Biomarker Assessment of Nicotine Exposure Among Adolescent E-Cigarette Users: 2018-2019

Despite the increasing prevalence of vaping e-cigarettes among adolescents, there remains a lack of population-level assessments regarding the objective measurement of nicotine exposure.

This study analyzed a nationally representative sample of adolescents aged 13 to 17 years from Wave 5 of the Population Assessment of Tobacco and Health Study conducted between 2018 and 2019. Urinary nicotine metabolites, including cotinine and trans-3'-hydroxycotinine (3-HC), were assessed among exclusive nonnicotine e-cigarette users (n = 56), exclusive nicotine e-cigarette users (n = 200), and nonusers (n = 1059). We further examined nicotine exposure by past 30-day vaping frequency (ie, occasional [1-5 days], intermittent [6-19 days], and frequent [20+ days]) and flavor types among nicotine e-cigarette users. Multivariable linear regressions tested pairwise group effects, and biomarkers were normalized by the log transformation.

Compared with nonusers, both nonnicotine and nicotine e-cigarette users exhibited higher levels of cotinine and 3-HC. Nicotine e-cigarette users had mean cotinine concentrations (61.3; 95% confidence interval, 23.8-158.0, ng/mg creatinine) approximately 146 times higher (P < .0001) than nonusers (0.4; 0.3-0.5), whereas nonnicotine users (4.9; 1.0-23.2) exhibited cotinine concentrations ∼12 times higher (P = .02). Among nicotine e-cigarette users, the levels of cotinine and 3-HC increased by vaping frequency, with cotinine increasing from 10.1 (2.5-40.1) among occasional users to 73.6 (31.8-170.6) among intermittent users and 949.1 (482.5-1866.9) among frequent users. Nicotine exposure was not significantly different by flavor type.

E-cigarette use poses health-related risks resulting from nicotine exposure among adolescents. Comprehensive regulations of e-cigarette products and marketing, vaping prevention, cessation, and public policies are needed to prevent youth from developing nicotine addiction.