Lack of sleep takes a toll on children

Sleep deprivation and obesity in children have been considered together in the past, but Dr. Elsie Taveras of Harvard Medical School tracked children from infancy, before they were overweight, to preschool age to see if there was a link.

She found that children who slept less than 12 hours per day were twice as likely to be overweight at age 3 than children who slept longer, even when how much television they watched was taken out of the equation. (Watching a lot of TV combined with not sleeping very much did appear to lead to higher weight in children, she wrote.)

"It really falls in line in general with the epidemiology of obesity," Dr. Christopher Landrigan of Brigham and Women's Hospital, who was not involved in the research, said in an interview. "Over the past decade there's been an increase in obesity at the same time the amount of sleep adults and children is falling in tandem, compared to the 1960s and '70s. It's causing real concern about the ill effects of sleep deprivation."

Another study of Dutch children said that lack of sleep during childhood may be a warning flag for emotional problems, attention difficulties, and aggression later in life. Short sleepers may not function as well during the day, having difficulty with other people or getting into accidents, leading to emotional and behavioral trouble, the authors suggest.

Unlike adults, when children don't get enough sleep, they can become hyperactive -- so much so their behavior can be confused with attention deficit disorder. Many children with ADD also have sleep problems, another study points out.

Good sleep hygiene -- bedtime rituals, a calm environment, allowing a child to learn how to fall back asleep alone -- can help. Sleep apnea or other physical causes should be treated or ruled out, Kothare and Landrigan said. Parents who stay with their children until they fall asleep or bring food when they awake during the night can interfere with good sleep patterns.

"A good night's sleep will lead to good daytime function in society and in school," Kothare said.