep problem trajectories: Normal Sleepers (89.4%) and Troubled Sleepers (10.6%). Gender was randomly distributed between these groups. Childhood attention problems, aggressive behavior, and the interaction between gender and anxiety/depression were significantly predictive of membership in the group of Troubled Sleepers. Group membership in Troubled Sleepers was associated with higher probability of having attention problems and aggressive behavior in mid-adolescence. Boys and girls with behavioral difficulties, and girls with emotional difficulties were at increased risk of having sleep problems during later childhood and adolescence. Developmental trajectories of sleep problems were also predictive of behavioral difficulties in later life. Findings from this study provide empirical evidence for the heterogeneity of sleep problems and their development, and emphasize the importance of understanding sleep problems and their relationship to children and adolescents’ mental health.

Impact of a modest delay in school start time in Hong Kong school adolescents

OBJECTIVE

To examine the effects of a modest delay (15 min) in school start time (SST) on adolescent sleep patterns, mood, and behaviors.

METHODS

Two secondary schools in Hong Kong with a total of 1173 students (intervention: n = 617; comparison school n = 556) completed both baseline and follow-up questionnaires. School start time was delayed by 15 min, from 7:45 a.m. to 8:00 a.m., in the intervention school. The comparison school maintained their regular SST at 7:55 a.m. Students' sleep-wake patterns, daytime sleepiness, and mental and behavioral aspects were assessed by validated questionnaires before and after the intervention.

RESULTS

Students in the intervention school significantly delayed their weekday wake-up time (p < 0.001) and increased their total time in bed (p < 0.001) when compared to students in the comparison school. Both groups experienced a delay in their weekday bedtime. The students in the intervention school showed improved mental health [General Health Questionnaire (GHQ) score, p = 0.015], better prosocial behaviors (p = 0.009), better peer relationships (p < 0.001), greater attentiveness (p < 0.001), less emotional problems (p = 0.002), and less behavioral difficulties (p < 0.001) as measured by Strengths and Difficulties Questionnaire (SDQ).

CONCLUSIONS

A modest delay (15 min) in school start time can increase adolescent sleep with corresponding improvement in mood and behaviors. Current findings have significant implications for education policy, suggesting that school administrators and policy makers should systematically consider delaying school start time to promote sleep and health among school-aged adolescents.

CLINICAL TRIAL REGISTRATION

ChiCTR-TRC-12002798. The trial protocol can be accessed at: http://www.chictr.org/en/proj/show.aspx?proj=3955.

Putting Children's Sleep Problems to Bed: Using Behavior Change Theory to Increase the Success of Children's Sleep Education Programs and Contribute to Healthy Development

Sleep is critical for the healthy development of children, yet most children simply don’t get enough. Whilst school based sleep education programs have been developed for parents and their children, they have had mixed success. We consider how existing school-based sleep education programs can be improved by applying a broader model to behaviour change theory. We find that the mixed success of school-based sleep education programs may be due to a plausible but misleading assumption that simply increasing information about the importance of sleep and the risks of insufficient and/or inefficient sleep, will necessarily result in improved sleep behaviours. We identify the potential benefits of using a more inclusive behavior change theory in the development of sleep education programs with a particular need for theories that incorporate the multiple biological, environmental and social impacts on children’s sleep. Bronfenbrenner’s Bioecological model is presented to illustrate how one such inclusive behavior change theory could significantly improve the success of sleep education programs and ultimately support the healthy development of children.

Identifying correlates and determinants of physical activity in youth: How can we advance the field?

This commentary provides a critical discussion of current research investigating the correlates and determinants of physical activity in young people, with specific focus on conceptual, theoretical and methodological issues. We draw on current child and adolescent literature and our own collective expertise to illustrate our discussion. We conclude with recommendations that will strengthen future research and help to advance the field.

Sleep Duration Trajectories and Body Composition in Adolescents: Prospective Birth Cohort Study

We aimed to estimate the association between sleep duration trajectories and body composition in adolescents. We used data from participants of the 1993 Pelotas (Brazil) Birth Cohort Study who were later followed up at age 18 years (response rate of 81.3%). At the time, 3974 adolescents had complete data on body composition, which was assessed by air displacement plethysmography. Sleep duration was self-reported by participants at ages 11 and 18 years. Analyses were sex-stratified. The mean sleep duration at 11 years was 9.7 (SD 1.4) and 8.4 (SD 1.9) at 18 years. Sleep duration was dichotomized as inadequate (<8 hours/day) or adequate (≥8 hours/day). Mean body mass, fat mass, and fat-free mass indices at 18 years were 23.4 kg/m² (SD 4.5), 6.1 kg/m² (SD 3.9) and 17.3 kg/m² (SD 2.5), respectively. Girls who reported inadequate sleep duration at 11 years of age, but adequate sleep duration at 18, on average experienced an increase in body mass index (β = 0.39 z-scores; 95% CI 0.13, 0.65), fat mass index (β = 0.30 z-scores; 95% CI 0.07, 0.53), and fat-free mass index (β = 0.24 z-scores; 95% CI 0.08, 0.39) compared to those who had adequate sleep duration at both time points. The results suggest that changes in sleep duration across adolescence may impact body composition in later adolescence and that this may differ by sex.

Sleep duration and risk of obesity among a sample of Victorian school children

Background

Insufficient sleep is potentially an important modifiable risk factor for obesity and poor physical activity and sedentary behaviours among children. However, inconsistencies across studies highlight the need for more objective measures. This paper examines the relationship between sleep duration and objectively measured physical activity, sedentary time and weight status, among a sample of Victorian Primary School children.

Methods

A sub-sample of 298 grades four (n = 157) and six (n = 132) Victorian primary school children (aged 9.2-13.2 years) with complete accelerometry and anthropometry data, from 39 schools, were taken from a pilot study of a larger state based cluster randomized control trial in 2013. Data comprised: researcher measured height and weight; accelerometry derived physical activity and sedentary time; and self-reported sleep duration and hypothesised confounding factors (e.g. age, gender and environmental factors).

Results

Compared with sufficient sleepers (67 %), those with insufficient sleep (<10 hrs/day) were significantly more likely to be overweight (OR 1.97, 95 % CI:1.11-3.48) or obese (OR 2.43, 95 % CI:1.26-4.71). No association between sleep and objectively measured physical activity levels or sedentary time was found.

Conclusion

The strong positive relationship between weight status and sleep deprivation merits further research though PA and sedentary time do not seem to be involved in the relationship. Strategies to improve sleep duration may help obesity prevention initiatives in the future.

Is sleep deprivation a contributor to obesity in children?

Chronic lack of sleep (called "sleep deprivation") is common in modern societies with 24/7 availability of commodities. Accumulating evidence supports the role of reduced sleep as contributing to the current obesity epidemic in children and youth. Longitudinal studies have consistently shown that short sleep duration is associated with weight gain and the development of obesity. Recent experimental studies have reported that sleep restriction leads to weight gain in humans. Increased food intake appears to be the main mechanism by which insufficient sleep results in weight gain. Voluntary sleep restriction has been shown to increase snacking, the number of meals eaten per day, and the preference for energy-dense foods. Although the causes of sleep loss in the pediatric population are numerous, more research looking at screen exposure before bedtime and its effects on sleep is needed given the pervasiveness of electronic media devices in today's environment. Health professionals should routinely ask questions about sleep and promote a good night's sleep because insufficient sleep impacts activity and eating behaviors. Future research should examine the clinical benefits of increasing sleep duration on eating behaviors and body weight control and determine the importance of adequate sleep to improve the treatment of obesity.

A Meta-Analysis of the Effect of Experimental Sleep Restriction on Youth's Attention and Hyperactivity

This meta-analysis examined the effect experimental sleep restriction has on youth's attention and hyperactivity outcomes. Thirteen published studies containing 17 independent samples were included (N = 496). Random- and fixed-effects models were used to estimate pooled effect sizes and moderator effects, respectively. Results indicate that sleep-restricted youth had significantly worse attention outcomes than youth with extended sleep, but no differences were evident regarding hyperactivity. Significant moderators of this effect included age and sex. These results have important implications for both the prevention and treatment of attention problems, highlighting the need for health professionals to screen for and treat underlying sleep issues.

[Sleep in adolescents of different socioeconomic status: a systematic review]

OBJECTIVE

To analyze the sleep characteristics in adolescents from different socioeconomic levels.

DATA SOURCE

Original studies found in the Medline/PubMed and SciELO databases without language and period restrictions that analyzed associations between sleep variables and socioeconomic indicators. The initial search resulted in 99 articles. After reading the titles and abstracts and following inclusion and exclusion criteria, 12 articles with outcomes that included associations between sleep variables (disorders, duration, quality) and socioeconomic status (ethnicity, family income, and social status) were analyzed.

DATA SYNTHESIS

The studies associating sleep with socioeconomic variables are recent, published mainly after the year 2000. Half of the selected studies were performed with young Americans, and only one with Brazilian adolescents. Regarding ethnic differences, the studies do not have uniform conclusions. The main associations found were between sleep variables and family income or parental educational level, showing a trend among poor, low social status adolescents to manifest low duration, poor quality of sleeping patterns.

CONCLUSIONS

The study found an association between socioeconomic indicators and quality of sleep in adolescents. Low socioeconomic status reflects a worse subjective perception of sleep quality, shorter duration, and greater daytime sleepiness. Considering the influence of sleep on physical and cognitive development and on the learning capacity of young individuals, the literature on the subject is scarce. There is a need for further research on sleep in different realities of the Brazilian population.

ABCs of SLEEPING: A review of the evidence behind pediatric sleep practice recommendations

The ABCs of SLEEPING mnemonic was developed to serve as an organizing framework for common pediatric sleep recommendations. The mnemonic stands for 1) age appropriate bedtimes and wake-times with consistency, 2) schedules and routines, 3) location, 4) exercise and diet, 5) no electronics in the bedroom or before bed, 6) positivity 7) independence when falling asleep and 8) needs of child met during the day, 9) equal great sleep. This review examines the empirical evidence behind the practices and recommendations captured by the ABCs of SLEEPING mnemonic for children aged 1 to 12. A search was conducted of key electronic databases (PubMed, PsycINFO, CINAHL, & EMBASE) to identify English articles that included the concepts of sleep, insomnia, and/or bedtime. 77 articles were eligible for inclusion and were coded to extract key details and findings regarding the relations between sleep practices identified in the ABCs of SLEEPING mnemonic and sleep outcomes. Findings provided preliminary support for many of the recommendations that are commonly made to families regarding healthy sleep practices. However, more robust investigations are needed to better understand the causal contributions of healthy sleep practices to the onset and maintenance of children's sleep problems.