Summary
The study by Sargent et al.1 suggests several useful methodological
issues for further research, such as analyzing for dose–response
effects and testing for improvement versus worsening of
respiratory symptoms over time. However, other studies have
documented e-cigarette use as consistently associated with respiratory
disease, independent of cigarette smoking.9 That body
of research includes findings based on persons without initial
respiratory disease and among healthy nonsmokers, and has
analyses that controlled for marijuana use and secondhand
smoke exposure. Additionally, a substantial body of experimental
research based on animal models, in vitro, and in vivo
studies about effects of e-cigarette aerosol10–13 has consistently
shown adverse biological effects of e-cigarette exposure on the
respiratory system, providing mechanistic grounds for how
e-cigarettes can lead to the respiratory disease noted in observational
studies of humans.9 Further research using clinical outcome
measures and studying e-cigarette effects in populations
that have lower rates of smoking and higher rates of e-cigarette
use will help to clarify the implications of e-cigarette use for
human health. At present, however, the convergence of epidemiological
and laboratory evidence9–13 suggests caution about
ignoring possible adverse health consequences of e-cigarette
use because of presumed confounding with cigarette smoking.
Citation
Wills Ta, Choi K, Perez MF. E-cigarettes and Respiratory Disorder: The Broader Context. Nicotine & tobacco research : official journal of the Society for Research on Nicotine and Tobacco. 2023;25(6):1215-1216. doi:10.1093/ntr/ntad029
