The small airways may play an important role in the clinical manifestations of asthma. Forced expiratory flow between 25% and 75% (FEF25%-75%) has been proposed as an approximate measure of the caliber of distal airways. Bronchial hyperreactivity (BHR) is a feature of asthma.Objective:
To evaluate the possible role of FEF25%-75% as a predictor of BHR in allergic patients with asthma and rhinitis.Methods:
A total of 726 patients (mean ± SD age, 24.7 ± 6.3 years) were evaluated. Spirometry and methacholine bronchial challenge were evaluated in all the participants.Results:
A difference between forced expiratory volume in 1 second and FEF25%-75% greater than 20 or a ratio between these variables greater than 1.24 discriminates between patients with no response to a mild response to methacholine vs patients with a moderate-to-severe response with high sensitivity (P < .001).Conclusion:
This study highlights the possible role of FEF25%-75% in predicting BHR in allergic individuals with airway disorders.