Young chronic e-cigarette users display cardiopulmonary abnormalities during exercise and blunted recruitment of pulmonary diffusing capacity.

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Williams, Thomas G; Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Alberta, Canada.
Collins, Sophie É;Brotto, Andrew R;D’Souza, Andrew W;+5 more

Chest,2026 Jan 02

  • Background: The prevalence of e-cigarette use is increasing, and e-cigarette users with no history of tobacco smoking report greater respiratory symptoms. Traditional evaluation of resting pulmonary function may fail to detect subclinical abnormalities.
  • Research Question: To what extent do young, otherwise healthy chronic e-cigarette users with no tobacco smoking history exhibit altered cardiopulmonary function during exercise, and altered recruitment of pulmonary diffusing capacity (DL CO )?
  • Study Design and Methods: 20 chronic e-cigarette users (mean age: 23±4 years) with no tobacco smoking history and 20 age-, height-, and sex-matched controls underwent a pulmonary function test and cardiopulmonary exercise test. Key outcomes included exercise capacity (V˙O 2peak ), ventilatory efficiency (V˙ E /V˙CO 2 nadir), exertional dyspnea, and operating lung volumes during exercise. A secondary aim investigated recruitment of resting DL CO and its components, measured as the change from the seated to supine posture. Adjusted linear regression models were used to evaluate the effect of group on key outcome variables at rest and during exercise.
  • Results: Both groups presented with normal pulmonary function (all p group >0.05). E-cigarette users demonstrated a lower V˙O 2peak (p group =0.017), elevated V˙ E /V˙CO 2 nadir (p group =0.037), and greater exertional dyspnea (p group <0.001, p group*workload <0.001), while operating lung volumes did not differ from controls (all p>0.05). E-cigarette users also displayed a blunted DL CO recruitment to a postural change (p group*posture =0.036). Between-group differences in dyspnea and DL CO recruitment were independent of V˙O 2peak .
  • Interpretation: Young, otherwise healthy chronic e-cigarette users exhibit evidence of abnormal cardiopulmonary responses to exercise, and blunted DL CO recruitment. These findings suggest early cardiopulmonary impairment and pulmonary vascular dysfunction in young e-cigarette users.