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Background: Flight attendants (FAs) who worked on commercial aircraft before the smoking ban in flights were exposed to high levels of secondhand smoke (SHS). SHS exposure in these FAs is associated with air trapping at rest. Objective: To determine whether longstanding exposure to SHS causes progressive airflow limitation and dynamic hyperinflation (DH) that in turn affects exercise capacity. Methods: 36 never-smoking FAs (all female; 55±9 years old; BMI=23±3 kg/m2) with a history of remote but intense chronic exposure to SHS (11±10 years of cabin SHS exposure) underwent a symptom-limited progressively increasing cycle exercise test to determine the maximum work (watts) and oxygen uptake (VO2) achieved. After 30 min rest, the expiratory flow limitation (% of the tidal volume loop that overlaps or surpasses the maximal expiratory flow, %EFL), and DH (an increase in end expiratory lung volume), were measured at 20, 40, and 80% of maximum observed work. Results: At 80% exercise level, 25 and 6 of the 36 subjects had airflow limitation and DH, respectively. In regression analysis, the adjusted rate of increase in %EFL with successive levels of exercise was associated with years of cabin SHS exposure (parameter estimate (PE)±SEM=14.0±3.3% increase in rate of progression of airflow limitation per 10 years of exposure in those with limitation, p |
