Children exposed to cigarette smoke at home have lower levels of enzymes that help them respond to asthma treatments properly, according to new research.
Previous studies have established that passive smoking worsens asthma in children and impair their healing process. But as to how this occurs is still unknown. Just recently, scientists from the Imperial College London found that children whose parents’ smoke at home have lower levels of HDAC2 than those whose parents do not smoke. This enzyme is required for steroids to exert their beneficial anti-inflammatory effects.
“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.”
The new study involved 19 children with severe asthma receiving treatment at Royal Brompton Hospital in London. 9 had parents who smoked at home and 10 were from non-smoking households. Findings revealed that cells from the lungs of children exposed to second-hand smoke had about half the levels of HDAC2 enzymes as those from children from non-smoking families.
“Children with asthma who are passively exposed to cigarette smoke have the same molecular abnormalities that lead to steroid resistance as adults who actively smoke,” reported Professor Barnes. “The mechanism we’ve identified will be a target for new treatments to help children with severe asthma.”
The American Lung Association (ALA) defines asthma as a reversible obstructive lung disease, caused by increased reaction of the airways to various stimuli. It is a chronic inflammatory condition with acute exacerbations, and can be a life-threatening disease if not properly managed. This condition results from a series of events that lead to the narrowing of airways, such as swelling of the lining, tightening of the muscle, and increased secretion of mucus in the airway. The narrowed airway is responsible for the difficulty in breathing with the familiar “wheeze”.
Secondhand Smoke and Asthma
Asthma is one of the most common respiratory health problems affecting children worldwide. Currently, 7.1 million children, or about 9.5 percent, in the US suffer from asthma, according to the Centers for Disease Control and Prevention (CDC). It is also the third leading cause of hospitalization among children under the age of 15.
400,000 to one million children with asthma have their condition worsened by exposure to secondhand smoke, suggests a 2005 study carried out by the California Environmental Protection Agency. Secondhand smoke has also been identified as a risk factor for new cases of asthma in preschool aged children who have not already exhibited asthma symptoms, reports the ALA. Aside from asthma, secondhand smoke is also linked to many other illnesses affecting children, including lung cancer, ear infections, bronchitis and pneumonia.