As obesity rates rise across the nation, so too the number of people with asthma. But successfully treating asthma in an overweight individual may require different medication than treating asthma in a person of average weight.
People who are overweight and have asthma may respond better to leukotriene-inhibitor pills than inhaled steroid medications, according to a preliminary study sponsored by the maker of the pills. Moreover, these inhaled steroids seem to have less of an effect the more a patient weighs. The results of the study, which were published in the European Respiratory Journal, are the first to suggest that weight plays in role in a person's response to asthma medications.
"It is increasingly recognized that obese people are more prone to develop asthma," said study author, Dr. Marc Peters-Golden, professor of internal medicine at the University of Michigan Medical School. "But there is no information about whether obesity influences people's responses to particular asthma medications."
Peters-Golden and colleagues reviewed four asthma studies which included over 3,000 patients with moderate asthma. All of the studies had documented the patients' body mass index (BMI), a measurement that uses both height and weight to determine obesity, and how the patients' asthma responded to the two main types of asthma medications: a leukotriene-inhibitor (Singulair) and an inhaled steroid.
Looking at BMI, the review found that inhaled steroids worked best in patients who were considered to be of normal weight. These patients woke up less often at night because of breathing difficulties and needed fewer puffs of an inhaler to stop asthma attacks than patients' of a similar weight taking the leukotriene-inhibitor. However, inhaled steroids showed less of an effect as a person's weight increased. In other words, the higher a person's BMI, the more asthma-related problems he or she had while on the inhaled steroid.
In contrast, while overweight patients tended to have more severe asthma-related problems, the leukotriene-inhibitor was able to consistently control asthma attacks better than an inhaled steroid in those with a BMI above 25, a number that is considered to be the threshold between being normal weight and overweight.
Peters-Golden suggests that weight itself may cause this difference in response to medications. He theorizes that the inflammation of the lungs that causes asthma may be fundamentally different in overweight or obese people than in patients of a normal weight. Since leukotriene-inhibitors and inhaled steroids work differently to control this inflammation, one may be better suited to controlling asthma in obese people.
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However, Peters-Golden doesn't recommend that anyone switch their medications on account of this early review. "This is an exploratory study," he said and emphasizes the need for more research on the topic as many factors other than weight may influence response to asthma medications.
