Overweight, obesity linked to worse asthma control, exacerbations
MedWire News: Children with asthma who are overweight or obese have poorer asthma control and worse exacerbations than their normal-weight counterparts, results from a US study suggest.
"Increased body mass index (BMI) has been associated with an increased incidence of asthma in children, but the association between BMI status and asthma control and exacerbations in children has been less well defined," comment Sandra Christiansen (University of California, San Diego) and colleagues.
To address this, the researchers studied 32,321 asthmatic children, aged 5 to 17 years, from the Kaiser Permanente database for Southern California who had at least one asthma medication prescription (controller or rescue) filled between 2004 and 2008.
BMI percentile for age was compared with dispensed β-agonist rates, oral corticosteroid use, hospitalizations, and emergency department visits for asthma exacerbations per year.
Children with a BMI percentile for age of 16-85%, 85-94%, and 95% or higher were classified, according to Centers for Disease Control and Prevention criteria, as being of normal weight, overweight, and obese, respectively.
The researchers found that β-agonist units dispensed per year increased linearly with BMI status. Indeed, for every 10% increase in BMI percentile for age the risk for receiving more than 6 units of β-agonist medication per year increased by a small but significant 0.3%, while the risk for receiving oral corticosteroids increased by 0.4%.
After adjustment for demographic factors, parental education, asthma controller use, gastroesophageal reflux disease, diabetes mellitus, and other variables, the researchers found that overweight and obese children were a respective 1.15 and 1.17 times more likely to receive at least 6 units of β-agonist medication per year than their normal-weight counterparts.
Overweight and obese children were also a corresponding 1.21 and 1.28 times more likely to be dispensed oral corticosteroids than their normal-weight peers.
In univariate analysis, overweight and obese children were significantly more likely to have been hospitalized or visited the emergency department for asthma compared with normal weight children, at odds ratios (ORs) of 1.10 and 1.12, respectively, but this finding was no longer significant in multivariate analysis, at ORs of 1.07 and 1.04.
Christiansen and team conclude in the journal Allergy and Clinical Immunology: "This study found that being overweight and obese as a child is associated with increased risk of worse asthma control and asthma exacerbations as measured by β-agonist units dispensed per year and oral corticosteroid dispensing."
They add: "Future research should be aimed at using longitudinal data to further evaluate the possible dose-dependent relationship between obesity and asthma control and exacerbation risk, as well as evaluating whether weight loss interventions improve asthma control and decrease exacerbation risk."