Obese children are more than three times more likely to develop asthma when exposed to high levels of air pollution when compared to their peers.
The finding, led by researchers at Columbia University Medical Center (CUMC), was based on more than 300 children living in New York City. The indoor air in each participant's home was monitored for two weeks while he or she was between 5-6 years old.
The researchers also measured the children's height and weight, in addition to administering questionnaires having to do with respiratory complications.
The results revealed that asthma associated with high exposure to PAH, or polycyclic aromatic hydrocarbons, was only found among children who were obese. Specifically, the association was tied to forms of PAH that are emitted by vehicles and cigarette smoke, along with cooking, burning candles, incense and other indoor sources.
"Our results suggest that obesity may magnify the effects of these air pollutants, putting children at greater risk for having asthma," said lead author Kyung Hwa Jung, an associate research scientist in the Department of Medicine at Columbia University College of Physicians and Surgeons.
Exactly why this is the case is unclear, although the researchers hypothesize that children who are obese spend more time indoors, increasing their exposure to indoor PAH. Another possibility is that the obese children's rapid breathing puts them at increased risk.
Either way, knowing that the link exists is an important first step in helping those affected by it, the researchers said.
"These findings suggest that we may be able to bring down childhood asthma rates by curbing indoor, as well as outdoor, air pollution and by implementing age-appropriate diet and exercise programs," said senior author Dr. Rachel Miller, chief of Pediatric Allergy and Immunology at CUMC.