Longitudinal association between short sleep, body weight, and emotional and learning problems in Hispanic and Caucasian children

Longitudinal impact of sleep on overweight and obesity in children and adolescents: a systematic review and bias-adjusted meta-analysis

Short sleep duration is considered a potential risk for overweight/obesity in childhood and adolescence. However, most of the evidence on this topic is obtained from cross-sectional studies; therefore, the nature and extent of the longitudinal associations are unclear. This study explores the prospective association between short sleep and overweight/obesity in young subjects. The MEDLINE, EMBASE, Pubmed, and CINAHL databases were searched for English-language articles, published until May 2014, reporting longitudinal association between sleep and body mass index (BMI) in children and adolescents. Recommendations of the Sleep Health Foundation were used to standardize reference sleep duration. Sleep category, with sleep duration less than the reference sleep, was considered as the short sleep category. Meta-analysis was conducted to explore the association between short sleep and overweight/obesity. A review of 22 longitudinal studies, with subjects from diverse backgrounds, suggested an inverse association between sleep duration and BMI. Meta-analysis of 11 longitudinal studies, comprising 24,821 participants, revealed that subjects sleeping for short duration had twice the risk of being overweight/obese, compared with subjects sleeping for long duration (odds ratio 2.15; 95% confidence interval: 1.64-2.81). This study provides evidence that short sleep duration in young subjects is significantly associated with future overweight/obesity.

Sleep patterns of a primarily obese sample of treatment-seeking children

STUDY OBJECTIVES

To examine the sleep patterns and the role of day of the week and school break in these patterns within a primarily obese sample of children.

METHODS

Participants included 143 obese children (8-12 years) and their parents initiating treatment in a weight-management study in a community-based setting. Demographics, anthropometrics, and objectively measured sleep (i.e., with use of Sensewear Armbands) were collected prior to treatment.

RESULTS

Sleep duration was insufficient in our sample, as approximately 88% obtained less than 8 hours of sleep (mean = 6.92, standard deviation = 0.85). Those with lower total sleep time included older children, those identified as African American (compared to those identified as Caucasian), and those identified as Non-Hispanic (compared to those identified as Hispanic). Children on school break initiated sleep later than those in school the week of measurement. Children woke later on weekends and when on school break. There were no differences in day of the week or school break in predicting child sleep duration and total wake time (p's > 0.05).

CONCLUSIONS

This study is one of the first to examine sleep patterns within a primarily obese sample of treatment-seeking rural children. There is a need for research to develop a better understanding of how sleep may affect health functioning and weight management, as well as quality of life and psychosocial functioning of children who are overweight or obese.

TXT me I'm only sleeping: adolescents with mobile phones in their bedroom

The purpose of this study was to determine if mobile phones interfere with adolescent sleep. We conducted a pilot test in a pediatric primary care practice of 454 patients, half female (51.2%), 12 to 20 years old (mean = 15) attending a well-child visit. Adolescents completed paper-and-pencil surveys in the waiting room. More than half took their mobile phone to bed (62.9%) and kept it turned on while sleeping (56.8%). Almost half used their phone as their alarm (45.7%). More than one-third texted after going to bed (36.7%). Two or more times per week, 7.9% were awakened by a text after going to sleep.

Sleep and body mass index in adolescence: results from a large population-based study of Norwegian adolescents aged 16 to 19 years

Background

The aim of this study was to examine the association between body mass index (BMI) and sleep duration, insomnia and symptoms of obstructive sleep apnea (OSA) in adolescents.

Methods

Data were taken from a large population based study of 9,875 Norwegian adolescents aged 16–19. BMI was calculated from the self-reported body weight and categorized according to recommended age and gender specific cut offs for underweight, overweight and obesity. Detailed sleep parameters (sleep duration, insomnia, and OSA symptoms) were reported separately for weekdays and weekends. Data were analyzed using Pearson’s chi-squared test and ANOVAs for simple categorical and continuous comparisons, and multinomial logistic regressions for analyses adjusting for known confounders.

Results

There was evidence for a curvilinear relationship between BMI and both sleep duration and insomnia for girls, whereas the relationship was linear for boys. Compared to the average weekday sleep duration among adolescents in the normal weight range (6 hrs 29 min), both underweight (5 hrs 48 min), overweight (6 hrs 13 min) and obese (5 hrs 57 min) adolescents had shorter sleep duration. OSA symptoms were linearly associated with BMI. Controlling for demographical factors as well as physical activity did not attenuate the associations. Additional adjustment for depression reduced the association between insomnia and obesity to a non-significant level. The evidence for a link between both underweight and overweight/obesity, and short sleep duration and OSA symptoms remained in the fully adjusted analyses. The associations were generally stronger for girls.

Conclusions

This is one of the first population-based studies to investigate the relationship between sleep and BMI in adolescents while simultaneously controlling for important confounding factors. These findings require further research to investigate the temporal association between weights and sleep problems.

Mother-reported sleep, accelerometer-estimated sleep and weight status in Mexican American children: sleep duration is associated with increased adiposity and risk for overweight/obese status

We know of no studies comparing parent-reported sleep with accelerometer-estimated sleep in their relation to paediatric adiposity. We examined: (i) the reliability of mother-reported sleep compared with accelerometer-estimated sleep; and (ii) the relationship between both sleep measures and child adiposity. The current cross-sectional study included 303 Mexican American mother-child pairs recruited from Kaiser Permanente Northern California. We measured sleep duration using maternal report and accelerometry and child anthropometrics. Concordance between sleep measures was evaluated using the Bland-Altman method. We conducted zero-ordered correlations between mother-reported sleep, accelerometer-estimated sleep and child BMI z-scores (BMIz). Using linear regression, we examined three models to assess child BMIz with mother-reported sleep (model 1), accelerometer-estimated sleep (model 2) and both sleep measures (model 3). Children had an average age of 8.86 years (SD = 0.82). Mothers reported that their child slept 9.81 ± 0.74 h [95% confidence interval (CI): 9.72, 9.89], compared to 9.58 ± 0.71 h (95% CI: 9.50, 9.66) based on accelerometry. Mother-reported sleep and accelerometer-estimated sleep were correlated (r = 0.33, P < 0.001). BMIz outcomes were associated negatively with mother-reported sleep duration (model 1: β = -0.13; P = 0.02) and accelerometer-estimated sleep duration (model 2: β = -0.17; P < 0.01). Accounting for both sleep measures, only accelerometer-measured sleep was related to BMIz (model 3: β = -0.14, P = 0.02). Each sleep measure was related significantly to adiposity, independent of covariates. Accelerometry appeared to be a more reliable measure of children's sleep than maternal report, yet maternal report may be sufficient to examine the sleep-adiposity relationship when resources are limited.

Effects of obstructive sleep apnea and obesity on exercise function in children

STUDY OBJECTIVES

Evaluate the relative contributions of weight status and obstructive sleep apnea (OSA) to cardiopulmonary exercise responses in children.

DESIGN

Prospective, cross-sectional study. Participants underwent anthropometric measurements, overnight polysomnography, spirometry, cardiopulmonary exercise function testing on a cycle ergometer, and cardiac doppler imaging. OSA was defined as ≥ 1 obstructive apnea or hypopnea per hour of sleep (OAHI). The effect of OSA on exercise function was evaluated after the parameters were corrected for body mass index (BMI) z-scores. Similarly, the effect of obesity on exercise function was examined when the variables were adjusted for OAHI.

SETTING

Tertiary pediatric hospital.

PARTICIPANTS

Healthy weight and obese children, aged 7-12 y.

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

Seventy-one children were studied. In comparison with weight-matched children without OSA, children with OSA had a lower cardiac output, stroke volume index, heart rate, and oxygen consumption (VO2 peak) at peak exercise capacity. After adjusting for BMI z-score, children with OSA had 1.5 L/min (95% confidence interval -2.3 to -0.6 L/min; P = 0.001) lower cardiac output at peak exercise capacity, but minute ventilation and ventilatory responses to exercise were not affected. Obesity was only associated with physical deconditioning. Cardiac dysfunction was associated with the frequency of respiratory-related arousals, the severity of hypoxia, and heart rate during sleep.

CONCLUSIONS

Children with OSA are exercise limited due to a reduced cardiac output and VO2 peak at peak exercise capacity, independent of their weight status. Comorbid OSA can further decrease exercise performance in obese children.

Does Short Sleep Lead to Obesity Among Children and Adolescents? Current Understanding and Implications

Childhood obesity continues to be a major public health concern in the United States. This work reviews the current understanding of the relationship between sleep duration and obesity among children and adolescents. A systematic search was conducted for papers published between January 2000 and July 2013 using keywords: (sleep) and (overweight or obesity or obese or body mass index or BMI or adiposity or body fat or fat) and (children or child or youth or teen or pediatric or adolescent or paediatric or childhood or adolescence or boy or girl). Reference lists of relevant articles and reviews or meta-analysis articles were checked to identify additional studies. Only empirical work and longitudinal studies that focused on children and adolescents were included in this review. The search identified 22 longitudinal studies. The majority of the reviewed studies support the presence of an inverse relationship between sleep duration and obesity. However, in some studies the relationship was not significant in adjusted analyses. Differences as a function of age and gender were also noted. Despite more than a decade of research, the debate on the association between sleep duration and obesity continues. Further research with repeated assessments, valid objective measures, and better control of potential confounding variables is warranted.

Ethnic variation in the association between sleep and body mass among US adolescents

Objective

We investigate whether differences in sleep duration help explain ethnic disparities in body mass index (BMI) among U.S. adolescents. We also evaluate the functional form of the association between sleep duration and BMI, and investigate whether this association varies by sex and ethnicity.

Participants and Methods

We analyzed restricted-use data from the first 2 waves of the National Longitudinal Study of Adolescent Health (n=30 133) to evaluate linear and quadratic associations between sleep duration and BMI. Through a series of models that incorporated interaction terms between sex, ethnicity and sleep duration, we also assessed whether (1) sleep duration mediates associations between ethnicity and BMI, and (2) associations between sleep duration and BMI differ for girls and boys from different ethnic groups.

Results

A linear association between sleep duration and BMI best fits the data in this large sample of U.S. adolescents. We find no evidence that sleep duration contributes substantially to ethnic disparities in BMI. However, we detect significant differences in the association between sleep duration and BMI by sex and ethnicity. Sleep duration is negatively associated with BMI among white, Hispanic and Asian boys, positively associated with BMI among black girls, and not related to BMI among black boys or girls from white, Hispanic or Asian ethnic groups.

Conclusion

Despite significant associations between sleep duration and BMI for certain groups of adolescents, we find no evidence that ethnic differences in sleep duration exacerbate ethnic disparities in BMI. Future research should explore mechanisms that underlie ethnic differences in the association between sleep and BMI.

Associations between sleep habits and mental health status and suicidality in a longitudinal survey of monozygotic twin adolescents

Several epidemiological studies have indicated that there is a relationship between sleep habits, such as sleep duration, bedtime and bedtime regularity, and mental health status, including depression and anxiety in adolescents. However, it is still to be clarified whether the relationship is direct cause-and-effect or mediated by the influence of genetic and other traits, i.e. quasi-correlation. To examine this issue, we conducted a twin study using a total of 314 data for monozygotic twins from a longitudinal survey of sleep habits and mental health status conducted in a unified junior and senior high school (grades 7-12), located in Tokyo, Japan. Three-level hierarchical linear model analysis showed that both bedtime and sleep duration had significant associations with the Japanese version of the 12-item General Health Questionnaire (GHQ-12) score, suicidal thoughts and the experience of self-harm behaviours when genetic factors and shared environmental factors, which were completely shared between co-twins, were controlled for. These associations were statistically significant even after controlling for bedtime regularity, which was also associated significantly with the GHQ-12 score. These suggest that the associations between sleep habits and mental health status were still statistically significant after controlling for the influence of genetic and shared environmental factors of twins, and that there may be a direct cause-and-effect in the relationship in adolescents. Thus, late bedtime and short sleep duration could predict subsequent development of depression and anxiety, including suicidal or self-injury risk. This suggests that poor mental health status in adolescents might be improved by health education and intervention concerning sleep and lifestyle habits.

[Sleep duration among school-age children in Hungary and Romania]

INTRODUCTION

Children's sleep duration is decreasing in the last decade. Despite of the well known negative consequences, there are no data on children's sleep duration in Hungary and Romania.

AIM

The aim of the authors was to assess sleep duration of school-age children in Hungary and Romania.

METHOD

A self-edited questionnaire was used for the study. 2446 children were enrolled. All elementary and secondary schools in a Hungarian city, and one elementary and secondary school in a Romanian city took part in the study.

RESULTS

Mean sleep duration was 8.3 ± 1.2 hours on weekdays. There was a significant difference between the two countries (Hungary vs. Romania, 8.5 ± 1.2 hours vs. 7.8 ± 0.9 hours, p = 0.001). Age correlated with sleep duration on weekdays (r= -0.605, p = 0.001), but not during weekend.

CONCLUSIONS

This is the first study on children's sleep duration in Hungary and Romania. The difference between countries may be due to the difference in mean age or cultural and/or geographical differences.

Rising Prevalence and Neighborhood, Social, and Behavioral Determinants of Sleep Problems in US Children and Adolescents, 2003-2012

We examined trends and neighborhood and sociobehavioral determinants of sleep problems in US children aged 6–17 between 2003 and 2012. The 2003, 2007, and 2011-2012 rounds of the National Survey of Children's Health were used to estimate trends and differentials in sleep problems using logistic regression. Prevalence of sleep problems increased significantly over time. The proportion of children with <7 days/week of adequate sleep increased from 31.2% in 2003 to 41.9% in 2011-2012, whereas the prevalence of adequate sleep <5 days/week rose from 12.6% in 2003 to 13.6% in 2011-2012. Prevalence of sleep problems varied in relation to neighborhood socioeconomic and built-environmental characteristics (e.g., safety concerns, poor housing, garbage/litter, vandalism, sidewalks, and parks/playgrounds). Approximately 10% of children in neighborhoods with the most-favorable social environment had serious sleep problems, compared with 16.2% of children in neighborhoods with the least-favorable social environment. Children in neighborhoods with the fewest health-promoting amenities or the greatest social disadvantage had 37%–43% higher adjusted odds of serious sleep problems than children in the most-favorable neighborhoods. Higher levels of screen time, physical inactivity, and secondhand smoke exposure were associated with 20%–47% higher adjusted odds of sleep problems. Neighborhood conditions and behavioral factors are important determinants of sleep problems in children.

Sleep duration and adolescent obesity

OBJECTIVES

Short sleep has been associated with adolescent obesity. Most studies used a cross-sectional design and modeled BMI categories. We sought to determine if sleep duration was associated with BMI distribution changes from age 14 to 18.

METHODS

Adolescents were recruited from suburban high schools in Philadelphia when entering ninth grade (n = 1390) and were followed-up every 6 months through 12th grade. Height and weight were self-reported, and BMIs were calculated (kg/m(2)). Hours of sleep were self-reported. Quantile regression was used to model the 10th, 25th, 50th, 75th, and 90th BMI percentiles as dependent variables; study wave and sleep were the main predictors.

RESULTS

BMI increased from age 14 to 18, with the largest increase observed at the 90th BMI percentile. Each additional hour of sleep was associated with decreases in BMI at the 10th (-0.04; 95% confidence interval [CI]: -0.11, 0.03), 25th (-0.12; 95% CI: -0.20, -0.04), 50th (-0.15; 95% CI: -0.24, -0.06), 75th (-0.25; 95% CI: -0.38, -0.12), and 90th (-0.27; 95% CI: -0.45, -0.09) BMI percentiles. The strength of the association was stronger at the upper tail of the BMI distribution. Increasing sleep from 7.5 to 10.0 hours per day at age 18 predicted a reduction in the proportion of adolescents >25 kg/m(2) by 4%.

CONCLUSIONS

More sleep was associated with nonuniform changes in BMI distribution from age 14 to 18. Increasing sleep among adolescents, especially those in the upper half of the BMI distribution, may help prevent overweight and obesity.

Risk of behavioral and adaptive functioning difficulties in youth with previous and current sleep disordered breathing

OBJECTIVES

To examine the rates of behavioral and adaptive functioning difficulties among youth who never had sleep disordered breathing (SDB), had remitted SDB, had incident SDB, or had persistent SDB; and to determine if there were increased odds of behavioral difficulties among youth with varying SDB histories relative to those who never had SDB.

METHODS

263 youth had valid polysomnography and neurobehavioral data at two time points approximately 5 years apart from the prospective Tucson Children's Assessment of Sleep Apnea study. Primary outcomes were the behavior assessment scale for children-2(nd) Edition parent report form (BASC-PRF) and Self-Report of Personality (SRP), and the Adaptive Behavior Assessment System-2(nd) Edition (ABAS-2).

RESULTS

Compared to those who never had SDB, individuals with persistent SDB had significant odds and met more cutoff scores on the BASC-2-PRF externalizing problems composite (odds ratio [OR] 3.29; 8.92% vs. 35.3%), behavioral symptoms index (OR 6.82; 7.4% vs. 35.3%) and Hyperactivity subscale (OR 6.82; 11.1% vs. 41.2%). Similarly, greater difficulties was seen for the group with persistent SDB (relative to never) on the ABAS-2 social domain (OR 3.39; 22% vs. 50%), and Communication (OR 4.26; 15% vs. 42.9%) and Self-Care subscales (OR = 2.97; 25.2% vs. 50%). Relative to youth who never had SDB, youth who developed SDB at Time 2 had compromised adaptive skills as evidenced by the BASC-2 PRF adaptive behavior composite (OR 3.34; 15.6% vs. 38.1%) and the ABAS-2 general adaptive composite (OR 2.83; 20.5% vs. 42.1%).

CONCLUSIONS

Youth with current SDB exhibited hyperactivity, attention problems, aggressivity, lower social competency, poorer communication, and/or diminished adaptive skills.

Short sleep and obesity in a large national cohort of Thai adults

OBJECTIVE

To investigate the relationship between short sleep and obesity among Thai adults.

DESIGN

Both 4-year longitudinal and cross-sectional analyses of a large national cohort.

SETTING

Thai adults residing nationwide from 2005 to 2009.

PARTICIPANTS

Cohort members were enrolled as distance learners at Sukhothai Thammathirat Open University (N=87 134 in 2005 and 60 569 at 2009 follow-up). At 2005 baseline, 95% were between 20 and 49 years of age.

MEASURES

Self-reported sleep duration was categorised as <6, 6, 7, 8 and ≥9 h. For all analyses (2005 and 2009 cross-sectional and 2005-2009 longitudinal), we used multinomial logistic regression models to assess the effect of sleep duration on abnormal body size (underweight, overweight-at-risk, obese). Results were adjusted for an array of relevant covariates.

RESULTS

At the last cohort follow-up in 2009, cross-sectional associations linked short sleep (<6 h) and obesity: adjusted ORs (AOR) =1.49, 95% CIs 1.32 to 1.68 for women and AOR=1.36, 95% CI 1.21 to 1.52 for men. The earlier cross-sectional baseline results in 2005 were quite similar. Longitudinal analysis (2005-2009) of 4-year incremental weight gain (5 to <10%, 10 to <20% and 20%+) strongly supported the short sleep-obesity relationship (significant AORs of 1.10, 1.30 and 1.69, respectively).

CONCLUSIONS

The results are internally consistent (2005 and 2009) and longitudinally confirmatory of a short sleep effect on obesity among Thai adults. Further research is needed to elucidate causal mechanisms underlying the sleep-obesity relationship.