Sex differences in childhood sleep and health implications

Associations between sleep opportunity, sleep problems, and social jetlag and toddlers' adiposity: A cross-sectional study

This study aims to analyze the associations between sleep characteristics, including sleep opportunity, problems and social jetlag, and toddlers' adiposity. It is part of a larger research project involving 344 children (mean ± SD age of 23.6 ± 6.3 months). Children's length/height, weight and waist circumference were measured at childcare centers. Body Mass Index (BMI), weight-for-length/height, and waist-to-length/height were calculated and classified according to percentiles, serving as surrogates of adiposity. Sleep problems were evaluated through questionnaire. Sleep opportunity was reported by parents and defined as the difference between bedtime and wake-up time. Social jetlag was calculated based on sleep midpoints. Parental questionnaires provided sociodemographic characteristics. Total energy intake was determined from a two-day dietary record, and motor development was assessed using the Bayley-III scales. Generalized linear models were used in the analysis. We found that nighttime sleep opportunity on weekdays was inversely associated with BMI percentile (B = -5.57, 95 % CI -9.79 to -1.35), even with covariates included. Additionally, later bedtime on weekend days were associated with lower weight-for-length/height and waist-to-length/height (B = -4.16, 95 % CI -8.01 to -0.30, and B = -10.62, 95 % CI -15.38 to -5.87, respectively), even when adjusted for potential confounders. Later bedtime on weekdays was associated with lower waist-to-length/height (B = -8.85, 95 % CI -14.95 to -2.74). Social jetlag was associated with lower waist-to-length/height (B = -7.19, 95 % CI -13.47 to -0.90). Future research is needed to clarify these associations and to encourage lifestyle-based interventions aimed at optimizing sleep patterns within this age group.

Sex Differences in Sleep and Physical Activity Patterns in Autism Spectrum Disorder

Physical activity (PA) programs have been found to result in improved sleep in males with autism spectrum disorder (ASD), but little is known about the female characteristics. The aim of this work was to assess sex differences in sleep and PA indices using an accelerometer over 7 days and 7 nights. Sleep and PA variables were measured with questionnaires and with accelerometry in twenty-four children with ASD (16 boys, 10.3 ± 2.8; 8 girls, 11.1 ± 3.9). Some significant differences were reported between girls and boys. The total time in bed and wake time after sleep onset (WASO) were significantly higher in girls compared to boys (p < 0.01), whereas sleep efficiency was significantly lower in girls (p < 0.01). The results obtained from the sleep questionnaire (CSHQ) show averages above the threshold of 41 in both groups (the threshold indicates the presence of sleep disorders or low sleep quality). The number of daily steps was significantly lower in the girls' group (p < 0.01), and the PA volume for vigorous and strong vigorous intensities was significantly higher in the boys' group (p < 0.01 and p < 0.05, respectively). Our results show major alterations in girls, with a low level of PA and sleep alteration. PA is a relevant non-pharmacological approach to improve sleep quality and achieve sufficient sleep duration. However, particularly for girls with ASD, more personalized approaches to improve sleep may be needed to manage specific associated disorders.

Sex differences in the association between short sleep duration and obesity: A systematic-review and meta-analysis

AIMS

Obesity is a leading contributor to global morbidity and mortality. Short sleep duration is significantly associated with the incidence of obesity, however, it remains unclear whether this relationship is influenced by sex. The purpose of this meta-analysis was to systematically evaluate the evidence of whether the association between short sleep duration and obesity differs between males and females.

DATA SYNTHESIS

The protocol was registered with PROSPERO (CRD42023374205). From inception through June 2023, Medline, Embase and Web of Science databases were searched for longitudinal cohort studies with minimum 12 months of observation. The quality of studies was assessed using the Newcastle-Ottawa Quality Assessment for Cohort Studies. Results were pooled using a random effects model. Results are expressed as ratio of odds ratios (ROR) with 95% confidence interval (CI). ROR directly estimates the relative strength of the association of interest (measured as odds ratio [OR] between females and males). Sensitivity analysis was performed and inconsistency between studies was assessed using I2 statistics. A total of 4582 articles were retrieved with the search strategy, of which 6 were included. The meta-analysis indicated that the association between short sleep duration and obesity incidence was statistically significant in both men [OR 1.26 (95% CI 1.13-1.40)] and women [OR 1.36 (95% CI 1.16-1.59)]. However, it did not differ significantly between sexes ROR (women/men) 1.04 (95%CI 0.79-1.36; I2 20.1%).

CONCLUSIONS

This meta-analysis indicates that women and men who subjectively report short sleep duration have similarly increased risks of incident obesity.

Sleep insufficiency and bedtime irregularity in children with ADHD: A population-based analysis

BACKGROUND

Sleep is impaired in children with attention-deficit/hyperactivity disorder (ADHD). However, population-based examination of indicators of sleep insufficiency and bedtime irregularity is limited. This investigation examined associations between ADHD, weeknight sleep insufficiency, and bedtime irregularity in a nationally-representative child sample, and indicators of these sleep outcomes in ADHD.

METHODS

Parents of children aged 3-17 years with ADHD (n = 7671) were surveyed through the 2020-2021 National Survey of Children's Health. Inverse probability of treatment weighting generated a weighted matched control sample (n = 51,572). Weighted generalized linear models were performed without and with age-stratification to examine associations between ADHD and sleep, adjusting for sociodemographics in the full sample, and between nineteen sociodemographic and clinical variables and sleep in ADHD.

RESULTS

Having ADHD was associated with increased odds of sleep insufficiency and bedtime irregularity relative to controls, even after adjusting for sociodemographic variables. In ADHD, older age was associated with lower sleep insufficiency and greater bedtime irregularity. Black race, increased poverty, higher ADHD severity, depression, and increased screen time were associated with greater sleep insufficiency and bedtime irregularity. Adverse childhood experiences (ACEs) were associated with greater sleep insufficiency. Behavioral/conduct problems, female sex, and absence of both ADHD medication use and ASD diagnosis were associated with poorer bedtime irregularity. Age-stratified results are reported in text.

CONCLUSIONS

Children with ADHD face heightened risk for insufficient sleep and irregular bedtimes. Findings suggest intervention targets (e.g., Black race, poverty, depression, screen time) to improve both sleep insufficiency and bedtime irregularity. Results highlight ACEs and behavioral/conduct problems as targets to improve sleep insufficiency and bedtime regularity, respectively. Age-stratified findings are discussed.

Sexual and Gender Minority Sleep Health Disparities and Minority Stress in Early Adolescence

PURPOSE

Sleep is essential to adolescent development. Sexual and gender minority (SGM; e.g., lesbian, gay, bisexual, transgender) adults are at high risk for poor sleep, partially due to minority stress (e.g., discrimination). However, sleep has rarely been studied among SGM adolescents. In a national sample of early adolescents, we analyzed sexual minority (SM) and gender minority (GM) identity, gender incongruence, and gender nonconformity in association with sleep and tested minority and general stressors as mediators.

METHODS

We cross-sectionally analyzed data from 10,070 adolescents aged 10-14 in the Adolescent Brain Cognitive Development℠ Study. Using logistic regression models, we analyzed associations between identity (SM and GM), sexual identity discrimination, minority and general stressors (sexual identity discrimination, teasing, and conflict with parents) and sleep health (duration, latency, and disturbance). We used Baron and Kenny's method to test for mediation.

RESULTS

Participants reported sexual identity (4% SM, 4% questioning) and gender identity (0.4% GM, 0.6% questioning); 65% were White, 20% were Hispanic, and 52% were assigned male at birth. Compared to heterosexual, SM participants had higher odds of short sleep duration, long sleep latency, and sleep disturbance. GM participants and those reporting gender incongruence and nonconformity had higher odds of long sleep latency and sleep disturbance. Sexual identity discrimination and general social stressors partially mediated some associations.

DISCUSSION

SGM participants reported poorer sleep. Minority and general social stressors partially accounted for some disparities. Policies need to address SGM identity-based discrimination and challenge social norms that produce minority stress for SGM early adolescents.

Improvements in sleep problems and their associations with mental health symptoms: A study of children and adolescents participating in a digital mental health intervention

Objective

A growing number of youth are utilizing digital mental health interventions (DMHIs) for treatment of mental health problems such as anxiety, depression, and ADHD. Although these mental health symptoms are closely related to sleep problems, it is unknown whether nonsleep DMHIs indirectly confer improvements in sleep. Using retrospective data, the current study assesses (1) whether youth sleep problems improve over participation in a nonsleep DMHI, and (2) whether mental health symptom severity and improvement are correlated with sleep problem severity over time.

Methods

Sleep problems and mental health symptoms were assessed every 30 days among children (ages 5-12) and adolescents (ages 13-17) participating in a pediatric digital mental health intervention (DMHI; N = 1219).

Results

Children and adolescents with elevated sleep problems (39.3%; n = 479) were older (P < .001), more predominantly female (P < .001), and more likely to have elevated anxiety (P < .001), depressive (P < .001) and inattention symptoms (P = .001), as compared to those with nonelevated sleep problems (60.7%; n = 740). From the baseline to last assessment, 77.3% (n = 269) of members with elevated sleep problems exhibited improvements, with sleep problems decreasing significantly over each month in care (P < .001). Members with improvements in anxiety, depressive, and/or ADHD symptoms had larger improvements in sleep over time compared to their peers with no improvement in their mental health symptoms (Months in care*Change type: P < .001 for all).

Conclusions

Our results provide preliminary evidence that participation in a pediatric DMHI is associated with improvements in sleep problems, even when youth are not being treated directly for sleep problems. These findings highlight a valuable secondary benefit of participating in mental health care within pediatric DMHIs and warrant further experimental research.

Leveraging Ecological Momentary Assessment to Examine Bi-directional Associations Between Sleep Quality, Adolescent/Young Adult Alcohol Craving and Use

BACKGROUND

Alcohol use is common among adolescents and young adults (AYA) and linked to poor sleep quality. Poor sleep quality may also increase alcohol use and alcohol craving, yet bi-directional relations between sleep quality and AYA alcohol use are poorly understood.

PURPOSE

This study examined bi-directional associations between sleep quality, alcohol craving, and alcohol use in AYA using ecological momentary assessment (EMA) and explored if biological sex, age, or race moderated these associations.

METHODS

This pre-registered secondary analysis pooled EMA data from the baseline, pre-randomization period (M = 8.18 days, range = 1-17) in two double-blind randomized placebo-controlled clinical trials examining medication effects on alcohol use in AYA (N = 115). Each morning, participants reported sleep quality and alcohol consumption (i.e., number of standard drinks) from the previous day, and craving was rated at several random points each day.

RESULTS

Multilevel modeling showed that poorer average sleep quality was associated with higher levels of alcohol craving for females but not for males, and better overall levels of sleep quality were associated with decreased likelihood of engaging in alcohol use. No other person- or day-level associations between sleep and alcohol use emerged.

CONCLUSIONS

Better sleep quality may be protective against alcohol use in AYA, and female AYA who report poorer sleep quality may experience higher levels of alcohol craving. Research and clinical assessment of AYA sleep quality can contribute to understanding of factors promoting alcohol craving and use.

Characteristics of 24-hour movement behaviours and their associations with mental health in children and adolescents

Background

Time-use estimates are typically used to describe 24-hour movement behaviours. However, these behaviours can additionally be characterised by other easily measured metrics. These include sleep quality (e.g., sleep efficiency), 24-hour rest-activity rhythmicity (e.g., between-day rhythm variability), and directly measured acceleration metrics (e.g., intensity gradient). Associations between these characteristics and youth mental health are unclear. This study aimed to [1] compare 24-hour movement behaviour characteristics by sex and age groups, [2] determine which movement behaviour characteristics were most strongly associated with mental health outcomes, and [3] investigate the optimal time-use behaviour compositions for different mental health outcomes.

Methods

Three-hundred-and-one children and adolescents (age 9-13 y; 60% girls) wore accelerometers for 24-hours/day over 7-days. Overall mental health, externalising, and internalising problems were self-reported using the Strengths and Difficulties Questionnaire. 24-hour movement behaviour characteristics were categorised as time-use estimates, sleep quality, 24-hour activity rhythmicity, and directly measured acceleration. Linear mixed models and compositional data analysis were used to analyse the data in alignment with the study aims.

Results

Time-use estimates, directly measured accelerations, and 24-hour rest-activity rhythm metrics indicated that children were significantly more physically active (p = .01-<0.001) than adolescents. Children were also less sedentary (p < .01), slept longer (p = .02-0.01), and had lower sleep efficiency. Boys were significantly more active than girls (p < .001) who in turn accrued more time in sleep (p = .02). The timing of peak activity was significantly later among adolescents (p = .047). Overall mental health and externalising problems were significantly associated with sleep, sedentary time, sleep efficiency, amplitude, and inter-daily stability (p = .04-0.01). The optimal time-use compositions were specific to overall mental health and externalising problems and were characterised by more sleep, light and vigorous physical activity, and less sedentary time and moderate physical activity than the sample's mean time-use composition.

Conclusions

Extracting and examining multiple movement behaviour characteristics from 24-hour accelerometer data can provide a more rounded picture of the interplay between different elements of movement behaviours and their relationships with mental health than single characteristics alone, such as time-use estimates. Applying multiple movement behaviour characteristics to the translation of research findings may enhance the impact of the data for research users.

Supplementary Information

The online version contains supplementary material available at 10.1186/s44167-023-00021-9.

The Association between Sedentary Behavior, Physical Activity, and Physical Fitness with Body Mass Index and Sleep Time in Chilean Girls and Boys: A Cross-Sectional Study

BACKGROUND

In recent decades, the school population has undergone behavioral changes that have affected their health and adult life. The current educational scenario presents high levels of sedentary behavior, physical inactivity, low physical fitness, high levels of obesity, and non-compliance with sleep recommendations. In Chile, the scientific evidence on associations between these behaviors is incipient.

OBJECTIVE

To analyze the association between sedentary behavior, physical activity, and physical fitness with BMI and minutes of sleep in Chilean children aged 10 to 11 years.

METHODS

A non-probabilistic convenience sample of 222 schoolchildren aged 10 to 11 years. The variables measured were body composition (BMI), cardiorespiratory fitness (20 m shuttle run test), lower and upper muscular strength (long jump test and handgrip dynamometry), speed (4 × 10 m running), and flexibility (sit and reach test). Physical activity and sleep were measured by accelerometers.

RESULTS

Of the participants, 60.4% and 90.6% did not comply with sleep and physical activity recommendations, respectively. Physical fitness was higher in boys in all components. The results of the linear regression show that in girls, moderate-vigorous-intensity physical activity, lower- and upper-body muscular strength, and cardiorespiratory endurance were associated with BMI and sleep. In boys, light-intensity physical activity and upper-body muscular strength were associated with both variables.

CONCLUSIONS

Physical activity intensity, strength, and cardiorespiratory fitness were associated with BMI and sleep; however, physical activity intensity and associated physical fitness components differed by gender.

Physical Activity and Sleep Quality in Spanish Primary School Children: Mediation of Sex and Maturational Stage

Background: sleep is a physiological process that is critical for physical and mental health in children. Childhood encompasses diverse developmental stages that may affect the impact of physical activity on sleep quality, which may also be influenced by sex. The purpose of this study was to examine the mediation effect of sex and, as well as maturational stage on the association between physical activity and sleep quality, among primary school children. Methods: this was a cross-sectional study of 954 Spanish primary school students (437 early childhood and 517 middle childhood) with a mean age of 10.5 ± 1.2 years. Participants reported their sleep quality using the Pittsburgh Sleep Quality Index and their physical activity levels using the Physical Activity Questionnaire. Results: our study found that physical activity is associated with improved sleep quality in children, particularly during middle childhood. Higher physical activity was linked to better sleep quality and reduced sleep latency (p = 0.044). Sleep quality was generally better in males than in females (p = 0.002) and was also better in early than middle childhood (p = 0.000). Conclusions: especially in middle childhood, physical activity promotes children’s sleep quality. Thus, educational institutions should promote or improve the implementation of physical activity in the school context in order to benefit children’s sleep quality and, hence, improve their quality of life and wellbeing.

Long wavelength light reduces the negative consequences of dim light at night

Many patients with autism spectrum disorders (ASD) show disturbances in their sleep/wake cycles, and they may be particularly vulnerable to the impact of circadian disruptors. We have previously shown that a 2-weeks exposure to dim light at night (DLaN) disrupts diurnal rhythms, increases repetitive behaviors and reduces social interactions in contactin-associated protein-like 2 knock out (Cntnap2 KO) mice. The deleterious effects of DLaN may be mediated by intrinsically photosensitive retinal ganglion cells (ipRGCs) expressing the photopigment melanopsin, which is maximally sensitive to blue light (480 nm). In this study, the usage of a light-emitting diode array enabled us to shift the spectral properties of the DLaN while keeping the intensity of the illumination at 10 lx. First, we confirmed that the short-wavelength enriched lighting produced strong acute suppression of locomotor activity (masking), robust light-induced phase shifts, and cFos expression in the suprachiasmatic nucleus in wild-type (WT) mice, while the long-wavelength enriched lighting evoked much weaker responses. Opn4DTA mice, lacking the melanopsin expressing ipRGCs, were resistant to DLaN effects. Importantly, shifting the DLaN stimulus to longer wavelengths mitigated the negative impact on the activity rhythms and 'autistic' behaviors (i.e. reciprocal social interactions, repetitive grooming) in the Cntnap2 KO as well as in WT mice. The short-, but not the long-wavelength enriched, DLaN triggered cFos expression in in the basolateral amygdala (BLA) as well as in the peri-habenula region raising that possibility that these cell populations may mediate the effects. Broadly, our findings are consistent with the recommendation that spectral properties of light at night should be considered to optimize health in neurotypical as well as vulnerable populations.

Factors Related to High-School Students’ Odds of Having Overweight or Obesity

This study used data the Youth Risk Behavior Surveillance System ( N = 7,088) to examine factors associated with the odds of overweight/obesity. Overweight/obese was defined as a body mass index ≥85th percentile, based on age- and sex-specific growth charts. Participants were categorized into meeting/not meeting guidelines for: sleep, moderate-to-vigorous PA (MVPA), muscle strengthening PA, screen time, breakfast eating, fruit and vegetable consumption, and soda and milk consumption. Logistic regression analyses determined whether meeting guidelines for each health behavior was associated with the odds of students having overweight/obesity in the total group and stratified by sex. Meeting MVPA guidelines was the only behavior associated with having a lower odds of overweight/obesity in both sexes. For females, meeting recommendations for breakfast eating and strength training were also associated with lower odds of having overweight/obesity, whereas for boys, getting the recommended amount of sleep was associated with having lower odds of overweight/obesity. Interventions to reduce the prevalence of overweight/obesity in youth should be implemented inside and outside of the school environment and should include components addressing physical activity, diet, and sleep. Such interventions should address barriers to healthy behaviors that are unique to adolescents already affected by overweight/obesity.