Pediatric patients with moderate-severe asthma who use potent inhaled corticosteroids (ICS) are at higher risk for either being overweight or obese, according to a new study published in the Journal of Asthma.
“Not only is obesity a risk factor for moderate-severe asthma, but obesity in children with asthma is associated with greater airflow obstruction and a diminished response to ICS, often leading to the use of frequent systemic steroids,” wrote the authors, led by Jennifer Han, PharmD, Rady Children’s Hospital, San Diego, CA. “Therein lies a potential vicious cycle—obesity disposing patients to moderate-severe asthma; treatment for moderate-severe asthma with corticosteroids leading to obesity.”
The researchers note that ascertaining the relationship between ICS and weight in children with moderate-severe asthma can help direct therapy by substituting biologics for higher steroid doses.
Primary outcomes in this study included identifying the link between obesity and ICS use, as well as analyzing BMI trajectory trends in children taking biologic therapy (omalizumab or mepolizumab). The team also looked at how BMI trajectory correlated with the number of emergency department (ED) visits.
Dr. Han and co-investigators performed a retrospective chart review for 93 patients at the Severe Asthma Clinic at Rady’s Children Hospital. All patients were between 18 months and 18 years of age, had moderate-severe asthma, were prescribed ICS, and were seen between 2011 and 2016. Notably, the researchers defined moderate-severe asthma as either uncontrolled with high-dose ICS or requiring regular systemic corticosteroids for control.
The team used a linear mixed-effects model to chart individual BMI trajectories with respect to factors correlated with BMI change during time. They figured in both individual patterns of change (ie, individual random effects) and population averages (ie, fixed effects).
The authors found a significant increase of 0.369 kg/m2/y in BMI trajectory in children taking high-dose steroids; those taking medium-dose steroids saw an increase of 0.243 kg/m2/y, and the low-dose group had an increase of 0.195 kg/m2/y (P < 0.05). In other words, the higher the ICS dose, the higher the risk of obesity.
In patients taking biologics, there was a significant drop in BMI trajectory of –0.818 kg/m2/y (P < 0.05). Furthermore, in patients who visited the ED during the study period five or more times secondary to asthma exacerbation, there was a significant increase in BMI trajectory (P < 0.05).
The authors used piecewise regression to demonstrate that between the ages of 5 and 9, children are possibly at greatest risk for crossing into the overweight category.
With regard to biologics, the authors wrote that “the decrease in BMI trajectory over time with the conversion from ICS to biologics provides valuable insight in considering the initiation of biologic therapy in the future.” Specifically, biologics could ameliorate adherence via either biweekly or monthly injections, thus obviating the challenge of daily adherence with ICS.
The researchers concede that the current study had limitations. First, the charts examined contained incomplete information about ICS start and stop dates. Second, selection bias could have played a role, as the patients were sampled from a specialty clinic, thus governing the generalizability of results to a general asthma population. Third, sample sizes in this population—especially of pediatric patients taking biologics (n=5)—were small.
In addition, the researchers couldn’t adjust for covariates such as food, diet, and exercise because the study was retrospective.
“The potency of ICS use in pediatric patients with moderate-severe asthma affects BMI trajectory; the higher the dose, the greater the projected BMI increase per year,” the researchers concluded. “Initiation of biologic therapy decreased BMI trajectory over time.”
To read more about this study, click here.