Short sleep duration and obesity among children: A systematic review and meta-analysis of prospective studies

The Importance of Sleep in Overcoming Childhood Obesity and Reshaping Epigenetics

The development of childhood obesity is a complex process influenced by a combination of genetic predisposition and environmental factors, such as sleep, diet, physical activity, and socioeconomic status. Long-term solutions for decreasing the risk of childhood obesity remain elusive, despite significant advancements in promoting health and well-being in school and at home. Challenges persist in areas such as adherence to interventions, addressing underlying social determinants, and individual differences in response to treatment. Over the last decade, there has been significant progress in epigenetics, along with increased curiosity in gaining insights into how sleep and lifestyle decisions impact an individual's health. Epigenetic modifications affect the expression of genes without causing changes to the fundamental DNA sequence. In recent years, numerous research studies have explored the correlation between sleep and the epigenome, giving a better understanding of DNA methylation, histone modification, and non-coding RNAs. Although significant findings have been made about the influence of sleep on epigenetics, a notable gap exists in the literature concerning sleep-related genes specifically associated with childhood obesity. Consequently, it is crucial to delve deeper into this area to enhance our understanding. Therefore, this review primarily focuses on the connection between sleep patterns and epigenetic modifications in genes related to childhood obesity. Exploring the interplay between sleep, epigenetics, and childhood obesity can potentially contribute to improved overall health outcomes. This comprehensive review encompasses studies focusing on sleep-related genes linked to obesity.

Does machine learning have a high performance to predict obesity among adults and older adults? A systematic review and meta-analysis

AIM

Machine learning may be a tool with the potential for obesity prediction. This study aims to review the literature on the performance of machine learning models in predicting obesity and to quantify the pooled results through a meta-analysis.

DATA SYNTHESIS

A systematic review and meta-analysis were conducted, including studies that used machine learning to predict obesity. Searches were conducted in October 2023 across databases including LILACS, Web of Science, Scopus, Embase, and CINAHL. We included studies that utilized classification models and reported results in the Area Under the ROC Curve (AUC) (PROSPERO registration: CRD42022306940), without imposing restrictions on the year of publication. The risk of bias was assessed using an adapted version of the Transparent Reporting of a multivariable prediction model for individual Prognosis or Diagnosis (TRIPOD). Meta-analysis was conducted using MedCalc software. A total of 14 studies were included, with the majority demonstrating satisfactory performance for obesity prediction, with AUCs exceeding 0.70. The random forest algorithm emerged as the top performer in obesity prediction, achieving an AUC of 0.86 (95%CI: 0.76-0.96; I2: 99.8%), closely followed by logistic regression with an AUC of 0.85 (95%CI: 0.75-0.95; I2: 99.6%). The least effective model was gradient boosting, with an AUC of 0.77 (95%CI: 0.71-0.82; I2: 98.1%).

CONCLUSION

Machine learning models demonstrated satisfactory predictive performance for obesity. However, future research should utilize more comparable data, larger databases, and a broader range of machine learning models.

Child routines moderate a brief behavioral intervention to enhance sleep in school-aged children

OBJECTIVE

To examine whether child routines (the consistency or variation in children's daily routines, household responsibilities, discipline routines, and homework routines) moderated the effectiveness of a brief behavioral intervention to enhance sleep in school-aged children.

METHODS

Secondary analysis was conducted with a subset of 66 families with short sleeping (≤9.5 hr/day) children, 8-11 years old (female = 68%; mean age = 9.76, SD = 1.02) who completed the Child Routines Inventory at baseline and were then randomized to receive a behavioral sleep intervention (n = 32) or to control (n = 34). Sleep period was objectively measured using wrist actigraphy at baseline and 2 months post-randomization. Moderation analysis was performed using ordinary least squares regression using the PROCESS macro for SPSS.

RESULTS

Controlling for sleep period at baseline, treatment condition was significantly related to the sleep period at 2 months post-randomization, with the intervention group achieving a longer sleep period compared to the usual sleep period group (control) (b = 46.30, p < .01). Intervention response was moderated by child routines (b = 1.43, p < .05). Specifically, the intervention produced the greatest change in sleep period for children who engaged in greater routine behaviors at baseline than those who engaged in fewer routine behaviors.

CONCLUSIONS

Families that engage in routine behaviors may be better equipped to adopt the behavioral modifications required to get a good night's sleep. The findings highlight the importance of working with families to establish routine behaviors to improve responses to behavioral sleep interventions.

Self-reported and accelerometry measures of sleep components in adolescents living in Pacific Island countries and territories: Exploring the role of sociocultural background

OBJECTIVES

The objective of this study is to assess the concordance and its association with sociocultural background of a four-question survey with accelerometry in a multiethnic adolescent population, regarding sleep components. Based on questions from the Pittsburgh Sleep Quality Index and adapted to a school context, the questionnaire focussed on estimating sleep onset time, wake-up time and sleep duration on both weekdays and weekends. This subjective survey was compared with accelerometry data while also considering the influence of sociocultural factors (sex, place of living, ethnic community and socio-economic status).

METHODS

Adolescents aged 10.5-16 years (n = 182) in New Caledonia completed the survey and wore an accelerometer for seven consecutive days. Accelerometry was used to determine sleep onset and wake-up time using validated algorithms. Based on response comparison, Bland-Altman plots provided agreement between subjective answers and objective measures. We categorized participants' answers to the survey into underestimated, aligned and overestimated categories based on time discrepancies with accelerometry data. Multinomial regressions highlighted the sociocultural factors associated with discrepancies.

RESULTS

Concordance between the accelerometer and self-reported assessments was low particularly during weekends (18%, 26% and 19% aligned for onset sleep time, wake-up time and sleep duration respectively) compared with weekdays (36%, 53% and 31% aligned, respectively). This means that the overall concordance was less than 30%. When considering the sociocultural factors, only place of living was associated with discrepancies in onset sleep time and wake-up time primarily on weekdays. Rural adolescents were more likely to overestimate both onset sleep time (B = -1.97, p < 0.001) and wake-up time (B = -1.69, p = 0.003).

CONCLUSIONS

The study found low concordance between self-assessment and accelerometry outputs for sleep components. This was particularly low for weekend days and for participants living in rural areas. While the adapted four-item questionnaire was useful and easy to complete, caution should be taken when making conclusions about sleep habits based solely on this measurement.

Interplay between actual and perceived weight on mental health among Canadian Indigenous post-secondary students

OBJECTIVES

Research increasingly focuses on the mental health implications of both actual and perceived weight, particularly among post-secondary students. Considering their unique socio-cultural context and the frequent oversight in research, this study examines these implications specifically among Canadian Indigenous post-secondary students. Recent evidence indicates that students with normal weight may also experience increased mental health risks due to negative weight perceptions. Therefore, this study explores the independent and combined effects of actual and perceived weight on the mental health of this group.

PARTICIPANTS AND METHODS

This study utilized data from the 2017 Aboriginal Peoples Survey, a nationally representative sample of First Nations peoples living off-reserve, Métis, and Inuit. The focus was on Canadian Indigenous post-secondary students aged 19-34 years (n = 1,518). Logistic regression models, stratified by sex, were employed to analyze the data.

RESULTS

Perceptions of being overweight were linked to a higher risk of mood and anxiety disorders, poor self-rated mental health, and suicidal ideation among female students. This pattern was less evident among male students. Notably, female students who were overweight and perceived themselves as such were more likely to report poor mental health across all four indicators examined. In contrast, male students exhibited a less clear pattern. Diverging from recent studies, the findings indicated less robust mental health disparities among students with normal weight who perceived themselves as overweight, potentially due to the insufficient cell size of this category among Indigenous post-secondary students.

CONCLUSIONS

The study highlights the complex interplay between actual and perceived weight and its impact on mental health, particularly among female Indigenous post-secondary students.

Longitudinal associations of screen time, physical activity, and sleep duration with body mass index in U.S. youth

BACKGROUND

Youth use different forms of screen time (e.g., streaming, gaming) that may be related to body mass index (BMI). Screen time is non-independent from other behaviors, including physical activity and sleep duration. Statistical approaches such as isotemporal substitution or compositional data analysis (CoDA) can model associations between these non-independent behaviors and health outcomes. Few studies have examined different types of screen time, physical activity, and sleep duration simultaneously in relation to BMI.

METHODS

Data were baseline (2017-2018) and one-year follow-up (2018-2019) from the Adolescent Brain Cognitive Development Study, a multi-site study of a nationally representative sample of U.S. youth (N = 10,544, mean [SE] baseline age = 9.9 [0.03] years, 48.9% female, 45.4% non-White). Participants reported daily minutes of screen time (streaming, gaming, socializing), physical activity, and sleep. Sex-stratified models estimated the association between baseline behaviors and follow-up BMI z-score, controlling for demographic characteristics, internalizing symptoms, and BMI z-score at baseline.

RESULTS

In females, isotemporal substitution models estimated that replacing 30 min of socializing (β [95% CI] = -0.03 [-0.05, -0.002]), streaming (-0.03 [-0.05, -0.01]), or gaming (-0.03 [-0.06, -0.01]) with 30 min of physical activity was associated with a lower follow-up BMI z-score. In males, replacing 30 min of socializing (-0.03 [-0.05, -0.01]), streaming (-0.02 [-0.03, -0.01]), or gaming (-0.02 [-0.03, -0.01]) with 30 min of sleep was associated with a lower follow-up BMI z-score. In males, replacing 30 min of socializing with 30 min of gaming was associated with a lower follow-up BMI z-score (-0.01 [-0.03, -0.0001]). CoDA estimated that in males, a greater proportion of time spent in baseline socializing, relative to the remaining behaviors, was associated with a higher follow-up BMI z-score (0.05 [0.02, 0.08]). In females, no associations between screen time and BMI were observed using CoDA.

CONCLUSIONS

One-year longitudinal associations between screen time and BMI may depend on form of screen time, what behavior it replaces (physical activity or sleep), and participant sex. The alternative statistical approaches yielded somewhat different results. Experimental manipulation of screen time and investigation of biopsychosocial mechanisms underlying the observed sex differences will allow for causal inference and can inform interventions.

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.

Effects of Early Wake-Up Time on Obesity in Adolescents

Background: Although numerous studies have reported that obesity in adolescents is related to shorter sleep duration, few studies have reported the effect of sleep timing, particularly early wake-up time, on obesity. Objectives: To investigate the association between wake-up time and adolescent obesity. Methods: Using the Korean National Health and Nutrition Examination Survey VII data, 1301 middle school and high school students were selected and grouped according to BMI. Sleep timing and lifestyle factors were evaluated using self-reported questionnaires. Results: The mean bedtime and wake-up time were 00:09 am and 07:06 am, respectively. Despite similar bedtimes, the group with overweight/obesity woke up earlier than the group with underweight/normal weight. The BMI z-score and the overweight/obesity relative risk decreased as the wake-up time was delayed, even after adjustment for covariates. Participants who woke up before 06:50 am had a 1.82-fold higher risk of having overweight/obesity than those who woke up after 07:30 am. Participants who woke up late tended to sleep longer than those who woke up early. Conclusions: Waking up early is significantly associated with an increased BMI z-score in adolescents and may be a risk factor for overweight/obesity.

Tobacco Smoke Exposure and Sleep Duration among U.S. Adolescents

OBJECTIVES

Tobacco smoke exposure (TSE) and poor sleep are public health problems with their own set of consequences. This study assessed whether TSE was associated with sleep duration among U.S. adolescents.

METHOD

We conducted a secondary analysis of 2013-2018 National Health and Nutrition Examination Survey data including 914 nontobacco-using adolescents ages 16-19 years. TSE measures included cotinine and self-reported home TSE groups including no home TSE, thirdhand smoke (THS) exposure, and secondhand smoke (SHS)+THS exposure. Sleep duration was assessed in hours and categorically as insufficient sleep (recommended hours). Weighted multiple linear regression and multinomial regression models were conducted.

RESULTS

Adolescents with higher log-cotinine levels had higher number of sleep hours (β = 0.31, 95%CI = 0.02,0.60) and were at increased odds of reporting excess sleep (AOR = 1.41, 95%CI = 1.40,1.42), but were at reduced odds of reporting insufficient sleep (AOR = 0.88, 95%CI = 0.87,0.89). Compared to adolescents with no home TSE, adolescents with home THS exposure and home SHS+THS exposure were at increased odds of reporting insufficient sleep (AOR = 2.27, 95%CI = 2.26,2.29; AOR = 2.75, 95%CI = 2.72,2.77, respectively) and excess sleep (AOR = 1.89, 95%CI = 1.87,1.90; AOR = 5.29, 95%CI = 5.23,5.34, respectively).

CONCLUSIONS

TSE may affect insufficient and excess sleep duration among adolescents. Eliminating TSE may promote adolescent respiratory and sleep health.

Effects of exercise on sleep in children with overweight/obesity: a randomized clinical trial

OBJECTIVE

The objective of this study was to examine the chronic effects of a 20-week exercise training program on device-assessed sleep and sleep-disordered breathing; and to determine whether participating in a session of the exercise program had effects on device-assessed sleep the subsequent night in children with overweight/obesity.

METHODS

A randomized clinical trial was conducted from November 2014 to June 2016. A total of 109 children (age 8-11 years) with overweight/obesity were randomized into an exercise training or control group. The exercise program included aerobic and resistance training 3 to 5 days/week. The control group participants continued their usual lifestyle. Device-assessed sleep outcomes were measured using wrist-worn actigraphy at baseline, in the middle of the exercise program (10th week), and at postintervention for seven consecutive days (24 h/day), and sleep-disordered breathing was measured via the Pediatric Sleep Questionnaire.

RESULTS

The exercise training program had a statistically significant effect on wake after sleep onset time (-10.8 min/day, -0.5 SDs, p = 0.040). No other chronic or acute effects (i.e., the subsequent night of attending a session of the exercise training program) were observed on the remaining sleep outcomes.

CONCLUSIONS

A 20-week exercise training program reduced wake after sleep onset time in children with overweight/obesity. Future randomized trials that include a sample of children with poor sleep health at baseline are needed to better appreciate the role of exercise in sleep health.

Impact of obesity on female puberty and pubertal disorders

The worldwide epidemic of obesity appears to be one of the crucial health problems. One-third of children and adolescents in the United States are classified as either overweight or obese and 6% of adolescents are severely obese. With the development of high technology, children, and adolescents, spend more time in sedentary life. Together with the availability of consuming fast caloric food, it is almost unavoidable to get an imbalance between caloric intake and caloric expenditure of energy, resulting in the accumulation of fat-energy stores. Obesity has an enormous impact on physical and psychological health and is associated with more than 29 adverse health consequences previously identified in the adult population only, such as type 2 diabetes mellitus, hypertension, metabolic syndrome, postmenopausal breast cancer, and others. In addition, excess adiposity may exert a harmful effect on the reproductive system, resulting in precocious puberty, irregular menstrual cycle, polycystic ovary syndrome, and high-risk sexual behavior. Intervention programs for healthy lifestyle modification, consisting of caloric restriction together with physical activity did not gain the expected efficacy. Other approaches as medical and surgical therapies are currently not evidence-based for the young population. The obesity crisis in children and adolescents requires a better understanding of etiology, pathophysiology, and management of obesity in this unique population. Researchers and physicians must "turn over every stone" to find a solution for deviating obesity ascent.

Risk factors for insomnia and burnout: A longitudinal population-based cohort study

Insomnia and burnout are highly prevalent in the general population, calling for understanding of its causes. Taking a broad approach, the aim of this study was to determine various mental and somatic risk factors for development of insomnia and burnout and stratifying for sex and age group. Questionnaire data were used from a Swedish population-based sample aged 18-79 years, from which cohorts without insomnia (n = 1702) and without burnout (n = 1972) at baseline were followed-up after 3 years. Self-reports of eight mental and somatic conditions at baseline were used as independent variables in logistic regression analyses to predict development of insomnia and burnout at 3-year follow-up. All eight studied conditions were significant risk factors for development of both insomnia (odds ratio, OR = 1.62-2.73) and burnout (OR = 2.20-3.21). Burnout and poor self-rated health had the highest ORs for insomnia, and poor self-rated health, anxiety and somatic symptoms had the highest ORs for burnout. The ORs were generally similar between men and women, whereas age groups tended to differ in some of the risk factors. The study highlights the importance of a broad assessment of both mental and somatic conditions in the prevention of insomnia and burnout.

Catastrophizing and acceptance are mediators between insomnia and pain intensity-an SQRP study of more than 6,400 patients with non-malignant chronic pain conditions

Background

Sleep problems (insomnia) and chronic pain are associated. Chronic pain and insomnia/insufficient sleep quality share similar symptoms and features. Although they have a bidirectional relationship, more research is needed to understand how they interact via mediators and how moderators influence this relationship.

Aims

In this large clinical registry-based cohort study (N = 6,497), we investigate important mediators between insomnia and pain intensity in a cross-sectional sample of chronic pain patients using advanced path analysis. In addition, we investigate whether some background variables were moderators of the identified important paths or not and the correlation patterns between insomnia and pain intensity in relation to the mediators.

Methods

This study includes a cohort of adult patients with chronic non-cancer pain from the Swedish Quality Registry for Pain Rehabilitation (SQRP) with data on patient-reported outcome measures (PROMs) (2008-2016). The PROMs cover the background, pain aspects, psychological distress, pain-related cognitions, activity/participation, and health-related quality of life variables of the patients. Partial least squares structural equation modeling was used to explore the direct and indirect (via mediators) relationships between insomnia and pain intensity at baseline.

Results

In this cohort study, insomnia was prevalent at 62.3%, and both direct and indirect mediating paths were present for the insomnia-pain intensity relationship. All of the mediating effects combined were weaker than the direct effect between insomnia and pain intensity. The mediating effects via catastrophizing and acceptance showed the strongest and equal mediating paths, and mediating effects via fear avoidance were the second strongest. Insomnia showed stronger direct significant correlations with psychological distress, catastrophizing, and acceptance compared with those of pain intensity. Sex, age, education level, spatial extent of pain, or body mass index did not moderate the mediating paths.

Discussion and conclusion

This study confirms the existence of significant direct and mediating paths between reported insomnia and pain intensity. Future studies should focus on illuminating how sleep interventions influence pain intensity and other important key factors that contribute to the distress of chronic pain patients.

The Longitudinal Interplay between Sleep, Anthropometric Indices, Eating Behaviors, and Nutritional Aspects: A Systematic Review and Meta-Analysis

Sleep is fundamental for adolescents' healthy development but undergoes dramatic changes in quantity and quality due to the conflict between biological and social rhythms. Insufficient sleep has been associated with worse physical health status and irregular eating behaviors in adolescents. This review aims to systematically synthesize the longitudinal associations between adolescents' sleep dimensions (i.e., duration, timing, quality, and insomnia symptoms) and physical health indicators (i.e., anthropometric indices, fat percentage, and risk of obesity), eating behaviors, and nutritional aspects (i.e., type of diet related to the intake of specific foods and nutrients, amount and timing of food consumption, energy expenditure). A total of 28 longitudinal studies were included. The meta-analytic results showed that longer sleep duration, better sleep quality, and lower insomnia symptoms were associated with lower BMI and fat percentage and that shorter sleep duration (<7 h) and lower sleep quality were associated with a higher risk of obesity. Conversely, anthropometric indices were not related to sleep over time. Limited literature examined the bidirectional association between adolescents' sleep and their eating behaviors and nutritional aspects. Such knowledge sheds new light on the role of sleep for adolescents' health, highlighting the need to examine further the interplay between these variables.

The association between internal polycyclic aromatic hydrocarbons exposure and risk of Obesity-A systematic review with meta-analysis

Exposure to polycyclic aromatic hydrocarbons (PAHs) is emerging as a risk factor for obesity, but with conflicting findings. The aim of this systematic review is to investigate and summarize the current evidence towards the associations between PAHs exposure and risk of obesity. We conducted a systematic search of online databases, including PubMed, Embase, Cochrane Library, and Web of Science up to April 28, 2022. Eight cross-sectional studies with data from 68,454 participants were included. The present study illustrated that there was a significant positive association between naphthalene (NAP), phenanthrene (PHEN), and total OH-PAH metabolites and risk of obesity, the pooled OR (95% CI) was estimated at 1.43 (1.07, 1.90), 1.54 (1.18, 2.02), and 2.29 (1.32, 3.99), respectively. However, there was no significant association between fluorene (FLUO) and1-hydroxypyrene (1-OHP) metabolite and risk of obesity. Subgroup analyses showed that associations between PAHs exposure and risk of obesity were more apparent in children, female, smokers and developing regions.

Short-term and intermediate-term fine particulate air pollution are synergistically associated with habitual sleep variability in adolescents - A cross-sectional study

BACKGROUND

Both air pollution and poor sleep have been associated with increased risk of cardiovascular diseases. However, the association between air pollution and sleep health, especially among adolescents, is rarely investigated.

METHODS

To investigate the association between fine particulate (PM2.5) air pollution and habitual sleep patterns, we analyzed data obtained from 246 adolescents who participated in the Penn State Child Cohort follow-up examination. We collected their individual-level 24-h (short-term) PM2.5 concentration by using a portable monitor. We estimated their residential-level PM2.5 concentration during the 60-day period prior to the examination (intermediate-term) using a kriging approach. Actigraphy was used to measure participants' sleep durations for seven consecutive nights. Habitual sleep duration (HSD) and sleep variability (HSV) were calculated as the mean and SD of the seven-night sleep duration. Multivariable-adjusted linear regression models were used to assess the association between PM2.5 exposures and HSD/HSV. An interaction between short-term and intermediate-term PM2.5 was created to explore their synergistic associations with HSD/HSV.

RESULTS

Elevated short-term and intermediate-term PM2.5 exposure were significantly (p < 0.05) associated with higher HSV, but not HSD. Specifically, the mean (95% CI) increase in HSV associated with 1 SD higher 24-h (26.3 μg/m3) and 60-day average (2.2 μg/m3) PM2.5 were 14.6 (9.4, 14.8) and 4.9 (0.5, 9.2) minutes, respectively. In addition, there was a synergistic interaction (p = 0.08) between short-term and intermediate-term PM2.5 exposure on HSV, indicative that the association between intermediate-term PM2.5 and HSV became stronger as short-term PM2.5 increases, and vice versa.

CONCLUSION

Short-term individual-level and intermediate-term residential-level PM2.5 exposures are adversely and synergistically associated with increased sleep variability, an indicator of instability of sleep quantity, in adolescents. Through such an association with sleep pattern, PM2.5 air pollution may increase long-term cardiometabolic risks.

The association between vitamin D status and sleep duration in school-aged children; the CASPIAN-V study

Background

Considering the high prevalence of both vitamin D deficiency (VDD) and sleep impairment in children and adolescents, this study was conducted to determine the association between VDD and sleep duration in the Iranian pediatric population.

Methods

This multicentric national study was conducted in 2019 on 2564 frozen sera obtained from 7 to 18- year students who were studied in the fifth survey of a national school-based surveillance program conducted in 30 provinces of Iran. Sleep duration was assessed using a questionnaire based on the World Health Organization-Global School-based Student Health Survey protocol. Short sleep duration was defined as sleep duration less than 8 h/day VDD Vitamin D < 20 ng/dL, and vitamin D insufficiency as 20-30 ng/dL.An adjusted logistic regression model was applied to evaluate the associations of vitamin D status with sleep duration.

Results

The Mean (SD) of students' age was 12.1(3.0) years; overall 10.6%of participants had VDD and 23% of participants had short sleep duration. in the adjusted logistic model, students with a low level of vitamin D (insufficient and deficient) had a higher odds of short sleep duration in comparison to those with normal vitamin D level (OR: 1.29, 95%CI: 1.02-1.62).

Conclusion

The current study showed that low Vitamin D levels (insufficient and deficient)were significantly associated with short sleep duration in school-aged children. Further studies are recommended to determine the efficacy of vitamin D replacement in improving sleep duration and quality.

Sleep Well, Study Well: A Systematic Review of Longitudinal Studies on the Interplay between Sleep and School Experience in Adolescence

Adolescents spend most of their daily time in school and performing school-related activities. Different aspects of their school experiences, such as school performance, psychological factors related to school, and structural factors, consistently impact adolescents' health and are likely to be intertwined with their sleep (i.e., quantity and quality, sleep disturbances). This systematic review aimed to comprehensively summarize the reciprocal and longitudinal associations between adolescents' sleep and multiple aspects of their school experience. Using multiple search strategies and applying a two-step selection process, 25 journal articles matched the eligibility criteria and were thus included in the review. The results highlighted the contribution of poor sleep quality and sleep disturbances in predicting longitudinal school experiences-related outcomes (i.e., decreasing school engagement and performance, and increasing school-related burnout, absenteeism, and bullying). At the same time, the results showed how experiences related to the school's psychological factors (e.g., high levels of school burnout and stressful environment) and structural characteristics (e.g., early school entrance time) affect youth sleep over time (i.e., decreasing sleep quality and quantity). These main findings provided novel insights into the bidirectional relationship between school experience and sleep health, highlighting the importance of more longitudinal research investigating all aspects of healthy sleep, including the size and direction of the association.

Sleep Is a Family Affair: A Systematic Review and Meta-Analysis of Longitudinal Studies on the Interplay between Adolescents' Sleep and Family Factors

Family is one of the primary socialization contexts influencing adolescents' psychological health. In this regard, a crucial indicator of adolescents' health is their sleep quality. Nevertheless, it is still unclear how multiple family factors (i.e., demographic and relational) are intertwined with adolescents' sleep quality. For this reason, this systematic review with meta-analysis aims to comprehensively summarize and integrate previous longitudinal research investigating the reciprocal relation between demographics (e.g., family structure) and positive (e.g., family support) and negative (e.g., family chaos) relational family factors and adolescents' sleep quality. Several search strategies were applied, and a final set of 23 longitudinal studies that matched the eligibility criteria were included in this review. The total number of participants was 38,010, with an average age at baseline of 14.7 years (SD = 1.6, range: 11-18 years). On the one hand, the meta-analytic results showed that demographic factors (e.g., low socio-economic status) were not related to adolescents' sleep quality at a later time point. On the other hand, positive and negative family relational factors were positively and negatively related to adolescents' sleep, respectively. Furthermore, the results suggested that this association could be bidirectional. Practical implications and suggestions for future research are discussed.

The Social Side of Sleep: A Systematic Review of the Longitudinal Associations between Peer Relationships and Sleep Quality

In adolescence, peer relationships become crucial since youths start to rely on their peers for support. Thus, multiple facets of adolescents' well-being are affected by their peer relationships. In this vein, one of the central well-being aspects that could be affected by the peer relationships of adolescents is sleep quality. Nevertheless, it is still unclear how multiple peer relationship factors (i.e., positive, negative, emotional, and behavioral issues related to peer relationships) are intertwined with adolescents' sleep quality. For this reason, this systematic review with meta-analysis aims to summarize longitudinal studies to uncover how the interplay between peer relationship factors and adolescents' sleep quality unfolds over time. Nineteen longitudinal studies involving a total of 21,232 adolescents were included. Overall, findings from this review showed that (a) positive peer relationships and sleep quality were not associated over time; (b) negative peer relationships and sleep quality were bidirectionally associated over time; (c) few studies evaluated the bidirectional relations between emotional and behavioral issues and sleep quality, showing links with sleep schedule and duration, but not with sleep quality. Meta-analytic results were discussed, considering their implications.

Short sleep duration at night in 2.5-year-old children is associated with childhood obesity at age 5.5 years: The Japanese children cohort study

BACKGROUND

Obesity in children contributes to higher risks of various chronic diseases in adulthood and the prevalence has increased worldwide including Japan.

OBJECTIVES

This study aims to examine the association between sleep duration at night in children aged 2.5 years and the subsequent risk of obesity at age 5.5 years.

METHODS

This study is embedded in the Longitudinal Survey on Babies Born in the 21st Century, which recruited families who had a child born in Japan in 2001. The multivariable logistic regression models were applied to calculate odds ratios (OR) and 95 % confidence intervals (CI) of childhood obesity at 5.5 years, defined as percentage of overweight (POW) ≥ 20 % and body mass index (BMI) ≥ 95th percentile of this study population according to sleep duration at night collected at 2.5 years child age.

RESULTS

Among 25,378 children, 2.6 % and 3.7 % were obese at age 5.5 years defined by POW and BMI respectively. Compared with night sleep duration > 11 h/d, shorter sleep durations in 2.5 years-old children were associated with higher risk of obesity at 5.5 years; the multivariable ORs (95 %CI) were 1.05 (0.81-1.35), 1.23 (0.93-1.62) and 1.54 (1.04-2.31) for sleep duration 10, 9 and ≤ 8 h/d, respectively; p-trend = 0.03. The observed association differed according to the children (child's sex, napping habits, and children frequently play at park), and family characteristics (mother's age at delivery and mother's level of education).

CONCLUSION

Short night sleep duration among girls aged 2.5 years was associated with risk of obesity at age 5.5 years, suggesting the importance of sufficient sleep duration at night for the prevention of obesity.

Sleep dimensions are associated with obesity, poor diet quality and eating behaviors in school-aged children

Objectives

The aim of this cross-sectional study was to investigate the association between sleep dimensions (duration, patterns, and disturbances) with body mass index (BMI), diet quality, and eating behaviors in school-aged children. Additionally, we aimed to investigate whether obesogenic eating behaviors (higher food responsiveness, lower satiety responsiveness, and less slowness in eating) and poor diet quality could mediate the potential association between sleep and obesity in school-aged children.

Materials and methods

For all participants (n = 588 children, age 5–12 years; 51% girls) we evaluated: sleep dimensions, BMI, diet quality, eating behaviors (food responsiveness, satiety responsiveness and slowness in eating). Linear regression models were used to test associations between exposure and outcome variables. Additionally, path analysis was conducted to test whether eating behaviors mediated the relationship between sleep and obesity.

Results

Shorter sleep duration (β = −0.722, p = 0.009) and greater sleep disturbances (β = 0.031, p = 0.012) were significantly associated with BMI. Additionally, we observed that diet quality was significantly associated with sleep duration (β = 0.430, p = 0.004), the midpoint of sleep (β = −0.927, p < 0.001), and sleep disturbances (β = −0.029, p < 0.001). Among other findings, greater sleep disturbances were associated with food responsiveness (β = 0.017, p < 0.001), satiety responsiveness (β = 0.015, p < 0.001), and slowness in eating (β = 0.012, p < 0.001). Importantly, food responsiveness was found as significant mediator of the relationship between sleep and BMI (R = 0.427, R² = 0.182, p < 0.001).

Conclusions

Late sleep patterns, short sleep duration, and greater sleep disturbances are significantly related with what and how school-aged children eat. Importantly, poor diet quality was significantly related to all three sleep dimensions, while eating behaviors had a significant relationship with greater sleep disturbances. These findings may be relevant to the development of behavioral targets to prevent childhood obesity, including sleep hygiene guidelines as a strategy to improve children's eating habits, as well as their BMI.

Maternal-child overweight relationship, assessment of maternal perception of child weight status and feeding behaviours

BACKGROUND

Parents play a key role in constructing children' behaviours. We studies maternal-child overweight relationship and compared maternal perception of child weight status and feeding behaviours between groups of normal-weight and overweight children.

METHODS

The cross-sectional study was conducted on 192 girls aged 10-13 years and their mothers. They were divided to two groups of overweight (n = 94) and normal-weight (n = 98) children. Anthropometric characteristics were measured for children and mothers. Logistic regression analysis was used to examine the association between child overweight and tertiles of maternal body mass index (BMI). Maternal perception of child's weight status and her engagement in promoting child's healthy behaviours was assessed.

RESULTS

BMI and waist circumference was significantly higher in children (P < 0.001) and mothers (P < 0.01) of overweight compared to normal-weight group. There was a significant relationship between children's overweight and tertiles of maternal BMI, which remained significant after adjusting for potential confounders. Mothers of overweight children were more concerned for their child's overeating and overweight, and for compelling the child to diet to maintain a desirable weight (P < 0.001). In contrast, mothers of normal-weight children restricted sugar-sweetened drinks (P = 0.008), offered fruit and vegetables (P = 0.035), and helped their children to get enough physical activity (P = 0.022) and night sleep (P = 0.001) more than mothers in other group.

CONCLUSIONS

This study showed a strong relationship between children and mothers' overweight. Despite being more concerned about their child weight status, mothers of overweight children reported behaviours which were less encouraging the children for healthy eating and lifestyle than mothers of normal-weight children.

Characteristic Sleep Patterns and Associated Obesity in Adolescents

Poor sleep adversely affects health and may cause obesity. Poor sleep includes short sleep duration, low quality of sleep, and sleep discrepancy. Although most studies have focused on the association between sleep duration and obesity, poor sleep is a significant risk factor for obesity. Adolescents have characteristic sleep patterns which correspond to poor sleep. Adolescents sleep late due to various biological and psychosocial factors; also, they wake up early to be on time for school. This causes them to sleep less. To make up for this sleep debt, adolescents sleep more on non-school days, which causes sleep discrepancies. Therefore, since adolescents have characteristic sleep patterns, an in-depth investigation is needed to identify whether poor sleep is a risk for obesity. This article presents an overview of the characteristic sleep patterns of adolescents, and reviews studies on the association of each sleep pattern with obesity.

Sleep and mental health in pregnancy during COVID-19: A parallel process growth model

Objectives

Pregnancy is associated with elevated risk for poor sleep quality, which increases the risk for poor obstetrical outcomes and parent mental health problems. The COVID-19 pandemic has seen increased reports of disturbed sleep worldwide; however, the degree this extends to pregnancy or influences pregnancy mental health outcomes has not been examined. The goal of this study was to examine changes in pregnant individuals’ sleep, anxiety, and depression during the pandemic, and to understand how sleep was associated with symptoms of anxiety and depression over time.

Methods

The Pregnancy During the COVID-19 Pandemic (PdP) study is a prospective longitudinal cohort of pregnant individuals (at enrollment) with repeated follow-ups during pregnancy and the postpartum period. About 3747 pregnant individuals participated between April and July 2020. The present analysis was restricted to participants who completed at least 2 assessments, yielding a final sample of 1842 pregnant individuals.

Results

Depression symptoms were elevated at baseline, compared to prepandemic estimates of prevalence, but declined gradually over time. Shorter sleep duration, higher sleep disturbance, and more sleep-related impairments at baseline predicted a slower decline in depression symptoms over time. More sleep disturbances at baseline also predicted slower decline in anxiety symptoms over time. In contrast, rates of depression and anxiety symptoms at baseline were not predictive of changes in any of the 3 sleep variables over time.

Conclusions

These findings highlight the importance of early intervention for sleep problems in pregnancy, in order to optimize mental health throughout pregnancy and mitigate long-term negative outcomes.

Associations of Sleep-Related Outcomes with Behavioral and Emotional Functioning in Children with Overweight/Obesity

OBJECTIVE

To evaluate the associations of parent-reported sleep-disordered breathing (SDB) and device-assessed sleep behaviors with behavioral and emotional functioning in pediatric patients with overweight/obesity.

STUDY DESIGN

A total of 109 children with overweight/obesity (mean age, 10.0 ± 1.1 years) were included in this cross-sectional study. We used the Spanish version of the Pediatric Sleep Questionnaire (PSQ) to assess SDB and its subscales (ie, snoring, daytime sleepiness, and inattention/hyperactivity). Device-assessed sleep behaviors (ie, wake time, sleep onset time, total time in bed, total sleep time, and waking after sleep onset) were estimated using wrist-worn accelerometers. We used the Behavior Assessment System for Children, second edition to assess behavioral and emotional functioning (ie, clinical scale: aggressiveness, hyperactivity, behavior problems, attention problems, atypicality, depression, anxiety, retreat, and somatization; adaptive scale: adaptability, social skills, and leadership).

RESULTS

SDB was positively associated with all clinical scale variables (all β > 0.197, P ≤ .041) and with lower adaptability and leadership (all β < -0.226, P < .021). Specifically, the PSQ subscale relating to daytime sleepiness was associated with higher attention problems, depression, anxiety, and retreat (all β > 0.196, P ≤ .045) and lower adaptability (β = -0.246, P = .011). The inattention/hyperactivity subscale was significantly associated with the entire clinical and adaptive scales (all β > |0.192|, P ≤ .046) except for somatization. The snoring subscale and device-assessed sleep behaviors were not related to any behavioral or emotional functioning variables.

CONCLUSIONS

Our study suggests that SDB symptoms, but not device-assessed sleep behaviors, are associated with behavioral and emotional functioning in children with overweight/obesity. Specifically, daytime sleepiness, a potential SDB symptom, was related to higher attention problems, depression, anxiety, and retreat and lower adaptability.

Associations between sleep duration, sleep quality, and weight status in Chinese children and adolescents

Background and objective

The high prevalence of obesity is a serious problem, and sleep is considered to be a factor for obesity. This study aimed to examine the relationship between sleep duration, sleep quality, and weight status among children and adolescents in China and to explore whether the relationship between sleep duration and weight status is independent of sleep quality. Sex and age differences were also explored.

Methods

A cross-sectional research was conducted among 2019 children and adolescents (1029 boys and 990 girls) aged 8–16 years in Shanghai. An open-question was used to obtain data on sleep duration, which was categorized into the following four groups based on the age-specific National Sleep Foundation Sleep Duration Recommendations: 1) very short, 2) short, 3) recommended, and 4) long. The Pittsburgh Sleep Quality Index was used to assess sleep quality. Weight and height were measured for all participants. The variable weight status was estimated with the Chinese children and adolescent age- and sex-specific body mass index (BMI) and was categorized into overweight/obesity and normal weight.

Results

Short sleep duration (7–8 and 6–7 h for 6–13 and 14–16 years old, respectively) significantly increased odds of overweight/obesity (OR = 1.32, 95% CI: 1.06–1.64) compared with that of the recommended sleep duration (9–11 and 8–10 h for 6–13 and 14–16 years old, respectively). The relationship between the two variables existed independent of sleep quality. No significant relationship was found between sleep quality and overweight/obesity of children and adolescents. Sleep quality (OR = 1.07, 95% CI: 1.01–1.14) and short sleep duration (OR = 1.51, 95% CI: 1.06–2.13) increased the risk for overweight/obesity among girls, whereas no significant relationships between sleep duration, sleep quality, and overweight/obesity were found among boys. Short sleep duration increased the risk of overweight/obesity in children aged 8–13 years (OR = 1.34, 95% CI: 1.05–1.71), independent of sleep quality, but no significant relationships between these two variables existed for adolescents aged 14–16 years.

Conclusions

Overall, short sleep duration increased the risks of overweight/obesity in children and adolescents in China, independent of sleep quality. This relationship is significant for girls and children aged 8–13 years instead of boys and adolescents aged 14–16 years. Interventions to extend the sleep duration of children and adolescents, especially girls and children aged 8–13 years in China, are necessary to improve their weight status.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-13534-w.

A Tailored Web-Based Video Intervention (ParentCoach) to Support Parents With Children With Sleeping Problems: User-Centered Design Approach

Background

Many parents frequently struggle with undesirable or problematic behavior (ie, temper tantrums and whining) displayed by their child. To support parents in promoting positive parenting skills (ie, recognizing challenging situations and reacting appropriately), the interactive video e-learning tool ParentCoach was developed. The tool aims to teach parents generic behavioral responses by means of situational learning, tailoring, and problem solving. The first demonstration focused on sleeping problems.

Objective

The aim of this paper is to illustrate the user-centered development of ParentCoach.

Methods

We conducted usability, understandability, and acceptance tests among the target group (29 parents, 7 youth health care professionals, and 4 individuals with former lower health literacy) in different phases of the development process via focus groups, interviews, and surveys. This allowed for relevant insights on specifications and user requirements to guide the development and revision of the tool in each iteration.

Results

Iterative testing and development allowed for the final demonstration of ParentCoach to be experienced as a relevant and accessible parenting intervention that can be used as a stand-alone program or in combination with another program.

Conclusions

This paper elaborates on the iterative development process and its benefits for the final demonstration of ParentCoach.

Sleep Duration/Quality With Health Outcomes: An Umbrella Review of Meta-Analyses of Prospective Studies

Background

To quantitatively evaluate the evidence of duration and quality of sleep as measured by multiple health outcomes.

Methods

This review is registered with PROSPERO, number CRD42021235587. We systematically searched three databases from inception until November 15, 2020. For each meta-analysis, the summary effect size using fixed and random effects models, the 95% confidence interval, and the 95% prediction interval were assessed; heterogeneity, evidence of small-study effects, and excess significance bias were also estimated. According to the above metrics, we evaluated the credibility of each association.

Results

A total of 85 meta-analyses with 36 health outcomes were included in the study. We observed highly suggestive evidence for an association between long sleep and an increased risk of all-cause mortality. Moreover, suggestive evidence supported the associations between long sleep and 5 increased risk of health outcomes (stroke, dyslipidaemia, mortality of coronary heart disease, stroke mortality, and the development or death of stroke); short sleep and increased risk of overweight and/or obesity; poor sleep quality and increased risk of diabetes mellitus and gestational diabetes mellitus.

Conclusions

Only the evidence of the association of long sleep with an increased risk of all-cause mortality was graded as highly suggestive. Additional studies are needed to be conducted.

Systematic Review Registration:https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42021235587

Sleep and the gut microbiota in preschool-aged children

Sleep plays a significant role in the mental and physical development of children. Emerging evidence in animals and human adults indicates a relationship between sleep and the gut microbiota; however, it is unclear whether the sleep of preschoolers during a key developmental period, associates with features of their gut microbiota. The objective of this study was to assess the relationship between sleep and gut microbiota in preschool-aged children (4.37 ± 0.48 years, n = 143). Sleep measures included total night-time sleep (TST), sleep efficiency (SE), and wake-time after sleep onset (WASO) assessed using actigraphy. Beta-diversity differences between children with low and high TST (p = .048) suggest gut microbiota community differences. Particularly, relative abundance of Bifidobacterium was higher in the high TST group and Bacteroides, was higher in children who had greater SE and less WASO (LDA score >2). In contrast, some Lachnospiraceae members including Blautia and Coprococcus 1 were associated with shorter night-time sleep duration and less efficiency, respectively. We also found a group of fecal metabolites, including specific neuroactive compounds and immunomodulating metabolites were associated with greater sleep efficiency and less time awake at night. Notably, tryptophan and its metabolizing products were higher in children who had higher SE or lower WASO (LDA score >2); concentration of propionate was higher in children with less WASO (p = .036). Overall, our results reveal a novel association between sleep and gut microbiota in preschool-aged children. Longer night-time sleep and greater sleep efficiency were associated with specific commensal bacteria that may regulate sleep through modulating neurotransmitter metabolism and the immune system.

The links between sleep duration, obesity and type 2 diabetes mellitus

Global rates of obesity and type 2 diabetes mellitus (T2DM) are increasing globally concomitant with a rising prevalence of sleep deprivation and sleep disorders. Understanding the links between sleep, obesity and T2DM might offer an opportunity to develop better prevention and treatment strategies for these epidemics. Experimental studies have shown that sleep restriction is associated with changes in energy homeostasis, insulin resistance and β-cell function. Epidemiological cohort studies established short sleep duration as a risk factor for developing obesity and T2DM. In addition, small studies suggested that short sleep duration was associated with less weight loss following lifestyle interventions or bariatric surgery. In this article, we review the epidemiological evidence linking sleep duration to obesity and T2DM and plausible mechanisms. In addition, we review the impact of changes in sleep duration on obesity and T2DM.

Longitudinal association of actigraphy-assessed sleep with physical growth in the first 6 months of life

STUDY OBJECTIVES

Suboptimal sleep is associated with obesity and its sequelae in children and adults. However, few studies have examined the association between sleep and physical growth in infants who experience rapid changes in sleep/wake patterns. We examined the longitudinal association of changes in objectively assessed sleep/wake patterns with changes in growth between ages 1 and 6 months.

METHODS

We studied 298 full-term infants in the longitudinal Rise & SHINE cohort study. Changes from 1 and 6 months in nighttime sleep duration, wake after sleep onset (WASO), and number of waking bouts ≥5 min were assessed using ankle actigraphy. Overweight was defined as age- and sex-specific weight for length ≥95th percentile. Generalized estimating equation analyses adjusted for infants' and mothers' characteristics.

RESULTS

The mean (SD) birth weight was 3.4 (0.4) kg; 48.7% were boys. In multivariable adjusted models, each 1-h increase in nighttime sleep duration between months 1 and 6 was associated with a 26% decrease in the odds of overweight from 1 to 6 months (odds ratio [OR] = 0.74; 95% confidence interval [CI, 0.56, 0.98]). Each 1-unit decrease in number of waking bouts was associated with a 16% decrease in the odds of overweight (OR = 0.84; 95% CI [0.72, 0.98]). Changes in WASO were not associated with the odds of overweight.

CONCLUSIONS

Greater increases in nighttime sleep duration and more consolidation of nighttime sleep were associated with lower odds of overweight from 1 to 6 months. Adverse sleep patterns as early as infancy may contribute to excess adiposity.

Relationship between Sleep Quality and the Percentage of Body Fat in Children (Ages 9–12 Years) in the Public Elementary School of IKIP I Makassar City

This study aimed to determine the relationship of sleep quality with the percentage of body fat in children (ages 9-12 years) in the Elementary School Complex of IKIP I Makassar. The study used the Analytical Survey design with a cross-sectional approach. The researcher will compare the causes and consequences variables simultaneously and explain the relationship between the research variables through hypothesis testing. This study uses quantitative methods, namely through assessing sleep quality and body fat percentage using a questionnaire. The data was collected through in-depth interviews and observations of children. Sampling uses purposive sampling and data analysis using the Chi-Square test.  The results of the study showed that there was no significant relationship between sleep quality and body fat percentage. However, after being tested based on the components of sleep quality, it was seen that good sleep quality and poor sleep quality in component 3 (sleep duration). Moreover, component 4 (daily sleep efficiency) had a significant relationship between sleep duration and daily sleep efficiency with body fat percentage. Recommendations from this research are needed on the relationship between sleep quality and student achievement index.

Obesogenic Behaviors of Rural Children on School and Nonschool Days

Background: Children living in rural areas are at increased risk of overweight and obesity compared with their urban-dwelling counterparts. The purpose of this study was to provide preliminary evidence of rural children's obesogenic behaviors (e.g., activity, sedentary behaviors, sleep, and diet) during school days, nonschool weekdays, and weekend days. Methods: A repeated measures 14-day observational study was conducted early March 2020. Children (n = 54, 92% 6-11 years old; 66% female; 98% non-Hispanic white; 22% overweight or obese) wore accelerometers on the nondominant wrist for 24 hours/day for 14 consecutive days to capture moderate-to-vigorous physical activity (MVPA), sedentary time, and sleep. Parents completed diaries to report daily activities, diet, and screen time of their child each day. Mixed effect models compared behaviors between school days, nonschool weekdays, and weekend days. Results: Children accumulated +16 additional minutes/day of MVPA (95% confidence interval, CI: +10 to +23 minutes/day), reduced sedentary time (-68 minutes/day, 95% CI: -84 to -51 minutes/day), and reduced screen time (-99 minutes/day; 95% CI: -117 to -81 minutes/day) on school days vs. nonschool weekdays. Similar patterns were observed on school weekdays days vs. weekend days, and on nonschool days when children attended a structured program vs. days they did not attend. Minimal differences were observed in reported consumption of food groups across different days. Conclusions: Preliminary evidence suggests rural children display multiple unfavorable obesogenic behaviors on days when they do not attend school or other structured programs. Future interventions targeting obesogenic behaviors of rural children may want to target times when rural children are not engaged in school and "school-like" environments.

Association between Short Hours of Sleep and Overweight/Obesity in Mexican Adolescent Population: A School-Based Cross-Sectional Study

Background/Aim: Obesity in adolescents is increasing; as such, the aim of this study was to determine the prevalence of obesity in Mexican adolescents and examine its possible association with hours of sleep. Methods: A school-based cross-sectional study was carried out. This study included 863 adolescents aged between 11 and 16 years. The prevalence of obesity was estimated using the body mass index (BMI). The duration of sleep (and other information) was assessed by a self-reported questionnaire. The Cochran–Mantel–Hansel test for categorical variables and a general linear model for continuous variables were used to evaluate the interaction effect of BMI and sex with respect to sleeping and assessed activity conditions. Results: It was found that 47.6% of the adolescents were overweight/obese. Men were more frequently overweight/obese than women (52.6% vs. 41.8%, p = 0.002). Moreover, overweight/obese adolescents were younger and spent fewer daily hours watching television (p < 0.05). Men practiced sports more hours per week than women (p = 0.04). However, women spent more daily time on the internet (p = 0.05), and overweight/obese adolescent women slept fewer hours than overweight/obese men and adolescents with normal weight (p = 0.008). Conclusions: The development of strategies for the prevention of overweight/obesity and the improvement of sleep duration should include a gender perspective to improve health habits in Mexican adolescents.

Nighttime sleep duration trajectories were associated with body mass index trajectories in early childhood

BACKGROUND

The respective contribution of total, daytime and nighttime sleep duration in childhood obesity remains unclear.

OBJECTIVES

To assess the longitudinal association between developmental trajectories of sleep duration and BMI z-score in early childhood.

METHODS

Data were from the Melbourne INFANT program, a prospective cohort with 4-month-old infants being followed-up until age 60 months (n = 528). Sleep duration (total, daytime, nighttime) and BMI z-score were measured using questionnaire at ages 4, 9, 18, 43 and 60 months. Group-based trajectory modelling was used to describe longitudinal trajectories from ages 4 to 60 months. Multivariable logistic regression was conducted to assess the association between sleep duration and BMI z-score trajectories.

RESULTS

Three nighttime sleep duration trajectory groups were identified: "Long stable" (10.5 to 11.0 hours, 61%), "catchup long" (8.0 to 11.5 hours, 23%) and "short stable" (8.7 to 9.8 hours, 16%) nighttime sleepers. BMI z-score trajectory groups were classified as "low-BMIz" (-1.5 to -0.5 unit, 21%), "mid-BMIz" (-0.5 to 0.5 unit, 58%) and "high-BMIz" (0.8 to 1.4 unit, 21%). With adjustment for child and maternal covariates, both "catchup long" (OR 3.69 95%CI 1.74, 7.92) and "long stable" nighttime sleepers (OR 4.27 95%CI 2.21, 8.25) revealed higher odds of being in the "mid-BMIz" than the "high-BMIz" group. By contrast, total or daytime sleep duration trajectories were not associated with BMI z-score trajectories.

CONCLUSIONS

Longer nighttime, but not total or daytime, sleep duration was associated with lower BMI z-score trajectories in early childhood. Our findings reinforce the importance of nighttime sleep for healthy body-weight development in early childhood.

Genetics of Sleep and Insights into Its Relationship with Obesity

Considerable recent advancements in elucidating the genetic architecture of sleep traits and sleep disorders may provide insight into the relationship between sleep and obesity. Despite the considerable involvement of the circadian clock in sleep and metabolism, few shared genes, including FTO, were implicated in genome-wide association studies (GWASs) of sleep and obesity. Polygenic scores composed of signals from GWASs of sleep traits show largely null associations with obesity, suggesting lead variants are unique to sleep. Modest genome-wide genetic correlations are observed between many sleep traits and obesity and are largest for snoring.Notably, U-shaped positive genetic correlations with body mass index (BMI) exist for both short and long sleep durations. Findings from Mendelian randomization suggest robust causal effects of insomnia on higher BMI and, conversely, of higher BMI on snoring and daytime sleepiness. Bidirectional effects between sleep duration and daytime napping with obesity may also exist. Limited gene-sleep interaction studies suggest that achieving favorable sleep, as part of a healthy lifestyle, may attenuate genetic predisposition to obesity, but whether these improvements produce clinically meaningful reductions in obesity risk remains unclear. Investigations of the genetic link between sleep and obesity for sleep disorders other than insomnia and in populations of non-European ancestry are currently limited. Expected final online publication date for the Annual Review of Nutrition, Volume 41 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Integrated metabolomics and proteomics analysis reveals energy metabolism disorders in the livers of sleep-deprived mice

Sleep deprivation (SD) has been linked to impaired mental and physical health, obesity, and various diseases. However, the molecular mechanism underlying the effects of SD in the liver is still unclear. To investigate the metabolome and proteome alterations in the liver, an in vivo model of SD was established based on automated random motion platform techniques by applying a strategy of 10 consecutive days of 20 h of sleep deprivation +4 h of resting. The liver's altered metabolites and proteins were detected by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and data analyses were performed with MetaboAnalyst 5.0. This study found 15 differential metabolites, including 12 upregulated- metabolites and 3 downregulated- metabolites. A total of 493 proteins were differentially regulated, including 377 upregulated- proteins and 116 downregulated- proteins. The glutathione metabolism, fructose and mannose metabolism, and pyruvate metabolism pathways had significant effects on the sleep-deprived mouse livers. These three active pathways cause energy metabolism disorder and may induce obesity. In conclusion, this study demonstrates that SD could change the metabolism of glucose, and specific fatty acids, amino acids, and critical enzymes in the liver, providing a reference for the health effects of insufficient sleep. SIGNIFICANCE STATEMENT: So far, little is known about the changes in metabolites and proteins in the liver of individuals who suffer from SD. Metabolites and proteins in serum, urine and hypothalamus do not entirely reflect the effects of sleep deprivation on the whole body. In addition, many SD-induced models used the multiplatform water environment method, which causes mice to fall into the water frequently. Under this condition, the physical exertion of mice is extremely high, and it is not suitable for long-term sleep deprivation. The SD induction process has caused some influence on the model. Finally, few studies have elucidated the imbalance of energy metabolism caused by SD to induce obesity from the molecular mechanism. This study used a rotary table deprivation apparatus to trigger SD. This method will not cause excessive consumption and stimulation of mice. Furthermore, this study analyzed the metabolic and proteomic changes in the liver and enriched the range and means of metabolic and proteomic changes in sleep deprived mice. Finally, this research provides reference for elucidating the molecular mechanism of sleep deprivation causing energy metabolism disorders in the liver of mice.

The relationship of sleep duration and quality to energy expenditure and physical activity in children

BACKGROUND

Shorter sleep duration has been linked to the risk for obesity in children. The pathways linking sleep duration and quality to the risk of obesity are unclear, particularly the effect of sleep on energetics.

OBJECTIVE

We investigated the relationship between sleep duration, quality and timing in children, to the basal metabolic rate (BMR), total energy expenditure (TEE) and physical activity (PA).

METHODS

Fifty nine children in two age-groups (5-11 and 12-18 years) underwent evaluation of body composition (DXA), BMR in a room calorimeter, free-living TEE by doubly labelled water method, sleep and PA (7-day Actiheart monitor) during school break.

RESULTS

Sleep duration contributed to the variance in BMR (β = 0.11, P = .009) after adjusting for age-group, sex, lean and fat mass, but not to the variance in TEE. Late sleep timing was related to lower PA. In the younger age-group, children who met recommended sleep duration on ≥50% of the 7 days had higher light PA (P = .03) and lower sedentary time (P = .009).

CONCLUSION

Suboptimal sleep is associated with lower BMR, lower PA, and higher sedentary behaviours in young children. Prospective studies are needed to confirm if insufficient sleep duration or late sleep timing contribute to obesity risk by increasing sedentary behaviours and decreasing BMR.

Weekday time in bed and obesity risk in adolescence

Introduction

Sleep curtailment is associated with obesity in children, but few studies have investigated this relationship in a longitudinal sample of adolescents. The aim of the present study was to examine the longitudinal association between weekday time in bed (TIB) at age 10–13 and overweight at age 16–19.

Methods

Adolescents and their parents (N = 3025 families), participating in a longitudinal population‐based study, completed questionnaires assessing habitual bedtime and wake time on weekdays, weight and height, socioeconomic status (SES), internalizing mental health problems and disturbed eating. Two surveys were administered with a 6‐year interval (T1 and T2). A one‐way analysis of covariance (ANCOVA) was performed examining the association between TIB and weight category 6 years later, with SES, internalizing problems and disturbed eating at baseline entered as covariates. Hierarchical and logistic regression analyses were used to assess TIB at age 10–13 years to as a predictor of body mass index (BMI) standardized deviation scores (SDS) and overweight status at age 16–19 adjusting for the same confounders and baseline BMI.

Results

A linear inverse relationship between TIB at age 10–13 and BMI category at age 16–19 was demonstrated by the ANCOVA, p < 0.001. Shorter TIB was related to higher weight, but the effect size was small (partial eta squared = 0.01). When adjusting for the included baseline confounders in the hierarchical regression model TIB significantly predicted later BMI SDS (β = −0.039, p = 0.02). The adjusted logistic regression model showed that for each hour reduction of TIB at T1 the odds of being overweight/obese at T2 increased with a factor of 1.6.

Conclusion

Shorter TIB was found to be a significant, yet modest, independent predictor of later weight gain in adolescence. The findings implicate that establishing healthy sleep habits should be addressed in prevention and treatment strategies for adolescent obesity.

Latent Profiles of Health Behaviors in Rural Children with Overweight and Obesity

OBJECTIVE

The objectives were to identify profiles of school-age children with overweight and obesity (OW/OB) from rural counties based on patterns of diet, activity, and sleep, to examine demographic predictors, and to examine whether profiles were differentially associated with psychosocial functioning.

METHODS

Participants included 163 children (Mage = 9.8) and parents. Children wore accelerometers to assess physical activity and sleep duration. Consumption of fruits and vegetables (F/V) and sugar-sweetened beverages (SSB) was assessed with a food frequency questionnaire. Self-report of emotional, social, and academic health-related quality of life (HRQOL), peer victimization, social skills, and social problem behaviors was collected, as well as parent-report of HRQOL. Latent variable mixture modeling (LVMM) was conducted.

RESULTS

Sleep did not significantly contribute to profile differentiation and was removed. Four profiles emerged: (a) Low F/V + Low SSB + Low activity, (b) Low F/V + Low SSB + Moderate activity, (c) High F/V + High SSB + Low activity, and (d) Moderate F/V + Moderate SSB + High activity. Older children were more likely to be in profile 1. After controlling for child age, parents of children in profile 1 reported significantly lower child social HRQOL than parents of children in profiles 2 and 4. Children in profile 4 reported experiencing significantly lower victimization than those in profile 3.

CONCLUSIONS

There are subgroups of rural children with OW/OB that engage in various combinations of healthy and unhealthy behaviors. LVMM has the potential to inform future interventions and identify needs of groups of children with OW/OB.

Association between objectively measured body composition, sleep parameters and physical activity in preschool children: a cross-sectional study

OBJECTIVE

Associations between self-reported sleep duration and obesity indices in children are well recognised; however, there are no studies on associations between objectively measured other sleep parameters and physical activity with body composition in preschoolers. Therefore, the aim of this study was to determine the associations between sleep parameters and moderate-to-vigorous physical activity (MVPA) with body composition indices in preschoolers using objective measures.

DESIGN

A cross-sectional study.

PARTICIPANTS

The study group consisted of 676 children aged 5-6 years, who were enrolled in kindergartens in the 2017/2018 school year.

OUTCOME MEASURES

Sleep parameters and MVPA were measured using accelerometers for 7 days. Bioelectrical impedance analysis was used to estimate body composition.

RESULTS

Sleep duration and sleep efficiency were inversely associated with body fat percentage (BFP) (β=-0.013 and β from -0.311 to -0.359, respectively) and body mass index (BMI) (β from -0.005 to -0.006 and from -0.105 to -0.121, respectively), and directly associated with fat-free mass (FFM) (β from 0.010 to 0.011 and from 0.245 to 0.271, respectively) and muscle mass (β from 0.012 to 0.012 and from 0.277 to 0.307, respectively) in unadjusted and adjusted models. BFP was inversely associated with MVPA and positively associated with number of awakenings and sleep periods. Number of sleep periods was inversely associated with FFM, and positively with BMI and muscle mass. Correlation matrix indicated significant correlation between BFP, FFM and muscle mass with sleep duration, sleep efficiency, number of sleep periods and MVPA.

CONCLUSIONS

Periodic assessment of sleep parameters and MVPA in relation to body composition in preschool children may be considered, especially in those who are at risk for obesity.

Cross-Sectional Relationship between Regular Bedtime and Weight Status and Obesity-Related Behaviors among Preschool and Elementary School Children: TX CORD Study

Background: This study examines the relations between a regular weekday bedtime with weight status, diet quality, physical activity, wellbeing, and parental rules among children 2 to 12 years of age from low-income populations. Methods: The study used baseline data collected in 2012, as part of a larger quasiexperimental study design. A convenience sample of parents of children in preschools, second, or fifth grade attending Head Start centers or elementary schools located in low-income catchment areas, in Houston and Austin, TX, were recruited to participate in the study (n = 32 elementary schools; n = 12 Head Start centers). Regular weekday bedtime was measured with the question "Does your child have a regular weekday bedtime?" Results: The sample of 1467 child-parent dyads were split approximately evenly by sex, and consisted of 44.4% Pre-K, 30.4% second grade, and 25.2% fifth grade students. Six hundred twenty-two (43.6%) children were overweight or obese. Children who had a regular bedtime had 15% lower odds of being overweight or obese (adjusted odds ratio [aOR]: 0.85, 95% confidence interval [CI]: 0.74-0.97, p-value: 0.017). Also, children who had a regular bedtime had 45% higher odds of eating the recommended number of fruits and vegetables (aOR: 1.45, 95% CI: 1.02-2.07, p-value: 0.039) and had physical activity more days of the week (β: 0.42, 95% CI: 0.26-0.57, p-value: <0.001). Conclusions: Having a regular weekday bedtime is associated with better weight status and several obesity-related health behaviors in children. Parental report of regular bedtimes for their children may be an indication of parenting skills related to other health-related behaviors for prevention of childhood obesity.

Path Analysis on Determinants of Childhood Obesity and Associated Risk Factors of Cardiovascular, Renal, and Hepatic Diseases: The CASPIAN-V Study

The interaction between several lifestyle and obesogenic environmental factors is considered as the main underlying factor for the escalating trend of childhood obesity and its adverse consequences. In this study, we assessed the mutual influence of lifestyle habits and body mass index (BMI) as well as risk factors for cardiometabolic, hepatic, and renal disorders to define the causality power of each item. This nationwide cross-sectional study was conducted as the fifth round of a school-based surveillance program. Overall, 14,800 students living in Iran were studied, and blood samples were obtained from 4,200 of them. Demographic factors, anthropometric and biochemical measures were used to define lifestyle-related latent variables as well as cardiac, renal, and hepatic risk indicators. Total, direct, and indirect effects between factors were analyzed using the standardized regression weights for each pathway. Data from 14,274 students (participation rate of 99%) and 3,843 blood samples were included. All of the latent variables had a significant direct effect on BMI, with the most potent effect of unhealthy nutrition (β ≅ 0.63) in boys and girls. BMI has significant direct effects on risk indicators of cardiovascular, renal, and hepatic diseases with the most powerful effect on cardiovascular risk factors (β ≅  − 0.08). The most important predisposing factor for obesity was unhealthy nutrition, whereas increased activity, adequate sleep, and better hygiene had protective roles. BMI shows the strongest association with indicator of cardiovascular diseases. These findings underscore the importance of implementing public health programs for the prevention of chronic noncommunicable diseases.

Breakfast skipping and overweight/obesity in first grade primary school children: A nationwide register-based study in Iceland

Although several studies have revealed an association between skipping breakfast and overweight (OW) or obesity (OB) in older children and adolescents, less is known about that association in younger children. The purpose of our study was to assess the association between skipping breakfast and OW/OB in children in the first grade. The sample included 4360 children (51.5% boys) aged 5.6 to 7.4 years who participated in the annual health examination in Iceland during 2016 and 2017, completed by 91% of all first graders in Iceland. Binary logistic regression analysis with odds ratios (ORs) and 95% confidence intervals (CIs) was used to assess the association between skipping breakfast and OW/OB. Skipping breakfast was assessed as not eating breakfast on the day of the assessment, whereas OW or OB was based on measured height and weight relative to the International Obesity Task Force reference. The final analyses were adjusted for bedtime, well-being in school, commuting to school and physical activity. 7.2% of the boys (n = 162) and 7.5% of the girls (n = 158) had not eaten breakfast. After multivariable adjustment, a statistically significant association emerged between skipping breakfast and OW/OB in girls (OR 1.66, 95% CI 1.17-2.36) but not in boys (OR 1.02, 95% CI 0.63-1.63). Because the study's results suggest an association between skipping breakfast and OW/OB only in first-grade girls in Iceland, sex-based differences should be further investigated to inform future strategies for preventing OW and OB in young children.

Maternal Sleep Quality is Associated with Personal and Parenting Weight-Related Behaviors

Mothers of young children tend to report poor-quality sleep, yet little is known about links between maternal sleep quality and weight-related behaviors and parenting practices. Thus, mothers of preschoolers completed an online cross-sectional survey assessing their sleep, physical activity, dietary behaviors, eating styles, child feeding practices, family meal behaviors, and health parameters. Comparisons by sleep quality using the Pittsburgh Sleep Quality Index item (i.e., very bad/bad, n = 87; fair, n = 255; and good/very good, n = 193) revealed mothers with poor-quality sleep had weight-related behaviors associated with higher Body Mass Index (BMI) (lower physical activity, fewer fruits/vegetables, more emotional and disinhibited eating). Poor-quality sleepers also engaged in parenting practices contrary to recommendations, such as less frequent modeling of healthy eating and physical activity, more control of child feeding, and fewer family meals. Mothers reporting poor-quality sleep tended to have lower parenting self-efficacy, poorer overall health status, more days of poor mental and physical health, greater depression, more stress, and higher BMIs. Future nutrition research should establish the directionality between sleep quality and health behaviors. Future interventions should help mothers develop strategies for improving sleep quality, such as increased physical activity and fruit and vegetable intake, and helping mothers realize how their sleep quality may affect parenting practices.