Some children are genetically less responsive to inhaled steroids for asthma

Some children may not be able to keep their asthma under control even if they consistently report using inhaled corticosteroids, a mainstay of asthma treatment, suggests a new study presented at the American Thoracic Society 2007 International Conference, on Wednesday, May 23.

The study of 914 children with mild to moderate asthma found that over a one-year period, children who reported consistent inhaled steroid use were 20% less likely to report having well-controlled asthma compared with those not using any inhaled steroids. This finding held even when the severity of the children's asthma was taken into account.

“There may be several reasons for our findings; It is possible that some children are genetically less responsive to steroids,” says researcher Gregory Sawicki, M.D. of Children's Hospital in Boston. “In addition to issues of medication adherence and inability to completely control for differences in underlying asthma, severity can never be completely ruled out.”

Several studies of adults with asthma have suggested that even rigorous use of inhaled steroids doesn't lead to well controlled asthma in all adults, Dr. Sawicki noted. “But this issue hasn't been looked at closely in children,” he said. “Further studies are needed to see what is different about children who don't respond to steroids, to see if there is a way to predict whether a child will respond to inhaled steroids.”

Of the 914 children in the study, inhaled steroids were recommended for 435 who had persistent asthma, meaning they had symptoms on a regular basis. Among children who weren't recommended for inhaled steroid treatment, most reported well-controlled asthma. Among those recommended for inhaled steroid treatment, 44% reported consistently using the medicine; 35% said they intermittently used the medicine and 21% said they didn't use it at all.

“The majority of children with mild asthma are less likely to have symptoms as they get older and may not need to be on daily steroids,” Dr. Sawicki said. “The flip side is that if a child has poor asthma control, the parents and doctor need to make sure the child is adhering to their inhaled steroid treatment. But variation in response to inhaled steroids, as other medications, is well described.”

The data comes from the Child Asthma Management Program Continuation Study (CAMPCS), one of the largest groups of children with mild to moderate asthma in the nation who have been followed over 10 years. “This study gives us a good sense of real-world practice in asthma management,” Dr. Sawicki says. “The children's care is not directed by anyone in the study; it's an observation of what goes on when the children's care is directed by their own physicians.”

“Patterns of Inhaled Steroid (ICS) Use and Asthma Control in Childhood Asthma Management Program Continuation Study” (Session D92; Abstract # 1393)