The role of E-liquid vegetable glycerin and exhaled aerosol on cue reactivity to tank-based electronic nicotine delivery systems (ENDS).

Introduction:
This text discusses a study examining the role of exhaled aerosol clouds on the cue potency of newer, tank-based electronic nicotine delivery systems (ENDS) or e-cigarettes. The study aimed to determine whether these ENDS evoke smoking urges and whether enhancing the visibility of exhaled aerosol clouds by increasing the e-liquid vegetable glycerin (VG) content strengthens the cue salience of ENDS.

Key Points:

* The study used a mixed design and randomized young adult smokers to observe a study confederate drinking bottled water (control cue) and vaping an ENDS mod containing e-liquid with either high (73%) or low (0%) VG.
* Participants completed the Brief questionnaire on Smoking Urges (BqSU) and visual analog scales (VaS) assessing cigarette and e-cigarette desire pre- and post-cue exposure.
* Increasing the e-liquid content of VG enhanced the size and visibility of the exhaled aerosol clouds and evoked a greater increase in smoking desire and a more sustained increase in e-cigarette desire relative to the low VG cue.
* Both cues elicited increases in smoking urges, and these results remained after controlling for sex, prior ENDS experience, recent smoking behavior, and menthol preference.

Main Message:
The study suggests that observation of tank-based ENDS use generalizes as a smoking cue and its cue salience is strengthened by increasing the e-liquid content of VG to enhance the visibility of the exhaled aerosol cloud. These findings may inform the regulation of ENDS products and e-liquids by the Food and Drug administration (FDa), particularly in relation to restrictions on maximum VG content.

Vena a, howe M, Cao D, King a. The role of E-liquid vegetable glycerin and exhaled aerosol on cue reactivity to tank-based electronic nicotine delivery systems (ENDS). Psychopharmacology. 2019;236(7):2083-2092. doi:10.1007/s00213-019-05202-6