Among adults who use e-cigarettes or don’t smoke at all, switching to cigarette smoking or combined e-cigarette and cigarette smoking increases the risk of cough and wheeze, according to study findings presented at the American Thoracic Society (ATS) International Conference 2022 held in San Francisco, CA, May 13 to 18.

With e-cigarettes, user are exposed to fewer toxins than with cigarettes, although the toxin level may still affect the lungs. Researchers sought to investigate the associations over time between transitioning to or from e-cigarettes and cigarettes and the occurrence of respiratory symptoms.

To accomplish this, they conducted a retrospective study of the longitudinal Population Assessment of Tobacco and Health (PATH) cohort study, which included 32,320 adults (50% female; mean 46.2 years of age) but excluded at baseline those already with respiratory disease or symptoms. Participants were split into 3-person trials with exposure intervals determined from cigarette and e-cigarette use. Participants were also stratified as non-users, e-cigarette users, cigarette users, or dual users, then further stratified into 16 possible transition groups.

Participants transitioning from nonuse to e-cigarette use showed a 62% increased risk of wheeze (incident rate ratio [IRR] 1.62; 95% CI, 1.21-2.16), though the risk of increased cough was nonsignificant (IRR 1.21; 95% CI, 0.96- 1.53). Participants transitioning from e-cigarettes to cigarettes or dual use showed almost 100% increased risk of wheeze (cigarettes: IRR 1.94; 95% CI, 1.09-3.47; dual use: IRR 2.03; 95% CI, 1.21-3.41). Increased risk of cough was noted only in the transition to cigarette use. Transitioning from cigarettes to e-cigarettes or to dual use showed no change in respiratory risks compared with frequent smokers.

Researchers concluded that, “transitioning from either nonuse or e-cigarette use to cigarette smoking or dual use were associated with increased risk of respiratory symptoms. While transitioning from nonuse to e-cigarettes use was associated with increased symptom risk, e-cigarette use may be associated with less risk than cigarette and dual use.”


Xie W, Goghari A, Stokes A. Association of cigarette–e-cigarette transitions with respiratory symptom incidence: a longitudinal analysis of the Path Study, 2014-2019. Presented at: the American Thoracic Society (ATS) International Conference 2022; May 13 to 18, 2022; San Francisco, CA. Abstract P513.

This article originally appeared on Pulmonology Advisor