Older patients with asthma are at increased risk for treatment failure, particularly those patients being treated with inhaled corticosteroids, according to a new study published online ahead of print in the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine.

“Asthma morbidity and mortality are known to be increased in middle-aged and older patients, and gender may also affect the incidence and course of the disease, but the impact of age and gender on asthma treatment response is not well understood,” said study author Michael E. Wechsler, MD, MMSc, professor of medicine and director of the Asthma Program at National Jewish Health in Denver.

“In our study of 1,200 patients with mild-to-moderate asthma, the risk of treatment failure was increased in patients aged 30 and above, and these failure rates increased proportionally with increasing age above age 30 across our study cohort. We also found that the rate of treatment failure did not significantly differ between males and females.”

Study subjects were drawn from Asthma Clinical Research Network data on patients participating in 10 trials from 1993 to 2003.

Treatment failures were observed in 17.3% of patients 30 years old and above, compared with 10.3% of those under age 30 (P < 0.001). Lower lung function measurements and longer duration of asthma were associated with a higher risk of treatment failure.

A greater proportion of patients ?30 years old receiving controller therapy experienced treatment failures. When stratified by specific treatment, failures increased consistently for every year above age 30 among those patients using inhaled corticosteroids. Patients aged 30 and older who were treated with inhaled corticosteroids, either alone or in combination, had more than twice the risk of experiencing a treatment failure compared with patients younger than 30.

Males and females had similar asthma control measures and treatment failure rates.

“Our novel finding of decreased responsiveness to asthma therapy with increasing age may involve not only biological mechanisms such as differences in the type of airway inflammation in older patients, but may also involve socioeconomic, geographic, or treatment adherence differences between older and younger patients,” said researcher Ryan Dunn, MD, of National Jewish Health in Denver . “Further research is needed to elucidate the causes underlying our observations and to examine whether older patients might benefit from a unique treatment approach.”