Children on Asthma Inhalers Do Not Catch Up With Peers, Say Researchers
Asthma inhalers containing steroids play an important role in maintaining the health and well-being of millions of children. Past research had shown that prepubescent children who began taking steroid-containing asthma inhalers grew at a slower rate than their peers; however, this decreased growth rate was believed to be temporary.
Common opinion at the time was that overall childhood growth while on asthma inhalers was slightly longer than normal, which would then compensate for the slower growth by allowing a child to reach his or her normal height eventually. However, a recent study says that this is not true and that children on asthma inhalers fall short of normal growth by about one-half an inch.
Asthma is an over-reaction of the airways upon exposure to pollen, dust or other allergens, as well as to stress, cold exposure and infection. With asthma, the airways become inflamed and swollen, which narrows the bronchial tubes and thereby makes the passage of air and breathing very difficult.
In cases where asthma is not chronic, immediate relief can be found with “relief inhalers” such as Ventolin (albuterol)—a bronchodilator that relaxes muscles in the airways and increases air flow to the lungs. These types of inhaler drugs are beta-adrenergic receptor agonists that stimulate beta receptors in the muscles around the airways. Stimulation of the beta receptors causes the muscles to relax, which opens up the airways and allows more air to get into and through the lungs.
In cases where asthma is chronic and of greater severity, corticosteroids (steroid) inhalers are used for prolonged periods on a daily basis. Steroid inhalers do give immediate relief, but are designed to act as long-lasting protection during the childhood years to prevent or suppress asthma attacks that could otherwise become fatal.
While side effects of taking steroid based inhalers have proven to be negligible in comparison the benefits achieved, concerns were raised a number of years ago when it was observed that the growth rate of children on steroid inhalers was slightly decreased. An early study determined that the effects of the growth rate decrease were only temporary and that by adulthood children on asthma inhalers reached their full height potential.
However, a new study finds that this may not be the case after all.
In a recent study published in The New England Journal of Medicine, researchers reveal their findings after following the growth of approximately 1,000 children between the ages of 5 and 13 years with mild-to-moderate asthma. The study compared the eventual final adult height attained by the children after years of taking either a steroid based asthma inhaler, a non-steroid asthma inhaler or a placebo.
The study was part of the Childhood Asthma Management Program (CAMP) clinical trial where the children were randomly selected and placed into one of three treatment groups lasting 4 years. One group received twice-daily an inhaled corticosteroid medication called “budesonide.” A second group received an inhaled non-steroid medication called “nedocromil.” And, a third group received a placebo. All children received a non-steroidal, fast-acting drug (albuterol) for relief of acute asthma symptoms, and oral steroids as needed for asthma symptoms during the study.
Four years following the trial, the children during their pre-teen and teen years were measured and weighed every 6 months. Over the next eight years into adulthood, their height and weight were measured again to determine if their height would catch up with their peers as had been originally believed.
What the researchers discovered was that whether a child was male or female and on prolonged used of steroid-based asthma inhalers, that he or she did not reach their full height potential and that they fell short of their non-steroid inhaler and placebo study control peers by approximately one-half inch.
According to a press release issued by Washington University in St. Louis:
“This was surprising because in previous studies, we found that the slower growth would be temporary, not affecting adult height,” says the study’s senior author, Robert C. Strunk, MD, and the Donald Strominger Professor of Pediatrics at Washington University School of Medicine. “But none of those studies followed patients from the time they entered the study until they had reached adult height.”
According to the results of the study, parents need not be alarmed, but careful observation of a child’s growth is warranted and should be monitored while on a steroid-based asthma inhaler.
“If a child is not growing as they should, we may reduce their steroid dose,” says Dr. Strunk. “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.”
Parents and physicians considering switching a child to a non-steroidal asthma inhaler will need to take into consideration and balance the benefits of taking a corticosteroid inhaler over a height decrease of one-half inch. Steroid inhalers such as the budesonide used in the study are effective and safe medications that result in far fewer hospitalizations and urgent care visits in comparison to children using a non-steroidal asthma inhalers like the nedocromil medication used by the second group in the study.
Reducing the dosage of a steroid-based asthma inhaler medication may be a preferable alternative choice for parents and their children on asthma inhalers. The authors of the paper state that it is appropriate to use the lowest effective dose for symptom control in order to minimize concern about the effects of inhaled glucocorticoids on adult height.
Image Source: Courtesy of Wikipedia
Reference: “Effect of Inhaled Glucocorticoids in Childhood on Adult Height” The New England Journal of Medicine (Sep. 3, 2012); H. William Kelly, Pharm.D., et al.