Reduced Vascular Function, Ventilatory Efficiency, and Exercise Capacity in Young Adult E-cigarette

Faisal A, Giles A, Jones S, et al.
Reduced Vascular Function, Ventilatory Efficiency, and Exercise Capacity in Young Adult E-cigarette Users
ERJ Open Res 2026; in press (https://doi.org/10.1183/23120541.00425-2026).

Background: Acute electronic cigarette (E-cigarette) use has shown adverse cardiorespiratory impacts similar to conventional cigarette (C-cigarette) smoking; however, its early effects remain unclear.

Objectives: We aimed to examine the early effects of E-cigarette use on systemic vascular function, cardiorespiratory responses to exercise, and exertional symptoms in young adults.

Methods: 75 healthy active young adults (18–30 years), divided into three age- and sex-matched groups (E-cigarette users, C-cigarette smokers, never-smoker controls; n=25 each, E-cigarette use or smoking duration ≥18 months), underwent an incremental cycle exercise test with standard metabolic, cardiorespiratory, blood lactate and sensory measurements. Brachial artery flow-mediated dilatation (FMD) was assessed using Doppler ultrasound. Blood samples were collected to assess vascular inflammatory markers.

Results: Cotinine (nicotine metabolite) levels were not different between E-cigarette users and C-cigarette smokers (80.7±33.0 versus 65.5±27.6 pg·ml⁻¹, p=0.2). At peak exercise, both E-cigarette users and C-cigarette smokers had lower exercise capacity, oxygen uptake, and ventilation compared to controls (182±31, 178±27 versus 219±43 watts; 35.1±6.4, 35.1±5.3 versus 41.2±5.9 mL·kg⁻¹·min⁻¹; 97.8±24.7, 98.9±21.6 versus 116.1±29.8 L·min⁻¹, respectively; all p<0.05). Furthermore, E-cigarette users and C-cigarette smokers demonstrated decreased exercise ventilatory efficiency, with higher ventilation, blood lactate, dyspnoea ratings, and leg discomfort during submaximal exercise compared to controls. E-cigarette users and C-cigarette smokers showed lower FMD compared to never-smokers (4.7±3.0, 4.5±2.9 versus 8.1±3.5%, p<0.05), which was inversely associated with vascular cell adhesion molecule-1 and thrombospondin-2.

Conclusion: E-cigarette use and C-cigarette smoking were both associated with early detrimental effects on exercise capacity, ventilatory efficiency, systemic vascular function, and amplified exertional symptoms.