Just because they’re sick doesn’t mean that children with chronic illness will sleep peacefully through the night, new research from Norway shows.

Children with sleep problems often don’t outgrow them, and these problems may be particularly persistent in kids with chronic illness, Dr. Mari Hysing and co-investigators report in the journal Child and Adolescent Psychiatry and Mental Health.

The findings highlight the importance of identifying sleep issues in these children, which can be treated effectively using behavioral strategies and other approaches, Hysing of the University of Bergen, one of the researchers on the study, told Reuters Health.

“Consistent bedtime routines, removal of distractions and general sleep hygiene advice are key elements,” she said via e-mail. “For some children with chronic illness, melatonin may be an effective treatment.”

Studies that have looked at a single point in time have shown that chronically ill kids have more sleep problems than healthy children, Hysing and her colleagues note in their report. However, there have been no studies that follow sleep problems in ill children over time.

To see how persistent these problems were in both chronically ill and healthy children, Hysing and her team used data from the Bergen Child Study, which includes all children attending schools in the city. Among the 4,025 children in the analysis, 295 (7.3 percent), had some type of chronic illness, such as epilepsy, diabetes, migraine, and cerebral palsy.

The researchers collected two “waves” of data, the first when the children were 7 to 9 years old, the second when they were 11 to 13. The researchers asked parents if their child had difficulty falling asleep or woke frequently during the night.

Their research showed that nearly 7 percent of the sick children had sleep problems at both time points, compared to almost 4 percent of healthy kids.

Rates of sleep difficulties tended to increase over time in both groups. At the first survey, 8 percent had sleep problems, while 12 percent had these problems at age 11 to 13.

Being hyperactive or having emotional problems at the first data collection point also increased the risk of later problems.

Helping chronically ill children sleep better could have major impacts on their quality of life - and that of their families, Hysing said. Lack of sleep can worsen the symptoms of many chronic illnesses, and making it harder for kids to learn. Too little sleep can also impair the immune system, making the child more prone to other illnesses.

Having shown that emotional health seems to affect children’s sleep, Hysing and her colleagues now plan to look at whether sleep affects their mental health. The team will also continue to follow the children in the current study into later adolescence and early adulthood.

SOURCE: Child and Adolescent Psychiatry and Mental Health, August 27, 2009.