In a study published in the New England Journal of Medicine, researchers found that children who use inhaled steroid drugs for asthma end up slightly shorter at their full adult height than children who don't use the drugs.

The findings were presented on Sept. 3 at the European Respiratory Society meeting in Vienna, Austria

The study involved more than 1,000 children ages 5-12 who were treated for mild to moderate asthma as part of the Childhood Asthma Management Program (CAMP) clinical trial. The children received treatment for more than four years.

They were divided into three groups: one received twice-daily budesonide, an inhaled corticosteroid medication; a second group received nedocromil, an inhaled non-steroid medication; and a third group received a placebo. All children received albuterol, a fast-acting drug for relief of acute asthma symptoms, and oral corticosteroids as needed for asthma symptoms.

The researchers followed 943 participants in the trial at regular intervals until they reached adult - age 18 for women and 20 for men - height.

In the first 4 1/2 years after the end of the trial, researchers took patients' height and weight every six months. Over the next eight years, height and weight were measured once or twice a year.

The mean adult height was about one-half inch, or 1.2 centimeters, shorter in the group that received budesonide than in the patients who received nedocromil or placebo. The patients who experienced the slower growth were primarily between 5-11 years old when they began using budesonide.

What researchers said was surprising was that the slower growth took place only in the first two years of the four-year study. As the study progressed, the children who took the budesonide remained one-half inch shorter through adulthood than the children who did not use the drug.

According to researchers, various factors that also might have contributed to the slower growth rate, including gender, age at the time the child entered the trial, how long the child had had asthma, as well as ethnicity, severity of asthma and reactivity to a skin test for allergies, did not have any impact on the results.

"If a child is not growing as they should, we may reduce their steroid dose," Senior Author Robert C. Strunk said. "But we think that the half-inch of lowered adult height must be balanced against the well-established benefit of inhaled corticosteroids in controlling persistent asthma. We will use the lowest effective dose to control symptoms to minimize concerns about effects on adult height."

Inhaled corticosteroids such as budesonide are the most effective form of anti-inflammatory treatment for asthma, which affects 9.4 percent of U.S. children. The drugs control symptoms and improve pulmonary function. Results from the original CAMP trial, begun in the mid-1990s, showed that using budesonide twice daily led to fewer hospitalizations and urgent care visits, fewer days in which additional asthma medications were needed and a reduced need for albuterol. Using nedocromil twice daily reduced urgent care visits and courses of oral steroids for severe symptoms but did not affect the number of hospitalizations, symptoms or airway responsiveness.