Children who wake frequently at night at 'double risk of asthma'
Thursday November 26 2009
Children who wake up frequently through the night may have double the chance of developing asthma, research has found.
Children who woke up twice or more times a week up to the age of three were twice as likely to go on to develop asthma, the teams from Australia and Canada found.
The findings have surprised experts who previously thought the connection between sleep patterns and asthma was that the wheezing symptoms were what was causing children to wake.
The study, published in the European Respiratory Journal, followed 2,400 children in Australia from birth to age 14 with their mothers filling out detailed questionnaires about the child's sleep patterns, their pregnancy, family lifestyle and any other medical conditions.
They found at age one, a third of children woke up at night more than twice a week which dropped by 27 per cent by age three.
The children who had broken sleep up to the age of three were more than twice as likely to be receiving treatment for asthma at age 14. The effect remained even after taking into account other factors that associated with asthma such as breastfeeding and sleeping with parents.
The link was found only with non-allergic asthma, the form of the disease brought on by cold weather, exercise, or infection and not with the allergic form, where wheezing is in reaction to pets or pollen.
Lead author Anita Kozyrskyj, of the Department of Paediatrics at the University of Alberta, Edmonton, Canada, said: "A reduction in the number of hours of sleep had already been blamed for ADHD and child obesity, but to our knowledge this is the first time the onset of asthma has been associated with broken sleep."
She said certain chemicals produced by the body encourage inflammation and are involved in both sleep control and sensitivity of the airways, which could be the reason for the link.
"The link between stress and asthma is well established, although the relationship is still not fully understood. Part of the link may be due to the effects of stress on the body's immune system and we know that the workings of the immune system can also be affected by sleep.
- Rebecca Smith
© Telegraph.co.uk
