title: 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 (FEF25-75%) might be considered as a marker of early airway obstruction. FEF25-75% impairment might suggest earlier asthma recognition in symptomatic subjects even in the absence of other abnormal spirometry values.
  
  
  OBJECTIVE
  The study was designed in order to verify whether FEF25-75% 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 (FeNO) 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), FeNO analysis and sputum induction. FEF25-75% <65% of predicted or <-1.64 z-score was considered abnormal.
  
  
  RESULTS
  All subjects had normal FVC, FEV1 and FEV1/FVC, while FEF25-75% was abnormal in 27.5% of them. FEF25-75% (z-score) was associated with PD20FEV1 (p < 0.001), FeNO (p < 0.001) and sputum eosinophils (p < 0.001). Patients with abnormal FEF25-75% showed higher levels of FeNO and eosinophils in induced sputum than did patients with normal FEF25-75% (p < 0.01 and p < 0.01, respectively). Subjects with abnormal FEF25-75% 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 FEF25-75% 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 FEF25-75% as a predictive marker of newly diagnosed asthma.
authors: Department of Internal Medicine, University of Brescia, Spedali Civili di Brescia, Brescia, Italy.
authors: Mario
authors: M
authors: Malerba
authors: Alessandro
authors: A
authors: Radaeli
authors: Alessia
authors: A
authors: Olivini
authors: Giovanni
authors: G
authors: Damiani
authors: Beatrice
authors: B
authors: Ragnoli
authors: Valentina
authors: V
authors: Sorbello
authors: Fabio L M
authors: FL
authors: Ricciardolo
mesh_terms: D000293:Adolescent; D000328:Adult; D001249:Asthma / Q000175:diagnosis* / Q000503:physiopathology; D016535:Bronchial Hyperreactivity / Q000175:diagnosis* / Q000503:physiopathology; D015331:Cohort Studies; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008450:Maximal Midexpiratory Flow Rate; D055815:Young Adult