Abstract
Background: Obese children with asthma may be characterized by neutrophil-mediated inflammation. Thus, it is postulated that children with obese-asthma may respond more favorably to leukotriene receptor antagonists (LTRAs) than inhaled corticosteroids (ICS).
Objective: To assess whether excess weight modifies the relative effectiveness of LTRA compared to low-dose ICS (Step-2) monotherapies in children with asthma.
Methods: We conducted a retrospective cohort study using health and drug administrative databases linked to the Montreal Children’s Hospital Asthma Center records. Children aged 2-18 years with confirmed asthma initiating low-dose ICS or LTRA between April 1st 2000 and Dec 31st 2006 were included. Children were followed until the first asthma exacerbation, end of health insurance, 1-year follow-up, or study, whichever occurred first. Excess weight was defined as a BMI of greater than the 85th percentile at baseline. An exacerbation event included any ED visit, hospital admission, or oral corticosteroids for asthma. We analyzed data using a marginal structural Cox model.
Results: Of the final sample (N=201), 166 children initiated low-dose ICS and 35 initiated LTRA. There were 121 (60.2%) exacerbations. LTRA users were at a higher risk (HR 3.27; 95%CI 1.24-8.62) for early exacerbations than ICS users. When compared to normal weight children using ICS, LTRA normal weight users had a HR of 2.98 (95%CI 0.97-9.24), ICS users with excess weight had a HR of 0.89 (95%CI 0.43-1.85), and LTRA users with excess weight had a HR of 1.67 (95%CI 0.40-7.02).
Conclusions: In this real-life pediatric cohort, LTRA appears to be much less effective at prolonging exacerbation-free time, irrespective of weight status.
- Copyright ©the authors 2017