Comparative effects of cigarette smoking, e-cigarette use, and dual use on pulmonary function, exercise capacity, and...

Tobacco smoking constitutes a primary cause of preventable cardiovascular and pulmonary diseases on a global scale. While smoking rates fall, e-cigarette use rises, especially in youth.

Assess effects of smoking, vaping, and dual use on lung function, exercise capacity and quality of life.

Participants were classified into five groups: Control, Cigarette use only, E-cigarettes use only, Ex-cigarette smoker current vaper, and Dual users (use of both e-cigarettes and combustible cigarettes). Participants performed spirometry, six minute walk test (6MWT) and completed health related quality of life (HRQoL) questionnaire.

A total of 222 participants, 86.9% were male, with median age 26 years. Age and body mass index (BMI) showed no significant differences across groups. Cigarette-only and dual users reported 20 cigarettes/day with 5-7 years smoking duration, while e-cigarette use duration was 4-5 years among exclusive vapers, ex-smoker vapers, and dual users. Spirometry revealed impairments: Forced expiratory volume in the first second (FEV₁; % predicted) was lower across groups versus controls (H = 80.69, df = 4, p < 0.001, η ² = 0.35), lowest in dual users. Forced vital capacity (FVC; L) showed no differences, while FVC (% predicted) decreased in smokers and dual users. FEV₁/FVC ratio was reduced (H = 66.54, df = 4, p < 0.001, η ² = 0.29), most in dual users. 6MWT showed no group differences. HRQoL indicated decline in physical functioning (H = 35.11, p < 0.001, η ² = 0.14), role limitations due to physical health social functioning, and emotional wellbeing, lowest in cigarette-only and dual users.

Young adults using cigarettes and e-cigarettes showed impaired lung function and quality of life compared to never-users. Daily dual users showed the greatest declines, while former smokers using e-cigarettes showed intermediate outcomes. Exclusive e-cigarette users exhibited least impairment.