E-cigarette use associated with increased risk for respiratory conditions

Former use and current use of e-cigarettes were associated with increased risk for a respiratory condition compared with no prior use in a prospective cohort study.

Researchers assessed data from 2013-2018 for a nationally representative cohort of U.S. adults from the Population Assessment of Tobacco and Health study. The analysis included individuals ages 18 years and older who had no prevalent respiratory conditions at baseline. The researchers assessed e-cigarette use by self-report (never, former, or current) at baseline. The main outcomes were incidence of chronic obstructive pulmonary disease (COPD), emphysema, chronic bronchitis, and asthma, and a composite of all four. Follow-up occurred from baseline to diagnosis with a respiratory condition, loss to follow-up, or the end of follow-up, whichever came first. Results were published on Nov. 12 by JAMA Network Open.

Of 21,618 respondents, 14,213 (65.7%) were never e-cigarette users, 5,076 (23.5%) were former users, and 2,329 (10.8%) were current users. After adjustment for cigarette and other combustible tobacco product use, demographic characteristics, and chronic health conditions, there was an increased risk of developing any respiratory disease among former (incidence rate ratio [IRR], 1.28; 95% CI, 1.10 to 1.48) and current e-cigarette users (IRR, 1.31; 95% CI, 1.08 to 1.59). The IRRs were slightly lower among respondents who self-reported good or better health: 1.21 (95% CI, 1.00 to 1.47) for former users and 1.43 (95% CI, 1.14 to 1.80) for current users. For specific respiratory diseases among current e-cigarette users, the IRR was 1.33 (95% CI, 1.06 to 1.67) for chronic bronchitis, 1.69 (95% CI, 1.15 to 2.49) for emphysema, 1.57 (95% CI, 1.15 to 2.13) for COPD, and 1.32 (95% CI, 1.01 to 1.72) for asthma. IRRs were similar for current versus former users.

Among other limitations, the study used self-reported data on e-cigarette and other tobacco product use and diagnosis of respiratory diseases, the authors noted. They added that the duration of follow-up was relatively short.

“Our longitudinal results are consistent with the findings of prior population studies. With a more refined study design assessing multiple respiratory conditions and extensive sensitivity checks to mitigate bias from reverse causation and residual confounding by cigarette smoking and other tobacco product use, our results strengthen the evidence of the potential role of e-cigarette use in pulmonary disease pathogenesis,” the authors wrote. “The findings may be used to inform counseling of patients on the potential risks of e-cigarette use.”