title: Small airway morphology and lung function in the transition from normality to chronic airway obstruction.
abstract: This study investigated the relationships between pathological changes in small airways (<6 mm perimeter) and lung function in 22 nonasthmatic subjects (20 smokers) undergoing lung resection for peripheral lesions. Preoperative pulmonary function tests revealed airway obstruction [ratio of forced expiratory volume in 1 s to forced vital capacity (FEV1/FVC) < 70%] in 12 subjects and normal lung function in 10. When all subjects were considered together, total airway wall thickness was significantly correlated with FEV1/FVC (r2 = 0.25), reactivity to methacholine (r2 = 0.26), and slope of linear regression of FVC against FEV1 values recorded during the methacholine challenge (r2 = 0.56). Loss of peribronchiolar alveolar attachments was significantly associated (r2 = 0.25) with a bronchoconstrictor effect of deep inhalation, as assessed from a maximal-to-partial expiratory flow ratio <1, but not with airway responses to methacholine. No significant correlation was found between airway smooth muscle thickness and lung function measurements. In conclusion, this study suggests that thickening of the airway wall is a major mechanism for airway closure, whereas loss of airway-to-lung interdependence may contribute to the bronchoconstrictor effect of deep inhalation in the transition from normal lung function to airway obstruction in nonasthmatic smokers.
authors.affiliation: Dipartimento di Medicina Interna, Università di Genova, 16132 Genova, Italy.
authors.forename: Angelo
authors.initials: A
authors.lastname: Corsico
authors.forename: Manlio
authors.initials: M
authors.lastname: Milanese
authors.forename: Simonetta
authors.initials: S
authors.lastname: Baraldo
authors.forename: Gian Luca
authors.initials: GL
authors.lastname: Casoni
authors.forename: Alberto
authors.initials: A
authors.lastname: Papi
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Riccio
authors.forename: Isa
authors.initials: I
authors.lastname: Cerveri
authors.forename: Marina
authors.initials: M
authors.lastname: Saetta
authors.forename: Vito
authors.initials: V
authors.lastname: Brusasco
mesh_terms: D000368:Aged; D001980:Bronchi / Q000473:pathology / Q000503:physiopathology*; D016535:Bronchial Hyperreactivity / Q000378:metabolism* / Q000503:physiopathology*; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008168:Lung / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D016210:Methacholine Chloride / Q000494:pharmacology; D018721:Muscarinic Agonists / Q000494:pharmacology; D029424:Pulmonary Disease, Chronic Obstructive / Q000473:pathology / Q000503:physiopathology*; D015656:Respiratory Mechanics / Q000502:physiology; D014797:Vital Capacity / Q000502:physiology
chemical_list: D018721:Muscarinic Agonists; D016210:Methacholine Chloride