According to a report in the latest edition of the Journal of Allergy and ClinicalImmunology, obesity may cause a patient to become unresponsive to certain asthma medications.
The study revealed that the effectiveness of inhaled corticosteroids was reduced by more than 50% in overweight individuals.
The team of researchers, headed by Dr. Sutherland, studied over 1,200 patients with persistent asthma of varying degrees of severity. 53% of the patients had a body mass index (BMI) of 25.0 kg/m2.
The research concentrated on the forced expiratory volume (FEV) of the overweight patients as compared to that of the leaner patients.
Although there were some differences between the two BMI groups in terms of FEV, Dr. Sutherland concludes that they are negligible when considered alongside the lack of difference in other important measures of asthma such as exhaled nitric acid level, morning peak expiratory flow rate, number of skin allergies and hyperresponsiveness of the airway to methacholine.
However, obesity did have an effect on the response of the patients to medication. Such patients exhibited reduced improvement in lung function in response to asthma treatments involving inhaled glucocorticoid and beta agonist.
Overall, the results of the study were largely congruent with the epidemiological opinion that obesity increases the risk and impairs the treatment of asthma.
The researchers were quick to point out that much of the analysis was post-hoc and did not include BMI as a priori, deducted variable in the individual trials.
Dr. Sutherland also noted that it was possible that the study was underpowered and that the results are not readily generalized to patients suffering from severe asthma.