Association between delayed bedtime and sleep-related problems among community-dwelling 2-year-old children in Japan

Paths towards a healthier BMI among short and adequate sleepers: A pathway network analysis considering movement behaviors in low-income preschoolers

INTRODUCTION

Short sleep duration has been seen as a predictor of higher body mass index (BMI) in youth. Sleep duration varies substantially along early childhood, and the paths towards a healthier BMI, considering the other movement behaviors (physical activity-PA and screen time) are unexplored in preschoolers.

AIM

To construct a sleep-BMI model to capture the direct and indirect paths to intervening towards a healthier BMI, according to low-income preschoolers' compliance with the other movement behaviors.

METHODS

Two hundred and seventy two preschoolers (4.5 ± 0.0; 138 boys) participated in the study. Sleep and screen time (ST) were assessed in a face-to-face interview with primary caregivers. PA was assessed using accelerometer (wGT3X-BT). Preschoolers were categorized as compliant or not with sleep, screen time, total and moderate to vigorous PA recommendations. BMIz-score was calculated according to preschoolers' sex and age. All the assessed variables, besides sex and age were included in a Network Pathway Analysis (NPA) according to age as nodes.

RESULTS

At 3 years old, a direct and negative path between sleep-BMIz score was observed. At four and 5 years old, this relationship became positive. Further, girls were more compliant with sleep, ST and total PA recommendations. Total PA (TPA) showed the highest expected influence value in the general, 3 and 4 years old NPA.

CONCLUSION

The NPA analysis showed different directions for the relationship between sleep and BMIz score, according to age. Intervention strategies to a healthier BMI among preschoolers compliant or not with sleep recommendations should focus in increasing TPA.

Comparing infant and toddler sleep patterns prior to and during the first wave of home confinement due to COVID-19 in Spain

Recent literature has shown that sleep patterns are shaped during the first years of life, playing a relevant role in children's functioning. We focused on comparing sleep patterns in infants and toddlers in Spain before and during COVID-19 home confinement to assess the immediate impact on sleep patterns. We compared data from two cross-sectional surveys from parents of 1658 children three to 36 months of age from Spain. One conducted before COVID-19 (2017-2018, n = 1380) and another during COVID-19 pandemic (March-May of 2020, n = 254). We used an internet self-administrated questionnaire using the Brief Infant Sleep Questionnaire (BISQ) criteria in both surveys. During confinement, infants and toddlers went to sleep later (median bedtime 21:30 before confinement vs. 21:36 during confinement (p = 0.004)). More infants and toddlers showed longer sleep latencies (> 30 min) during confinement median 33.9% versus 12.3% (p < 0.001). Based on the recommended BISQ criteria, we observed an increase in poor sleepers meeting at least one criterion of inadequate patterns during confinement (p < 0.001). Parental perception of a child's sleep as problematics were 39.4% and 44.1% (adjusted p = 0.363) before and under lockdown, respectively.

CONCLUSION

Home confinement generally affected infant's and toddler's sleep patterns negatively; however, parents did not report worse perception of sleep quality of their children. Follow-up studies can help understand the potential long-term effects of the COVID-19 pandemic on sleep patterns.

WHAT IS KNOWN

• Adequate sleep patterns in infants and toddlers are relevant as they are linked to proper and long-term social-emotional development as well as adequate daytime functioning. • Regarding sleep patterns in paediatrics during the COVID pandemic, recent literature has described an increase in total daily sleep time as well as more exposure to screens in children and adolescents, providing evidence of immediate collateral consequences of the COVID-19 outbreak.

WHAT IS NEW

• Comparing sleep patterns in two samples of infants and toddlers in Spain before and during COVID-confinement, we found later bedtimes as well as a significant increase in infants' and toddlers' sleep latency by >30 min during confinement. • Parental self-reported questionnaire during COVID-19 home confinement reported an overall worsening of their children's sleep based on the BISQ criteria.

Association of maternal sleep before and during pregnancy with sleep and developmental problems in 1-year-old infants

This study investigated the association of maternal sleep before and during pregnancy with sleeping and developmental problems in 1-year-old infants. We used data from the Japan Environment and Children's Study, which registered 103,062 pregnancies between 2011 and 2014. Participants were asked about their sleep habits prior to and during pregnancy. Follow-up assessments were conducted to evaluate the sleep habits and developmental progress of their children at the age of 1 year. Development during infancy was evaluated using the Ages and Stages Questionnaire (ASQ). Maternal short sleep and late bedtime before and during pregnancy increased occurrence of offspring's sleeping disturbances. For example, infants whose mothers slept for less than 6 h prior to pregnancy tended to be awake for more than 1 h (risk ratio [RR] = 1.49, 95% confidence interval [CI] 1.34-1.66), sleep less than 8 h during the night (RR = 1.60, 95% CI 1.44-1.79), and fall asleep at 22:00 or later (RR = 1.33, 95% CI 1.26-1.40). Only subjective assessments of maternal sleep quality during pregnancy, such as very deep sleep and feeling very good when waking up, were inversely associated with abnormal ASQ scores in 1-year-old infants.

Correlates of Sleep Duration in Early Childhood: A Systematic Review

OBJECTIVE

This systematic review aimed to summarize correlates of sleep duration in children under 5 years of age.

METHODS

Six electronic databases (PubMed, PsycINFO, MEDLINE, CINAHL, SPORTDiscus, and Scopus) were searched from inception to May 2019. Observational studies and intervention studies reporting cross-sectional results from baseline data were considered. Data were extracted using a predesigned form and potential correlates were categorized following a sociological framework.

RESULTS

One-hundred and sixteen studies, representing 329,166 children, met the inclusion criteria, with a high risk of bias in 62 included studies. A total of 83 correlates of sleep duration were identified. Among the associations studied four or more times, correlates of nap duration were child's age and nighttime sleep onset/bedtime; correlates of nighttime sleep duration were household income, parent marital status, parental adiposity level, nighttime sleep duration at younger age, nighttime sleep onset/bedtime, nighttime sleep wakeup time, and frequency of current bedtime routine; correlate of total sleep duration was screen time.

CONCLUSIONS

Young children from low-income households, single families, or having overweight parents may be at risk for short sleep duration. Promoting healthy sleep duration from an early age appears essential. Effective practices may include encouraging an earlier bedtime, limiting screen time, and establishing a regular bedtime routine. The absence of consistent evidence in the psychological, cognitive, and emotional domain as well as the physical environmental domain warrants further research.

Reciprocal Longitudinal Associations Between Adolescents' Media Consumption and Sleep

Background/Objective: Associations between adolescents' sleep and their media consumption have been shown in several cross-sectional studies. However, longitudinal investigations are still sparse and have mainly investigated associations between sleep duration and the usage of TV or computer games. The present study explored reciprocal longitudinal relationships between the consumption of different screen-based media and sleep-related problems in German adolescents. Participants: Four hundred sixty-seven 10- to 17-year-old adolescents participated in the LIFE Child Study in Leipzig, Germany. Methods: The consumption of screen-based media (TV or video, computer and Internet, mobile phones) as well as sleep-related problems (problems at bedtime, sleep behavior problems, daytime sleepiness) were assessed at two time points, 12 months apart. Reciprocal longitudinal relations were assessed by multiple regression analyses. All associations were controlled for age, gender, socioeconomic status, and dependent variables at baseline. Results: The consumption times of the different screen-based media were significantly related. Similarly, the different sleep-related problems showed significant interrelations. Most importantly, the analyses revealed significant associations between a high baseline consumption of computer and Internet with more problems at bedtime, as well as more daytime sleepiness at follow-up. Furthermore, baseline daytime sleepiness was associated with a higher consumption of TV or video at follow-up. Conclusions: These results indicate a mutual dependency of media consumption and sleep over time.

Did kindergarteners who experienced the Great East Japan earthquake as infants develop traumatic symptoms? Series of questionnaire-based cross-sectional surveys: A concise and informative title: traumatic symptoms of kindergarteners who experienced disasters as infants

BACKGROUND

The Great East Japan Earthquake (GEJE) and tsunami of March 11, 2011 left behind many survivors, including children. This study aimed to assess changes in traumatic symptoms with time among kindergarteners who experienced GEJE as infants and to discuss the relationship between these symptoms and the disaster experience.

METHODS

The 15-item Post-Traumatic Stress Symptoms for Children (PTSSC-15) questionnaire were distributed to the parents of kindergarteners (children aged 4-5 years) at 8, 20, 30, and 42 months after GEJE. Questionnaires regarding environmental damage conditions affecting the children were distributed to teachers 8 months after the tsunami.

RESULTS

The number of kindergarteners was 262, 255, 236, and 202 at 8, 20, 30, and 42 months after the disaster. The PTSSC-15 total score was not different between kindergartners with and without environmental damage conditions. After 8 and 20 months, the PTSSC-15 total score of children who usually ate breakfast was significantly higher than that of children who did not. Moreover, after 30 and 42 months, the PTSSC-15 total score of kindergarteners who usually ate breakfast was not significantly higher than that of kindergarteners who did not.

CONCLUSIONS

The traumatic symptoms of kindergarteners were not related to disaster experiences.

Study Protocol of Sleep Education Tool for Children: Serious Game "Perfect Bedroom: Learn to Sleep Well"

Promoting a healthy sleep is a big challenge and becomes a strategic priority in public health, due to the severe consequences on children's development and risk to psychiatric diseases. Interventions that promote healthy sleep, such as those that focus on the dissemination of behavioral and environmental recommendations of sleep hygiene with children, are presented as an alternative. Serious game design offers wide-reaching domains in health applications and is increasing in popularity, particularly with children and teens because of it's potential to engage and motivate players differently from other interventions. This study aims to evaluate effects of serious game on sleep hygiene recommendations "Perfect Bedroom: learn to sleep well," on sleep habits and sleep parameters of healthy children. This is an experimental, prospective and quantitative study. We will randomize children in experimental (n = 88) and no intervention groups (n = 88). The experiment has four stages (pre-intervention, intervention, post-intervention, and follow-up), which will count with participation of children and their parents/guardians. In the evaluation stages, the guardians will answer questionnaires and scales to assess sociodemographic and health data, sleep habits and sleep pattern of their child. The children themselves will answer the following: a scale to assess sleepiness levels, a questionnaire to evaluate the serious game and the game itself, will characterize their bedroom and the activities they perform before sleep, with strategies developed by researches. Intervention with experimental group conducted with the serious game "Perfect Bedroom" will happen twice a week, for 3 weeks in a row, resulting in six sessions of 50 min each. Inferential analysis will be conducted for comparisons between groups and intragroups to measure effect of intervention in primary outcomes (sleep habits) and secondary outcomes (sleep parameters). We expect that the intervention with this game can provide valuable evidence to a new approach in promoting healthy sleep habits, with applications in clinical, educational, and familiar settings, which could diminish future health issues and risk at psychiatric diseases, decreasing the social burden of treatments for these conditions in children.

Associations between Parents' Health Literacy and Sleeping Hours in Children: A Cross-Sectional Study

Background: Sleep in preschool children is an important factor for their health and active lives. The lack of adequate sleep in preschool children is a serious public problem in Japan. The relationship between health literacy (HL) and health status is well recognized. The purpose of this study was to investigate the association between the sleep duration of preschool children and the HL of their parents. Methods: In the present study, participants were preschool children (3–6 years) and their parents. We assessed the HL of the parents with the 14-item Health Literacy Scale (HLS-14) questionnaire. Sleep duration of the children was reported by their parents. We divided parents into two groups according to HLS-14 score and analyzed children’s sleeping time separately. Results: Data from 279 parents and their children were ultimately analyzed. The high HL group comprised 210 families (75.3%) and the low HL group comprised 69 families (24.7%). Average children’s sleep duration was significantly longer in the high HL group (9.5 ± 0.9 h) than in the low HL group (9.1 ± 1.1 h) (p = 0.013). A positive correlation was found in the low HL group between parents’ HL and their children’s sleeping times (p < 0.01, r = 0.32) but the difference was not significant in the high HL group (p = 0.98, r = −0.0009). Conclusion: The HL of parents appears to affect their children’s sleep duration, suggesting that parental HL may be an appropriate target for interventions aiming to lengthen children’s sleeping time.

Reliability and validity of a brief sleep questionnaire for children in Japan

BACKGROUND

There is a dearth of sleep questionnaires with few items and confirmed reliability and validity that can be used for the early detection of sleep problems in children. The aim of this study was to develop a questionnaire with few items and assess its reliability and validity in both children at high risk of sleep disorders and a community population.

METHODS

Data for analysis were derived from two populations targeted by the Children's Sleep Habits Questionnaire (CSHQ): 178 children attending elementary school and 432 children who visited a pediatric psychiatric hospital (aged 6-12 years). The new questionnaire was constructed as a subset of the CSHQ.

RESULTS

The newly developed short version of the sleep questionnaire for children (19 items) had an acceptable internal consistency (0.65). Using the cutoff value of the CSHQ, the total score of the new questionnaire was confirmed to have discriminant validity (27.2 ± 3.9 vs. 22.0 ± 2.1, p < 0.001) and yielded a sensitivity of 0.83 and specificity of 0.78 by receiver operator characteristic curve analysis. Total score of the new questionnaire was significantly correlated with total score (r = 0.81, p < 0.001) and each subscale score (r = 0.29-0.65, p < 0.001) of the CSHQ.

CONCLUSIONS

The new questionnaire demonstrated an adequate reliability and validity in both high-risk children and a community population, as well as similar screening ability to the CSHQ. It could thus be a convenient instrument to detect sleep problems in children.

The association between chronotype and sleep problems in preschool children

OBJECTIVE

Adolescents and adults who are evening-types exhibit shorter sleep duration and more sleep problems than individuals with an earlier chronotype. We hypothesized that already at a preschool age, evening-types would exhibit more sleep problems relative to children who are morning or intermediate chronotypes. The aim of this study was to examine the association between chronotype and sleep problems among preschool children.

METHODS

We studied a subset of typically-developing 4.5-year-olds taking part in the Growing Up in Singapore Towards healthy Outcomes birth cohort study (n = 244). The Children's Chronotype Questionnaire (CCTQ) was used to categorize children into morning-, intermediate-, and evening-types. Sleep problems were measured using the Children's Sleep Habits Questionnaire (CSHQ), with higher scores corresponding to greater sleep problems. The relation between chronotype, sleep-wake timing, and nocturnal sleep time was also evaluated in a subsample of 117 children using actigraphy recordings with parent-reported sleep diaries.

RESULTS

After controlling for potential confounders (maternal education, child's sex, birth order, and ethnicity), a significant main effect of chronotype on sleep problems was observed, in which evening-types exhibited greater CSHQ scores compared to morning- and intermediate-types (all p < 0.001). Actigraphy data in the subsample confirmed that evening-types had later bedtimes (p < 0.001) and get-up times (p = 0.02) during weekdays and weekends, but shorter nocturnal sleep time (p = 0.034) only during weekdays, compared to children who had earlier chronotypes.

CONCLUSIONS

In preschool children, sleep problems were greater in evening-types compared to morning- and intermediate-types, suggesting that chronotype could be a contributing factor to sleep disturbances in early childhood.

Late circadian phase in adults and children is correlated with use of high color temperature light at home at night

Light is the strongest synchronizer of human circadian rhythms, and exposure to residential light at night reportedly causes a delay of circadian rhythms. The present study was conducted to investigate the association between color temperature of light at home and circadian phase of salivary melatonin in adults and children. Twenty healthy children (mean age: 9.7 year) and 17 of their parents (mean age: 41.9 years) participated in the experiment. Circadian phase assessments were made with dim light melatonin onset (DLMO). There were large individual variations in DLMO both in adults and children. The average DLMO in adults and in children were 21:50 ± 1:12 and 20:55 ± 0:44, respectively. The average illuminance and color temperature of light at eye level were 139.6 ± 82.7 lx and 3862.0 ± 965.6 K, respectively. There were significant correlations between color temperature of light and DLMO in adults (r = 0.735, p < 0.01) and children (r = 0.479, p < 0.05), although no significant correlations were found between illuminance level and DLMO. The results suggest that high color temperature light at home might be a cause of the delay of circadian phase in adults and children.