WASHINGTON — Heavier people may have worse asthma control than do their lighter counterparts, but they are not significantly less likely to respond to treatment, based on data from a pair of studies presented at the annual meeting of the American Academy of Allergy, Asthma, and Immunology.
In one study of 221 adults with severe asthma, body mass index (BMI) had no significant effect on impaired prednisone absorption or on any abnormalities in prednisone clearance.
Previous studies have shown a relationship between increased weight and asthma severity, said Dr. Joshua Davidson of National Jewish Health in Denver. Dr. Davidson and his colleagues measured the in vitro glucocorticoid responses to prednisone, dexamethasone, fluticasone propionate, and budesonide in asthma patients in three different weight categories.
BMI was positively associated with an increased number of steroid side effects, said Dr. Davidson, who had no conflicts of interest to disclose. But BMI was not associated with any reduction in prednisone absorption or clearance, or in steroid response.
But asthma control remains a problem for heavier patients. Dr. Hector Ortega of GlaxoSmithKline and his colleagues reviewed data from the Asthma Control Characteristics and Prevalence Survey Study (ACCESS), which included 2,238 patients aged 15 years and older from 35 asthma clinics across the United States.
The researchers found that 65% of the adults with a BMI greater than 30 had poorly controlled asthma vs. 52% of those with a BMI of 30 or less. This difference was statistically significant, Dr. Ortega said.
After controlling for multiple variables, a BMI greater than 30 was independently associated with a 54% increased risk of poorly controlled asthma, Dr. Ortega said.