Secondhand smoke disturbs asthmatics' sleep

Children with asthma have a harder time getting a good night's sleep if they live with a smoker.

Children with asthma are especially vulnerable to the effects of tobacco smoke exposure. Childhood sleep disturbances can have significant consequences, including attention and behavior problems, and poor school performance. To investigate the relationship between exposure to secondhand smoke at home and child sleep patterns, researchers studied 219 American children, aged between 6 and 12 years, who were enrolled in an asthma intervention trial and were exposed regularly to secondhand smoke. The researchers also took blood samples from the children to measure levels of cotinine - a byproduct of nicotine that serves as a marker of exposure to tobacco smoke. Parents were interviewed about their children's sleep habits, asthma severity and exposure to secondhand smoke at home and elsewhere.

It was found that the children who were exposed to secondhand smoke tended to have poorer sleep at night and more drowsiness during the day.  Sleep problems included more difficulty falling asleep, more night-time breathing symptoms and more so-called parasomnias - problems such as sleepwalking, nightmares and night terrors. The link between secondhand smoke and sleep problems was still apparent when the researchers accounted for the severity of the children's asthma overall, suggesting that exposure to smoking, itself, was affecting the children's quality of sleep.

While the reasons for the connection are uncertain, the researchers say it's likely that asthmatic children exposed to tobacco smoke have more night-time breathing problems, which in turn disrupts their sleep. Along with the effects of tobacco smoke on children's airways, nicotine - a known stimulant may directly affect sleep patterns.