Correlates of Sleep Duration in Early Childhood: A Systematic Review

How many adults have sufficient muscle-strengthening exercise and the associated factors: A systematic review consisting of 2,629,508 participants

Purpose

The aim of this systematic review was to (1) estimate the prevalence of adhering to the MSE guidelines (at least 2 times/days a week) among adults; and (2) synthesize evidence on the correlates of adhering to the MSE guidelines.

Methods

Five electronic databases were searched (March 2022), with a total of 30 observational studies consisting of 2,629,508 participants meeting the eligibility criteria. A meta-analysis was conducted to pool the prevalence of adhering to the MSE guidelines using the results of 21 eligible studies (study aim 1); and data reporting correlates of adhering to the MSE guidelines using 12 eligible studies were synthesized and categorized based on the Socioecological Model Framework (study aim 2).

Results

Overall, 22.8 % (95%CI: 18.18 % ─ 27.77 %) of adults adhered to the MSE guidelines, and 23 potential correlates at five levels were examined. Five variables (i.e., sex, age, education level, socioeconomic status) at the sociodemographic level and two variables (i.e., body mass index, self-rated health) at the physical related level were identified as consistent correlates, but displaying weak to moderate association strengths.

Conclusions

Less than a quarter of adults meet the MSE guidelines and multidimensional correlates are associated with the adherence to the guidelines, particularly sociodemographic correlates (e.g., sex, age, and educational level). Findings highlight the need to further promote the importance of engaging in MSE among adults and investing effective interventions that not only provide opportunities for MSE for adults, but also facilitate the development of skills and confidence to engage in MSE.

Associations between media use at bedtime and sleep: a cross-sectional analysis on differences between girls and boys

Objectives

This study investigated associations between the use of electronic media and sleep in children and young adolescents, with a specific focus on the moderation of associations by sex and age.

Methods

Between 2021 and 2022, 453 10- to 14-year-old children participating in the LIFE Child cohort study (Germany) reported on their use of electronic media (daily screen time, use at bedtime, device ownership) and on their sleep difficulties (Sleep Self Report). Associations between media use and sleep as well as interactions with age and sex were assessed using linear regression analyses.

Results

The analyses revealed significant associations between the use of media at bedtime and bedtime problems (in girls only), sleep behavior problems (in girls only), and daytime sleepiness (in girls and boys). Daily screen time, in contrast, was associated with none of the sleep difficulties. The number of media devices owned by the child was only associated with bedtime problems in girls, and this association lost statistical significance once media use at bedtime was included as further predictor.

Conclusion

The findings underline the potentially sleep-disturbing role of electronic media at bedtime. Furthermore, they suggest that this effect is more pronounced in girls than in boys.

Sleep characteristics and changes in sleep patterns among infants in Bhaktapur, Nepal

OBJECTIVE

Sleep undergoes major changes during the first year of life, but the characteristics of sleep among infants in low and middle-income countries are not well documented. This study describes sleep characteristics and changes in sleep patterns in infants at 6 and 12months of age from Bhaktapur, Nepal.

METHODS

This was a community-based longitudinal study comprising 735 infants. Sleep characteristics were obtained by interview with the mother using the Brief Infant Sleep Questionnaires. The stability of sleep duration and night awakenings were estimated by logistic regression analysis.

RESULTS

Cosleeping in the parent's bed at 6 and 12months of age was almost universal (>97%). At 6months of age, 254 (35%) and at 12months of age, 341 (46%) infants had a total 24-hour sleep duration <12 hours. Night awakenings >3 times per night were common (65%) both at 6 and 12months of age. Infants with frequent nightly awakenings at 6months had increased odds of frequent nightly awakenings at 12months (OR=2.2; 95% CI: 1.6, 2.9). Very few (<3%) mothers reported sleep problems in their infants at 6 and 12months of age.

CONCLUSIONS

Cosleeping was almost universal among Nepalese infants, and very few of the mothers reported sleep problems in their infants. Infants at 6 and 12months had similar patterns for both sleep duration and nocturnal awakenings. For infants, there were increased odds of having similar sleep duration and nocturnal awakening at 6 and 12months.

Prevalence of toddlers meeting 24-hour movement guidelines and associations with parental perceptions and practices

OBJECTIVES

Whether toddlers (1-2 years) meet 24-hour Movement Guidelines and how parental practices and perceptions are related to compliance are uncertain. This study: a) estimated the proportion of toddlers meeting individual and combined movement guidelines; and b) examined associations between parental perceptions/practices and toddlers' compliance with movement guidelines.

DESIGN

Cross-sectional study.

METHODS

Australian parents self-reported their parenting practices/perceptions (routines, co-participation, restrictions, concerns, knowledge) and toddlers' movement behaviours in the baseline assessment of Let's Grow (n=1145), a randomised controlled trial. The World Health Organization's Guidelines on Physical Activity, Sedentary Behaviour, and Sleep for children under 5 years were used to estimate the prevalence of compliance with individual and combined movement guidelines. Logistic models assessed cross-sectional associations.

RESULTS

The prevalence of meeting guidelines was 30.9% for screen time, 82.3% for sleep, 81.6% for physical activity, 20.1% for combined, and 2.1% meeting none. Parents' knowledge of the guidelines, fewer concerns and more favourable restrictions concerning movement behaviours were associated with greater compliance with individual and combined movement guidelines. Routines for screen time and for combined behaviours were associated with adherence to their respective guidelines. Less co-participation in screen time and more co-participation in physical activity were associated with greater compliance with the relevant guidelines.

CONCLUSIONS

Given only 20% of toddlers met all guidelines, strategies early in life to establish healthy movement behaviours, especially screen time, are needed. Future studies could target the parental practices/perceptions identified in this study to support toddlers with optimal sleep and physical activity and reduced screen time.

The cross-sectional and prospective associations of parental practices and environmental factors with 24-hour movement behaviours among school-aged Asian children

BACKGROUND

Parental practices and neighbourhood environmental factors may influence children's movement behaviours. We aimed to investigate the cross-sectional and prospective associations of parental practices and neighbourhood environmental factors with accelerometer-measured 24-hour movement behaviours (24 h-MBs) among school-aged children in Singapore.

METHODS

The Growing Up in Singapore Towards healthy Outcomes (GUSTO) study collected information on dimensions of parental practices and neighbourhood environment at age 5.5 years. Confirmatory factor analyses were performed to generate latent variables and used to compute overall parental practices [involvement in PA + support for PA + control of screen viewing context] and environmental scores [facilities for active play + active mobility facilitators + barriers*-1]. Children wore an accelerometer on their non-dominant wrist for seven consecutive days at ages 5.5 and 8 years. The R-package GGIR 2.6 was used to derive moderate-to-vigorous-intensity physical activity (MVPA), light-intensity physical activity (LPA), inactivity, and total-sleep (napping+night sleep) minutes per day. Associations were determined using compositional data analysis with multivariate linear regression models, taking into account potential confounders.

RESULTS

Among 425 children (48% girls, 59% Chinese), higher parental involvement in PA, parental support for PA and overall parental practices were associated with 24 h-MBs at ages 5.5 and 8 years, specifically with greater time spent in MVPA and less time being inactive relative to the remaining movement behaviours. The corresponding mean changes in the overall 24 h-MB for increasing parental practices from lowest to highest scores (- 2 to + 2 z-scores) indicated potential increases of up to 15-minutes in MVPA, 20-minutes in LPA, 5-minutes in sleep duration, and a reduction of 40-minutes in inactivity at age 5.5 years. At age 8 years, this could translate to approximately 15-minutes more of MVPA, 20-minutes more of LPA, a 20-minute reduction in sleep duration, and a 20-minute reduction in inactivity. Parental control of screen viewing contexts and neighbourhood environmental factors were not associated with 24 h-MBs.

CONCLUSIONS

Parental practices but not environmental factors were associated with higher MVPA and lower inactivity among Singaporean children, even at a later age. Further research may provide insights that support development of targeted public health strategies to promote healthier movement behaviours among children.

STUDY REGISTRATION

This study was registered on 4th August 2010 and is available online at ClinicalTrials.gov: NCT01174875.

Null Association Between Isolated Orofacial Clefts and Sleep Duration: A Cohort Study From the Japan Environment and Children's Study

Although children with orofacial clefts have an increased risk for sleep-disordered breathing, no studies have examined the association of sleep duration. Thus, this study aimed to examine associations between orofacial clefts and sleep duration at 1 month, 6 months, 1 year, and 3 years of age in Japan.

A cohort study from the Japan Environment and Children's Study.

This study consisted of 91 497 children, including ones with isolated cleft lip and palate (n = 69), isolated cleft lip only (n = 48), and isolated cleft palate only (n = 37), for which recruitment was undertaken during 2011 to 2014.

Seep durations (hours per day) at 1 month, 6 months, 1 year, and 3 years of age, as reported by their mothers.

In the control group, mean sleep durations and standard deviations at 1 month, 6 months, 1 year, and 3 years of age were 15.2 (2.5), 13.6 (1.9), 12.9 (1.6), and 11.6 (1.2) h, respectively. Compared to the control group, linear regression models reported effect sizes and 95% confidence intervals shorter than 1 h for sleep duration of each type of isolated orofacial cleft at each time point.

This study suggested null associations between isolated orofacial clefts and sleep duration at 1 month, 6 months, 1 year, and 3 years of age. Children with isolated orofacial clefts had sufficient mean sleep duration.

Maternal Perceptions of Evidence-Based Early Childhood Sleep Health Promotion Recommendations: An Explanatory Sequential Study

OBJECTIVES

The purpose of this explanatory sequential design study was to better understand caregivers' perceptions about and interest in evidence-based early childhood sleep health promotion recommendations.

METHOD

A purposeful sample of mothers of 20 1-5-year-old children (10 children exhibiting optimal sleep and 10 children exhibiting insufficient/fragmented sleep) attending a preschool serving a low socio-economic (SES) status metropolitan community were invited to participate in qualitative interviews. Data were coded according to a grounded theory approach and themes were identified within the optimal and suboptimal sleeper groups.

RESULTS

Mothers reported different approaches to managing electronics by optimal/suboptimal sleeper group, with mothers of optimal sleepers limiting access to electronics more than mothers in the suboptimal sleep group. Other themes of sleep health practices did not differ meaningfully between groups.

CONCLUSIONS

Maternal perspectives about early childhood sleep health were similar across optimal and suboptimal sleepers on most elements of child sleep health. Managing child sleep was contextually influenced and these results highlight the complexities of how families living in lower SES environments perceive common sleep recommendations. Thus, sleep health education efforts should be tailored to the needs and values of specific families and communities.

Sociodemographic, temporal and bedtime routine correlates of sleep timing and duration in South Asian and white children: A Born in Bradford study

Objective

The study aimed to examine sociodemographic, temporal and bedtime routine correlates of parent-reported sleep duration and timing in a biethnic sample of 18 month and 36 month old children from a disadvantaged location.

Methods

Between October 2010 and September 2012, parents completed a bespoke three day sleep diary when their child was approximately 18 months (n = 276) and 36 months of age (n = 262) (45.1% South Asian; 54.9% white). Parents reported their child's overnight sleep duration (h/day), the time their child fell asleep, their wake time and their child's bedtime and napping routines. Data were available at both time points for 135 children.

Results

In line with previous literature, South Asian children had shorter overnight sleep duration and later sleep and wake times than white children. In both ethnic groups, children slept and woke up later on weekends, and children went to bed earlier and slept longer in winter. In white children only, napping duration was associated with overnight sleep period. No significant associations were found between napping frequency and overnight sleep duration. Based on parent-reported data, children who consistently adhered to regular bedtimes and had set times for sleeping tended to go to sleep earlier, wake earlier and have longer overnight sleep.

Conclusions

The data showed parent-reported variation in sleep patterns between two ethnic groups within a single geographical and deprived area. It is important that researchers, clinicians and early years workers are considerate of cultural norms in sleep practices.

Promoting healthy sleep in Chinese kindergarteners through a family-based intervention: protocol of the "Healthy Sleep" randomised controlled trial

BACKGROUND

Sleep is instrumental for growth and development in children, making it critical to establish healthy sleep habits from the earliest years of life. Many kindergarteners (3-6 years) in China have inadequate and poor sleep, necessitating targeted interventions. This research protocol details the "Healthy Sleep" intervention that was designed to promote healthy sleep among kindergarteners in China.

METHODS

The "Healthy Sleep" intervention will be family-based and will support parents as change agents. The development of the intervention is based on evidence regarding correlates of sleep in young children and guided by Bandura's social cognitive theory. A 12-month randomised controlled trial will be conducted to examine the efficacy of the intervention for promoting healthy sleep in Chinese kindergarteners and the intervention's effects on child development outcomes. A targeted sample of 160 kindergarteners and their parents will be recruited through social media. The intervention group (n = 80) will receive monthly webinars for one year that include multiple intervention components - including educational training, goal setting and planning, as well as follow-up support sessions. The control group (n = 80) will receive videos of the recorded educational sessions after the study end. For primary outcomes, child sleep behaviours will be examined using the Child Sleep Health Questionnaire. For secondary outcomes, communication, fine motor, gross motor, personal-social, and problem-solving development will be examined using the Ages and Stages Questionnaire; executive functions will be examined using the Head, Toes, Knees, and Shoulders Revised tasks. Potential intervention mediators and covariates will be measured using a parental questionnaire. Mixed models will be conducted.

DISCUSSION

This intervention targets sleep behaviours among kindergarteners in China. It has the potential to inform programs to support parents in helping their child establish healthy sleep habits from the earliest years of life. The study will provide high-quality experimental evidence on sleep behaviours in relation to development outcomes in kindergarteners. This evidence will inform family-based strategies to optimise early childhood development and inform national and international updates of the sleep recommendations for young children.

TRIAL REGISTRATION

The trial was registered prospectively at Chinese Clinical Trial Registry (ID: ChiCTR2300072105) on 2 June 2023.

Parental Overprotection and Sleep Problems in Young Children

Poor sleep in children predicts mental and physical disorders later in life. Identifying and changing modifiable factors associated with sleep problems in young children may improve their health trajectory. Our aim was to establish whether overprotective parenting was associated with problems sleeping in children. Parents of children aged 2-6 years completed questionnaires about their own anxiety, parenting style, and about their children's sleep. We obtained 307 reports on 197 children from 240 parents. Using mixed-effects linear regression, we found that maternal (beta = 0.26, 95% CI 0.11 to 0.41, p = 0.001) and paternal (beta = 0.35, 95% CI 0.17 to 0.53, p < 0.001) overprotection were associated with impaired sleep in children. This relationship remained unchanged when controlling for parental anxiety. Decreasing parents' overprotection may improve children's sleep, and reduce the risk of physical and mental disorders later in their life.

The influence of sleep patterns and screen time on the sleep needs of infants and toddlers: A cross-sectional study

PURPOSE

The purpose of this study was to examine the effects of screen time and sleep patterns on the sleep needs of infants and toddlers.

DESIGN AND METHODS

A descriptive cross-sectional data were collected from 304 parents of children aged 6 to 36 months old. The screen use of children and parents was assessed with seven questions and A Brief Infant Sleep Questionnaire (BISQ) was used to assess infant sleep.

RESULTS

The results of this study indicate that children's adherence to the recommended sleep standards is poor. The most important criteria that caused poor sleeping were the number of awakenings at night, the duration of sleeplessness at night and the minimum total sleep time of <9 h. The most frequently used screen type in all of the age groups and parents was TV, followed by smartphones. As the age of the children increased, the rate of all screen-type use also increased. Factors predicting sleep needs included bedtime, the PED usage of children, parents' watching TV and care of the children by the babysitter.

CONCLUSIONS

Sleep needs are associated with the sleep patterns and screen usage of the children and parents.

PRACTICE IMPLICATIONS

Given that screen usage behaviors are tracked from infancy to early childhood, these findings highlight the need for prevention and intervention efforts, as well as for education and policy measures, to limit screen use and exposure from an early age.

Play-Sleep Nexus in Indonesian Preschool Children before and during the COVID-19 Pandemic

The COVID-19 pandemic has transformed Indonesians' behaviors and has had an impact on many facets of daily life. People's lives are becoming increasingly dependent on digital technologies, which is a phenomenon with conflicting effects on people's health and happiness. This cross-sectional study focused on one such influence, namely, how the shift from the period before to during COVID-19 has affected children's playtime and sleep duration. As part of a multicenter study, 618 adult caregivers (parents, family members, or babysitters) who visited the kindergarten in question on behalf of preschool children aged 2-5 years (4.04 ± 1.39) were surveyed on the children's play and sleep habits before and during the COVID-19 pandemic in Indonesia, particularly Java Island (before pandemic, N = 309; during pandemic, N = 309). ANOVA was used for a statistical analysis to describe the difference between groups and within time collections. Significant favorable relationships were found between pre-pandemic and post-pandemic playtime and sleeping time on weekdays, weekends, and averaged weekday-weekend (r = 0.437; 0.180 and 0.321, all p < 0.05) were detected. Before the pandemic, children's playtime (4.11 vs. 3.55 h) and sleep duration (10.92 vs. 10.70 h) were significantly greater on the weekend than on the weekday (p < 0.05) but not during the pandemic (playtime: 3.48 vs. 3.45 h and sleep duration: 10.83 vs. 10.80 h; all p > 0.05). The COVID-19 pandemic had no impact on sleep duration or playtime in Javanese preschool children. Efforts should be intensified to promote the value of playtime and sleep duration among children in this age range so that the future of Indonesian children's can be ensured.

Early Childhood Diet in Relation to Toddler Nighttime Sleep Duration Trajectories

The objective of this study was to evaluate whether dietary habits at age 2 associate with sleep duration trajectories through age 5 in children from north and central Appalachia. A total of 559 children from the Center for Oral Health Research in Appalachia (COHRA) cohort 2 were followed via caregiver phone interviews up to six times between ages 2 and 5. Exposures included data from the year 2 interview: sleep habits, household and demographic characteristics, meal patterns and consumption frequencies of fruits, vegetables, water, juice, milk, and soda. Sleep duration trajectories were identified using group-based trajectory models from ages 2 to 5. Three distinct nightly sleep duration trajectories were identified: short, increasing duration (4.5% of the study population); steady, 9 h of sleep (37.3%); and longer, slightly decreasing sleep duration (58.2%). Using multinomial logistic models that accounted for confounders, children with consistent meal patterns (i.e., meals and snacks at same time every day) and with higher fruit and vegetable consumption were more likely to follow the longer duration sleep trajectory compared to the steady sleep trajectory. In contrast, children who drank milk more frequently at age 2 were less likely to be in the longer duration sleep trajectory than the steady sleep trajectory.

Associations of sleep characteristics with cognitive and gross motor development in toddlers

OBJECTIVE

To examine cross-sectional associations of sleep characteristics (duration, consolidation, timing, variability) with cognitive and gross motor development in toddlers.

METHODS

Participants were 205 toddlers (19.6 ± 4.3 months) from the GET-UP!

STUDY

Nap/nighttime sleep onset and offset were measured using an accelerometer and used to calculate nap/nighttime sleep duration. Total sleep duration was calculated and classified as meeting or not meeting the sleep recommendation of the Australian 24-Hour Movement Guidelines (11-14 h/d). Nighttime sleep ratio (ie, nighttime sleep duration: total sleep duration), indicative of consolidation, was expressed as a percent value. Nighttime sleep midpoint (ie, the midpoint between nighttime sleep onset and offset), indicating the lateness of sleep schedules, was converted to a decimal hour. For sleep variability, the intraindividual standard deviation of nighttime sleep duration and nighttime sleep midpoint was calculated, respectively. Cognitive development (Bayley Scales of Infant and Toddler Development-III) and specific domains of gross motor development (Peabody Developmental Motor Scales, 2nd edition) were measured.

RESULTS

Shorter nap duration (B = -0.87, 95%CI: -1.71, -0.02) and higher nighttime sleep ratio (B = 0.13, 95% CI: 0.02, 0.24) were associated with better cognitive development. Regarding gross motor development, positive associations were found for nighttime sleep duration (object manipulation: B = 0.26, 95% CI: 0.01, 0.51; gross motor quotient: B = 1.21, 95% CI: 0.04, 2.38) and total sleep duration (object manipulation: B = 0.28, 95% CI: 0.03, 0.52); negative associations were found for nighttime sleep midpoint (stationary: B = -0.31; 95% CI: -0.58, -0.06) and nighttime sleep duration variability (stationary: B = -0.32, 95% CI: -0.64, -0.004).

CONCLUSIONS

In toddlers, more consolidated sleep may be an indicator of better cognitive development. Promoting longer and more consistent nighttime sleep duration, as well as an earlier nighttime sleep schedule, may facilitate gross motor development. However, our findings for the associations of sleep characteristics with cognitive and gross motor development need to be confirmed in prospective studies.

Sleep Deficiency in Young Children

There is growing public health concern about the high prevalence of sleep deficiency in early childhood and the associated risk for sleep-associated poor health outcomes, including metabolic, cardiovascular, and mental health. The recent shift to conceptualize sleep health as a multidimensional construct, influenced by socioecological factors, highlights the potential role of sleep in health disparities. Understanding the development of sleep health and the emergence of sleep disorders in early life is a current priority in pediatric sleep research. Future behavioral sleep interventions should consider the multiple socioecological influences on children's sleep health and be tested using inclusive sampling methods.

A Longitudinal Approach to the Relationships Among Sleep, Behavioral Adjustment, and Maternal Depression in Preschoolers

This study aimed to investigate the longitudinal associations between children’s sleep duration (SD) and problems (SPs), behavioral adjustment [externalizing behaviors (EB) and internalizing behaviors (IB)], and maternal depressive symptoms (MDS) in preschoolers over a period of 3 years (4–6 years of age). For this purpose, latent growth modeling (LGM) was conducted using 2012(W₅) to 2014(W₇) data from the National Panel Study on Korean Children (PSKC), while controlling for family contextual factors (i.e., responsive parenting, developmental stimulations, and marital conflict) and child temperament (children’s negative emotionality). First, children who slept longer at four were concurrently associated with lower levels of EB, while more SPs were associated with higher levels of EB and IB, concurrently. Second, greater decreases in SPs were associated with greater decline in EB and IB. Higher levels of MDS at four were associated with higher levels of child EB, IB, and SPs, concurrently. However, no longitudinal associations were found between the rates of change in MDS and children’s sleep and adjustment (EB and IB). Finally, the magnitude of the associations among the variables was greater overall in the SPs models than in the SD models. These findings suggest that addressing sleep problems, rather than sleep duration, seem to be more important in predicting and preventing young children’s adjustment problems and also that more attention should be paid to MDS during preschool years as much as during the postpartum period for better child adjustment outcomes.

The role of daytime napping on salivary cortisol in children aged 0-5 years: a systematic review and meta-analysis

Cortisol levels are implicated in emotional and cognitive development in children. However, it is not clear whether daytime napping influences cortisol levels in early childhood. This systematic review and meta-analysis aimed to synthesize the available evidence regarding the association between daytime napping and salivary cortisol in early childhood. The Medline, Embase, Web of Science, PsycINFO, and Cochrane Collaboration databases were searched for observational and experimental studies reporting data about napping behavior and salivary cortisol in children 0-5 years of age. Salivary cortisol levels were analyzed in three situations: CAR, cortisol awakening response from nap awakening; PRE-POST, before and after a daytime nap; and DIURNAL, from morning awakening to bedtime. Five studies showed a significant CAR after napping (mean difference, MD: 0.11μg/mL; 95% confidence interval, CI: 0.04, 0.18). In the PRE-POST analysis, a small decrease was observed for at-home naps (MD: -0.05 μg/mL; 95% CI: - 0.09, - 0.02) but not for at-childcare naps (MD: 0.04 μg/mL; 95% CI: - 0.01, 0.09). A similar pattern of DIURNAL salivary cortisol decrease was observed when children took a nap (MD: - 0.34 μg/mL; 95% CI: - 0.41, - 0.28) and when they did not sleep during the day (MD: - 0.28 μg/mL; 95% CI: - 0.38, - 0.19).

CONCLUSIONS

Daytime napping plays a minor role in the fluctuation of salivary cortisol levels during the day. The conditions of the home or the childcare environment under which napping occurs might have a greater influence on cortisol levels than daytime napping itself in early childhood. PROSPERO Identifier: CRD42020212249.

WHAT IS KNOWN

• The regulation of sleep involves circadian rhythmicity of cortisol secretion via activation of the HPA axis and a subsequent release of cortisol upon morning awakening followed by a decline throughout the day.

WHAT IS NEW

• The available evidence supports the occurrence of a cortisol awakening response after a daytime nap. • A small decrease in cortisol after napping was observed when the nap occurred at home but not at childcare. • The conditions of the home or childcare environment under which the nap occurs and the activities before and after napping may have a greater influence on cortisol levels than napping itself.

The Impact of COVID-19 on Preschool-Aged Children's Movement Behaviors in Hong Kong: A Longitudinal Analysis of Accelerometer-Measured Data

During the COVID-19 pandemic, many preschool-aged children were forced to remain indoors due to social distancing measures and school closures. In this study, we examined how children’s movement behaviors (sedentary behaviors, physical activity, and sleep) were affected by the pandemic. Children’s (N = 25, age = 4.4 years, SD = 0.3) movement behaviors were measured before and after the COVID outbreak, respectively. Data collected using accelerometers were analyzed using compositional data analyses. A significant change in the overall time-use composition (F = 5.89, p = 0.002) was found. Results suggested that children spent more time sleeping (8% increase) and in moderate-to-vigorous physical activity (16% increase), with less time spent in sedentary behaviors (9% decrease). However, parent reports suggested that children were less active and had more screen time. In conclusion, the current evidence suggests that children’s physical activity is not negatively impacted by the pandemic. However, the continuous surveillance of movement behaviors of young children during the pandemic is needed.

Is There a Dose-Response Relationship between Acute Physical Activity and Sleep Length? A Longitudinal Study with Children and Adolescents Living in Sweden

A declining physical activity (PA) and sleep in children and adolescents have been observed during the previous decades. PA could benefit sleep, but the findings are mixed. The aim of the present study was to examine if there is a dose-response relationship between time spent in acute moderate and vigorous physical activity (MVPA) and sleep length in children and adolescents. Additional aims were to examine if the sleep length is higher for children and adolescents who conduct at least an average of 60 min in MVPA/day and to study differences between sex and school years. The study population consists of 262 participants in school year 5 (aged 11 years), 7 (aged 13 years), and 9 (aged 15 years). Accelerometers measured MVPA while sleep diaries measured sleep length. A linear and longitudinal mixed effect linear regression was conducted to study the primary aim. The secondary aims were studied with linear regressions. Included confounders were sex, school year, school stress, screen time, menstruation onset, family household economy, and health status. A stratified regression for sex and school year was conducted. The linear regression showed no statistically significant findings in the crude or adjusted model. The stratified linear regression found a significant positive association for girls but a negative association for school year 5. No associations were found in the longitudinal regression or when comparing sleep length for participants that did and did not spend an average of at least 60 min in MVPA/day. A dose-response relationship was found in the stratified linear regression, implying a possible weak association. The statistically non-significant differences between participants that did and did not spend an average of at least 60 min in MVPA/day implies that spending an average of at least 60 min in MVPA/day may not be associated with a higher mean sleep length.

Systematic review of the correlates of outdoor play and time among children aged 3-12 years

BACKGROUND

Due to the myriad of benefits of children's outdoor play and time, there is increasing concern over its decline. This systematic review synthesized evidence on the correlates of outdoor play and outdoor time among children aged 3-12 years.

METHODS

A total of 12 electronic databases in five different languages (Chinese, English, Korean, Spanish, Portuguese) were searched between October 28, 2019 and July 27, 2020. Covidence software was used for screening and Microsoft Excel with a predesigned coding form was used for data extraction. Evidence was synthesized and correlates were categorized using the socioecological model framework.

RESULTS

Based on 107 studies representing 188,498 participants and 422 childcare centers from 29 countries, 85 studies examined potential correlates of outdoor play while 23 studies examined that of outdoor time (one examined both). The duration of outdoor play and outdoor time ranged between 60 and 165 min/d and 42-240 min/d, respectively. Out of 287 (outdoor play) and 61 (outdoor time) potential correlates examined, 111 correlates for outdoor play and 33 correlates for outdoor time were identified as significant correlates. Thirty-three variables were identified as key/common correlates of outdoor play/time, including eight correlates at the individual level (e.g., sex/gender, race/ethnicity, physical activity), 10 correlates at the parental level (e.g., parental attitude/support/behavior, parenting practice), nine at the microsystem level (e.g., proximal home/social environment such as residence type, peer influence), three at the macrosystem/community level (e.g., availability of space children can play), and three at the physical ecology/pressure for macrosystem change level (e.g., seasonality, rurality). No key correlates were found at the institutional level.

CONCLUSIONS

Individual, parental, and proximal physical (home) and social environments appear to play a role in children's outdoor play and time. Ecological factors (i.e., seasonality, rurality) also appear to be related to outdoor play/time. Evidence was either inconsistent or lacking at institutional and macrosystem/community levels. Standardizing terminology and measures of outdoor play/time is warranted. Future work should investigate the interactions and processes of multiple variables across different levels of socioecological modelling to better understand the mechanisms through which outdoor play/time opportunities can be optimized for children while paying special attention to varying conditions in which children are born, live, and play.

Longitudinal correlates of sleep duration in young children

OBJECTIVE

The primary aim of this study was to longitudinally examine potential demographic and screen time correlates of nap duration, nighttime sleep duration, and total sleep duration in young children over two time points.

METHODS

Data from the supporting Healthy physical AcTive Childcare setting (HATCH) study were analyzed. Participants were 206 toddlers (19-35 months) and preschoolers (36-60 months) in Alberta and Ontario, Canada. Child age, screen time (television, video games), and sleep duration (nap, nighttime) were measured at baseline and six-month follow-up, while other demographic variables were assessed at baseline only using the HATCH parental questionnaire. Mixed models were performed to examine the associations between potential correlates and sleep duration over time.

RESULTS

In the multiple regression models, significant correlates of total sleep duration (min/d) were child age (months; B = -3.03; 95%CI:-3.88,-2.19) and parental education (bachelor's degree vs. below bachelor level; B = 29.74, 95%CI:7.43,52.06). Significant correlates of nighttime sleep duration (min/d) included child age (B = -0.81; 95CI%:-1.53,-0.10), child race/ethnicity (Caucasian vs. non-Caucasian; B = 15.31; 95%CI:0.38,30.25), household income (>$150,000 vs. <$50,000; B = 32.93, 95%CI:9.80,56.06), television time (B = -0.19, 95%CI:-0.32,-0.05), video games time (B = -0.19, 95%CI: -0.38, -0.01) and total screen time (B = -0.19; 95%CI:-0.29,-0.08). Significant correlates of nap duration (min/d) were child age (B = -2.10; 95%CI:-2.68,-1.51) and race/ethnicity (Caucasian vs. non-Caucasian; B = -13.73; 95%CI:-25.78,-1.68).

CONCLUSION

Young children who were non-Caucasian, from lower income families, who had less-educated parents, or who had more screen time tended to have shorter sleep duration. Targeting these demographic groups and screen time appears important for promoting adequate sleep duration in early childhood.

Digital media, book reading, and aspects of sleep and sleep-related fears in preschoolers: the Ulm SPATZ Health Study

Background

High levels of digital media use with screen-based devices has been found to threaten several aspects of child and adolescent health. However, the rapid change in digital media use behavior in our society over the past decade has rendered much of the existing evidence outdated.

Materials and methods

The present work reports data ascertained from 2016 to 2019 on preschoolers’ digital media use and book reading among 4‑ to 6‑year-old children from the longitudinal Ulm SPATZ Health Study. These data are supplemented by exploring the association of child digital media use and book reading with aspects of children’s sleep and sleep-related fears.

Results

After data management, 581 children participated at the age of 4 years. At the ages of 5 and 6 years, data were available for 508 and 426 participants, respectively. Median age of the mothers was 33 years (range 21–54) and 70% had graduated from high school. Most time spent using digital media was represented by passive activities in front of a screen. Time spent using digital media increased with children’s age. An increased risk of the fear of sleeping alone (RR: 1.35, [95% CI: 1.07; 1.70]) and fear of the dark (1.47 [95% CI 1.16; 1.87]) was documented for exposure to “all media” higher than the median as compared to lower levels. Exposure to “books” above the median and compared to lower levels was tentatively associated with a relevant 18% reduction in the risk of both fear of sleeping alone and fear of the dark (0.82 [95% CI 0.65; 1.03] and 0.82 [95% CI 0.64; 1.05], respectively).

Conclusion

Our results suggest that reducing time spent using digital media and potentially substituting this time by reading books, which seem to be a safe alternative, is a valid solution to reduce some common aspects of poor sleep in preschoolers.