Sleep of pre-school children: relationships to health
Sleep Habits in Youngsters (the SHINY Study)
There is strong and consistent epidemiological evidence that short sleep duration is associated with increased risk of obesity from early childhood. Childhood obesity and inadequate sleep have negative consequences for health and well-being, and the ability to target both of these public health concerns with a novel obesity intervention involving sleep extension is appealing; yet little is known about the mechanisms linking short sleep with obesity. In adults, hormonal mechanisms have been proposed; in young children, behavioural mechanisms and parenting are likely to be involved. Furthermore, the wider social and cultural determinants of short sleep and obesity should be incorporated into sleep-obesity research. This study aimed to explore some aspects of the sleep-obesity link in preschool children, using an exploratory design with a mixture of quantitative and qualitative methods, and applying an evolutionary medicine perspective.
Participants were 109 3-year-old children and their parents in Stockton-on-Tees. Children's sleep (validated by actigraphy), food intake and activity over 4 days/5 nights were assessed by parental diary report, and body composition was measured. Parents' attitudes were explored using semi-structured interviews. Combined daytime and nighttime sleep duration was associated with central fat. Alternate parenting strategies were identified, based on regulation and consistency (routine-led), or child-governance and lack of regulation (routine-free). Building on the trends identified and the literature reviewed, we proposed two hypotheses to explain the short sleep-obesity link in young children: the Behavioural Mechanisms Hypothesis (dietary and activity behaviours mediate or confound the association), and the Parental Confounding Hypothesis (parenting strategies, which vary with SES, impact on both children's sleep duration and obesity risk). Parenting impacts children's health by either limiting or facilitating discordance between children's experiences in evolutionarily novel environments, and their biological make-up. We conclude that sleep-based obesity interventions should consider the wider context of children's behaviours, particularly strategies of parenting.
To explore whether child sleep duration might be extended via educational interventions, two sleep interventions were delivered between 2009 and 2010. One targeted parents of preschool children through Sure Start children's centres. The second targeted preschool children through local school and private nurseries. Data were collected pre and post intervention via questionnaires and interviews. A control group was also recruited for the study.
The parent intervention and was designed, delivered and evaluated via participatory research with local parents. Participatory research enabled parents to discuss and define their concerns regarding their children's sleep. Access to sleep research and resources were provided by the Sleep Lab. The participatory research group combined this information with their own experiences to generate solutions to sleep issues. This knowledge led to the group producing Sleep Solutionz materials, a series of leaflets and posters addressing common sleep issues in early childhood, featuring the participatory research groups' families. These were displayed and available to parents in a number of Sure Start children's centres within Stockton-on-Tees. The leaflets can be downloaded here:
- Everything you need to know for a blissful bedtime for you and your child
- Dealing with night waking: young children and babies
- Handy hints for your child's development
- Sleep, eat and exercise
- Sharing our stories
The nursery intervention was designed with the input of local parents, educators and Sure Start staff. It incorporated stories, games, role play and creative activities intended to encourage children to think and talk about sleep; why we sleep, where we sleep, and when we sleep, and their own bedtimes. Children used disposable cameras to record their favourite activities at bedtime. The project provided the parents of participating children with a booklet of the activities, including photos and quotes from the children.
The success of the two interventions was evaluated for Dr Meg Newark (Smith)'s PhD (see below).