Associations of e-cigarette use with lung function and structure

<bold>Background:</bold> E-cigarettes (e-cigs) are the most used tobacco product in adolescents and young adults in the US. Prior literature suggests that e-cigs may promote emphysema development. <bold>Aims:</bold> Test if e-cig use associates with emphysema-relevant measures of lung structure and function in young adults. <bold>Methods:</bold> Participants aged 18-50 years were recruited from the New York City area to participate from May 2021 to January 2024. They were enrolled into four groups by self-reported e-cig and cigarette (cig) use: never (control), exclusive e-cig (vaper), e-cig with former cig (vaper/former-smoker), and current e-cig and cig (dual). Pre-bronchodilator spirometry and non-contrast quantitative lung computed tomography were performed. Lung measures were regressed on enrollment group adjusting for age, sex, BMI, asthma, and current use of other smoked products (pipe, cigar, hookah, or marijuana). <bold>Results:</bold> Among 174 participants (mean [SD] 28 [7] years old, 48% male, mean [SD] BMI 26 [5] kg/m2, 16% asthma), 56% used e-cigs, 19% used cigs, and 5% smoked other products. In adjusted models, e-cig users showed lower FEV1/FVC, lower diffusing capacity divided by alveolar volume, and greater low attenuation areas (<-910HU) compared to controls (Figure). <bold>Conclusion:</bold> Associations of e-cig use with lung function and structure could be consistent with early emphysema development although sample size was small and confounding by cig and other exposures cannot be excluded. <fig><object-id>erj;64/suppl_68/PA4037/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig>