Do adolescents who use e-cigarettes have more frequent bronchitis symptoms and wheezing than nonusers?

In this study, adolescents who used e-cigarettes had nearly a twofold increased risk of chronic bronchitis than nonusers. However, the researchers found no association between e-cigarette use and wheezing. (LOE = 2b)

McConnell R, Barrington-Trimis JL, Wang K, et al. Electronic cigarette use and respiratory symptoms in adolescents. Am J Respir Crit Care Med 2017;195(8):1043-1049.  [PMID:27806211]

Cross-sectional

Government

Population-based

These authors surveyed 2086 adolescents in 11th and 12th grades who were part of a cohort of 2412 children enrolled in the Children's Health Study since kindergarten or 1st grade. Among other things, the researchers asked about a range of respiratory conditions, symptoms, environmental exposures, and the use of various tobacco products. The researchers deemed that teens had chronic bronchitis if they reported a daily cough or congestion or phlegm for 3 consecutive months unless accompanied by a cold. Approximately 25% of the teens reported ever using e-cigarettes; 10% reported current use. Approximately half of the current e-cigarette smokers reported using them on 3 or more days per month. Among teens with symptoms consistent with chronic bronchitis (20% of the sample), 10% reported secondhand smoke exposure and 25% reported past or current e-cigarette smoking. Among those reporting wheezing at the time of the survey (12% of the sample), 7% reported secondhand smoke exposure and 29% reported past or current e-cigarette smoking. After adjusting for multiple confounding factors, the researchers estimate that past e-cigarette use, but not current use, was associated with nearly a doubled increase in the risk of bronchitis. Finally, they found no association between e-cigarette use and wheezing.