Detection of Small Airway Dysfunction in Asymptomatic Smokers with Preserved Spirometry: The Value of the Impulse Oscillometry System
Roberta Pisi, Marina Aiello, Annalisa Frizzelli, Luigino Calzetta, Laura Marchi, Giuseppina Bertorelli, Giovanna Pisi, Alfredo Chetta
Abstract
PURPOSE: Smoking-induced bronchiolitis with progressive small airway dysfunction (SAD) is a leading cause of chronic obstructive pulmonary disease. We investigated the value of using the impulse oscillometry system (IOS) to detect SAD in asymptomatic smokers with preserved spirometry. PATIENTS AND METHODS: We included 75 asymptomatic smokers (37 females, mean age 47±12 years, 26±17 pack/year) with preserved spirometry [forced expiratory volume at 1st second (FEV1)/forced vital capacity (FVC) ≥0.70 and normal FVC] and 34 never-smokers (19 females, mean age 42±15 years). RESULTS: , considered as IOS index of SAD, but not with FEV3/FEV6 less than a lower limit of normal, a spirometry index of SAD, was significantly higher than that of mild smokers (<30 pack/year) and never-smokers (p < 0.05). CONCLUSION: This study demonstrates that IOS has the potential to detect SAD in asymptomatic heavy smokers with preserved spirometry and with FEV3/FEV6 values in the normal range. We confirm that IOS provides parameters which can complement traditional measurements of pulmonary function.