Project Summary/Abstract
Impact: This research explores the premise that e-cig users are able to compensate for lower nicotine
products by adapting their behavior to maintain their desired nicotine level. When presented with a lower
nicotine product, nicotine addicted e-cig users may alter their puffing topography to generate a more highly
dense aerosol, and thus increase their consumption of total particulate matter in order to achieve their dose of
nicotine. In addition, users may alter their respiratory parameters such as increasing inhalation volume, pulling
the aerosol deeper into the lung and increasing the surface area available for gas exchange, or holding the
aerosol in their lungs for a longer period of time, allowing for more nicotine uptake before exhaling. All of these
changes in behavior are considered compensation, and may result in increased exposure to total particulate
matter and ultimately increase the harm potential of what would otherwise be consider a reduced harm
product. Study Design: The project involves a 17-day natural environment study with a two arm, two period
cross-over design. N=80 current established adult vape pen users, currently using eliquids with nicotine
strengths greater than or equal to 13 mg/mL, with no intention to quit e-cig use, and no use of combustible or
other tobacco products will be randomized by age, gender, usual brand nicotine strength, and nicotine
dependence score into control (non-switching) and test (switching) arms. The test arm will be switched to a
lower nicotine strength eliquid (6 mg/mL) matching their usual flavor, while the control arm will continue to use
their usual nicotine strength. The RIT wPUMTM vape pen monitor will record puff topography (puff volume, flow
rate, duration, interpuff interval) and the Hexoskin wearable sensorized garment will record respiratory
parameters (inhalation/exhalation volume and time, breath hold) for every puff taken while vaping ad-lib in their
natural environment. Participants will provide salivary cotinine samples and complete a daily log of product
use, compliance and subjective effects including craving, withdrawal symptoms and positive/negative
emotional state on users’ ability to compensate for low nicotine eliquids. Specific Aims: The objective of Aim 1
is to quantify changes in topography, respiration and TPM exposure upon switching from their usual to a lower
nicotine strength eliquid. The objective of Aim 2 is to assess the extent to which users are able to compensate
their behavior using salivary cotinine levels before and after the switch as a proxy for compensation efficacy.
We will test two hypotheses; (H1) exposure to TPM will increase upon switching to a reduced nicotine eliquid
and (H2) salivary cotinine levels will remain unchanged. We will investigate the presence of random subjective
effects, and age/gender on compensation using a generalized linear mixed-effects model. Regulation:
Knowledge gained informs regulations related to limiting nicotine in eliquids. Exposure to both nicotine and
total particulate matter are important in risk assessment, and the potential to inadvertently increase one by
decreasing the other must be considered in product regulation.