Sleep and the body mass index and overweight status of children and adolescents

Understanding Accelerated Summer Body Mass Index Gain by Tracking Changes in Children's Height, Weight, and Body Mass Index Throughout the Year

Background: Drivers of summer body mass index (BMI) gain in children remain unclear. The Circadian and Circannual Rhythm Model (CCRM) posits summer BMI gain is biologically driven, while the Structured Days Hypothesis (SDH) proposes it is driven by reduced structure. Objectives: Identify the mechanisms driving children's seasonal BMI gain through the CCRM and SDH. Methods: Children's (N = 147, mean age = 8.2 years) height and weight were measured monthly during the school year, and once in summer (July-August). BMI z-score (zBMI) was calculated using CDC growth charts. Behaviors were measured once per season. Mixed methods regression estimated monthly percent change in children's height (%HΔ), weight (%WΔ), and monthly zBMI for school year vs. summer vacation, seasonally, and during school months with no breaks vs. school months with a break ≥1 week. Results: School year vs. summer vacation analyses showed accelerations in children's %WΔ (Δ = 0.9, Standard Error (SE) = 0.1 vs. Δ = 1.4, SE = 0.1) and zBMI (Δ = -0.01, SE = 0.01 vs. Δ = 0.04, SE = 0.3) during summer vacation, but %HΔ remained relatively constant during summer vacation compared with school (Δ = 0.3, SE = 0.0 vs. Δ = 0.4, SE = 0.1). Seasonal analyses showed summer had the greatest %WΔ (Δ = 1.8, SE = 0.4) and zBMI change (Δ = 0.05, SE = 0.03) while %HΔ was relatively constant across seasons. Compared with school months without a break, months with a break showed higher %WΔ (Δ = 0.7, SE = 0.1 vs. Δ = 1.6, SE = 0.2) and zBMI change (Δ = -0.03, SE = 0.01 vs. Δ = 0.04, SE = 0.01), but %HΔ was constant (Δ = 0.4, SE = 0.0 vs. Δ = 0.3, SE = 0.1). Fluctuations in sleep timing and screen time may explain these changes. Conclusions: Evidence for both the CCRM and SDH was identified but the SDH may more fully explain BMI gain. Interventions targeting consistent sleep and reduced screen time during breaks from school may be warranted no matter the season.

Physical Activity, Sleep, and Screen Time in Children and Adolescents Before and During the COVID-19 Pandemic: An Analysis of the 2019-2020 National Survey of Children's Health

PURPOSE

The purpose of this study was to examine whether engagement in health behaviors changed from pre-pandemic (2019) to during the pandemic (2020).

METHODS

The combined 2019-2020 National Survey of Children's Health (NSCH) was used to inform this study. The NSCH is an annual survey designed to provide national estimates of key indicators of childhood health and well-being. Physical activity (number of days/week with >60 min of activity), screen-time (hours/day of TV viewing and computer use), and sleep (hours/day) were assessed by parental report. Adjusted binomial and multinomial logistic regression models were used to determine the association between survey year and health behaviors.

RESULTS

Children and adolescents were 36% more likely to be physically inactive in 2020 compared to 2019. Additionally, children and adolescents were 14% more likely to meet sleep guidelines and 39% less likely to meet screen-time guidelines in 2020 compared to 2019, independent of age, sex, race/ethnicity, and poverty level. Children (6-13 year) and adolescents (14-17 years) were 10% and 15% less likely to get below the recommended amount of sleep in 2020 compared to 2019, respectively.

CONCLUSION

Prevalence of meeting sleep guidelines increased among children and adolescents in 2020 but decreased for physical activity and screen-time. Initiatives targeting activity and screen-time may be urgently needed. Whether rates of these health behaviors return to pre-pandemic levels over the next few years should be closely assessed.

The relationship between multiple sleep dimensions and obesity in adolescents: A systematic review

Sleep is an involuntary behaviour, biologically fundamental to survival and wellbeing. However, sleep is increasingly neglected, with significant health implications. Recent research has identified associations between sleep duration, quality, timing and risk of overweight/obesity in children and adults. The aim of this review was to systematically identify and examine research that investigates the relationships between multiple objective and subjective sleep outcomes and objective adiposity measures in adolescents. A systematic review of literature, published to December 2022, was conducted using ten bibliographic databases. Search terms included objective and subjective sleep/circadian rhythm outcomes, objective adiposity measurements, and adolescents aged 8-18 years. Eighty-nine studies were included in the final review. Sleep outcomes were synthesized into three sleep domains: pre-sleep, during sleep and post-sleep outcomes. In summary, pre-sleep outcomes (including poor sleep hygiene, later chronotype and increased variability and later sleep timings) and increased sleep disturbance are consistently significantly associated with increased obesity and adiposity in adolescents. The relationship between during-sleep outcomes (sleep quality and efficiency) with adiposity and obesity measures was mixed. These findings suggest that adapting an individual's schedule to best suit chronotype preference and improving sleep hygiene, including a consistent bedtime routine, could reduce adiposity and obesity in adolescents.

Age-Specific Quantification of Overweight/Obesity Risk Factors From Infancy to Adolescence and Differences by Educational Level of Parents

Objectives: To explore the age-dependent associations between 26 risk factors and BMI in early life, and differences by parental educational level. Methods: Data of 10,310 children (24,155 measurements) aged 2-16 years participating in a multi-centre European cohort from 2007 to 2014 were utilized. Trajectories of overweight/obesity risk factors and their age-specific associations with BMI were estimated using polynomial mixed-effects models. Results: Exposure to most unfavourable factors was higher in the low/medium compared to the high education group, e.g., for PC/TV time (12.6 vs. 10.6 h/week). Trajectories of various risk factors markedly changed at an age of 9-11 years. Having a family history of obesity, maternal BMI, pregnancy weight gain and birth weight were positively associated with BMI trajectories throughout childhood/adolescence in both education groups; associations of behavioural factors with BMI were small. Parental unemployment and migrant background were positively associated with BMI in the low/medium education group. Conclusion: Associations of risk factors with BMI trajectories did not essentially differ by parental education except for social vulnerabilities. The age period of 9-11 years may be a sensitive period for adopting unfavourable behaviours.

Food Intake and Sleep Disorders in Children and Adolescents with Obesity

Over the last few decades, numerous scientific studies have investigated the possible association between sleep duration and adiposity during childhood, since it has been reported that sleep deprivation causes a related increase in caloric intake. Even though the underlying pathogenetic mechanisms are still under study and not completely known, the effect of dietetic habits and nutrient intake on sleep quality and patterns has been reported. The aim of this study is to explore the intricate interplay between food intake/diet patterns and pediatric sleep disturbances in children and adolescents with obesity, emphasizing the importance of not underestimating this aspect in the prevention and treatment of this complex disease. Recent evidence supports a high correlation between specific diet patterns and foods with sleep disturbances in children at all ages. Diets rich in fiber, fruit, vegetables, and anti-inflammatory nutrients and low in saturated fats seem to promote better sleep quality. Sleep disturbances are, in turn, risk factors for the development of obesity. Therefore, food strategies should be applied to counteract this harmful process. Unraveling the complex links between dietary habits, sleep patterns, and obesity is essential for developing effective strategies to combat this critical public health issue.

Childhood obesity risk factors by race and ethnicity

OBJECTIVE

Childhood obesity is a public health concern that often worsens with age. Although several risk factors at the child and maternal levels have been identified in cross-sectional studies, less is known about their long-term contribution to racial/ethnic disparities in childhood obesity. This study examines child- and maternal-level factors associated with the growth trajectories of White, Black, and Latino children.

METHODS

Group-based trajectory models were used to identify BMI z score trajectories from birth to 9 years of age among White, Black, and Latino children. The associations of child- and maternal-level factors with the trajectory group identified as at risk for obesity were examined using adjusted logistic regression analysis, stratified by race/ethnicity.

RESULTS

Among White children, fast-food consumption (odds ratio [OR] = 1.66; 95% CI: 1.09-2.52) was associated with higher odds of following an at-risk trajectory. Among Black and Latino children, prepregnancy BMI was associated with following an at-risk trajectory (OR = 1.05; 95% CI: 1.03-1.08 for Black children, and OR = 1.12; 95% CI: 1.07-1.17 for Latino children).

CONCLUSIONS

These findings showed racial/ethnic differences in the risk factors that influence the likelihood of obesity during childhood. Further research is needed to identify modifiable racial/ethnic specific risk factors to guide obesity-prevention interventions.

Changes in Sleep Patterns in Korean Early Adolescents during Sexual Maturation

Purpose: Teenagers’ sleep patterns show physiological delays influenced by sexual maturation and other external time-related factors. However, Korean adolescents show differences in the onset of pubertal development and have shorter sleep durations than other adolescents worldwide. Therefore, we assessed sleep patterns and sexual maturation in Korean early adolescents to evaluate changes in sleep patterns in relation to sexual maturation in early adolescents with sleep deprivation.Methods: From March to August 2017, we surveyed children aged 10 to 12 years in Seongnam (Seongnam Atopy Project). We evaluated items related to sleep and sexual maturation, assessed sleep duration and sleepiness scale scores, and analyzed the relationships of sleep parameters with sex, height, weight, and sexual maturation rating (SMR).Results: In total, 620 children were included. Sleep duration was 8.63±0.81 hours in boys and 8.40±0.98 hours in girls. Sleep started from PM 11:00±AM 0:47 in boys and PM 11:13±AM 1:06 in girls, and ended at AM 7:38±AM 0:27 in boys and AM 7:34±AM 0:27 in girls. After adjusting for sex and standardized body mass index, bedtime was delayed as the SMR increased (mean delay for each rating increase, 0.251 hours; P=0.001; 95% confidence interval [CI], 0.105 to 0.397). SMR did not influence the wake-up time, although sleep duration decreased as the SMR increased (mean decrease for each rating increase, 0.258 hours; P=0.001; 95% CI, –0.403 to –0.114). The sleepiness scale scores showed no relationship with SMR. Conclusion: Sleep patterns, especially sleep duration and bedtimes, show changes with sexual maturation in adolescents, who are vulnerable to sleep deprivation.

Daily associations between family interaction quality, stress, and objective sleep in adolescents

OBJECTIVE

To better understand the short-term impact of family interactions on adolescent sleep, this study examined daily associations between family interaction quality and sleep duration, sleep maintenance efficiency, and subjective sleep quality.

METHODS

Participants were 517 diverse youth (M_age = 15.4 years, Range = 15-18) in the Fragile Families and Child Wellbeing Study who completed daily reports of family interaction quality, mood and subjective sleep quality and provided actigraphy-based estimates of sleep duration and sleep maintenance efficiency.

RESULTS

Following days when youth reported that they got along with their parents, they slept 26 minutes (95% CI [2.93, 49.88]) longer. Youth who reported greater quality interactions with other family members on average had longer sleep duration, and youth who reported higher levels of family stress perceived lower sleep quality.

CONCLUSIONS

Findings highlight the importance of considering daily family life, including the quality of brief family interactions, as an entry point for future sleep interventions for adolescents.

Neighborhood Disadvantage Is Associated with Lower Quality Sleep and More Variability in Sleep Duration among Urban Adolescents

Differential social and contextual environments may contribute to adolescent sleep disparities, yet most prior studies are limited to self-reported sleep data and have not been conducted at a national level, limiting the variation in neighborhood contexts. This study examined the association between neighborhood disadvantage and objective measures of adolescent sleep. A racially and geographically diverse sample of American adolescents (N = 682) wore wrist-worn accelerometers, "actigraphs," for ≥ 5 nights. Neighborhood disadvantage was calculated using a standardized index of neighborhood characteristics (proportion of female-headed households, public assistance recipients, households in poverty, adults without high school degrees, and unemployed). Adolescents in more disadvantaged neighborhoods spent more time awake after falling asleep (4.0 min/night, p < .05), a greater percentage of nighttime sleep intervals awake (1%, p < .01), and had less consistent sleep duration (11.6% higher standard deviation, p < .05). Sleep duration and timing did not differ across neighborhood groups. These findings demonstrate that adolescents who live in more disadvantaged neighborhoods have lower quality, less consistent sleep.

The impact of reducing the frequency of night feeding on infant BMI

BACKGROUND

Teaching caregivers to respond to normal infant night awakenings in ways other than feeding is a common obesity prevention effort. Models can simulate caregiver feeding behavior while controlling for variables that are difficult to manipulate or measure in real life.

METHODS

We developed a virtual infant model representing an infant with an embedded metabolism and his/her daily sleep, awakenings, and feeds from their caregiver each day as the infant aged from 6 to 12 months (recommended age to introduce solids). We then simulated different night feeding interventions and their impact on infant body mass index (BMI).

RESULTS

Reducing the likelihood of feeding during normal night wakings from 79% to 50% to 10% lowered infant BMI from the 84th to the 75th to the 62nd percentile by 12 months, respectively, among caregivers who did not adaptively feed (e.g., adjust portion sizes of solid foods with infant growth). Among caregivers who adaptively feed, all scenarios resulted in relatively stable BMI percentiles, and progressively reducing feeding probability by 10% each month showed the least fluctuations.

CONCLUSIONS

Reducing night feeding has the potential to impact infant BMI, (e.g., 10% lower probability can reduce BMI by 20 percentile points) especially among caregivers who do not adaptively feed.

IMPACT

Teaching caregivers to respond to infant night waking with other soothing behaviors besides feeding has the potential to reduce infant BMI. When reducing the likelihood of feeding during night wakings from 79% to 50% to 10%, infants dropped from the 84th BMI percentile to the 75th to the 62nd by 12 months, respectively, among caregivers who do not adaptively feed. Night-feeding interventions have a greater impact when caregivers do not adaptively feed their infant based on their growth compared to caregivers who do adaptively feed. Night-feeding interventions should be one of the several tools in a multi-component intervention for childhood obesity prevention.

[Sleep duration, overweight and consumption of ultra-processed foods among adolescents]

The scope of this article is to analyze the relationship between insufficient sleep duration, overweight/obesity and the consumption of ultra-processed foods among adolescents aged 10 to 14 years. This is a cross-sectional study, with an evaluation of 1,384 adolescents from public schools in João Pessoa-PB, participating in the Longitudinal Study on Sedentary Behavior, Physical Activity, Diet and Adolescent Health (LONCAAFS). Sociodemographic variables, sleep duration, class shift, anthropometric nutritional status, sedentary behavior and food consumption were measured. Linear and logistic regression of the following were performed using Stata 13.0 Software: the prevalence of short sleep duration of 29.5% (<9h/night); a significant association between short sleep duration and excess weight only for adolescents <12 years old. With respect to the relationship between sleep duration and the consumption of ultra-processed foods, the longer the sleep duration, the lower the consumption of snacks by adolescents under 12 years old, with a positive association for ≥12 years old only with adjustment by the physical activity variable. There was no association with the "sugary drinks" and "cookies" groups for any of the age groups analyzed.

REM Sleep: An Unknown Indicator of Sleep Quality

Standard polysomnographic analysis of sleep has not provided evidence of an objective measure of sleep quality; however, factors such as sleep duration and sleep efficiency are those more consistently associated with the subjective perception of sleep quality. Sleep reduction as currently occurs in our 24/7 society has had a profound impact on sleep quality; the habitual sleep period should fit within what is a limited nighttime window and may not be sufficient to satisfy the whole sleep process; moreover, the use of artificial light during the evening and early night hours can delay and disturb the circadian rhythms, especially affecting REM sleep. The correct phase relationship of the sleep period with the circadian pacemaker is an important factor to guarantee adequate restorative sleep duration and sleep continuity, thus providing the necessary background for a good night's sleep. Due to the fact that REM sleep is controlled by the circadian clock, it can provide a window-like mechanism that defines the termination of the sleep period when there is still the necessity to complete the sleep process (not only wake-related homeostasis) and to meet the circadian end of sleep timing. An adequate amount of REM sleep appears necessary to guarantee sleep continuity, while periodically activating the brain and preparing it for the return to consciousness.

Prevalence of Sleep Disturbances in Pediatric Cancer Patients and Their Diagnosis and Management

Sleep disturbances represent an understudied yet common source of distress among pediatric cancer patients and survivors, with deleterious effects on quality of life. Sleep issues stem from multiple risk factors, yet individual contributors are difficult to isolate, consequently impeding the identification of targets for intervention. In many pediatric cancer patients, disrupted sleep and its negative impact on quality of life continue into adulthood and may affect various functional domains. This literature review highlights the types and prevalence of sleep disturbances in pediatric cancer patients during active treatment and through survivorship. Potential etiological and risk factors for disturbed sleep are summarized, including the effects of cancer and its treatment, psychosocial and family factors, as well as individual-patient aspects, such as genetics, mood and coping skills. While existing assessment and management strategies are reviewed, the literature is incomplete, and significant gaps emerge in our understanding of sleep disturbances in pediatric cancer patients and survivors. The review concludes with recommendations of areas where further research is needed. The aims of this review include increasing clinicians' awareness of sleep disturbances as a significant source of poor quality of life in pediatric cancer patients and survivors and directing researchers to gaps in our understanding of sleep disturbances in pediatric cancer patients and survivors.

Sleeping Late Increases the Risk of Myocardial Infarction in the Middle-Aged and Older Populations

Objective: Sleep has a significant influence on the incidence of myocardial infarction (MI). The purpose of this study was to investigate the association between sleep timing including bedtime, wake-up time and sleep midpoint, and the incidence of MI.

Methods: A total of 4,576 patients (2,065 men, 2,511 women; age 63.4 ± 11.0 years) were selected from the Sleep Heart Health Study. Sleep timings on weekdays and weekends were recorded or calculated based on the sleep habits questionnaire completed by the participants at baseline. Bedtime was divided into 10:00 PM and before, 10:01 PM−11:00 PM, 11:01 PM−12:00 AM, and later than 12:00 AM. Cox proportional hazards regression analysis was used to examine the relationship between sleep timings and MI.

Results: Participants with a weekday bedtime later than 12:00 AM, between 11:01 PM−12:00 AM, and 10:00 PM or before had a higher incidence of MI than those with a bedtime between 10:01 PM and 11:00 PM (9.2% vs. 7.0% vs. 6.9% vs. 5.1%, respectively; P = 0.008). Multivariable Cox regression analysis showed that sleeping on weekdays later than 12:00 AM was associated with an increased risk of incident MI after adjusting for potential covariates (hazard ratio, 1.628; 95% confidence interval, 1.092–2.427; P = 0.017). However, there was no significant association between late bedtime on weekends and MI. In addition, no significant association of late wake-up time and delayed sleep midpoint on both weekdays and weekends with the incidence of MI was observed.

Conclusion: Sleeping late on weekday (>12:00 AM) independently increased the risk of MI. This finding emphasizes the importance of a proper bedtime for the maintenance of the health of the cardiovascular system.

Impact of a year-round school calendar on children's BMI and fitness: Final outcomes from a natural experiment

BACKGROUND

Structure may mitigate children's accelerated summer BMI gain and cardiorespiratory-fitness (CRF) loss.

OBJECTIVES

Examine BMI and CRF change during school and summer for year-round and traditional calendar school children.

METHODS

Three schools (N = 2279, 1 year-round) participated in this natural experiment. Children's BMI z-score (zBMI) and CRF (PACER laps) were measured from 2017 to 2019 each May/August. Mixed effects regression estimated monthly zBMI and CRF change during school/summer. Secondary analyses examined differences by weight status and race. Spline regression models estimated zBMI and CRF growth from kindergarten-sixth grade.

RESULTS

Compared to traditional school, children attending a year-round school gained more zBMI (difference = 0.015; 95CI = 0.002, 0.028) during school, and less zBMI (difference = -0.029; 95CI = -0.041, -0.018), and more CRF (difference = 0.834; 95CI = 0.575, 1.093) monthly during summer. Differences by weight status and race were observed during summer and school. Growth models demonstrated that the magnitude of overall zBMI and CRF change from kindergarten-sixth grade was similar for year-round or traditional school children.

CONCLUSIONS

Contrary to traditional school children zBMI increased during the traditional 9-month school calendar and zBMI decreased during the traditional summer vacation for year-round school children. Structured summer programming may mitigate accelerated summer BMI gain and CRF loss especially for overweight or obese, and/or Black children.

COVID-19 Leads to Accelerated Increases in Children's BMI z-Score Gain: An Interrupted Time-Series Study

INTRODUCTION

The COVID-19 pandemic may have negatively impacted children's weight status owing to the closure of schools, increased food insecurity and reliance on ultraprocessed foods, and reduced opportunities for outdoor activity.

METHODS

In this interrupted time-series study, height and weight were collected from children (n=1,770 children, mean age=8.7 years, 55.3% male, 64.6% Black) and were transformed into BMI z-score in each August/September from 2017 to 2020. Mixed-effects linear regression estimated yearly BMI z-score change before the COVID-19 pandemic year (i.e., 2017-2019) and during the COVID-19 pandemic year (i.e., 2019-2020). Subgroup analyses by sex, race (i.e., Black, White, other race), weight status (overweight or obese and normal weight), and grade (i.e., lower=kindergarten-2nd grade and upper=3rd-6th grade) were conducted.

RESULTS

Before the COVID-19 pandemic, children's yearly BMI z-score change was +0.03 (95% CI= -0.10, 0.15). Change during the COVID-19 pandemic was +0.34 (95% CI=0.21, 0.47), an acceleration in BMI z-score change of +0.31 (95% CI=0.19, 0.44). For girls and boys, BMI z-score change accelerated by +0.33 (95% CI=0.16, 0.50) and +0.29 (95% CI=0.12, 0.46), respectively, during the pandemic year. Acceleration in BMI z-score change during the pandemic year was observed for children who were Black (+0.41, 95% CI=0.21, 0.61) and White (+0.22, 95% CI=0.06, 0.39). For children classified as normal weight, BMI z-score change accelerated by +0.58 (95% CI=0.40, 0.76). Yearly BMI z-score change accelerated for lower elementary/primary (+0.23, 95% CI=0.08, 0.37) and upper elementary/primary (+0.42, 95% CI=0.42, 0.63) children.

CONCLUSIONS

If similar BMI z-score accelerations occurred for children across the world, public health interventions to address this rapid unhealthy BMI gain will be urgently needed.

Is self-reported short sleep duration associated with obesity? A systematic review and meta-analysis of cohort studies

CONTEXT

A possible association between self-reported short sleep duration and risk of obesity has been studied.

OBJECTIVE

To analyze the association between sleep duration and obesity.

METHODS

The LILACS, Medline, Central, Embase, and OpenGrey databases were searched from inception until July 2020. Two authors screened the studies independently according to the PECO strategy, as follows: participants: > 18 years old; exposure: short sleep duration; control: regular sleep; outcome: obesity). Only cohort studies were included. A total of 3286 studies were retrieved with the search strategy, but only 36 were included. Disagreements were resolved by a third author. The quality of studies was assessed with Newcastle-Ottawa Quality Assessment Form for Cohort Studies. The certainty of the evidence was assessed using Grading of Recommendations Assessment, Development, and Evaluation.

RESULTS

Thirty-six studies were included, and 22 contributed quantitative data. Most of the studies (n = 27) assessed sleep by self-report. The meta-analysis showed a significant association between self-reported short sleep and development of obesity, and the chances of developing obesity increased when self-reported sleep duration decreased.

CONCLUSIONS

Self-reported short sleep was significantly associated with a higher incidence of obesity, with moderate quality of evidence.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42019130143.

What is the relationship between obesity and new circadian rhythm parameters in Turkish children and adolescents? A case-control study

BACKGROUND

Although the relationship between circadian rhythm parameters and obesity in children and adolescents is recognized, there are few studies on this topic. The concept of sleep-corrected social jetlag (SJLsc) has been formulated recently, but its relationship with childhood obesity has not yet been established. Therefore, we thought that SJL might play an important role in the etiology of obesity. Accordingly, we aimed to compare circadian rhythm parameters between obese and normal-weight children and adolescents.

METHODS

Seventy-nine obese and eighty-two normal-weight children and adolescents aged between 8 and 17 years participated in this case-control study, which took place in the Mardin province of Turkey. Data were collected with a sociodemographic information form, the Childhood Chronotype Questionnaire, and anthropometric measurements.

RESULTS

The average ages of the obese participants and controls were 12.3 ± 2.3 and 12.4 ± 2.2 years, respectively. Obese young people had greater evening preference, longer sleep debt duration, SJL duration and SJLsc duration, and higher Morningness-Eveningness Scale (MeScale) scores; and shorter mean sleep duration (p<0.005). In regression analyses, BMI z scores were significantly correlated with all circadian rhythm parameters, except SJLsc duration, while WC z scores were significantly correlated with all circadian rhythm parameters, except mean sleep duration. After adjustment, the high MeScale scores (OR: 1.142, p<0.05) and the presence of psychiatric disorder in the mother (OR: 15.075, p<0.05) were associated with obesity.

CONCLUSIONS

Circadian rhythm parameters can play an important role in the etiology of obesity. Future studies with larger samples and fewer confounding factors are needed to clarify the etiological factors.

Associations of language-based bedtime routines with early cognitive skills and academic achievement: A follow-up from kindergarten to middle school

OBJECTIVE

This study aimed to investigate the extent to which language-based bedtime routines (LBR) reported by parents before kindergarten were associated with early cognitive skills at kindergarten and subsequent academic achievement in typically developing children.

METHOD

We followed a community-based sample of 664 French-speaking adolescents from kindergarten (5-6 years) to the end of middle school (15 years). Kindergarten measures included a parental questionnaire aimed at assessing the presence or absence of any kind of LBR, such as storytelling, looking at children's books, reading a story, listening to songs, or singing nursery rhymes, as well as family contextual characteristics. Children also performed standardized assessments of oral language, pre-reading skills, and non-verbal reasoning. In middle school, children sat a national diploma typically used as an indicator of general academic achievement in Grade 9.

RESULTS

After adjusting for family characteristics, the presence of language-based bedtime routines (57%) predicted cognitive-academic skills in kindergarten, and was positively associated with academic achievement at Grade 9, related to the beneficial effect on children's vocabulary in kindergarten.

CONCLUSION

The presence of language-based bedtime routines may provide an indicator of positive parental behaviour including exposure to literacy activities, contributing to children's early cognitive development and subsequent academic achievement.

Body mass index and potential correlates among elementary school children in Jordan

PURPOSE

Childhood obesity and overweight are on the rise worldwide, and Jordanian children are no exception to this rule. Childhood Obesity has major implications on the physical and mental health of individuals, and it can often develop into adult obesity. Obesity/overweight correlates have not been researched extensively in the Middle East region, where Jordan is central. This region is undergoing tremendous changes because of wars, globalization, and the influx of refugees. The cultural and eating habits of the people are changing along with demographical changes. Thus, timely research is required to assess the current health state of this dynamic society. The main goal of this study is to understand the environmental and cultural factors that are associated with Body Mass Index (BMI) z score in elementary school children in Jordan.

METHODS

A total of 1260 children enrolled in this descriptive, cross-sectional study. The study used a parental self-reporting questionnaire that contains possible factors associated with BMI, zBMI, demographics, and other pertinent information.

RESULTS

Several factors have been associated with higher zBMI among elementary school children: if a child owns a smartphone (p = 0.0037), uses electronics to play ([Formula: see text]), uses electronics for longer hours ([Formula: see text]), eats food while using electronics or watching TV ([Formula: see text] and [Formula: see text], respectively), sleeps less hours in weekends ([Formula: see text]), was breastfed for lower number of months ([Formula: see text]), lives in rural areas ([Formula: see text]), goes to a private school ([Formula: see text]) and is a male ([Formula: see text]).

CONCLUSION

Investigating characteristics and environmental determinants of childhood obesity play an essential role in establishing effective intervention program and reduce future risks of morbidity.

LEVEL OF EVIDENCE

Level V, descriptive (cross-sectional) study.

A Systematic Review on Cross-Cultural Comparative Studies of Sleep in Young Populations: The Roles of Cultural Factors

Recent studies have shown that sleep is influenced and shaped by cultural factors, including cultural values, beliefs and practices. However, a systematic understanding of how cultural factors in countries may influence sleep duration and sleep disturbances is still lacking. Therefore, we focused on a comparison of sleep duration and disturbances in young populations between countries. We report cross-cultural differences between the child, parent and environmental factors, and their association with sleep duration and disturbances. The review is based on literature searches of seven databases published until December 2020. Studies were included if they investigated sleep duration and disturbances of individuals up to 18 years across at least two or more countries. The results of this review have shown that sleep duration and disturbances vary between countries and regions and certain factors (e.g., bedtime routines, sleeping arrangement, physical activity and psychological functioning) have been associated with sleep duration or disturbances. This review also demonstrates that certain factors which were associated with sleep duration or disturbances in one country, were not shown in other countries, suggesting a need for recommendations for age-related sleep duration and sleep interventions to consider cultural differences that influence sleep duration or disturbances in individual countries or regions.

Systematic review and meta-analyses of the relationship between short sleep and incidence of obesity and effectiveness of sleep interventions on weight gain in preschool children

The aim of this study is to determine (a) whether short sleep is associated with the incidence of obesity and (b) whether interventions beneficial for sleep reduce weight gain in preschool children. We systematically searched PubMed, Embase, Web of Science and Cochrane up to 12/09/2019. (a) Studies that were included were prospective, had follow-up ≥1 year, with sleep duration at baseline and required outcome measures. (b) Intervention trials with sleep intervention and measures of overweight or obesity were included. Data were extracted according to PRISMA guidelines. (a) The risk of developing overweight/obesity was greater in short sleeping children (13 studies, 42 878 participants, RR: 1.54; 95% CI, 1.33 to 1.77; p < 0.001). Sleep duration was associated with a significant change in BMI z-score (10 studies, 11 cohorts and 29 553 participants) (mean difference: -0.02 unit per hour sleep; -0.03 to -0.01; p < 0.001). (b) Four of the five intervention studies reported improved outcomes: for BMI (-0.27 kg/m² ; -0.50 to -0.03; p = 0.03); for BMI z-score (-0.07 unit; -0.12 to -0.02; p = 0.006). Short sleep duration is a risk factor or marker of the development of obesity in preschool children. Intervention studies suggest that improved sleep may be beneficially associated with a reduced weight gain in these children.

Sounding the Alarm on Sleep: A Negative Association Between Inadequate Sleep and Flourishing

OBJECTIVE

To assess the national prevalence of inadequate sleep among school-age children and its relationship with childhood flourishing.

STUDY DESIGN

This cross-sectional study analyzed 49 050 parental responses from the 2016-2017 National Survey of Children's Health for school-age children. Inadequate sleep duration was defined as <9 hours for 6- to 12-year-olds and <8 hours for 13- to 17-year-olds on an average weeknight. Five markers of flourishing were examined individually and as a combined measure. Logistic regression was used with complex survey design and applied weights.

RESULTS

Inadequate sleep was found in 36.4% of 6- to 12-year-olds and in 31.9% of 13- to 17-year-olds. Compared with children with adequate sleep, 6- to 12-year-olds with inadequate sleep had increased odds of not showing interest and curiosity in learning (aOR, 1.61; 95% CI, 1.34-1.94), not caring about doing well in school (aOR, 1.45; 95% CI, 1.23-1.71), not doing homework (aOR, 1.44; 95% CI, 1.24-1.68), and not finishing tasks (aOR, 1.18; 95% CI, 1.03-1.35). Children aged 13-17 years with inadequate sleep had increased odds of not doing homework (aOR, 1.36; 95% CI, 1.17-1.58), not staying calm and in control when challenged (aOR, 1.34; 95% CI, 1.16-1.54), not showing interest and curiosity in learning (aOR, 1.34; 95% CI, 1.14-1.58), not finishing tasks (aOR, 1.20; 95% CI, 1.03-1.40), and not demonstrating the combined flourishing measure (aOR, 1.35; 95% CI, 1.17-1.56).

CONCLUSIONS

Nationally representative data show that one-third of school-age children have inadequate sleep. Inadequate sleep is associated with decreased flourishing. These data will help inform sleep policies and optimize child development.

Later bedtime is associated with angina pectoris in middle-aged and older adults: results from the Sleep Heart Health Study

OBJECTIVES

Sleep timing is related to several risk factors for angina pectoris (AP), such as obesity and diabetes. This study was designed to evaluate the relationship between sleep timing and AP, specifically whether later bedtime was associated with AP in middle-aged and older adults.

METHODS

This community-based study was based on the Sleep Heart Health Study cohort and included 4710 participants (45.9% men, aged 63.3 ± 11.0 years). Lifestyle and epidemiological information were obtained from baseline records. Self-reported sleep measures provided information on bedtime and wake-up time of weekdays and weekends. Individuals were divided into three categories according to bedtime (≤22:00, 22:01-23:00, and >23:00). Odds ratios (OR) and 95% confidence intervals (CIs) of AP for bedtimes were estimated with multivariate logistic regression analysis.

RESULTS

The prevalence of AP was 44.2% and the distribution of weekday bedtimes ≤22:00, 22:01-23:00_, and >23:00 were 36.6%, 47.5% and 46.0%, respectively. After adjusting for potential confounders, weekday bedtimes >23:00 (OR 1.34; 95% CI 1.13-1.60; P = 0.001) and 22:01-23:00 (OR 1.54; 95% CI 1.29-1.82; P < 0.001) were significantly associated with an increased risk of AP compared with the reference group (≤22:00). In addition, weekend bedtimes >23:00 (OR 1.44; 95% CI 1.20-1.73; P < 0.001) and 22:01-23:00 (OR 1.70; 95% CI 1.40-2.05; P < 0.001) increased the risk of AP.

CONCLUSIONS

Later bedtimes on both weekdays and weekends were significantly associated with an increased prevalence of AP. Early bedtimes may help people decrease the risk of AP.

Sleep duration and obesity in children and adolescents: evidence from an updated and dose-response meta-analysis

BACKGROUND AND OBJECTIVES

The association between sleep duration and obesity in children and adolescents has been widely evaluated, whereas the current findings are mixed and prospective studies are limited. To shed more light on this issue and explore the dose-response relationship, we performed the present updated meta-analysis by synthesizing the results of prospective cohorts.

METHODS

Literature retrieval, study selection and data extraction were completed independently and in duplicate. Effect-size estimates are expressed as relative risk (RR) with 95% confidence interval (CI) or standardized regression coefficient (β) with standard error.

RESULTS

Data from 33 articles, involving 57,848 children and adolescents, were meta-analyzed. Overall analyses revealed statistically significant associations of short (adjusted RR = 1.57, 95% CI: 1.36 to 1.81, P < 0.001) and long sleep duration (0.83, 0.75 to 0.93, 0.001) with obesity. Short sleep duration was also associated with significant changes in body mass index z-score (mean difference = -0.06; 95% CI: -0.09 to -0.04; P < 0.001). By contrast, long sleep duration was identified as a protective factor for childhood obesity. In dose-response analyses, short sleep duration was significantly associated with obesity in toddlers (1-2 years) (adjusted RR = 1.20, 95% CI: 1.07 to 1.34, P = 0.001), preschool-aged (3-5 years) children (1.58, 1.36 to 1.83, <0.001), and school-aged (6-13 years) children (1.82, 1.51 to 2.21, <0.001). In subgroup analyses, geographic region, sleep duration assessment, age, and follow-up interval were possible sources of heterogeneity.

CONCLUSIONS

Our findings indicate that short sleep duration can increase the risk of obesity in children and adolescents, especially within 3-13 years of age, and long sleep duration seemed beneficial in preventing obesity.

Perceived Barriers and Facilitating Factors in Implementing Delayed School Start Times to Improve Adolescent Sleep Patterns

BACKGROUND

Most adolescents in the United States do not obtain sufficient sleep. Early school start times play a significant role in adolescent sleep deprivation. Most primary and secondary schools begin classes earlier than the 8:30 am. Perceived barriers to implementing a delayed school start time have been suggested in the literature but have not been quantified. This study explored perceived barriers and facilitating factors for implementing delayed high-school start times.

METHODS

A cross-sectional study. School administrators who had delayed their school start times were invited to complete an online questionnaire ranking the perceived barriers and facilitating factors for implementing the delayed start times.

RESULTS

Most commonly cited perceived barriers were lack of a tiered bus system, school athletes missing more afternoon classes, and less time after school for athletics. Most commonly cited facilitating factors were school-administrator involvement in the decision-making process and sleep education for family members and school administrators.

CONCLUSIONS

Participants found that providing sleep education to fellow administrators, teachers, school staff members, families, and students and including them in the decision-making process positively facilitated the implementation of delayed school start times. Perceived barriers to implementation may be overcome with support from stakeholders and planning committees.

Evidence Base Update on Assessing Sleep in Youth

BACKGROUND

Sleep is vital to youth well-being and when it becomes disturbed - whether due to environmental or individual factors - mental and physical health suffer. Sleep problems can also be a symptom of underlying mental health disorders. Assessing different components of sleep, including quality and hygiene, can be useful both for identifying mental health problems and for measuring changes in well-being over time. However, there are dozens of sleep-related measures for youth and it can be difficult to determine which to select for a specific research or clinical purpose. The goal of this review was to identify sleep-related measures for clinical and/or research use in youth mental health settings, and to update the evidence base on this topic.

METHOD

We generated a list of candidate measures based on other reviews and searched in PubMed and PsycINFO using the terms "sleep" AND (measure OR assessment OR questionnaire) AND (psychometric OR reliability OR validity). Search results were limited to studies about children and adolescents (aged 2-17) published in English. Additional criteria for inclusion were that there had to be at least three publications reporting on the measure psychometrics in community or mental health populations. Sleep measures meeting these criteria were evaluated using the criteria set by De Los Reyes and Langer (2018).

RESULTS

Twenty-six measures, across four domains of sleep - insomnia, sleep hygiene, sleepiness, sleep quality - met inclusion criteria. Each measure had at least adequate clinical utility. No measure(s) emerged as superior across psychometric domains.

CONCLUSION

Clinicians and researchers must evaluate sleep measures for each use case, as the intended purpose will dictate which measure is best. Future research is necessary to evaluate measure performance in transdiagnostic mental health populations, including youth with serious mental illness.

Effects of Coparenting Quality, Stress, and Sleep Parenting on Sleep and Obesity Among Latinx Children: A Path Analysis

INTRODUCTION

We sought to examine the associations among parent-level constructs, sleep-related parenting practices, and child sleep in Latinx families.

METHOD

A quantitative study was conducted with 101 Latinx parents of children aged 2-5 years. Key variables that were examined included parental stress, coparenting quality, bedtime routine consistency, parent-child sleep interactions, and child's sleep duration.

RESULTS

Path analysis results indicated that (1) parent stress had a direct effect on child sleep duration (p =.005) and was mediated by parent-child sleep interactions (p =.021); (2) coparenting quality had a direct effect on child sleep duration (p =.001) and was mediated by bedtime routine consistency (p =.010); and (3) bedtime routine consistency had an indirect effect on child body mass index percentile and was mediated by sleep duration (p =.049).

DISCUSSION

Coparenting quality and parental stress may be important constructs to consider when designing interventions to improve Latinx child sleep duration.

Does context matter? A multilevel analysis of neighborhood disadvantage and children's sleep health

OBJECTIVES

To determine how demographic, socioeconomic, and neighborhood characteristics are associated with bedtimes among US kindergarteners.

DESIGN

Parents reported bedtimes of their children as well as personal, household, and residential characteristics via interviews in the Early Childhood Longitudinal Study-Kindergarten (ECLS-K) Class of 1998-1999. The ECLS-K links individual households to US Census tracts.

SETTING

A random selection of 1,280 schools and surrounding communities in the US.

PARTICIPANTS

A random selection of 16,936 kindergarteners and their parents.

MEASUREMENTS

The 2 outcomes were regular and latest weekday bedtimes of kindergarteners. Through a series of nested multilevel regression models, these outcomes were regressed on individual- and neighborhood-level variables, including race/ethnicity, sex, family type, household income, mother's educational attainment, neighborhood disorder, and several additional neighborhood characteristics.

RESULTS

Models showed significant (P < .05) bedtime disparities by race/ethnicity, sex, family income, and mother's educational attainment. Additionally, models tended to indicate that kindergarteners from disadvantaged neighborhoods experienced later bedtimes than children from more advantaged areas. Neighborhood characteristics accounted for a portion of racial/ethnic differences, suggesting that bedtime disparities are partly rooted in disparate environmental conditions.

CONCLUSIONS

Reducing disparities in childhood sleep may require programs that target not only children and their parents, but also the communities in which they reside.

Synergistic interaction between bedtime and eating speed in predicting overweight and obesity in Chinese preschool-aged children

This study aimed to examine the association of late bedtime and fast eating speed, both individually and interactively, in predicting overweight and obesity in Chinese preschool-aged children. This was a cross-sectional survey among children aged 3-6 years. Overweight and obesity is defined according to the WHO, IOTF, and China criteria, respectively. Total 1123 preschool-aged children were analyzed. After multivariable adjustment, late bedtime after 11:00 pm and fast eating speed increased the risk of overweight and obesity significantly under the WHO (odds ratio [OR]=1.92 and 1.37, 95% confidence interval [CI]: 1.31-2.80 and 1.00-1.88), IOTF (OR=1.47 and 1.46; 95% CI: 1.00-2.15 and 1.07-2.00), and China (OR=1.66 and 1.39; 95% CI: 1.20-2.29 and 1.07-1.80) criteria. Relative to bedtime before 11:00 pm and eating speed ≥30 min, there was a graded increase with presence of either bedtime after 11:00 pm or eating speed 15-30 min and <15 min. Particularly, the presence of both bedtime after 11:00 and eating speed <15 min yielded the largest OR under the WHO (adjusted OR, 95% CI: 3.98, 1.27-12.51), IOTF (3.59, 1.12-11.50), and China (4.84, 1.71-13.69) criteria. Taken together, our findings indicate a synergistic interaction between bedtime and eating speed in predicting overweight and obesity in Chinese preschool-aged children.

Sleep Extension Increases the Effect of Caloric Restriction Over Body Weight and Improves the Chronic Low-Grade Inflammation in Adolescents With Obesity

PURPOSE

Diminution of sleep may be associated with obesity. However, evidence that extending sleep duration might favor weight loss is insufficient. The aim of this study was to compare the effect of dietary restriction with or without prescription of sleep extension on weight loss in adolescents with obesity.

METHODS

A total of 52 adolescents with obesity (24 males and 28 females) received a diet with 500 calories restriction, randomly allocated to groups without (n = 27) and with sleep extension (n = 25) for 4 weeks. We collected data on anthropometry, caloric intake, and self-reported sleep diaries. Serum interleukin 6, tumor necrosis factor α, leptin, and insulin levels were quantified by enzyme-linked immunosorbent assay. Cortisol and 6-sulfatoxymelatonin excretions were measured in the first urine collection in the morning by liquid chromatography-mass spectrometry. Measurements were carried out at baseline and at the end of the intervention.

RESULTS

After diet, weight decreased in both groups. Sleep extension, improved weight loss (p < .00001), and waist girth reduction (p = .00003), with diminution of insulin (p = .002) and interleukin 6 levels (p = .02). Caloric restriction was less effective in adolescent females. No differences in cortisol or 6-sulfatoxymelatonin excretion were found.

CONCLUSIONS

A sleep extension favors weight loss in adolescents under caloric restriction and improves inflammation and metabolic conditions, thus supporting a possible additional benefit to diet in the treatment of obesity in adolescents.

Associations of sleep duration and social jetlag with cardiometabolic risk factors in the study of Latino youth

OBJECTIVE

We investigated associations of sleep duration and social jetlag with cardiometabolic outcomes.

PARTICIPANTS

Boys and girls aged 8-16 years from the Hispanic Community Health Study/Study of Latino Youth.

MEASUREMENTS

Participants (n = 1,208) completed a clinical examination where anthropometric characteristics, health behaviors, and health history were measured. Sleep duration was calculated as the weighted average of self-reported weekday and weekend bedtimes and wake times and categorized into age-specific cutoffs for short vs. normal sleep. "Social jetlag" was defined as the absolute difference in the midpoint of the sleep period between weekdays and weekends, measured continuously and dichotomized (≥2 hours), with higher values indicating more displacement of sleep timing across the week. Regression models tested the associations between sleep measures (separately) and cardiometabolic outcomes (e.g., healthy eating index [0-100], physical activity-minutes per week, obesity, diabetes, hypertension) after adjustment for covariates.

RESULTS

The average sleep duration was 9.5 hours (95% confidence interval: 9.3, 9.6) and the mean social jetlag was 2.5 (2.4, 2.7) hours. Participants with social jetlag reported more physical activity (β = 34.8 [13.14], P < .01), had a higher healthy eating index (β = 1.77 [0.87], P < .05] and lower odds of being overweight [OR = 0.66, (95% confidence interval 0.44, 0.99)]. Short sleep duration was associated with less physical activity but did not relate to other cardiometabolic outcomes.

CONCLUSIONS

Social jetlag was associated with healthier behaviors and a lower odds of being overweight. Given these mixed findings, future research should further evaluate how to best characterize sleep timing differences in youth to identify health consequences.

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

BACKGROUND/OBJECTIVES

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

SUBJECTS/METHODS

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

RESULTS

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

CONCLUSION

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

The potential of a year-round school calendar for maintaining children's weight status and fitness: Preliminary outcomes from a natural experiment

Purpose

To evaluate the potential of a year-round school calendar (180-day school year distributed across 12 months) as an intervention compared to a traditional school calendar (180-day school year distributed across 9 months) for mitigating children's weight gain and fitness loss via a natural experiment.

Methods

Height, weight, and cardiorespiratory fitness (CRF) (i.e., Fitnessgram Progressive Aerobic Cardiovascular Endurance Run) were measured in children (5-12 years old) in 3 schools (2 traditional, 1 year-round, n = 990 students, age = 8.6 ± 2.4 years, 53.1% male, 68.9% African American) from 1 school district. Structure (represented by the presence of a school day) was the independent variable. Changes in body mass index (BMI), age- and sex-specific BMI z-scores (zBMI), BMI percentile, percent of overweight or obese children, and CRF (Progressive Aerobic Cardiovascular Endurance Run laps completed) were assessed for summer 2017 (May-August 2017), school year 2017/2018 (August 2017-May 2018), and summer 2018 (May-August 2018). Primary analyses examined the overall change in weight and CRF from summer 2017 until summer 2018 via multilevel mixed effects regression, with group (traditional vs. year-round calendar), time, and a group-by-time interaction as the independent variables. Secondary regression analyses estimated differences in change within and between groups during each time period, separately.

Results

Year-round students gained less BMI (difference in ∆ = -0.44, 95% confidence interval (CI): -0.67 to -0.03) and less CRF (difference in ∆ = -1.92, 95%CI: -3.56 to -0.28) than students attending a traditional school overall. Compared with traditional students, during both summers, year-round students gained less BMI (summer 2017 difference in ∆ = -0.15, 95%CI: -0.21 to -0.08; summer 2018 difference in ∆ = -0.16, 95%CI: -0.24 to -0.07) and zBMI (summer 2017 difference in ∆ = -0.032, 95%CI: -0.050 to -0.010; summer 2018 difference in ∆ = -0.033, 95%CI: -0.056 to -0.009), and increased CRF (summer 2017 difference in ∆ = 0.40, 95%CI: 0.02-0.85; summer 2018 difference in ∆ = 0.23, 95%CI: -0.25 to 0.74). However, the opposite was observed for the school year, with traditional students gaining less BMI and zBMI and increasing CRF compared with year-round students (difference in BMI ∆ = 0.05, 95%CI: 0.03-0.07; difference in zBMI ∆ = 0.012, 95%CI: 0.005-0.019; difference in Progressive Aerobic Cardiovascular Endurance Run laps ∆ = -0.43, 95%CI: -0.58 to -0.28).

Conclusion

The year-round school calendar had a small beneficial impact on children's weight status but not CRF. It is unclear if this benefit to children's weight would be maintained because gains made in the summer were largely erased during the school year. Trajectories of weight and CRF gain/loss were consistent with the structured days hypothesis.

Time use and sexual maturity-related indicators differentially predict youth body mass indices, Peruvian girls versus boys

Rapid development in Latin America has been accompanied by lifestyle shifts, including changes in time use and social environments. Overweight/obesity has also emerged as a public health challenge. We examined whether lifestyle changes and sexual maturity-related indicators (early pubertal development and having a child) predict increases in adiposity among Peruvian youth. Using longitudinal data from Young Lives, we examined changes in adiposity between ages 8 and 15 years old for the younger cohort and ages 15 and 22 years old for the older cohort. Boys and girls in both cohorts demonstrated substantial increases in age-adjusted adiposity measures, but predictors were different for boys versus girls. For boys, increases in time spent in work and domestic chores predicted increases in adiposity body mass index and BMI-for-age Z-score and increases in time spent sleeping were associated with decreases in adiposity (waist circumference and waist-to-height ratio). For girls, sexual maturity-related indicators (early menarche and childbearing) predicted increases in adiposity, regardless of time use. Potential mechanisms for these results may include diet, physical activity, wealth, and urban-rural residence. Time use among youth was associated with diet quality and physical activity, but in different ways for boys versus girls. Strategies for dealing with rising overweight and obesity should incorporate sex-based specificities.

The relationship between obesity and sleep timing behavior, television exposure, and dinnertime among elementary school-age children

STUDY OBJECTIVES

The daily lifestyle behaviors of children have been shown to be associated with obesity. There are limited studies on the association of sleep timing behavior and body mass index (BMI), specifically in elementary school-age children. This study aimed to investigate the relationship between obesity and sleep timing patterns, television exposure time, and dinnertime among elementary school-age children.

METHODS

Children (n = 169) aged 6 to 10 years who were residents of Alabama were recruited for this study. The questionnaires were used to determine the bedtime, wake-up time, television exposure time, and dinnertime of the participants. The participants were categorized into four groups depending on the bedtime and wake-up time behavior habits: early bed/early wake-up (EE); early bed/late wake-up (EL); late bed/early wake-up (LE); and late bed/late wake-up (LL) time. The BMI z-score, television exposure time, and dinnertime of these groups were compared.

RESULTS

The LL group had a significantly higher BMI z-score compared to the EE group. The higher BMI z-score in the LL group may be associated with late bedtime and not late wake-up time. Approximately 71% of children with late bedtime (8:48 pm), 75% of children who watch television for more than 1 hour, and 54% of children who have dinner after 7:00 pm have obesity.

CONCLUSIONS

Daily behavior habits such as late bedtime, increased television exposure, and late dinnertime are associated with obesity.

Sexual Orientation and Sleep Behaviors in a National Sample of Adolescents Followed Into Young Adulthood

STUDY OBJECTIVES

Sexual minority adolescents experience mental and physical health disparities attributable to increased discrimination and minority stress. These same factors may also impair sleep health, although available literature on this topic is limited. This study examined longitudinal associations between adolescent sexual minority status and seven sleep behaviors in young adulthood and tested depressive symptoms and overweight as mediators.

METHOD

Data were drawn from Waves 2 (11th grade) to 7 (4 years after high school) of the NEXT Generation Health Study, a national longitudinal cohort study of US adolescents (n = 1946; 6.3% sexual minorities).

RESULTS

There were no significant sexual orientation disparities in sleep duration, trouble falling asleep, trouble staying asleep, or trouble waking up during young adulthood. Relative to heterosexual females, sexual minority females had higher odds of snoring/stop breathing (36.6% versus 19.2%; adjusted odds ratio = 2.57; 95% confidence interval = 1.30, 5.09) and reported more frequent daytime sleepiness (b = 0.66, 95% confidence interval = 0.05, 1.27). Mediation analyses revealed that female sexual minority status was associated with increased risk of snoring/stop breathing though overweight status (mediated 43.6% of total effect) and was also associated with increased daytime sleepiness through higher depressive symptoms (mediated 70.8% of total effect).

CONCLUSIONS

Among US youth, no sexual orientation disparities were found except for snoring/stop breathing and daytime sleepiness among females. Sexual orientation disparities in these aspects of sleep are partially due to worse mental and physical health among sexual minority females, highlighting depressive symptoms and overweight problems as potential intervention targets.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Title: Health Behavior in School-Aged Children: NEXT Longitudinal Study 2009-2016; Identifier: NCT01031160.

A preliminary study of a composite sleep health score: associations with psychological distress, body mass index, and physical functioning in a low-income African American community

OBJECTIVES

Although multiple individual sleep measures (eg, sleep duration, satisfaction) have been linked to a wide range of physical and mental health conditions, scant research has examined how individual sleep dimensions may act independently or additively to influence health. The current study investigates associations of 5 sleep dimensions (duration, satisfaction, efficiency, timing, and regularity), analyzed separately and simultaneously, with psychological distress, body mass index, and physical functioning among a low-income, predominantly African American population.

DESIGN

We constructed a composite sleep health (SH) score from the sum of scores, representing "good' and "poor" ranges of 5 sleep measures (range 0-5).

SETTING

Two low-income, predominantly African American neighborhoods in Pittsburgh.

PARTICIPANTS

Participants included 738 community-dwelling adults (78% female and 98% black).

MEASUREMENTS

Actigraphy-based measures of sleep duration, regularity, timing, and efficiency, and self-reported sleep satisfaction. Outcomes included self-reported psychological distress, physical functioning, and measured body mass index (BMI).

RESULTS

Each 1-unit higher SH score was associated with 0.55-unit lower psychological distress score (range 0-24) and 2.23-unit higher physical functioning score. Participants with at least 2, 3, or 4 sleep dimensions in the "healthy" range, vs fewer, had lower psychological distress scores. Greater sleep satisfaction was associated with higher physical functioning, and longer sleep duration was associated with lower physical functioning. Neither the composite SH score nor any of the individual sleep dimensions were associated with BMI.

CONCLUSIONS

Assessing multiple sleep dimensions may provide a more comprehensive understanding of associations of sleep with psychological distress than assessing any single sleep dimension. Although no sleep measures were related to BMI in the current sample, analyses should be replicated in other samples to determine generalizability.

Association of Sleep Duration with Obesity and Cardiometabolic Risk Factors in Children and Adolescents: A Population-Based Study

This study aimed to evaluate the relationships between sleep duration and overweight/obesity, obesity, and metabolic syndrome (MetS) and its components in children and adolescents. A total of 6,048 participants aged 10–18 years were divided into the following four sleep-duration groups based on age-specific sleep duration: i) very short; ii) short; iii) recommended; and iv) long. The participants in the very short sleep-duration group had an increased odds ratio (OR) of 1.76 for overweight/obesity, 1.69 for obesity, and 1.49 for elevated waist circumference (WC) compared with the recommended sleep-duration group. The subjects in the long sleep-duration group had an increased OR of 2.71 for elevated triglyceride (TG) compared with those in the recommended sleep-duration group. In subgroup analyses, boys in the very short sleep-duration group exhibited an increased OR of 1.78 for overweight/obesity compared with those in the recommended sleep-duration group. Compared with girls in the recommended sleep-duration group, those in the very short sleep-duration group exhibited an increased OR of 1.69 for overweight/obesity, 2.28 for obesity, and 1.57 for elevated WC; in contrast, girls in the very short sleep-duration group exhibited a decreased OR of 0.58 for elevated TG. The girls in the long sleep-duration group had an increased OR of 3.86 for elevated TG compared with those with recommended sleep-duration. Our results suggest that shorter sleep durations may be related to overweight/obesity, obesity, and central obesity, and longer sleep durations may be associated with elevated TG. However, the nature of these relationships may be dependent on sex.

Study protocol for a cluster randomized controlled trial to test "¡Míranos! Look at Us, We Are Healthy!" - an early childhood obesity prevention program

BACKGROUND

One in three Head Start children is either overweight or obese. We will test the efficacy of an early childhood obesity prevention program, "¡Míranos! Look at Us, We Are Healthy!" (¡Míranos!), which promotes healthy growth and targets multiple energy balance-related behaviors in predominantly Latino children in Head Start. The ¡Míranos! intervention includes center-based (policy changes, staff development, gross motor program, and nutrition education) and home-based (parent engagement/education and home visits) interventions to address key enablers and barriers in obesity prevention in childcare. In partnership with Head Start, we have demonstrated the feasibility and acceptability of the proposed interventions to influence energy balance-related behaviors favorably in Head Start children.

METHODS

Using a three-arm cluster randomized controlled design, 12 Head Start centers will be randomly assigned in equal number to one of three conditions: 1) a combined center- and home-based intervention, 2) center-based intervention only, or 3) comparison. The interventions will be delivered by trained Head Start staff during the academic year. A total of 444 3-year-old children (52% females; n = 37 per center at baseline) in two cohorts will be enrolled in the study and followed prospectively 1 year post-intervention. Data collection will be conducted at baseline, immediately post-intervention, and at the one-year follow-up and will include height, weight, physical activity (PA) and sedentary behaviors, sleep duration and screen time, gross motor development, dietary intake and food and activity preferences. Information on family background, parental weight, PA- and nutrition-related practices and behaviors, PA and nutrition policy and environment at center and home, intervention program costs, and treatment fidelity will also be collected.

DISCUSSION

With endorsement and collaboration of two local Head Start administrators, ¡Míranos!, as a culturally tailored obesity prevention program, is poised to provide evidence of efficacy and cost-effectiveness of a policy and environmental approach to prevent early onset of obesity in low-income Latino preschool children. ¡Míranos! can be disseminated to various organized childcare settings, as it is built on the Head Start program and its infrastructure, which set a gold standard for early childhood education, as well as current PA and nutrition recommendations for preschool children.

TRIAL REGISTRATION

ClinicalTrials.Gov ( NCT03590834 ) July 18, 2018.

Associations of sleep patterns with metabolic syndrome indices, body composition, and energy intake in children and adolescents

BACKGROUND

Self-reported short sleep duration is associated with greater risk for metabolic syndrome (MetS), obesity, and higher energy intake (EI). However, studies of these associations in children using objective methods are sparse.

OBJECTIVES

The study aims to determine the associations for sleep patterns with MetS indices, body composition, and EI using objective measures in children.

METHODS

Free-living sleep and physical activity were measured in 125 children (aged 8-17 years, BMI z = 0.57 ± 1.0, 55% female) using wrist-worn actigraphs for 14 nights. Blood pressure, fasting blood levels of lipids, insulin, glucose, waist circumference, and body composition (dual-energy X-ray absorptiometry [DXA]) were obtained during outpatient visits. EI was assessed during an ad libitum buffet meal.

RESULTS

Later weekday and weekend bedtimes were associated with higher systolic blood pressure (Ps < 0.05). Sleep duration and bedtime were not significantly associated with other components of MetS, body composition, or EI. Short sleepers (duration less than 7 hours) consumed a greater percentage of carbohydrates than those with adequate (greater than or equal to 7 hours) sleep (P < 0.05).

CONCLUSION

Indicators of sleep duration were variably associated with children's eating patterns and risk for chronic disease. Prospective data are needed to determine whether these indicators of sleep quality represent unique or shared risk factors for poor health outcomes.

Early life socioeconomic status moderates associations between objective sleep and weight-related indicators in middle childhood

OBJECTIVES

This study tested whether early socioeconomic status moderated links between objective and subjective sleep and weight indicators during middle childhood.

DESIGN

The study design was cross-sectional but included data from earlier assessment points in the study.

SETTING

Data were collected from families across the state of Arizona.

PARTICIPANTS

Participants were 382 children recruited from birth records (49.5% female; M_age = 8.47 years; 56.5% European American; 25.1% Latino; 25% living at or below the poverty line).

MEASUREMENTS

Assessments included socioeconomic status at 12 months of age, and sleep and weight indicators at 8 years.

RESULTS

Longer sleep durations predicted lower body mass index and decreased odds of being overweight/obese across all children, regardless of socioeconomic background. For children from low socioeconomic backgrounds, longer sleep duration predicted lower percent body fat, greater efficiency predicted lower percent body fat and body mass index and smaller waist circumference, and more sleep problems predicted larger waist circumference. For children from low socioeconomic backgrounds, greater sleep duration and efficiency also predicted the lowest odds of being overweight/obese, and more sleep problems predicted the greatest odds of being overweight/obese.

CONCLUSIONS

Early life may be a sensitive period that sets the stage for stronger links between sleep and weight indicators in middle childhood. Findings offer important information regarding the protective role of sleep in the promotion of health, as well as the negative consequences that may be stronger for children who experienced low early-life socioeconomic status.

Adolescent profiles of ethnicity/race and socioeconomic status: Implications for sleep and the role of discrimination and ethnic/racial identity

The present study seeks to explore the intersectionality of ethnicity/race and socioeconomic status (SES) among ethnic/racial minority adolescents in their developmental contexts, examining its implications for sleep disparities and the roles of discrimination and ethnic/racial identity (ERI; i.e., adolescents' understanding and feelings about who they are in relation to their ethnic/racial group). With 350 adolescents (Asian 41.4%, Black, 21.7%, and Latinx 36.9%, female=69.1%, Mage=14.27), we conducted a latent class analysis (LCA) to identify latent classes of adolescents' ethnicity/race, ethnic/racial diversity in their schools and neighborhoods along with SES of their families, schools, and neighborhoods. Next, with hierarchical regression, we tested the association between class membership and subjective and objective sleep duration and quality, followed by the moderating effect of discrimination and ERI. We expected to find adolescents living in low diversity and low SES across various developmental contexts to experience lower levels of subjective and objective sleep duration and quality compared to their counterparts. We also expected to find exacerbating effects of discrimination and ERI exploration, and protective effects of ERI commitment in these associations. Three latent groups were identified (C1: "Black/Latinx adolescents in low/moderate SES families in varying diversity and low SES schools and neighborhoods," C2: "Predominantly Latinx adolescents in low SES families and moderate diversity and SES schools and neighborhoods," and C3: "Predominantly Asian adolescents in low/moderate SES families in moderate/high diversity and SES schools and neighborhoods"). The class memberships to C1 and C2 were associated with compromised sleep duration and quality compared to C3. An interaction effect of discrimination was found for C1 in subjective sleep duration and for C2 in objective sleep duration. While no interactions were found for ERI, ERI commitment had a direct association with objective sleep duration and quality. Interpretations and implications for intersectionality approach in studies on sleep disparities and the roles of discrimination and ERI are discussed.

Sleep Duration and Risk of Obesity by Sex: Nine-Year Follow-Up of the Young Lives Study in Peru

Background: We aimed to evaluate if there is association between hours of sleep and the risk of obesity among children and whether this association differs by sex. Methods: A secondary data analysis, using information of the Young Lives study, was conducted. The outcome was obesity, based on the BMI for age z-score; the exposure was child's sleep duration (reported by parents) categorized using the National Sleep Foundation guidelines, and as a numerical variable. Baseline and three follow-ups information were used to evaluate association, reporting relative risks (RRs), and 95% confidence intervals (CIs), as well as coefficients and 95% CI. Results: Data from 1949 children, baseline mean age 4.3 (standard deviation: 0.3) and 962 (49.5%) females, were analyzed. Short sleep duration was present in 26.0% (95% CI: 24.0-28.0) at baseline. After 9.6 years of follow-up, the incidence of obesity was 0.83 (95% CI: 0.70-0.98) per 100 person-years at risk. In multivariable model (n = 1579), there was no association between short sleep duration and obesity in the whole sample (p = 0.13); but the risk of obesity was lower among girls (n = 816; RR = 0.45; 95% CI: 0.21-0.96; p = 0.03) compared with boys (n = 763; RR = 1.43; 95% CI: 0.95-2.14; p = 0.09). On the contrary, each additional hour of sleep was associated with an increase of boy's BMI mean (0.05; 95% CI: 0.02-0.08; p < 0.001), but not among girls (-0.02; 95% CI: -0.05 to 0.01; p = 0.11). Conclusions: Our results evidenced a lower risk of obesity due to short sleep duration in girls, but not in boys. Each additional hour of sleep was associated with an increase of BMI in boys, but not in girls. Strategies are needed to guarantee adequate sleep duration in Peruvian children.

Electronic Media Use and Sleep Among Preschoolers: Evidence for Time-Shifted and Less Consolidated Sleep

This study examined the association between electronic media use and sleep among preschoolers, using a national sample of 402 mothers of 3- to 5-year-olds. Participants completed an online survey assessing preschoolers' electronic media use, bedtime and wake time, sleep time, napping behaviors, and sleep consolidation. Results showed that heavier television use and tablet use, both overall and in the evening, were associated with later bedtimes and later wake times, but not with fewer hours of sleep, providing evidence for a time-shifting process. In addition, heavier daily television use and evening smartphone use were associated with increased daytime napping. Moreover, heavier daily television use, daily and evening smartphone use, and evening tablet use were associated with poorer sleep consolidation, suggesting less mature sleep patterns. These findings indicate that media effects on the timing of sleep and the proportion of sleep that occurs at night are important to consider when assessing the health risks of electronic media on children.

Relationship between Physical Activity, Screen Time, and Sleep Quantity and Quality in US Adolescents Aged 16⁻19

Despite the health benefits associated with physical activity (PA), screen time reduction, and sleep quantity and quality, the relationships between PA, screen time, and sleep quantity and quality remain unclear in adolescents. The present study is a cross-sectional analysis of data from adolescents aged 16–19 years who participated in the 2005–2006 National Health and Nutrition Examination Survey (n = 542). Multivariable logistic regression models, adjusted for confounders, examined the relationship between objectively measured PA, self-reported screen time, and sleep quantity and quality. Respondents who met the current PA recommendation had 50% lower odds of having sufficient sleep (≥8 h) than those not meeting the recommendation (OR = 0.50, 95% CI: 0.26, 0.94). Respondents who met the screen time recommendation (≤2 h/day) had 55% lower odds of reporting poor sleep quality than those whose screen time exceeded the recommendation (OR = 0.45, 95% CI: 0.22, 0.91), with similar patterns observed for females and males. However, males who met both PA and screen time recommendations had 73% lower odds of reporting poor sleep quality than males who met neither recommendation (OR = 0.27, 95% CI: 0.07, 0.99). In conclusion, PA and screen time are associated with sleep quantity or sleep quality in adolescents, and there are differences in these associations by sex.

During day and night: Childhood psychotic experiences and objective and subjective sleep problems

BACKGROUND

Psychotic experiences comprise auditory and visual perceptive phenomena, such as hearing or seeing things that are not there, in the absence of a psychotic disorder. Psychotic experiences commonly occur in the general pediatric population. Although the majority of psychotic experiences are transient, they are predictive of future psychotic and non-psychotic disorders. They have been associated with sleep problems, but studies with objective sleep measures are lacking. This study assessed whether psychotic experiences were associated with actigraphic sleep measures, symptoms of dyssomnia, nightmares, or other parasomnias.

METHODS

This cross-sectional population-based study comprises 4149 children from the Generation R Study. At age 10 years, psychotic experiences including hallucinatory phenomena were assessed by self-report; dyssomnia and parasomnia symptoms were assessed by mother- and child-report. Additionally, at age 11 years, objective sleep parameters were measured using a tri-axial wrist accelerometer in N = 814 children, who wore the accelerometer for five consecutive school days.

RESULTS

Psychotic experiences were not associated with objective sleep duration, sleep efficiency, arousal, or social jetlag. However, psychotic experiences were associated with self-reported dyssomnia (B = 2.45, 95%CI: 2.13-2.77, p < 0.001) and mother-reported parasomnia, specifically nightmares (OR_adjusted = 3.59, 95%CI 2.66-4.83, p < 0.001). Similar results were found when analyses were restricted to hallucinatory phenomena.

CONCLUSIONS

Childhood psychotic experiences were not associated with objective sleep measures. In contrast, psychotic experiences were associated with nightmares, which are a known risk indicator of psychopathology in pre-adolescence. More research is needed to shed light on the potential etiologic or diagnostic role of nightmares in the development of psychotic phenomena.

Changes in children's sleep and physical activity during a 1-week versus a 3-week break from school: a natural experiment

Study Objectives

To examine changes in elementary aged children's sleep and physical activity during a 1-week and a 3-week school break.

Methods

Sleep and physical activity of elementary children (n = 154, age = 5-9 years, 44.8% female, 65.5% African American) were collected over 7 weeks that included a 1-week break in two schools and a 3-week break in a single school. Mixed regression models estimated sleep and physical activity changes within and between groups (i.e. 1-week vs. 3-weeks) during school and school break weeks.

Results

Compared to school weeks, bed times shifted 72.7 (95% CI = 57.5, 87.9) and 75.4 (95% CI = 58.1, 92.7) minutes later on weekdays during the 1-week and 3-week break, respectively. Wake times shifted 111.6 (95% CI = 94.3, 128.9) and 99.8 (95% CI = 80.5, 119.1) minutes later on weekdays during 1-week and 3-week breaks. On weekdays during the 3-week break, children engaged in 33.1 (95% CI = 14.1, 52.2) more sedentary minutes and -12.2 (-20.2, -4.2) fewer moderate-to-vigorous physical activity minutes/day. No statistically significant changes in children's sedentary, light, or moderate-to-vigorous physical activity (MVPA) minutes were observed on weekdays during the 1-week break. Between-group differences in the change in time sedentary (32.1-95% CI = 5.8, 58.4), and moderate-to-vigorous (-13.0-95% CI = -23.9, -2.0) physical activity were observed.

Conclusions

Children's sleep shifted later on both 1-week and 3-week breaks. Children's activity changed minimally on weekdays during a 1-week school break and more during a 3-week school break. Displaced sleep and reductions in activity are intervention targets for mitigating unhealthy weight gain during extended breaks from school.