Nighttime Asthma Squeezes School Attendance

"Nighttime asthma may be a marker that asthma is out of control, or it may be a different phenomenon, caused by different triggers," said Diette. "If asthma disrupts the amount or quality of sleep, the children don't function as well the next day. And parents may suffer when they lose sleep to care for their sick children."

Diette and his colleagues surveyed 400 parents whose children suffered asthma and were treated by doctors at managed care clinics. During the month leading up to the survey, nocturnal asthma attacks awakened 56 percent of the children one or more nights, and 30 percent missed one or more days of school because of their asthma. Thirty-six percent of the parents felt nocturnal attacks hindered their child's school performance.

And parents suffered as well -- 30 percent of them reported missing work or other important activities on days following their children's nighttime tossing and turning. Diette and his colleagues at Hopkins in Baltimore and researchers at Merck and Co., West Point, Pa., also found that children who woke up more often tended to miss more school and their parents tended to miss more work. This positive correlation held even when the researchers took into account the severity of the child's daytime symptoms and reliance on medication.

"No matter how severe the child's daytime symptoms, the more frequently they woke up at night, the more likely they were to miss school," said Diette. "The explanation may be as simple as a sleep disturbance interfering with routine daytime functioning."

One reason for nighttime asthma may be the environment, says Diette. Triggers like dust mites and cockroach antigens tend to be more prevalent at home and may cause attacks when children head for bed.

Diette adds that doctors could better target nighttime symptoms by using treatments that work overnight, such as long-acting beta agonists, or by prescribing appropriate doses of long-term control medicines like anti-inflammatories.