Despite fears that Australian children are not getting enough sleep, it turns out we can rest easy.
A national snapshot of the health of Australian 11-12 year olds and their parents has found that pre-teens and middle aged adults are usually getting the recommended amount of sleep and that family-based routines are an important part of that.
But while Aussie families in this age-bracket are getting the right amount, researchers in the Murdoch Children's Research Institute's Child Health CheckPoint study found they are not always sleeping soundly.
Lead investigator Professor Timothy Olds from the University of South Australia's Alliance for Research in Exercise, Nutrition and Activity (ARENA) said Australian children tend to sleep more than the rest of the world, although it is not clear why.
"All around the world children have been getting 25 minutes less sleep than the previous generation for over 100 years, but not in Australia. So far, we are not seeing the same sleep crisis in children here," Prof Olds said.
As part of the study 1261 children and 1358 parents wore a physical activity monitor (wrist accelerometer) for seven days and also kept a written record of their sleep patterns over that time. The device recorded the time each person went to sleep, how long they slept, time of waking, day-to-day differences and soundness of sleep, which is defined as the percentage of actual sleep between falling asleep and waking.
The results, published in BMJ Open, showed that almost all the parents and more than 70 per cent of children aged 11-12 years met established sleep recommendations. According to the benchmark US National Sleep
Foundation recommendations, children aged six to 13 years should have nine to 11 hours sleep, while adults should be getting seven to nine hours a night.
The Child Health CheckPoint study also found that sleep efficiency - or soundness and continuity of sleep - was less than optimal in 42 per cent of parents and 55 per cent of children.
Similarities between parents and children were strongest for the time of falling asleep and waking - probably reflecting the shared home environment - with more modest links for duration, variability of sleep routine and quality of sleep.
Prof Olds said the study moved beyond the traditional approach of examining isolated sleep characteristics to look at the many facets of healthy sleep, with problem sleep known to affect cognitive function, mood, weight, diabetes and cardiovascular risk.
He said sleep patterns were most likely built on a combination of environmental factors - such as traffic noise, parenting styles and family routines - and genetic causes such as the rate and timing of melatonin and serotonin release, which help regulate sleep/wake cycles.
"Our findings are in line with growing awareness that optimal healthy sleep may be the result of multiple sleep characteristics," Prof Olds said.
"It depends on when we go to sleep, how long we sleep, how well we sleep and the regularity of sleep and wake times. Early to bed, early to rise is the healthiest pattern and if a family can introduce that as a whole, then it's healthy for everyone."
• Funded by the Federal Government, the Child Health CheckPoint is nested within the Growing Up in Australia, which is run by the Department of Social Services, Australian Institute of Family Studies and Australian
Bureau of Statistics. The Child Health CheckPoint was supported by the National Health and Medical Research Council (Project Grants 1041352, 1109355), Royal Children's Hospital Foundation (2014-241), Murdoch
Children's Research Institute, National Heart Foundation of Australia (100660), Financial Markets Foundation for Children (2014-055, 2016-310) and the Victoria Deaf Education Institute.
