JUUL and Combusted Cigarettes Comparably Impair Endothelial Function

Objectives: JUUL and earlier generation electronic cigarettes (e-cigs) are promoted as being less hazardous than cigarettes. JUUL Labs, in particular, claims that switching from smoking to vaping has beneficial impacts; however, the health effects of such products are not well understood. We investigated whether exposure to JUUL and previous generation e-cig aerosol impairs endothelial function comparably to cigarette smoke. Methods: We exposed rats to aerosol from Virginia Tobacco flavor JUUL, an e-cig tank system using unflavored free-base nicotine e-liquid, Marlboro Red combustible tobacco cigarettes, or clean air for 10 cycles of 2 second inhalation over 5 minutes. We measured endothelial function pre- and post-exposure. Blood was collected 20 minutes post-exposure for serum nicotine analysis. Results: Aerosol/smoke from JUUL, previous generation e-cigs, and cigarettes all impaired endothelial function. The extent of impairment ranged from 34% to 58%, although the differences between groups were not statistically significant. Nicotine was highest in serum from the JUUL group; for the other e-cig and cigarette groups, nicotine levels were lower and comparable to each other. Conclusions: Aerosol from JUUL and previous generation e-cigs impairs endothelial function in rats, comparable to impairment by cigarette smoke.