A new study from the University of Pennsylvania has found evidence suggesting the harmful effects of vaping could be present after a single use of an e-cigarette.

An analysis of the short-term impacts of vaping found e-cigarette use led to reduction in femoral artery dilation, peak blood flow, venous oxygen, and blood acceleration after cuff release.

“The common belief is that the nicotine is what is toxic, but we have found that dangers exist, independent of nicotine," said lead investigator Felix W. Wehrli, PhD, professor of radiologic science and biophysics at the Perelman School of Medicine at the University of Pennsylvania. "Clearly if there is an effect after a single use of an e-cigarette, then you can imagine what kind of permanent damage could be caused after vaping regularly over years."



With more than 10 million adults using e-cigarettes, vaping has become an ever-growing concern for physicians. In an effort to further understand the short-term impacts of vaping, investigators performed a prospective analysis on 31 healthy participants who were classified as never-smokers.

Investigators enrolled participants between the ages of 18 and 35 with a BMI between 18 and 30 with no history of smoking or overt cardiovascular or neurovascular disease at the Hospital of the University of Pennsylvania. To assess the impact of nicotine-free e-cigarette use, investigators performed multi vascular MRI with a 3.0-T imager before and after participants used the e-cigarette.

The MRI quantified peripheral vascular reactivity in the superficial femoral artery and vein, cerebrovascular reactivity in the superior sagittal sinus, and aortic arch pulse wave velocity. Before the MRI was performed, investigators also measured the participants’ blood pressure.

Of the 31 participants included in the study, 17 were men and the mean age of the cohort was 24 years and the mean BMI was 23. The supervised vaping use consisted of 16 3-second inhalations that were monitored by a research coordinator and they were considered successful in the absence of coughing or swallowing of the vapor.

Upon analysis, investigators found that multiple changes in patients after e-cigarette use. Investigators noted patients had higher resistivity index (0.03 of 1.30 (2.3%); P = .05), luminal flow-mediated dilation was severely blunted (23.2% of 9.4% (-34%); P < .001), and peak velocity (-9.9 of 56.6 cm per second2 (-17.5%); P < .001) and hyperemic index (-3.9 of 15.1 cm per second2 (-25.8%); P < .001) were also reduced.

Additionally, time to peak was delayed (2.1 of 7.1 sec [-9.6%]; P = .005), baseline SvO2 was lower (-13 of 65% HbO2 (-20%); P < .001), and overshoot higher (10 of 19% HbO2 (52.6%); P < .001). Investigators pointed out that aortic pulse wave velocity also increased (0.19 of 6.05 m per sec (3%); P = .05) after e-cigarette use.

"Beyond the harmful effects of nicotine, we've shown that vaping has a sudden, immediate effect on the body's vascular function, and could potentially lead to long-term harmful consequences,” Wehrli said.

Investigators noted multiple limitations within their study. They evaluated test-retest repeatability of each element separately rather than of the MRI protocol as a whole. Investigators also focused on the effects of aerosol and did not accommodate a second arm to compare the impact of e-cigarettes with nicotine to those without. Lastly, investigators noted that because participants were never-smokers, inter subject variations in adherence to inhalation protocol could not be entirely excluded.

The study, “Acute Effects of Electronic Cigarette Aerosol Inhalation on Vascular Function Detected at Quantitative MRI,” was published online in Radiology.