Excess Weight Exacerbates Asthma Symptoms in Preschoolers

Jason E. Lang, MD, MPH

Being overweight can increase the severity of asthma symptoms in preschool-age patients, though excess weight doesn’t appear to affect the efficacy of inhaled corticosteroids, according to new research.

The study is based on a post hoc analysis of three large multi-center studies of children aged 2 to 5 years old. The researchers, representing a number of American universities, used body mass index (BMI) and asthma severity metrics to elucidate the connection between the 2.

Overall, children in the 84th percentile by weight who were not using an inhaler had 37 more days with asthma symptoms each year, compared to peers who were not overweight.

“We showed that children with asthma who were overweight or obese at baseline had significantly more severe asthma exacerbations and day-to-day milder symptom impairment compared to leaner children,” Jason E. Lang, MD, MPH, an associate professor at the Duke University School of Medicine, and the lead author on the study, said.

This marks the first time researchers have looked at the impact of being overweight on asthma patients at such a young age. It adds to a body of evidence suggesting that obesity can factor into asthma severity at all ages.

Lang told MD Magazine that his study wasn’t designed to elucidate whether there is any causal relationship between obesity and asthma. However, while he’s unable to say whether excess weight causes asthma, he speculated that it’s possible losing weight can lessen the severity of asthma symptoms.

“It is very possible and perhaps likely that the development of excess weight gain does lead to worse asthma, and also conversely that returning to a healthier weight would promote reduced asthma severity,” Lang said.

However, he also noted that their study did not intervene and to create weight loss in study participants, and thus the study can’t prove the link one way or the other.

If the first finding of the study confirmed existing research into excess weight’s impact on asthma, the study’s other key finding offered an interesting contradiction to conventional wisdom.

The researchers found that being overweight doesn’t make inhaled corticosteroids less effective at controlling asthma symptoms. That finding contradicts other research into the effectiveness of inhalers on older overweight patients. Lang suggested that this could mean that the pathways of inflammation are somewhat different in younger patients, or perhaps that obesity takes time to cut down on the effectiveness of inhalers.

Lang said it’s not necessary to make treatment decisions based on weight at this young age.

“My advice to a pediatrician regarding asthma management in this case would be the same regardless of body size,” he said. “The relationship between overweight/obesity and inhaled corticosteroids is different in young children and should be prescribed if indicated.”

And while he can’t say for sure that losing weight would improve asthma symptoms, he said getting to a healthy weight should still be a priority.

“I would also advise pediatricians and caregivers that a healthy diet, reduced high-fat meals and daily healthy activity may also go a long way to keeping the lungs healthy and reducing the need higher doses of asthma medicines,” Lang said.

The study, “Overweight/obesity status in preschool children associates with worse asthma but robust improvement on inhaled corticosteroids," was published last month in The Journal of Allergy and Clinical Immunology.