Rundong Qin1, Jiaying An2, Jiaxing Xie1, Renbin Huang1, Yanqing Xie2, Li He1, Hui Xv2, Geng Qian2, Jing Li3. 1. Department of Allergy and Clinical Immunology, State Key Laboratory of Respiratory Disease, National Clinical Researcher Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, P.R. China. 2. State Key Laboratory of Respiratory Disease, National Clinical Researcher Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, P.R. China. 3. Department of Allergy and Clinical Immunology, State Key Laboratory of Respiratory Disease, National Clinical Researcher Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, P.R. China. Electronic address: lijing@gird.cn.
Abstract
BACKGROUND: Reduced forced expiratory flow between 25% and 75% of vital capacity percent predicted (FEF25-75%) representing small airway dysfunction (SAD) was associated with asthma development and progression. OBJECTIVE: To investigate whether FEF25-75% was superior to forced expiratory volume in 1 second in predicted (FEV1%) in reflecting asthma features in adult patients. METHODS: A retrospective spirometry dataset comprising 1801 adult patients with confirmed asthma and a subgroup of 332 patients having detailed clinical data were used to explore the association of FEF25-75% and/or FEV1% with clinical features of asthma. RESULTS: Of the 1801 subjects, FEV1% and FEF25-75% ranged from 136.8% to 10.2% and 127.3% to 3.1%, respectively. FEF25-75% < 65% was present in 1,478 (82.07%) of patients. FEF25-75% was strongly correlated with matched FEV1% (r = 0.900, P < .001). FEF25-75% and FEV1% were both correlated with airway hyperresponsiveness (r = 0.436, P < .001; r = 0.367, P < .001), asthma control test score (r = 0.329, P < .001; r = 0.335, P < .001), and sputum eosinophil count (r = -0.306, P < .001; r = -0.307, P < .001). Receiver-operating characteristic curves showed that FEF25-75% had greater value in predicting severe asthma (area under the curve: 0.84 vs 0.81, P = .018), airflow obstruction (0.97 vs 0.89, P < .001), and severe bronchial hyperresponsiveness (0.74 vs 0.69, P = .012) as compared with FEV1%. Patients with SAD (FEF25-75% < 65%) in the presence of normal FEV1% exhibited higher sputum eosinophil counts and had an increased dosage of daily inhaled corticosteroids (P < .001 and P = .010) than patients with normal lung function and their FEF25-75% values correlated with sputum eosinophil count (r = -0.419, P = .015), but not FEV1%. CONCLUSION: FEF25-75% represented small airway function and was more sensitive at reflecting airway hyperresponsiveness, inflammation, and disease severity as compared with FEV1% in patients with asthma. Our data suggest further assessment of FEF25-75% in asthma management, particularly for those with SAD who present normal FEV1%.
BACKGROUND: Reduced forced expiratory flow between 25% and 75% of vital capacity percent predicted (FEF25-75%) representing small airway dysfunction (SAD) was associated with asthma development and progression. OBJECTIVE: To investigate whether FEF25-75% was superior to forced expiratory volume in 1 second in predicted (FEV1%) in reflecting asthma features in adult patients. METHODS: A retrospective spirometry dataset comprising 1801 adult patients with confirmed asthma and a subgroup of 332 patients having detailed clinical data were used to explore the association of FEF25-75% and/or FEV1% with clinical features of asthma. RESULTS: Of the 1801 subjects, FEV1% and FEF25-75% ranged from 136.8% to 10.2% and 127.3% to 3.1%, respectively. FEF25-75% < 65% was present in 1,478 (82.07%) of patients. FEF25-75% was strongly correlated with matched FEV1% (r = 0.900, P < .001). FEF25-75% and FEV1% were both correlated with airway hyperresponsiveness (r = 0.436, P < .001; r = 0.367, P < .001), asthma control test score (r = 0.329, P < .001; r = 0.335, P < .001), and sputum eosinophil count (r = -0.306, P < .001; r = -0.307, P < .001). Receiver-operating characteristic curves showed that FEF25-75% had greater value in predicting severe asthma (area under the curve: 0.84 vs 0.81, P = .018), airflow obstruction (0.97 vs 0.89, P < .001), and severe bronchial hyperresponsiveness (0.74 vs 0.69, P = .012) as compared with FEV1%. Patients with SAD (FEF25-75% < 65%) in the presence of normal FEV1% exhibited higher sputum eosinophil counts and had an increased dosage of daily inhaled corticosteroids (P < .001 and P = .010) than patients with normal lung function and their FEF25-75% values correlated with sputum eosinophil count (r = -0.419, P = .015), but not FEV1%. CONCLUSION: FEF25-75% represented small airway function and was more sensitive at reflecting airway hyperresponsiveness, inflammation, and disease severity as compared with FEV1% in patients with asthma. Our data suggest further assessment of FEF25-75% in asthma management, particularly for those with SAD who present normal FEV1%.
Authors: Marcello Cottini; Carlo Lombardi; Giovanni Passalacqua; Diego Bagnasco; Alvise Berti; Pasquale Comberiati; Gianluca Imeri; Massimo Landi; Enrico Heffler Journal: Front Med (Lausanne) Date: 2022-05-23