Electronic cigarette use and its association with asthma, chronic obstructive pulmonary disease (COPD) and asthma-COPD overlap syndrome among never cigarette smokers

INTRODUCTION: Although smoking is a strong risk factor for lung diseases including asthma, COPD, and asthma-COPD overlap syndrome (ACOS), studies are needed to examine the association between e-cigarettes and asthma, COPD, and ACOS. This study evaluated the association between e-cigarette use and self-reported diagnosis of asthma, COPD, and ACOS using a large nationally representative sample of adults aged ≥18 years in the United States. METHODS: Cross-sectional data from the Behavioral Risk Factor Surveillance System (BRFSS) from 2016 to 2018 were used to examine self-reported information on current e-cigarette use, demographic variables, and asthma and COPD status among never cigarette smokers (n=8736). Asthma and COPD were measured by self-reported diagnosis, and respondents who reported having both diagnoses were then classified as having ACOS. Of the 469077 never cigarette smokers, 4368 non-e-cigarette users were 1:1 propensity score-matched to e-cigarette users on age, sex, race/ethnicity and education level. We used multinomial logistic regression to examine association between current e-cigarette use and self-report asthma, COPD, and ACOS while controlling for marital status and employment in addition to matching variables. RESULTS: Compared with never e-cigarette users, e-cigarette users had increased odds of self-reported ACOS (OR=2.27; 95% CI: 2.23–2.31), asthma (OR=1.26; 95% CI: 1.25–1.27) and COPD (OR=1.44; 95% CI: 1.42–1.46). CONCLUSIONS: Our findings suggest that e-cigarette use is associated with an increased odds of self-reported asthma, COPD, and ACOS among never combustible cigarette smokers. BRFSS provides cross-sectional survey data, therefore a causal relationship between e-cigarette use and the three lung diseases cannot be evaluated. Future longitudinal studies are needed to validate these findings.