Passive Smoking Lowers Treatment Effectiveness in Children with Asthma

Asthmatic Children exposed to cigarette smoke at home don't respond to treatment due to lower levels of a key enzyme, a latest study has found. The research shows that it is important to protect these children from secondhand smoke, both in public and at home.

Previous studies had shown the effects of treatment for secondhand smoking in children with asthma. In this study, researchers at Imperial College London found that children exposed to cigarette smoke at home tend to have lower levels of the enzyme HDAC2.

Asthma is a chronic, lung condition, according to the National Heart Lung and Blood Institute. The disease causes chest tightening, wheezing and coughing. Steroids are often used to treat the condition.

The enzyme HDAC2 is required for steroids to lower inflammation in children with asthma.

"The mechanism we've identified makes children less sensitive to inhaled steroid treatment, so they suffer more symptoms and might have to take higher doses of steroids, which may lead to side effects," said Professor Peter Barnes FRS, from the National Heart and Lung Institute at Imperial College London.

"These findings underline the importance of legislation aimed at protecting children from being exposed to cigarette smoke. Restricting smoking in cars is a positive step, but the same should be applied in homes," said Barnes in a news release.

The study was based on data from 19 children who were being treated for asthma at the Royal Brompton Hospital in London. Nine participants were exposed to cigarette smoke at home while 10 were from non-smoking households.

Researchers found that cells of children exposed to smoking had half the levels of HDAC2 enzymes than other children.

The study is published in the journal Chest.

In the U.S., about 25 million people suffer from asthma, of which at least 7 million are children, according to NHLBI.