Small airway function improvement after smoking cessation in smokers without airway obstruction.
OBJECTIVE
Studying smokers with normal spirometry requires monitoring tools of the peripheral lung. A validated multiple breath washout technique was used to assess possible recovery of smoking-induced small airway malfunction in acinar and conductive lung zones.


METHODS
Eighty-seven smokers with a smoking history of at least 10 pack-years but absence of spirometric airflow obstruction were invited for assessment of lung function and small airway function at baseline and after 1 wk, 3 mo, 6 mo, and 12 mo of smoking cessation. A control group of 16 persistent smokers was studied at the same time intervals.


RESULTS
Of the 87 smokers, 66, 32, 28, and 21% successfully ceased smoking for 1 wk, 3 mo, 6 mo, and 12 mo, respectively. Lung function parameters remained essentially unaffected by smoking cessation. Ventilation heterogeneity showed transient improvements after 1 wk in the acinar lung compartment with a return to baseline afterwards. By contrast, there were persistent improvements in the conductive airway compartment; for example, smokers who successfully quit smoking for 12 mo (n=18) showed a 30 and 42% reduction of conductive airways abnormality after 1 wk and 1 yr, respectively.


CONCLUSIONS
Smokers with early signs of small airway malfunction who successfully quit smoking show sustained improvements of conductive airway malfunction. In contrast, acinar airway malfunction quickly returns to baseline after a transient improvement.
Verbanck
Sylvia
S
Respiratory Division, Academic Hospital, Vrije Universiteit Brussel, Brussels, Belgium. sylvia.verbanck@az.vub.ac.be
Schuermans
Daniël
D
Paiva
Manuel
M
Meysman
Marc
M
Vincken
Walter
W
D000328:Adult; D000402:Airway Obstruction; D001980:Bronchi / Q000503:physiopathology*; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012123:Pulmonary Ventilation / Q000502:physiology*; D012907:Smoking / Q000009:adverse effects / Q000503:physiopathology*; D016540:Smoking Cessation; D013147:Spirometry