Secondhand Smoke Can Hurt Kids With Asthma More

Passive smoking can inhibit the action of corticosteroids used to relieve asthma in children

(RxWiki News) Secondhand smoke can make asthma worse and have other serious health effects in children. Recent research suggests it can also change how well asthma medications work in kids.

According to the US Environmental Protection Agency (EPA), secondhand smoke can cause asthma, pneumonia, bronchitis and middle ear infections in children. Children who are too young to leave the area of the secondhand smoke are especially vulnerable to the health effects.

In some children who already have asthma, their asthma is made worse by passive smoke and their asthma treatments may not work well.

Researchers recently found two important cell proteins that were different in kids exposed to secondhand smoke. This might help explain why corticosteroid asthma medications didn't work in these kids.

"Never smoke around children."

Yoshiki Kobayashi, MD, from the Airway Disease Section of the National Heart and Lung Institute at Imperial College London in England, led a team of researchers who investigated how passive smoking affected children's response to their asthma medication.

The study included 19 children with an average age of 10 who were having a bronchoscopy — a procedure that allows doctors to look at lung airways — because of severe asthma.

While the bronchoscopy was being done under anesthesia, the doctors rinsed some cells off the lining of the lung airways. These cells were studied in the lab to determine the amount and activity of several proteins needed for corticosteroids to work properly.

The researchers noted which children came from homes where they were exposed to secondhand smoke, as reported by the children's parents. There were nine children in the non-smoking home group and 10 in the passive smoking home group. The children in the passive smoking home group were exposed to secondhand smoke for an average of 10 years.

Results of the experiments showed that, in children from passive smoking homes, the amount of a protein called histone deacetylase-2 (HDAC2) was decreased by 54 percent and its activity was decreased by 47 percent, compared to protein from cells of children in non-smoking homes. This protein is an enzyme that is necessary for corticosteroids to be able to switch off the inflammatory process associated with asthma.

The authors concluded that exposure to passive smoke impairs proteins that contribute to making asthma resistant to steroid therapy.

This study was published in the February issue of Chest.

Funding for the study was provided by the Wellcome Trust and the National Institute of Health Research Respiratory Disease Biomedical Research Unit at the Royal Brompton and Harefield NHS Foundation Trust and Imperial College London.

The researchers reported having no potential conflicts of interest.

Review Date: 
February 21, 2014