Involuntary Smoke Exposure Affects Asthma Severity Among Children

The study, which is reported in the August edition of CHEST, the peer-reviewed journal of the American College of Chest Physicians, looked at 523 children aged four through 16 years who had physician-diagnosed asthma. Using the biomarker cotinine, a nicotine metabolite that accumulates in the blood and urine following tobacco smoke inhalation, children were classified into ETS exposure groups to determine the indicators of asthma severity among children with high and low levels of tobacco smoke exposure.

"Many studies have demonstrated that smoke exposure is harmful for children with asthma, and studies also have used cotinine levels to determine worsened asthma severity in children exposed to tobacco smoke," said lead study author David M. Mannino, MD, FCCP. "What makes this study unique is that it is nationally representative and uses serum cotinine levels to document exposure."

Children with a greater exposure to tobacco smoke were significantly more likely to have more severe asthma, as indicated by increased symptoms of cough and wheeze, an increased number of respiratory illnesses, and lung function that was 8 percent lower than asthmatic children without smoke exposure.

Data for the study was taken from the Third National Health and Nutrition Examination Survey (NHANES III), a United States-wide health study. Of the analytic sample, 78.6 percent of the children had mild asthma, 6.8 percent had moderate asthma, and 14.6 percent of the children had severe asthma. Asthma severity was based on the frequency of symptoms and respiratory illnesses. A greater proportion of asthmatic children aged four through six had high blood cotinine concentrations than older children.

"The results of this study are not surprising," said ACCP President Sidney Braman, MD, FCCP. "What is shocking is that these 523 children represent approximately 4.3 million U.S. children with asthma, making the no-smoking message to parents and caretakers of children with asthma even more compelling."

CHEST is a peer-reviewed journal published by the ACCP. It is available online each month at http://www.chestjournal.org. ACCP represents more than 15,000 members who provide clinical, respiratory, and cardiothoracic patient care in the U.S. and throughout the world. ACCP's mission is to promote the prevention and treatment of diseases of the chest through leadership, education, research and communication.