Kids with asthma who are obese likely to respond poorly to ICS

Children with asthma are less likely to respond to inhaled corticosteroid (ICS) if they also happen to obese or overweight, suggests a study presented at ERS 2021.  

“We know that children with asthma, whose symptoms are poorly controlled, tend to gain weight. This is possibly because they exercise less,” explained presenting author Dr Cristina Longo of Amsterdam University Medical Center in Amsterdam, The Netherlands.

“Children with asthma who are overweight or obese are more likely to have worse symptoms despite being on the recommended treatment of ICSs, making it not only challenging to achieve a healthy weight but also to improve their quality of life,” she said.

The multicentre Mendelian randomization study included 1,511 children aged 2–16 years (pooled mean age 9 years, BMI z-score of 0.69) from five observational studies (four cross-sectional and one cohort study) who had asthma and were using ICS. Participants who had at least one asthma exacerbation requiring oral corticosteroids or urgent medical care within the preceding 1 years before study entry (or at the subsequent follow-up questionnaire in cohort study) were considered to have poor ICS response. [ERS 2021, abstract OA4221]

The researchers also analysed 97 genetic variants known to be predictive of BMI based on genome-wide association studies and constructed a weighted risk score, in which higher score indicates the presence of more BMI-related genetic variants. A BMI z-score of >1 indicates risk of being overweight, >2 is suggestive of being overweight, and >3 indicates obesity.

For every 1-unit increase in BMI z-score, the risk of having poor ICS response increased by more than twofold (odds ratio, 2.31, 95 percent confidence interval, 1.19– 4.46), Longo reported.

“These results suggest that clinicians need to take a more personalized approach to treating overweight and obese children. Paediatricians and asthma specialists need to be aware that children with higher BMI could be taking ICS without any benefit,” she highlighted. “However, whether alternative treatments, like biologicals, are more effective in this subgroup of children remains to be investigated.”

“For children and their parents, our results shed light on the reasons why some children may not be responding to their steroid inhaler as expected, especially if they are having more frequent asthma attacks than expected after starting this therapy,” Longo pointed out. “Our results might also be the catalyst that parents and their children need to modify their diet and increase exercise. This might improve the child’s BMI status and their response to inhaled steroids.”

As she explained, steroids are guideline-recommended therapy for asthma children with higher-than-normal BMI.

“Our research group felt that the one-size fits-all approach to treating children with asthma with inhaled steroids as their first-line treatment, particularly those with excess weight, warrants revision,” she said, in light of the current findings which suggest that children with high BMI may be using ICS to no avail.

“At the very least, research identifying potential alternative treatments should be encouraged and prioritised, especially since 30 percent of children with asthma are also obese. With the childhood obesity epidemic rising, we expect this percentage to increase meaning this problem of poor control will be seen more frequently in routine clinical practice,” she stated.