Effects of Nicotine Concentration Levels in E-cigarettes on Biomarkers of Exposure to Toxicants and Tobacco Use Behaviors - Project Summary
Electronic Nicotine Delivery System (ENDS, or e-cigarette) is a new class of tobacco products and may represent
a reduced harm alternative for combustible cigarette smokers. In 2020, 3.7% (9.2 million) of adults aged 18 years
and older reported current use of ENDS. Current everyday or some-day ENDS use is most prevalent among
current cigarette smokers (13.8%) and former smokers (13.3%) and is uncommon among adult never smokers
(2.2%). E-liquid nicotine concentration level is one of the primary product-level determinants of nicotine delivery
and sensorimotor characteristics and there is a variety of nicotine concentration levels available in ENDS.
Modern vaping products (e.g., pod-mod style like JUUL) contain nicotine in the salt formulation and tend to
deliver nicotine to the lung more efficiently. Most recently, the Food and Drug Administration (FDA) has granted
several ENDS products in the Premarket Tobacco Product Marketing review with varying nicotine levels, such
as 0% (Logic Pro), 1.5% (Vuse Ciro), 3.0% (Vuse Viper), 4.5% (NJOY Daily Rich), and 6.0% (NJOY Daily Extra
Rich). Meanwhile, FDA announced plans for proposed rules to reduce nicotine levels to minimally addictive or
non-addictive levels among cigarettes (Cig). The research on the effects of e-liquid nicotine concentration levels,
especially how different nicotine levels are related to health effects, tobacco use behaviors, and nicotine
dependence and how nicotine levels interplay with vaping devices at the population level, can have important
implications for future tobacco regulatory sciences. This large-scale population study will link the Population
Assessment of Tobacco and Health (PATH) Waves 1-6 restricted biomarker with the PATH Adult Interview
surveys. In Aim 1, we will analyze the pooled PATH biomarker-adult interview data to 1) examine between-
subjects differences in biomarkers of exposure (BOEs) by nicotine concentration levels (e.g., zero, low, medium
and high), and 2) test interaction effects of nicotine levels and vaping products on BOEs from 5 classes of FDA
defined harmful and potentially harmful constituents (HPHC): nicotine metabolites, TSNAs, metals, PAHs, VOCs
and the BOE of health effects (e.g., oxidative stress) in urine and serum panels using weighted multivariable
regression models. In Aim 2, we will leverage the harmonized longitudinal Waves 1-6 PATH Adult Interview data
to prospectively examine associations of nicotine levels in ENDS and vaping devices with tobacco use behaviors
(e.g., subsequent abstinence from cigarette smoking or subsequent relapse to cigarette smoking) and nicotine
dependence. This study is innovative in its focus on the effects of e-liquid nicotine concentration levels and
vaping devices on population health (biomarkers), ENDS ↔ Cig use transitions and nicotine dependence by
leveraging the nationally longitudinal data. Such information has important implications for future tobacco
regulatory sciences at the population level and can guide FDA as to whether future Premarket Tobacco Product
Application (PMTA) submissions for higher nicotine products should be authorized.
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