Being poor, black or Puerto Rican increases chances of developing the breathing disorder
Being poor, black or Puerto Rican are the most important factors determining a child’s asthma risk, according to a new study. This flies in the face of decades of public health assumptions that inner-city children have a higher risk of the disease simply because of where they live.
“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 Corinne Keet, M.D., a pediatric allergy and asthma specialist at Johns Hopkins in Baltimore, and lead investigator of the study. “Instead, we see that poverty and being African American or Puerto Rican are the most potent predictors of asthma risk.”
Earlier studies looked at asthma rates within specific cities, but no study has compared asthma rates in inner cities across the country, or how asthma compares in other types of communities.
Keet’s study, published in the Journal of Allergy and Clinical Immunology, used national survey data on more than 23,000 children aged 6 to 17 from 2009-2011. Researchers looked at asthma rates based on population figures as well as factors such as income, race and ethnicity. After adjusting for those factors, the team found no statistically significant difference in the rates of asthma between children living in urban areas and those who lived elsewhere.
But black and Puerto Rican children had much higher asthma rates, at 17 and 20 percent, respectively, compared with white children (10 percent), other Hispanic children (9 percent) and Asian children (8 percent). This study did not look at reasons for the disparity, but researchers note other studies suggest potential genetic and biologic causes for the racial and ethnic differences.
The study found that asthma rates varied widely by geography, too, with 17 percent of children living in northeastern cities having asthma, compared with 8 percent in cities in western states. And children with asthma didn’t reside only in cities: Asthma rates were slightly higher, 21 percent, in poor suburban areas of the Northeast, compared with 17 percent in neighboring cities.
For half a century, public health experts have attributed some features of inner-city life—pollution, cockroach allergens, exposure to secondhand smoke and higher rates of premature birth—to the increase in children’s risk of asthma. And though these factors do boost asthma risk, they may no longer be restricted to urban centers. Researchers note increasing poverty levels in suburban and rural areas, and point out that racial and ethnic minorities are moving out of inner cities.
“Our findings suggest 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,” said study senior author Elizabeth Matsui, M.D., a pediatric asthma specialist and associate professor of pediatrics and epidemiology at Hopkins.
According to the Centers for Disease Control and Prevention, asthma, a chronic inflammatory disease of the airways, affects nearly 7 million children in the United States, and the numbers are rising. Black children are 3.6 times more likely to visit the emergency room for asthma symptoms, and they have a death rate seven times that of their white counterparts.