Nicotine, Carcinogen, and Toxin Exposure in Long-Term E-Cigarette and Nicotine Replacement Therapy Users: a Cross-sectional Study

Introduction: This text provides a summary of a study on the metabolite levels of nicotine and important carcinogens and toxins in long-term e-cigarette or NRT users. The study aims to compare the levels of these substances in users of combustible cigarettes, NRT, and e-cigarettes.

Key Points:

* The study had a cross-sectional design, with participants recruited through diverse methods and controlled for important confounders.
* The sample was too small to allow for more sophisticated analyses, and the lack of between-group differences in nicotine intake has to be interpreted cautiously.
* Long-term NRT-only or e-cigarette-only use among former smokers is associated with substantially reduced levels of selected carcinogens and toxins compared with combustible cigarette smoking.
* Dual use of e-cigarettes with combustible cigarettes did not reduce exposure appreciably.
* There is no evidence that e-cigarette-only use compared with NRT-only use is associated with greater levels of carcinogens and toxins.
* Nicotine delivery of e-cigarettes and NRTs, although variable, is roughly similar to combustible cigarettes.
* Smaller meaningful differences in exposure may exist, and further longitudinal work is needed to confirm these findings.

Main Message: The study suggests that long-term NRT-only or e-cigarette-only use among former smokers is associated with substantially reduced levels of selected carcinogens and toxins compared with combustible cigarette smoking. however, dual use of e-cigarettes with combustible cigarettes does not seem to offer this benefit. The study highlights the need for further research to confirm these findings and to evaluate the effect of potential interactions of users with device characteristics on the delivery of toxins to users and bystanders.

Shahab, Lion, Maciej L. Goniewicz, Benjamin C. Blount, Jamie Brown, ann McNeill, K. Udeni alwis, June Feng, Lanqing Wang, and Robert West. “Nicotine, Carcinogen, and Toxin Exposure in Long-Term E-Cigarette and Nicotine Replacement Therapy Users: a Cross-Sectional Study.” annals of Internal Medicine 166, no. 6 (March 21, 2017): 390. https://doi.org/10.7326/M16-1107.