A pilot randomized controlled trial examining the impact of a sleep intervention targeting home routines on young children's (3-6 years) physical activity

The Overflow Effects of Movement Behaviour Change Interventions for Children and Adolescents: A Systematic Review and Meta-Analysis of Randomised Controlled Trials

BACKGROUND

Considering the finite time within a 24-h day, the distribution of time spent on movement behaviours has been found to be associated with health outcomes.

OBJECTIVES

This systematic review and meta-analysis aimed to summarise and evaluate the overflow effects of interventions targeting a single behaviour (physical activity, sedentary behaviour/screen time, or sleep) on other non-targeted behaviours among children and adolescents.

METHODS

Six databases (MEDLINE [Ovid], PsycINFO [ProQuest], EMBASE [Ovid], PubMed, Web of Science and SPORTDiscus [EBSCO]) were searched for relevant studies published before 13 May, 2024. Randomised controlled trials and clustered randomised controlled trials that targeted a single behaviour and also assessed the effects on non-targeted behaviours, comprised of healthy children under the age of 18 years, were included. Movement behaviours can be measured either objectively or subjectively. The revised Cochrane risk-of-bias tool for randomised trials was adopted to evaluate the risk of bias.

RESULTS

A total of 102 studies with 45,998 participants from 21 countries were identified, and 60 of them with 26,183 participants were incorporated into the meta-analysis. The meta-analysis demonstrated that physical activity interventions led to a reduction in the proportion of each day spent in sedentary behaviour (mean difference =  - 0.95% of wear time, 95% confidence interval - 1.44, - 0.45, I2 = 39%). Sedentary behaviour interventions resulted in increased standing time (mean difference = 3.87%, 95% confidence interval 1.99, 5.75, I2 = 0%). Interventions targeting screen time did not yield changes in physical activity or sleep. The findings on the effectiveness of sleep interventions on non-targeted behaviours and of physical activity interventions on sleep were inconclusive.

CONCLUSIONS

Overall, the findings suggested that interventions aimed at increasing physical activity or reducing sedentary behaviour had overflow effects on non-targeted behaviours, but the effect sizes were small. Additional evidence is needed to reach definitive conclusions regarding the impact of behaviour change interventions on sleep and of the overflow effects of sleep interventions.

Effectiveness of a Parent-Based eHealth Intervention for Physical Activity, Dietary Behavior, and Sleep Among Preschoolers: Protocol for a Randomized Controlled Trial

BACKGROUND

Preschoolers' lifestyles have become physically inactive and sedentary, their eating habits have become unhealthy, and their sleep routines have become increasingly disturbed. Parent-based interventions have shown promise to improve physical activity (PA), improve dietary behavior (DB), and reduce sleep problems among preschoolers. However, because of the recognized obstacles of face-to-face approaches (eg, travel costs and time commitment), easy access and lower costs make eHealth interventions appealing. Previous studies that examined the effectiveness of parent-based eHealth for preschoolers' PA, DB, and sleep have either emphasized 1 variable or failed to balance PA, DB, and sleep modules and consider the intervention sequence during the intervention period. There is an acknowledged gap in parent-based eHealth interventions that target preschoolers raised in Chinese cultural contexts.

OBJECTIVE

This study aims to investigate the effectiveness of a parent-based eHealth intervention for PA, DB, and sleep problems among Chinese preschoolers.

METHODS

This 2-arm, parallel, randomized controlled trial comprises a 12-week intervention with a 12-week follow-up. A total of 206 parent-child dyads will be randomized to either an eHealth intervention group or a control group. Participants allocated to the eHealth intervention group will receive 12 interactive modules on PA, DB, and sleep, with each module delivered on a weekly basis to reduce the sequence effect on variable outcomes. The intervention is grounded in social cognitive theory. It will be delivered through social media, where parents can obtain valid and updated educational information, have a social rapport, and interact with other group members and facilitators. Participants in the control group will receive weekly brochures on PA, DB, and sleep recommendations from kindergarten teachers, but they will not receive any interactive components. Data will be collected at baseline, 3 months, and 6 months. The primary outcome will be preschoolers' PA. The secondary outcomes will be preschoolers' DB, preschoolers' sleep duration, preschoolers' sleep problems, parents' PA, parenting style, and parental feeding style.

RESULTS

Parent-child dyads were recruited in September 2023. Baseline and posttest data collection occurred from October 2023 to March 2024. The follow-up data will be obtained in June 2024. The results of the study are expected to be published in 2025.

CONCLUSIONS

The parent-based eHealth intervention has the potential to overcome the barriers of face-to-face interventions and will offer a novel approach for promoting a healthy lifestyle among preschoolers. If this intervention is found to be efficacious, the prevalence of unhealthy lifestyles among preschoolers may be alleviated at a low cost, which not only has a positive influence on the health of individuals and the well-being of the family but also reduces the financial pressure on society to treat diseases caused by poor lifestyle habits.

TRIAL REGISTRATION

ClinicalTrials.gov NCT06025019; https://clinicaltrials.gov/study/NCT06025019.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/58344.

Effectiveness of a parent-focused intervention targeting 24-hour movement behaviours in preschool-aged children: a randomised controlled trial

BACKGROUND

Interventions focusing on individual behaviours (physical activity, sedentary behaviour, sleep) of preschool-aged children have been widely studied. However, there is a lack of understanding about integrated interventions that target all three 24-hour movement behaviours. This is the first study to assess the effectiveness of an intervention aimed at improving all three 24-hour movement behaviours among preschoolers in Hong Kong.

METHODS

A 12-week randomised controlled trial with a 12-week follow-up was conducted. Parent-child pairs were randomised to integrated approach (targeting all three behaviours), dyadic approach (targeting physical activity and sedentary behaviour including screen time), or wait-list control group. Utilising the Internet-based delivery, this intervention consisted of education materials, workshops, and interactive questionnaires and reminders. Two intervention groups employed the same strategies, with the only difference being that the integrated approach targeted sleep in addition to physical activity and sedentary behaviour. The outcomes were preschoolers' overall 24-hour movement behaviours which were assessed by the Activity Sleep Index (ASI), movement behaviour composition, and absolute duration of movement behaviours. Generalised estimating equations were conducted to evaluate the intervention.

RESULTS

A total of 147 preschoolers (4.8 ± 0.9 years old, 56.5% boys) and their parents were included. Preschoolers in all groups had a lower ASI at follow-up compared with baseline. Preschoolers in the integrated approach had a smaller decline in ASI at follow-up, compared to that in the control group (3.41; 95% confidence interval [CI] = 0.07, 6.76). Preschoolers in both intervention groups had a smaller reduction of the composition of time spent in physical activity at follow-up, and a decreased screen time at postintervention and follow-up. No significant differences were found for the sleep subcomponent. Furthermore, preschoolers in the dyadic approach had a smaller increase in the sedentary behaviour subcomponent (vs.

CONTROL

- 0.21; 95% CI = - 0.37, - 0.05) at follow-up.

CONCLUSIONS

Both intervention groups showed a decrease in screen time at postintervention, but there were no significant changes in other behaviours. The favourable changes observed at follow-up demonstrated the effectiveness of both intervention approaches on alleviating the decline in the composition of time spent in physical activity and reducing screen time and revealed the possible effectiveness of the integrated approach in promoting overall movement behaviours among preschoolers.

TRIAL REGISTRATION

The study is prospectively registered at the Chinese Clinical Trial Registry (ChiCTR2200055958).

Classifying intervention components used in sleep duration interventions for children: A systematic review and meta-analysis

The Multiphase Optimization Strategy (MOST) is a three-phase iterative framework that could accelerate the development of behavioral interventions. This systematic review and meta-analysis was conducted within the MOST preparation phase and aimed to classify components included in pediatric sleep duration interventions, using the Behavior Change Technique (BCT) Taxonomy. Across 37 interventions, 46 out of 93 BCTs have been used, with an average of 8 techniques used per study. The most common BCTs used were instruction on how to perform the behavior (N = 29; code 4.1), practical social support (N = 22; code: 3.2), and behavioral practice/rehearsal (N = 22; code: 8.1). A latent class analysis identified two classes of interventions, distinguished by the presence of BCTs falling within the following behavior change groups: shaping knowledge, natural consequences, comparison of behavior, and repetition and substitution. Our meta-analysis revealed that interventions belonging to the latent class with these behavior change groups (N = 15) had a pooled positive intervention effect of 14 min (95 % CI: 8-21) versus 8 min (95 % CI: 1-15) for interventions without these behavior change groups (N = 19). This systematic review and meta-analysis will enhance the development of sleep promotion interventions and guide the selection of candidate intervention components for future optimization and randomized control trials.

Effects of eHealth Interventions on 24-Hour Movement Behaviors Among Preschoolers: Systematic Review and Meta-Analysis

BACKGROUND

The high prevalence of unhealthy movement behaviors among young children remains a global public health issue. eHealth is considered a cost-effective approach that holds great promise for enhancing health and related behaviors. However, previous research on eHealth interventions aimed at promoting behavior change has primarily focused on adolescents and adults, leaving a limited body of evidence specifically pertaining to preschoolers.

OBJECTIVE

This review aims to examine the effectiveness of eHealth interventions in promoting 24-hour movement behaviors, specifically focusing on improving physical activity (PA) and sleep duration and reducing sedentary behavior among preschoolers. In addition, we assessed the moderating effects of various study characteristics on intervention effectiveness.

METHODS

We searched 6 electronic databases (PubMed, Ovid, SPORTDiscus, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials) for experimental studies with a randomization procedure that examined the effectiveness of eHealth interventions on 24-hour movement behaviors among preschoolers aged 2 to 6 years in February 2023. The study outcomes included PA, sleep duration, and sedentary time. A meta-analysis was conducted to assess the pooled effect using a random-effects model, and subgroup analyses were conducted to explore the potential effects of moderating factors such as intervention duration, intervention type, and risk of bias (ROB). The included studies underwent a rigorous ROB assessment using the Cochrane ROB tool. Moreover, the certainty of evidence was evaluated using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) assessment.

RESULTS

Of the 7191 identified records, 19 (0.26%) were included in the systematic review. The meta-analysis comprised a sample of 2971 preschoolers, which was derived from 13 included studies. Compared with the control group, eHealth interventions significantly increased moderate to vigorous PA (Hedges g=0.16, 95% CI 0.03-0.30; P=.02) and total PA (Hedges g=0.37, 95% CI 0.02-0.72; P=.04). In addition, eHealth interventions significantly reduced sedentary time (Hedges g=-0.15, 95% CI -0.27 to -0.02; P=.02) and increased sleep duration (Hedges g=0.47, 95% CI 0.18-0.75; P=.002) immediately after the intervention. However, no significant moderating effects were observed for any of the variables assessed (P>.05). The quality of evidence was rated as "moderate" for moderate to vigorous intensity PA and sedentary time outcomes and "low" for sleep outcomes.

CONCLUSIONS

eHealth interventions may be a promising strategy to increase PA, improve sleep, and reduce sedentary time among preschoolers. To effectively promote healthy behaviors in early childhood, it is imperative for future studies to prioritize the development of rigorous comparative trials with larger sample sizes. In addition, researchers should thoroughly examine the effects of potential moderators. There is also a pressing need to comprehensively explore the long-term effects resulting from these interventions.

TRIAL REGISTRATION

PROSPERO CRD42022365003; http://tinyurl.com/3nnfdwh3.

Parent-reported compared with researcher-measured child height and weight: impact on body mass index classification in Australian pre-school aged children

ISSUE ADDRESSED

Parent-reported data may provide a practical and cheap way for estimating young children's weight status. This study aims to compare the validity and reliability of parent-reported height and weight to researcher-measured data for pre-school aged children (aged 2-6 years).

METHODS

This was a nested study within a cluster randomised controlled trial (October 2016-April 2017), conducted within 32 Early Childhood Education and Care (ECEC) services across New South Wales, Australia. Parents of children reported on demographics and child height and weight via a survey. For the same child, height and weight data were objectively collected by trained research staff at the service. We calculated mean differences, intra-class correlations, Bland-Altman plots, percentage agreement and Cohen's kappa coefficient (>0.8 = "excellent"; 0.61-0.8 = "good"; 0.41-0.60 = "moderate"; 0.21 and 0.4 = "fair [weak]"; <0.2 = "poor").

RESULTS

Overall, 89 children were included (mean age: 4.7 years; 59.5% female). The mean difference between parent-reported and researcher-measured data were small (BMI z-score: mean difference -0.01 [95% CI: -0.45 to 0.44]). There was "fair/weak" agreement between parent-categorised child BMI compared with researcher-measured data (Cohen's Kappa 0.24 [95% CI: 0.06 to 0.42]). Agreement was poor (Cohen's kappa <0.2) for female children, when reported by fathers or by parents with a BMI > 25 kg/m2 .

CONCLUSION

There was "fair/weak" agreement between parent-reported and measured estimates of child weight status. SO WHAT?: Parent's report of weight and height may be a weak indicator of adiposity at the level of individuals however it may be useful for aggregate estimates.

Effectiveness of a Parent-Focused Intervention Targeting 24-H Movement Behaviors in Preschool-Aged Children: Study Protocol for a Randomized Controlled Trial

Background

Interventions targeting single behaviors of preschool-aged children have been mainstream for some time, but integrated interventions targeting all three 24-h movement behaviors (physical activity [PA], sedentary behavior [SB], and sleep hygiene) are less studied. The aims of this study will be to test the feasibility, acceptability, and effectiveness of a parent-focused intervention for preschool-aged children targeting multiple 24-h movement behaviors.

Methods

This three-arm randomized controlled trial will comprise a 12-week intervention and a 12-week follow-up. A total of 150 parent-child dyads will be recruited and randomly allocated to one of three arms: (1) a PA + SB group (dyadic approach), (2) a PA + SB + sleep group (integrated approach), and (3) a wait-list control group. The theory of planned behavior and behavioral change techniques will guide the development of the intervention via workshops, education materials, interactive questionnaires, and reminders. The intervention strategies for the integrated group will be the same as for the dyadic approach except that the intervention will also target sleep hygiene in addition to PA and SB. The primary outcomes will be preschoolers' 24-h movement behaviors (e.g., activity sleep index, compositional data of PA, SB, screen time, and sleep duration). The secondary outcomes will be preschoolers' sleep quality, weight status, cognitive function, and parents' movement behaviors. The feasibility and acceptability of the intervention will also be evaluated.

Discussion

The proposed study will be a theory-based, parent-focused intervention designed to improve all three 24-h movement behaviors among preschoolers. The trial is expected to improve preschoolers' movement behaviors and health outcomes, as well as their parents' movement behaviors. Given the urgent need to promote active lifestyles, our findings will help to determine best practices for movement behavior change among young children.

Trial Registration

The study is prospectively registered at the Chinese Clinical Trial Registry (ChiCTR2200055958).

Sleep Quality: A Narrative Review on Nutrition, Stimulants, and Physical Activity as Important Factors

Sleep is a cyclically occurring, transient, and functional state that is controlled primarily by neurobiological processes. Sleep disorders and insomnia are increasingly being diagnosed at all ages. These are risk factors for depression, mental disorders, coronary heart disease, metabolic syndrome, and/or high blood pressure. A number of factors can negatively affect sleep quality, including the use of stimulants, stress, anxiety, and the use of electronic devices before sleep. A growing body of evidence suggests that nutrition, physical activity, and sleep hygiene can significantly affect the quality of sleep. The aim of this review was to discuss the factors that can affect sleep quality, such as nutrition, stimulants, and physical activity.

A Systematic Review of the Relationships Between Physical Activity and Sleep in Early Childhood

The aim of this systematic review was to examine the associations between physical activity and sleep in children aged less than 6 years. Articles were included if participants were primarily aged less than 6 years and study designs were observational or experimental. Study characteristics were extracted, and the Grading Recommendations Assessment, Development and Evaluation framework was used to assess study quality. Thirty-six studies (16 sleep, 16 physical activity, and three fitness outcomes) from 18 countries reported in 29 articles were included. The majority of sleep and physical activity outcome studies reported mixed effects with very low to low quality of evidence. Fitness outcome studies were limited, and therefore, evidence was insufficient. The high prevalence of mixed and null results could be related to study limitations. Importantly, this review points to the critical need for higher quality studies of sleep and physical activity in young children, which would support health recommendations and intervention strategies for healthier child development.

Sleep-Disordered Breathing and Cardiovascular Disease in Children and Adolescents: A Scientific Statement From the American Heart Association

Obstructive sleep apnea (OSA) is a known risk factor for cardiovascular disease in adults. It is associated with incident systemic hypertension, arrhythmia, stroke, coronary artery disease, and heart failure. OSA is common in children and adolescents, but there has been less focus on OSA as a primary risk factor for cardiovascular disease in children and adolescents. This scientific statement summarizes what is known regarding the impact of sleep‐disordered breathing and, in particular, OSA on the cardiovascular health of children and adolescents. This statement highlights what is known regarding the impact of OSA on the risk for hypertension, arrhythmia, abnormal ventricular morphology, impaired ventricular contractility, and elevated right heart pressure among children and adolescents. This scientific statement also summarizes current best practices for the diagnosis and evaluation of cardiovascular disease–related complications of OSA in children and adolescents with sleep apnea and highlights potential future research in the area of sleep‐disordered breathing and cardiovascular health during childhood and adolescence.

Relationships of physical activity and sedentary behaviour with the previous and subsequent nights' sleep in children and youth: A systematic review and meta-analysis

The interrelationships between sleep and daytime movement behaviours have been examined at interindividual level. Studies of within-person, temporal relationships of daytime physical activity (PA) and sedentary behaviour with the previous and subsequent nights' sleep are increasing. The present systematic review and meta-analysis synthesised the results of studies in school-aged children and youth. Eight databases (MEDLINE, PsycINFO, EMBASE, Global Health, PubMed, Web of Science, SPORTDiscus, and CINAHL) were searched for peer-reviewed articles that examined the association between daytime movement behaviours (including PA, sedentary time, or sedentary recreational screen time) and night-time sleep on the same day, or the association between night-time sleep and daytime movement behaviours the next day, in children and youth. A total of 11 studies comprising 9,622 children and youth aged 5-15 years met the inclusion criteria. Sedentary time was negatively associated with the subsequent night's sleep duration (r = -0.12, 95% confidence interval -0.23 to -0.00; I²  = 93%; p = .04). Positive relationships between PA and the previous or subsequent night's sleep duration were observed only for studies that adjusted for accelerometer wear time. There was some evidence suggesting that a longer sleep duration was associated with less sedentary time and a higher proportion of the daytime spent being physically active and vice versa, although the association was weak and based on a limited number of studies. From a clinical perspective, promotion of either sleep hygiene or daytime PA should be planned with considerations of the virtuous or vicious circle between these behaviours and monitor concurrent effects on the others.

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.

Do sleep interventions change sleep duration in children aged 0-5 years? A systematic review and meta-analysis of randomised controlled trials

This review investigated whether randomised controlled trials attempting to improve sleep or prevent sleep problems in 0-5 year olds influenced nocturnal sleep duration, day-time naps, or 24-h sleep. Medline (Ovid), EMBASE, and CINAHL were searched from inception until 9 July 2020 and supplemented with hand searching. Search results were screened, eligible data were extracted, and risk of bias was assessed by at least two reviewers. Of 8571 publications considered, 32 trials which used a variety of subjective and objective sleep measurements were included in generic inverse variance random effects meta-analysis of nocturnal (n = 24), day-time (n = 14), and 24-h (n = 13) sleep duration. Overall, sleep interventions increased nocturnal sleep duration by a mean of 9 min (95% CI 4.1 to 13.8, I²28%) per night when compared with no sleep intervention. Increases were predominantly seen in sleep-only, rather than multi-component interventions. Total 24-h sleep duration tended to increase by a similar amount (8.6 min (95% CI -2.7 to 19.8, I² = 59%)), but this was mainly only seen in studies that assessed sleep using diaries. There was no evidence that interventions changed day-time sleep duration. Future studies should involve sleep-only rather than multi-component interventions, and use objective sleep measures (reviewregistry857).

Associations of sleep with gray matter volume and their implications for academic achievement, executive function and intelligence in children with overweight/obesity

BACKGROUND

Children with overweight/obesity have poorer sleep and smaller gray matter volume (GMV) than normal-weight children. No studies have investigated the associations of objectively-assessed sleep and GMV in children with overweight/obesity, or their implications for academic and cognitive outcomes.

OBJECTIVES

To explore the associations of sleep behaviors with GMV in the whole brain and particularly the hippocampus as a region of interest independent of sedentary time (SED) and physical activity; and to assess whether GMV in the associated regions was related to academic achievement, executive function and intelligence quotient (IQ).

METHODS

Ninety-six children with overweight/obesity (10 ± 1 year) were included. Sleep behaviors were assessed with accelerometers. GMV was acquired by magnetic resonance imaging. Academic achievement, executive function and IQ were assessed with separate tests. Analyses were adjusted for sex, peak height velocity and parent education as well as SED and physical activity.

RESULTS

Earlier wake time, less time in bed, wakening after sleep onset (WASO) and WASO occurrences were associated with higher GMV in eight cortical brain regions (k:56-448, P's < .001). Longer total sleep time, higher sleep efficiency and less WASO time were associated with higher GMV in the right hippocampus (β:0.187-0.220, P's < .05). The inferior temporal, fusiform, supramarginal, and postcentral gyri, the superior parietal cortex, precuneus and hippocampus associated with academic achievement and/or IQ. Associations remained after adjustments for SED and physical activity.

CONCLUSIONS

Sleep behaviors are associated with GMV in multiple cortical regions including the right hippocampus in children with overweight/obesity, which in turn, were associated with academic achievement and IQ.

Effects of Family Intervention on Physical Activity and Sedentary Behavior in Children Aged 2.5-12 Years: A Meta-Analysis

Introduction: To use a quantitative approach to examine the effects of family interventions on physical activity (PA) and sedentary behavior (SB) in children aged 2. 5-12 years. Methods: PubMed, OVID, Web of Science, and others were searched from their inception to May 2020. Intervention studies that examined the effects of family interventions on PA among children aged 2.5-12 years were included in this meta-analysis. Lastly, subgroup analyses were conducted to examine the potential modifying effects of family intervention's characteristics and study quality. Results: Eleven articles met the inclusion criteria for this review. Studies investigated a range of PA outcomes, including moderate-to-vigorous PA (MVPA), total PA (TPA), daily steps, and SB levels. Meta-analysis showed that family intervention had a significant effect on PA [standardized mean difference (SMD) = 0.10; 95% CI = 0.01-0.19], especially for daily steps [weight means difference (WMD) = 1,006; 95% CI = 209-1,803], but not for SB (WMD = -0.38; 95% CI = -7.21-6.46). Subgroup analyses indicated the improvements in PA occurred when children were 6-12 years old, intervention focused on PA only, intervention duration ≤ 10 weeks, and "low risk of bias" study performed. Conclusions: Family intervention may be a promising way to promote children's PA levels, especially for daily steps. Trial Registration: Meta-analysis protocol was registered on PROSPERO: CRD42020193667.

The cross-sectional and prospective associations between sleep characteristics and adiposity in toddlers: Results from the GET UP! Study

BACKGROUND

The associations between sleep characteristics and adiposity in children under three years are not fully understood yet.

OBJECTIVE

The objective of the study is to examine the cross-sectional and prospective associations between sleep characteristics and adiposity in toddlers over a 12-month period.

METHODS

Participants were 202 toddlers from the GET-UP!

STUDY

Sleep duration, sleep timing, and sleep variability were assessed using 24-hour accelerometry for seven consecutive days. Height and weight were measured, and BMI z scores were calculated. Linear mixed models were performed to examine the cross-sectional and prospective associations between sleep characteristics and adiposity, with adjustments for clustering effects and demographic factors.

RESULTS

Total sleep duration was negatively associated with higher adiposity cross-sectionally (B = -0.12; 95% CI: -0.23, -0.01; .033) but not prospectively (B = 0.01; 95% CI: -0.13, 0.10; .843). Nap duration was prospectively associated with higher levels of adiposity (B = 0.41; 95% CI: 0.14, 0.68; .003). Sleep variability and sleep timing were not associated with concurrent or subsequent adiposity.

CONCLUSION

Although sleep duration is an important factor associated with obesity in toddlerhood, the potential effects of different types of sleep duration may vary. While longer total sleep duration may protect children from increasing adiposity, longer nap duration seems to be risk factor. As evidence in this age group is scarce, more research is needed to confirm this finding.