Nearly one-third of morbidly obese participants had undiagnosed asthma, despite experiencing comparable symptoms to diagnosed patients, while others were taking inhaled corticosteroids unnecessarily, according to findings published in Respiratory Medicine.

Of the 86 participants, 32 had physician-diagnosed asthma that could not be confirmed in 41%; those patients failed to show bronchodilator reversibility or respond to a negative provocation test. In the remaining 54 patients, who were never diagnosed with asthma, 31% had asthma symptoms, reversible airway obstruction, or airway hyper-reactivity.

“A diagnosis of asthma based on symptoms alone is unreliable in the morbidly obese, and pulmonary function testing is an essential part of the diagnosis of asthma in the morbidly obese,” the authors concluded.

“As a result of the most likely high prevalence, potential health risk and the high economic burden of misdiagnosis, characterization of these patients is important.”