SAN FRANCISCO – Children aged 12 years and older may be less likely to have asthma exacerbations than are younger children, according a 44-week trial in 288 children with mild, persistent asthma.
Girls also may be less likely to have asthma exacerbations than are boys. The lower risk in girls and older children means that these patients probably don’t need inhaled corticosteroids (ICS) daily, but only for symptoms or rescue, said Dr. Joseph Gerald of the University of Arizona, Tucson.
"It’s a reasonable" approach that limits impaired growth and other potential ICS side effects when "the benefit to be gained from daily inhaled steroids is not that great," he said at an international conference of the American Thoracic Society.
The researchers randomized 72 children to daily ICS, 71 to rescue ICS only, 71 to combined treatment with ICS and inhaled albuterol, and 74 to placebo. The daily ICS regimen consisted of one 40-mcg puff of beclomethasone twice daily; combined treatment consisted of one 40-mcg puff of beclomethasone with each albuterol puff used for symptom relief. Dummy inhalers were used as needed to maintain blinding. The participants were 6-18 years old.
Compared with placebo, all three ICS regimens reduced treatment failures (defined as more than two exacerbations requiring oral corticosteroids) in boys, in children 6-11 years old, and in children with allergic forms of the disease as indicated by eczema, positive skin tests, methacholine PC20 (a provocative concentration of methacholine causing a 20% fall in forced expiratory volume in 1 second) at or below 12.5 mg/dL, and IgE levels at or above 185 kU/L. For instance, 29.3% of boys (12 of 41) in the placebo group failed treatment, but only 2.4% of boys (1 of 42) in the daily ICS group did so.
The investigators were unable to show a statistically significant benefit for any ICS strategy in girls, in children 12-18 years old, and in those with higher methacholine PC20 levels, lower IgE levels, negative skin tests, and no eczema.
That’s probably not because inhaled steroids work better in boys and other responders, but rather because nonresponders had lower exacerbation rates in general, making it harder to detect a benefit, Dr. Gerald said.
For example, although almost 30% of boys in the placebo group failed treatment, only 15.2% of girls (5 of 33) in the placebo group failed. Similarly, 26% of children aged 6-11 years (13 of 50) failed treatment in the placebo arm, but only 16.7% of children aged 12-18 years (4 of 24) did so.
"We think the baseline [exacerbation] risk is what we are detecting here. [Nonresponders] started from a lower risk and just didn’t benefit as much," Dr. Gerald said. The study did not determine the best ICS regimen among responders.
Dr. Gerald and his coinvestigators said they have no relevant disclosures.