News: Nicotine-Free E-Cigarettes Can Damage Blood Vessels

Single instance of vaping by non-smokers immediately leads to reduced vascular function

To study the short-term impacts of vaping, researchers at the University of Pennsylvania performed MRI exams on 31 healthy, non-smoking adults before and after vaping a nicotine-free e-cigarette. Comparing the pre- and post-MRI data, the single episode of vaping resulted in reduced blood flow and impaired endothelial function in the femoral arteries.

“While e-cigarette liquid may be relatively harmless, the vaporization process can transform the molecules — primarily propylene glycol and glycerol — into toxic substances,” said the study’s principal investigator Felix W. Wehrli, PhD.

In this study, the researchers examined the impact of an e-cigarette that contained propylene glycol and glycerol with tobacco flavoring, but no nicotine, from which study participants took 16, 3-second puffs. To evaluate vascular reactivity, the group constricted the vessels of the thigh with a cuff and then measured how quickly the blood flowed after its release. Using a multi-parametric MRI procedure, researchers scanned the femoral artery and vein in the leg before and after each vaping episode to see how vascular function changed.

The researchers then performed a statistical analysis to determine group differences in vascular function before and after vaping. They observed, on average, a 34% reduction in femoral artery dilation. E-cigarettes exposure also led to a 17.5% reduction in peak blood flow, 20% reduction in venous oxygen, and 25.8% reduction in blood acceleration after the cuff release. These findings suggest that vaping can cause significant changes to the inner lining of blood vessels, said study lead author Alessandra Caporale, PhD.

“Many e-cigarette users are convinced that they are just inhaling water vapor,” Caporale said. “But the solvents, flavorings and additives in the liquid base, after vaporization, expose users to multiple insults to the respiratory tract and blood vessels.”

Wehrli noted that they observed these striking changes after the participants (all of whom never smoked previously) used an e-cigarette a single time. Earlier this year, his research group found that acute exposure to e-cigarettes causes vascular inflammation. 

  1. Caporale A, Langham MC, Guo W, et al. Acute effects of electronic cigarette aerosol inhalation on vascular function detected at quantitative MRI. Radiology. 2019; 190562. doi: 10.1148/radiol.2019190562. [Epub ahead of print]