Summary
Introduction:
This text is a letter to the editors of a respiratory journal discussing the saliva cotinine levels in users of electronic cigarettes (ENDS). The letter provides information on the study design, key points from two previous studies, and the results of their own study measuring cotinine in the saliva of experienced ENDS users.
Key Points:
* The study was conducted online and targeted users of ENDS who were contacted in real-life settings.
* Participants were asked to provide saliva samples using a cotton roll and vial provided to them.
* The samples were then sent to a lab for cotinine analysis by gas chromatography.
* The study found substantial amounts of cotinine in the saliva of ENDS users, which contrasts with two previous laboratory reports that concluded that ENDS did not reliably increase blood nicotine levels.
* The differences between the studies may be due to different durations of exposure, users' experience with the devices, puffing characteristics, models used, and the swallowing of nicotine.
* Cotinine levels in ENDS users were similar to levels previously observed in smokers and higher than levels previously found in NRT users.
* The results suggest that ENDS are used much like NRT, to assist quitting, with similar or even larger effects on nicotine exposure.
* The study relied on self-selected samples and self-reports of use of ENDS, tobacco, and NRT, with no objective verification.
Main Message:
The main message of this letter is that the study found substantial amounts of cotinine in the saliva of ENDS users, which suggests that ENDS can deliver nicotine to users. This finding has important implications for ENDS use by smokers who want to quit, future research, and the regulation of these products. The study also highlights the need for confirmation in representative samples or with different methods and notes that technology progresses rapidly, and the results may not apply to future ENDS models. Additionally, the study suggests that ENDS use should be evaluated similarly to NRT use, given the similarity in nicotine exposure. The study also notes the potential health risks associated with repeatedly inhaling a vapor containing propylene glycol over long periods, which is currently unknown.
Citation
Etter, J.-F., and C. Bullen. “Saliva Cotinine Levels in Users of Electronic Cigarettes.” European Respiratory Journal 38, no. 5 (November 1, 2011): 1219–20. https://doi.org/10.1183/09031936.00066011.
