Young “Healthy” Smokers Have Functional and Inflammatory Changes in the Nasal and the Lower Airways

BackgroundSmoking is responsible for most COPD. Although people with COPD often have concomitant nasal disease, there are few studies that report physiologic or inflammatory changes in the upper airways in young asymptomatic smokers. We investigated physiologic and inflammatory changes in the nasal and lower airways of young smokers and if these changes were related to smoking history.MethodsSeventy-two subjects aged between 18 and 35 years (32 healthy nonsmokers and 40 young smokers) participated in this study. We measured nasal mucociliary clearance (MCC), nasal mucus surface contact angle, cell counts, myeloperoxidase and cytokine concentrations in nasal lavage fluid, exhaled breath condensate (EBC) pH, and lung function.ResultsSmokers had faster MCC, an increased number of cells (macrophages, ciliated cells, and goblet cells), increased lavage myeloperoxidase concentration, and decreased EBC pH compared with nonsmokers. There was a significant inverse relationship between pack-year smoking history and EBC pH. There were no differences in lung function or mucus surface properties comparing smokers to nonsmokers.ConclusionsYoung adult smokers have functional and inflammatory changes in the nasal and lower airways and these correlate with smoking history. However, in these young smokers, smoking history was not associated with pulmonary function decline, probably because it is unlikely that spirometry detects early physiologic changes in the airways.Trial registryClinicalTrials.gov; No.: NCT01877291; URL: www.clinicaltrials.gov