How E-Cigarette Flavors Impact Cardiovascular Health

E-cigarettes and flavored e-liquids may increase the risk for cardiovascular diseases, according to a new study that demonstrated that acute exposure to the products worsens endothelial dysfunction, a precursor to cardiovascular disease. 

For their study, the researchers examined the effect of 6 different e-liquids with varying nicotine concentrations on endothelial integrity. The researchers also measured how the serum from those who use e-cigarettes affected endothelial integrity. The study was conducted using human-induced pluripotent stem cell–derived endothelial cells and a screening approach.

Of the 6 e-liquids, the cytotoxicity level of the cinnamon-flavored product was most potent. This flavor in particular was associated with significantly decreased cell viability, increased reactive oxygen species levels, impaired tube formation and migration, caspase 3/7 activity, low-density lipoprotein uptake, and activation of oxidative stress-related pathway, which confirmed endothelial dysfunction.

The increase in reactive oxygen species levels was due to the production of interleukin-1β and -6, which was initiated after conditioned media promoted macrophage polarization into a pro-inflammatory state.

When the researchers exposed the human-induced pluripotent stem cell–derived endothelial cells to the serum of those who used e-cigarettes, impaired pro-angiogenic properties demonstrated that an increase in reactive oxygen species was connected to endothelial dysfunction.  

According to the researchers, the e-cigarette users’ serum also had an increase in inflammatory cytokine expression.

—Colleen Murphy

Reference:

Lee WH, Ong S-G, Zhou Y, et al. Modeling cardiovascular risks of e-cigarettes with human-induced pluripotent stem cell–derived endothelial cells. J Am Coll Cardiol. 2019;73(21):2722-2737. DOI: 10.1016/j.jacc.2019.03.476.