Electronic Cigarette Smoking Increases Arterial Stiffness and Oxidative Stress to a Lesser Extent Than a Single Conventional Cigarette: An Acute and Chronic Study

Introduction:
This text is a summary of a research letter examining the effects of electronic cigarette (e-cig) smoking on aortic stiffness, exhaled CO concentration, and oxidative stress, compared to tobacco cigarettes (con-cigs). The study aims to evaluate both the acute and chronic effects of e-cig use.

Key Points:

* The study included 70 current smokers, divided into two groups: one using nicotine-free e-cigs and the other using e-cigs with nicotine.
* Participants underwent a baseline sham smoking for 7 minutes, followed by smoking a single con-cig or vaping an e-cig for 7 minutes.
* The study measured vascular markers and blood sampling during a 20-minute period after smoking/vaping, with a 40-minute interval before crossing over to the alternative cigarette.
* In the chronic phase, all 70 subjects were instructed to replace con-cigs with an e-cig containing nicotine for 1 month.
* Both con-cig and e-cig resulted in increased PWV, AIX75, and MDA (P<0.05), whereas brachial SBP and heart rate remained similar to baseline.
* The nicotine-free e-cig caused a smaller increase of PWV and MDA than the e-cig containing nicotine (P=0.03 and P=0.01, respectively).
* At 1 month, the compliant group (94%) showed an improvement in central SBP, brachial SBP, AIX75, and MDA (P<0.01).
* No changes in vascular markers and MDA were observed in the control group after 1 month (P>0.1).

Main Message:
The study suggests that both con-cigs and e-cigs adversely affect arterial elasticity and oxidative stress burden acutely. However, nicotine-free e-cigs result in a smaller increase of arterial stiffness. Replacement of conventional cigarettes by nicotine-containing e-cigs may reduce central and brachial SBP, arterial wave reflections, and oxidative stress within 1 month. These findings suggest that e-cigs may be used in a medically supervised smoking-cessation program, but further research is needed to confirm these results and address the limitations of the study.

Ikonomidis, Ignatios, Dimitrios Vlastos, Kallirrhoe Kourea, Gavriela Kostelli, Maria Varoudi, George Pavlidis, Panagiotis Efentakis, et al. “Electronic Cigarette Smoking Increases Arterial Stiffness and Oxidative Stress to a Lesser Extent Than a Single Conventional Cigarette: An Acute and Chronic Study.” Circulation 137, no. 3 (January 16, 2018): 303–6. https://doi.org/10.1161/CIRCULATIONAHA.117.029153.