Obesity Can Add 5 Weeks of Asthma Symptoms Per Year in Preschoolers

Asthma symptoms may be worse for children aged 2 to 5 who are overweight, according to a study published in the Journal of Allergy and Clinical Immunology.

Preschoolers with a body mass index (BMI) beyond the 84th percentile who weren't using an inhaler had 70% more days with asthma symptoms per year than untreated peers of a healthy weight.

Compared with healthy-weight peers, asthma sufferers who were untreated and overweight suffered 37 more symptom-days -- more than 5 extra weeks -- per year.

The researchers also found that untreated children who were overweight had more asthma attacks than untreated peers of a healthy weight.

However, obesity doesn't seem to lessen the effectiveness of corticosteroid inhalers. When used daily, inhalers reduced the number of symptom-days and asthma attacks in both healthy and overweight children, and may even be more protective to overweight children.

"The impact of overweight and obesity on asthma has not been studied in the youngest asthma patients, and this finding is the opposite of what has been seen in older kids and adults who are overweight," said Jason Lang, MD, Duke Children's Pulmonary Function Laboratory, Durham, North Carolina. "Reports in older children and adults with asthma who are overweight have shown a poor response to inhaled corticosteroids to manage their asthma. This study suggests either pathways of inflammation are a bit different in preschool-aged patients, or that it takes years for obesity to reduce the effectiveness of steroid inhalers."

The researchers analysed data from the randomised INFANT, PEAK, and MIST trials. The 3 studies comprised 736 children, of which about one-third had a BMI above the 84th percentile. Some trial participants were randomised to use inhalers daily while some used them intermittently; some received placebos and some received no treatment.

The authors believe this is the first study on whether obesity impacts asthma severity and the effectiveness of inhalers in preschoolers, but the study does have limitations, including that it was a retrospective analysis. A prospective study with a larger number of children could offer more insights into the best asthma treatments for overweight preschoolers and include strategies that address weight loss.

"This study uses the best, mostly highly controlled data to demonstrate that early-life weight gain does worsen the severity of asthma in the youngest patients," said Dr. Lang. "Weight does not hamper the effectiveness of inhaled steroids in preschoolers, but this study provides clear evidence that maintaining a healthy weight in preschoolers may be an effective strategy for controlling asthma."

Reference: http://dx.doi.org/10.1016/j.jaci.2017.09.043
SOURCE: Duke Health