Study shows that African American children with asthma have significantly higher levels of cotinine

Mar 6 2005

A new study may help explain why African American children suffer disproportionately from tobacco-related illness.

The Cincinnati Children's Hospital Medical Center study shows that African American children with asthma have significantly higher levels of cotinine -- a substance produced when the body breaks down nicotine -- even though these children's parents report lower exposure to environmental tobacco smoke, commonly known as second-hand smoke.

"There are at least two possible reasons why African Americans have higher levels of cotinine," says Stephen E. Wilson, MD, a scientist at the Cincinnati Children's Center for Environmental Health and the study's lead author. "Numerous studies have demonstrated significant racial differences in the metabolism of tobacco-related products. But differences in additives to cigarettes commonly smoked by African Americans, such as menthol, could also explain the observed racial differences."

The study will be published in the March issue of Environmental Health Perspectives and is currently available online at http://ehp.niehs.nih.gov/

The study is based on data from the Cincinnati Asthma Prevention study, an ongoing study of the Cincinnati Children's Center for Environmental Health. Dr. Wilson and his colleagues measured cotinine in the blood and hair of 222 children with asthma. Cotinine is considered the best marker of environmental tobacco smoke exposure. The investigators also assessed exposure to environmental tobacco smoke using a validated survey.

Surprisingly, the investigators found that African American children with asthma had higher levels of cotinine in the blood (1.41 ng/ml vs. 0.97 ng/ml) and hair (0.25 ng/mg vs. 0.07 ng/mg) compared to white children. This pattern held true even after taking into account tobacco smoke exposure, size of home and other sociodemographic characteristics, according to Dr. Wilson.

"These differences in cotinine could provide clues to the racial differences in tobacco-associate morbidity and mortality," says Dr. Wilson. "If African American children are more susceptible to tobacco-induced toxicity, we should target policy initiatives to reduce exposure among this population."