A new study entitled, “Influence of childhood growth on asthma and lung function in adolescence” published by a group of scientists at Johns Hopkins Children’s Center identified several factors that were originally not thought to play as large of a role in children’s risk of asthma as their environment. The study sampled over 23,000 American children, and found that asthma risk did not depend on whether they lived in the city or in suburban/rural areas. The findings are currently published in the Journal of Allergy and Clinical Immunology.
The researchers, led by Corinne Keet, M.D., Ph.D., found alarmingly uneven prevalence rates of asthma among the sampled children that negated established concepts on which residential areas posed higher asthma risks. Specifically, the researchers discovered income, race and ethnic origin were more impactful factors to consider over a child’s environment.
“Our results highlight the changing face of pediatric asthma and suggest that living in an urban area is, by itself, not a risk factor for asthma,” said Keet, who is a pediatric allergy and asthma specialist at Johns Hopkins. “Instead, we see that poverty and being African American or Puerto Rican are the most potent predictors of asthma risk.”
While the more than 50-year-old notion of asthma being largely fueled by one’s environment (i.e. pollution, pest allergens, premature birth, smoke, etc.) remains valid, these findings suggest living in an urban area does not necessarily increase one’s asthma risk, and that clinicians should take note of other predisposing factors.
“Our findings suggest that focusing on inner cities as the epicenters of asthma may lead physicians and public health experts to overlook newly emerging ‘hot zones’ with high asthma rates,” says senior author Elizabeth Matsui, M.D., M.H.S., pediatric asthma specialist and associate professor of pediatrics and epidemiology at the Johns Hopkins University School of Medicine.
Keet and her teem emphasized that their study focused solely on children’s baseline asthma risk, and did not include comparing the disease severity of urban-dwelling and rural-living asthmatic children. This concern will be addressed in a separate study currently ongoing.
The study sampled children between the ages 6 and 17 years old, and found 13% of urban-dwelling children had asthma, compared to the 11% of those living outside of the city. While the difference did not appear clinically meaningful at first, the numbers changed drastically once the researchers factored in variables, like race, ethnicity and geographic region.
Additionally, it was found that children coming from lower income families had higher asthma risk, and risk of experiencing asthma-related emergencies. One’s “poor” neighborhood did not seem to play as big of a role, compared to one’s family being below the national poverty threshold. The researchers also found that African-American children (17%) and those of Puerto Rican descent (20%) were significantly more at risk of developing asthma, compared to whites (10%), Hispanics (9%), and Asians (8%).