Sally Staton

Napping, development and health from 0 to 5 years: a systematic review

Background Duration and quality of sleep affect child development and health. Encouragement of napping in preschool children has been suggested as a health-promoting strategy. Objectives The aim of this study is to assess evidence regarding the effects of napping on measures of child development and health. Design This study is a systematic review of published, original research articles of any design. Subjects Children aged 0–5 years. Method Electronic database search was performed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and assessment of research quality was carried out following a Grading of Recommendations, Assessment, Development and Evaluations (GRADE) protocol. Results Twenty-six articles met inclusion criteria. These were of heterogeneous quality; all had observational designs (GRADE-low). Development and health outcomes included salivary cortisol, night sleep, cognition, behaviour, obesity and accidents. The findings regarding cognition, behaviour and health impacts were inconsistent, probably because of variation in age and habitual napping status of the samples. The most consistent finding was an association between napping and later onset, shorter duration and poorer quality of night sleep, with evidence strongest beyond the age of 2 years. Limitations Studies were not randomised. Most did not obtain data on the childrens habitual napping status or the context of napping. Many were reliant on parent report rather than direct observation or physiological measurement of sleep behaviour. Conclusions The evidence indicates that beyond the age of 2 years napping is associated with later night sleep onset and both reduced sleep quality and duration. The evidence regarding behaviour, health and cognition is less certain. There is a need for more systematic studies that use stronger designs. In preschool children presenting with sleep problems clinicians should investigate napping patterns.

Mandatory Naptimes in Child Care and Children's Nighttime Sleep.

Objectives: To examine the relationship between mandatory naptimes in child care and childrens nighttime sleep duration, both concurrently and 12 months later once in school. Methods: A sample of 168 children (50–72 months; 55% males) attending licensed child care centers were observed across their morning and throughout their scheduled naptime. Mandatory naptime was determined as the period in which children were not permitted any alternative activity except lying on their bed. Teachers reported each childs napping in child care. Nighttime and total sleep duration was reported by parents at 2 time points, in child care and in the second semester of their first school year. General linear models were used to examine group differences in sleep duration between children experiencing 0 to 60 minutes and >60 minutes of mandatory naptime, adjusting for key confounders. Path analysis was conducted to test a mediation model in which mandatory naptime is associated with nighttime sleep duration through increased napping in child care. Results: Children who experienced >60 minutes of mandatory naptime in child care had significantly less nighttime sleep than those with 0 to 60 minutes of mandatory naptime. This difference persisted at 12-month follow-up, once children were in school. Napping in child care mediated the relationship between mandatory naptime and duration of nighttime sleep. Conclusions: Exposure to mandatory naptimes of >60 minutes in child care is associated with decreased duration of nighttime sleep that endures beyond child care attendance. Given the large number of children who attend child care, sleep practices within these settings present an important focus for child health.

“Do I really need a nap?”: The role of sleep science in informing sleep practices in early childhood education and care settings

A compelling body of studies identifies the importance of sleep for children’s learning, behavioral regulation, and health. These studies have primarily focused on nighttime sleep or on total sleep duration. The independent contribution of daytime sleep, or napping, in childhood is an emerging research focus. Daytime sleep is particularly pertinent to the context of early childhood education and care (ECEC) where, internationally, allocation of time for naps is commonplace through to the time of school entry. The biological value of napping varies with neurological maturity and with individual circumstance. Beyond the age of 3 years, when monophasic sleep patterns become typical, there is an increasing disjuncture between children’s normative sleep requirements and ECEC practice. At this time, research evidence consistently identifies an association between napping and decreased quality and duration of night sleep. We assess the implications of this evidence for educational practice and health policy. We identify the need to distinguish the functions of napping from those of rest, and assert the need for evidence-based guidelines on sleep–rest practices in ECEC settings to accommodate individual variation in sleep needs. Given both the evidence on the impact of children’s nighttime sleep on long-term trajectories of health and well-being and the high rates of child attendance in ECEC programs, we conclude that policy and practice regarding naptime have significant implications for child welfare and ongoing public health.

Conflict, closeness and comfort: the inter-twin relationship as a risk factor for behavioral difficulties.

BACKGROUND There is currently little evidence concerning the impact of the inter-twin relationship on behavioral outcomes and yet the twin relationship is frequently hypothesized to be a unique source of psychopathology in twins. The current study asked whether the inter-twin relationship is a predictor of behavioral difficulties and whether there are zygosity differences in this relationship. METHOD An Australian sample of same sex twins (N = 356, 164 MZ and 192 DZ) was studied in the year prior to school (Time 1) and again in first year of school (Time 2). Associations between twin-relationship and behavior problems were examined via path-analysis, and Satorra-Bentler chi-square difference tests were used to compare twins across zygosity. RESULTS Results show that both conflict and lower levels of warmth at Time 1 were predictive of hyperactivity and conduct disorder at Time 2, but they were not associated with emotional difficulties or peer problems. While DZ twins shared less warmth than MZ twins, there were no differences in behavior problems. CONCLUSION Conflict and lower levels of warmth in the inter-twin relationship are associated with hyperactivity and conduct disorder and may serve as important considerations when making decisions regarding class separation at entry to school.

Environmental Light Exposure Is Associated with Increased Body Mass in Children

The timing, intensity, and duration of exposure to both artificial and natural light have acute metabolic and physiological effects in mammals. Recent research in human adults suggests exposure to moderate intensity light later in the day is concurrently associated with increased body mass; however, no studies have investigated the effect of light exposure on body mass in young children. We examined objectively measured light exposure and body mass of 48 preschool-aged children at baseline, and measured their body mass again 12 months later. At baseline, moderate intensity light exposure earlier in the day was associated with increased body mass index (BMI). Increased duration of light exposure at baseline predicted increased BMI 12-months later, even after controlling for baseline sleep duration, sleep timing, BMI, and activity. The findings identify that light exposure may be a contributor to the obesogenic environment during early childhood.

To separate or not to separate? Parental decision-making regarding the separation of twins in the early years of schooling

In recent times concerns about possible adverse effects of early separation and advocacy for individual rights have resulted in a movement away from organizational level policies about the separation of twin children as they enter school. Instead, individualized approaches that focus on the twin children’s characteristics and family perspectives have been proposed. This study, conducted in Australia where all but a few families had choice about the class placement of their twin children, questioned parents (N = 156) about their placement decisions. Results indicated that most parents opted for placement together in the early years of schooling. The choice to separate twins at school entry was associated with parent identification of risk in the twin relationship, while being kept together was associated with parent identification of absence of such risk. The findings are discussed in light of the current evidence against separation, and suggest that parent choices regarding the separation of twin children in the early years are informative to educational policy and practice.

Mandatory Nap Times and Group Napping Patterns in Child Care: An Observational Study.

Policy provision for naps is typical in child care settings, but there is variability in the practices employed. One practice that might modify children’s early sleep patterns is the allocation of a mandatory nap time in which all children are required to lie on their beds without alternate activity permitted. There is currently limited evidence of the effects of such practices on children’s napping patterns. This study examined the association between duration of mandatory nap times and group-level napping patterns in child care settings. Observations were undertaken in a community sample of 113 preschool rooms with a scheduled nap time (N = 2,114 children). Results showed that 83.5% of child care settings implemented a mandatory nap time (range = 15–145 min) while 14.2% provided alternate activities for children throughout the nap time period. Overall, 31% of children napped during nap times. Compared to rooms with ≤ 30 min of mandatory nap time, rooms with 31–60 min and > 60 min of mandatory nap time had a two-and-a-half and fourfold increase, respectively, in the proportion of children napping. Nap onset latency did not significantly differ across groups. Among preschool children, exposure to longer mandatory nap times in child care may increase incidence of napping.

Supporting sleep in early care and education: an assessment of observed sleep times using a sleep practices optimality index

AIM The aim was to investigate whether the sleep practices in early childhood education (ECE) settings align with current evidence on optimal practice to support sleep. BACKGROUND Internationally, scheduled sleep times are a common feature of daily schedules in ECE settings, yet little is known about the degree to which care practices in these settings align with the evidence regarding appropriate support of sleep. METHODS Observations were conducted in 130 Australian ECE rooms attended by preschool children (Mean=4.9years). Of these rooms, 118 had daily scheduled sleep times. Observed practices were scored against an optimality index, the Sleep Environment and Practices Optimality Score, developed with reference to current evidence regarding sleep scheduling, routines, environmental stimuli, and emotional climate. Cluster analysis was applied to identify patterns and prevalence of care practices in the sleep time. RESULTS Three sleep practices types were identified. Supportive rooms (36%) engaged in practices that maintained regular schedules, promoted routine, reduced environmental stimulation, and maintained positive emotional climate. The majority of ECE rooms (64%), although offering opportunity for sleep, did not engage in supportive practices: Ambivalent rooms (45%) were emotionally positive but did not support sleep; Unsupportive rooms (19%) were both emotionally negative and unsupportive in their practices. CONCLUSIONS Although ECE rooms schedule sleep time, many do not adopt practices that are supportive of sleep. Our results underscore the need for education about sleep supporting practice and research to ascertain the impact of sleep practices in ECE settings on childrens sleep health and broader well-being.

Mandatory naptimes in childcare do not reduce children's cortisol levels

The majority of preschool children (aged 3–5 years) no longer habitually nap, yet in childcare settings daily mandated naptimes in which children lie down without alternative activity remains a common practice. Mandated naptimes are associated with observed reductions in emotional climate and increased incidence of distress. While intended to be restful, mandatory naptimes may induce stress in those children unable to sleep. To examine this possibility, we applied a 2 (mandated/flexible practice) × 2 (nap/no-nap) design to test group difference in stress responses of children (N = 43, mean age 56.3 months). Salivary cortisol level was measured at 4 time-points (waking, pre-naptime, post-naptime, and bedtime) across two days at childcare. Overall our results show a significant decline in cortisol level from wake to pre-naptime and from post-naptime to bedtime. No significant change in cortisol level was observed from pre- to post- naptime. Significant group differences in cortisol patterns were observed. Notably, children under mandatory naptime conditions who did not nap showed no significant reduction in cortisol level from post-naptime to bedtime. While cortisol measurement suggests naptime is neither stressful nor restful for children in any group, implications for bedtime arousal are raised for those unable to sleep under conditions of mandated naptimes.

Investigating the association between sleep parameters and the weight status of children: night sleep duration matters

Objectives: To examine the associations between sleep parameters and weight status in a large sample of preschool children. Design: Cross‐sectional survey data from the Effective Early Educational Experiences for children (E4Kids) study were analyzed. Participants: 1111 children aged 3 to 6 years from Queensland and Victoria, Australia. Measurements: General linear modeling, with adjustment for significant control variables, assessed the impact of night sleep duration, total sleep duration, napping frequency, sleep timing (onset, offset and midpoint), and severity of sleep problems on standardized body mass index (BMI z score). General linear modeling was conducted for the total sample and then separately by sex. Results: For the total sample, there was a significant association between short sleep duration (≤10 hours) and increased BMI z score. No other sleep parameters were associated with BMI z score in this sample. Analyses by sex revealed that, among girls, there were no associations between any sleep parameter and BMI z score. However, among boys, short night sleep duration and napping frequency were both significantly associated with weight status even after adjustment for controls. Conclusion: Night sleep duration is a consistent independent predictor of body mass in young children. These results identify a complex relationship between sleep and body mass that implicates sex. Potential mechanisms that might explain sex differences warrant further investigation.