Association of FEF25-75% Impairment with Bronchial Hyperresponsiveness and Airway Inflammation in Subjects with Asthma-Like Symptoms

Abstract

Background: Forced expiratory flow at 25 and 75% of the pulmonary volume (FEF_25-75%) might be considered as a marker of early airway obstruction. FEF_25-75% impairment might suggest earlier asthma recognition in symptomatic subjects even in the absence of other abnormal spirometry values. Objectives: The study was designed in order to verify whether FEF_25-75% impairment in a cohort of subjects with asthma-like symptoms could be associated with the risk of bronchial hyperresponsiveness (BHR) and with airway inflammation expressed as fractional exhaled nitric oxide (Fe<smlcap>NO</smlcap>) and eosinophil counts in induced sputum. Methods: Four hundred adults with a history of asthma-like symptoms (10.5% allergic) underwent spirometry, determination of BHR to methacholine (PD₂₀FEV₁), Fe<smlcap>NO</smlcap> analysis and sputum induction. FEF_25-75% <65% of predicted or <-1.64 z-score was considered abnormal. Results: All subjects had normal FVC, FEV₁ and FEV₁/FVC, while FEF_25-75% was abnormal in 27.5% of them. FEF_25-75% (z-score) was associated with PD₂₀FEV₁ (p < 0.001), Fe<smlcap>NO</smlcap> (p < 0.001) and sputum eosinophils (p < 0.001). Patients with abnormal FEF_25-75% showed higher levels of Fe<smlcap>NO</smlcap> and eosinophils in induced sputum than did patients with normal FEF_25-75% (p < 0.01 and p < 0.01, respectively). Subjects with abnormal FEF_25-75% had an increased probability of being BHR positive (OR = 13.38; 95% CI: 6.7-26.7; p < 0.001). Conclusions: Our data show that abnormal FEF_25-75% might be considered an early marker of airflow limitation associated with eosinophilic inflammation and BHR in subjects with asthma-like symptoms, indicating a role for FEF_25-75% as a predictive marker of newly diagnosed asthma.

Global and regional degree of obstruction determined by electrical impedance tomography in patients with obstructive ventilatory defect

“…Early airway obstruction group (n = 26, normal FEV 1 and FEV 1 /FVC, but Forced expiratory flow over the middle half of the FVC (FEF 25-75% ) <65% of predicted) [23];…”

<p>FEF_25-75% Values in Patients with Normal Lung Function Can Predict the Development of Chronic Obstructive Pulmonary Disease</p>

“…FEF 25-75% is the most sensitive measure of airflow in peripheral airways where primary airflow obstruction originates, 7 and it is reduced in early bronchial impairment, which is associated with small airway disease. [8][9][10][11] Airway remodeling, mucus plugging, and immune cell infiltration induced by cigarette smoking ultimately result in small airway disease, which is a cardinal feature of COPD. 12 Some researchers have found that decreased FEF 25-75% is frequently observed in patients with COPD.…”

Maximal mid-expiratory flow is a surrogate marker of lung clearance index for assessment of adults with bronchiectasis

“… Although the use of MMEF has been criticized for the failure to contribute to clinical decision-making 34 , we found that MMEF correlated significantly with various clinical variables and that the coefficient of variation for two acceptable maneuvers was small. Furthermore, the usefulness of MMEF in terms of correlation with airway hyperresponsiveness and inflammation in asthma 35 36 and asthma-like symptoms 37 has been demonstrated. Despite different settings, it is still likely that MMEF% predicted would have clinical significance to guide severity assessment of bronchiectasis.…”

“…Furthermore, the usefulness of MMEF in terms of correlation with airway hyperresponsiveness and inflammation in asthma3536 and asthma-like symptoms37 has been demonstrated. Despite different settings, it is still likely that MMEF% predicted would have clinical significance to guide severity assessment of bronchiectasis.…”