Comparable Impairment of Vascular Endothelial Function by a Wide Range of Electronic Nicotine Delivery Devices

Abstract

Introduction Electronic nicotine delivery systems (ENDS; i.e., vaping devices) such as e-cigarettes, heated tobacco products, and newer coil-less ultrasonic vaping devices are promoted as less harmful alternatives to combustible cigarettes. However, their cardiovascular effects are understudied. We investigated whether exposure to aerosol from a wide range of ENDS devices, including a new ultrasonic vaping device, impairs endothelial function. Methods We measured arterial flow-mediated dilation (FMD) in rats (n=8/group) exposed to single session of 10 cycles of pulsatile 5s exposure over 5 minutes to aerosol from e-liquids with and without nicotine generated from a USONICIG ultrasonic vaping device, previous generation e-cigarettes, 5% nicotine JUUL pods (Virginia Tobacco, Mango, Menthol), and an IQOS heated tobacco product; with Marlboro Red cigarette smoke and clean air as controls. We evaluated nicotine absorption and serum nitric oxide levels after exposure, and effects of different nicotine acidifiers on platelet aggregation. Results Aerosol/smoke from all conditions except air significantly impaired FMD. Serum nicotine varied widely from highest in the IQOS group to lowest in USONICIG and previous generation e-cig groups. NO levels were not affected by exposure. Exposure to JUUL and similarly acidified nicotine salt e-liquids did not affect platelet aggregation rate. Despite lack of heating coil, the USONICIG under airflow conditions heated e-liquid to ~77˚C. Conclusions A wide range of ENDS, including multiple types of e-cigarettes with and without nicotine, a heated tobacco product, and an ultrasonic vaping device devoid of heating coil, all impair FMD after a single vaping session comparably to combusted cigarettes. Implications The need to understand the cardiovascular effects of various ENDS is of timely importance, as we have seen a dramatic increase in the use of these products in recent years, along with the growing assumption among its users that these devices are relatively benign. Our conclusion that a single exposure to aerosol from a wide range of ENDS impairs endothelial function comparably to cigarettes indicates that vaping can cause similar acute vascular functional impairment to smoking and is not a harmless activity.

Pod-based e-liquids impair human vascular endothelial cell function

“…Studies evaluating the acute and chronic effects of e-cigarettes in rodent models found increased arterial stiffness (via pulse wave velocity) [ 31 ] and reduced endothelial function (via flow-mediated dilation) [ 32 , 33 ]. One acute exposure mouse study evaluating the effects of a range of e-cigarette and heated tobacco products found that all tested JUUL e-liquids and the vehicles PG and VG similarly decreased flow-mediated dilation to levels comparable to that of combustible cigarettes [ 34 ]. Similarly, a short-term exposure of female mice to aerosolized PG:VG or to formaldehyde led to aortic endothelial dysfunction ex vivo [ 21 ].…”

Exposure, Retention, Exhalation, Symptoms, and Environmental Accumulation of Chemicals During JUUL Vaping

“…In rodent studies, JUUL aerosols produced adverse effects on the vascular, immune, and reproductive systems. In rats, various JUUL flavors, including “Menthol”, impaired endothelial function. , In mice, JUUL “Menthol” aerosols (2 weeks, 70 puffs/daily) caused hyperactivation of platelets and shortened thrombus occlusion and bleeding times, while 2 weeks of JUUL aerosol exposure to a higher dose (192 puffs/day, flavor not reported) disrupted the blood–brain barrier, resulting in ischemic stroke . In mice, JUUL aerosols also increased inflammation and altered plasma and urinary metabolites, which could increase disease risk. , JUUL “Mango” and “Mint” aerosols induced inflammation of the brain, lungs, heart, and colon, and JUUL “Mint” significantly increased lung neutrophils and oxidative stress .…”

Emerging ENDS products and challenges in tobacco control toxicity research

“…These products have not been heavily studied. However, while the assertion of fewer chemical reaction products is reasonable to expect, the aerosol generated from the USONICIG Zip has been shown to impair vascular endothelial function in rats comparably to impairment by JUUL, previous generation freebase nicotine ENDS and tobacco cigarettes,64 indicating that claimed reduction of HPHCs does not necessarily reduce the risk of some of the adverse effects of vaping and smoking. Further related research is warranted.…”

“…A relatively new approach is to produce aerosols via an ultrasonically vibrating membrane as opposed to a heating coil. While the vibration heats up the liquid to some extent (~75°C under airflow conditions according to early experiments with the USONICIG Zip64), the increased temperature does not approach the relatively high temperatures at a heating coil. The companies that produce such devices (figure 1) have an interesting marketing angle that asserts that conventional vaping is potentially harmful due to the reactions at the coil, so their ultrasonic devices are harm reduction products.…”