MONDAY, April 7, 2008 (HealthDay News) -- Babies who get less than 12 hours of sleep a day face twice the risk of being overweight as preschoolers.
And, some parents may inadvertently contribute to their child's sleep problems by taking steps intended to soothe the child that, in reality, lead to disrupted sleep.
That's the conclusion of two reports in April's special issue of the Archives of Pediatrics & Adolescent Medicine, which is devoted to children and sleep.
"The combination of too little sleep and too much TV is associated with markedly elevated risk of obesity," explained Dr. Elsie M. Taveras, an assistant professor of ambulatory care and prevention at Harvard Medical School and lead author of the first study.
For the study, Taveras and her colleagues collected data on 915 children whose mothers reported on their child's sleep habits during the first two years of life. Using this information, researchers were able to determine how much sleep the children had each day between 6 months and 2 years of age.
On average, the children slept 12.3 hours a day. When the children reached 3 years of age, 83 were overweight. The researchers found that 3-year-olds who slept less than 12 hours a day as infants weighed more for their age and sex, compared with children who slept 12 hours a day or more as babies.
Also, babies who watched two or more hours of television a day had a 16 percent increased risk of being overweight, compared to a 1 percent risk for babies who didn't watch TV, Taveras said.
"The combination of low sleep and high TV might be acting independently to be a higher risk for obesity," Taveras said. The explanation may trace to hormones that control appetite, she added.
In the second study, Valerie Simard, of the Hopital du Sacre-Coeur de Montreal and the University of Montreal, and colleagues found that parents' behavior at bedtime was linked to sleep disturbances of their children.
The researchers had the parents of 987 children fill out questionnaires about their children's sleep habits each year from the time the children were 5 months old until they were 6 years old. They found that sleep disturbances among very young children (5 to 17 months old) were primarily due to "maladaptive parenting behaviors," such as the mother being present when the child was going to sleep, or feeding the child after he or she woke up. And "co-sleeping" -- when a parent sleeps with a child -- was found to make it harder for a child to fall back asleep after awakening.
"Our findings clarify the long-debated relationship between parental behaviors and childhood sleep disturbances," the authors concluded. "They suggest that co-sleeping and other uncommon parental behaviors have negative consequences for future sleep and are thus maladaptive."
In another study in the journal, Australian researchers found that children with attention-deficit/hyperactivity disorder were more likely to have sleep problems than children without the disorder.
"Sleep problems in schoolchildren with ADHD are extremely common and strongly associated with poorer quality of life, daily functioning and school attendance in the child and poorer caregiver mental health and work attendance," wrote the researchers, who were headed by Valerie Sung, of the Centre for Community Child Health in Parkville.
"Implementation of a sleep intervention in children with ADHD could feasibly improve outcomes beyond treatment of ADHD alone. It is possible that such intervention could reduce the need for medication in some children," they added.
A fourth study, led by Alice M. Gregory of the University of London, found that children who get less sleep are more likely to suffer from symptoms of anxiety, depression and aggression later in life. Among 2,076 children studied, the researchers found that those who had sleep problems when they were 4 to 16 years of age scored higher on measures of anxiety, depression and aggressive behavior when they were 18 to 32 years of age.
"The results suggest that children reported to sleep for short periods may be at risk for later difficulties," the authors concluded.
One expert thinks that good sleep behaviors for infants are extremely important and need to be started early.
"We have to pay attention to the very early effects of sleep and health and eating in children. It probably does pave the way for a lifestyle, even in early childhood, that is going to be difficult to steer away from," said Dr. Ann Halbower, medical director of the Pediatric Sleep Disorders Program at Johns Hopkins University Children's Center in Baltimore.
Halbower thinks good sleep behaviors for infants need to be taught to parents before the child is born.
"If I meet with moms while they are pregnant and start discussing sleep behaviors, sleep routines, proper sleep habits and safe sleep for their child, they were much more likely to start that pattern than trying to change a behavior after it had become routine," she said.
To learn more about children and sleep, visit the National Sleep Foundation.