Ιωάννης Λεκάκης, Καθηγητής, Ιατρικής Σχολής, ΕΚΠΑ
Ιγνάτιος Οικονομίδης, Αναπληρωτής Καθηγητής, ΕΚΠΑ
Καλλιρόη Κουρέα, Διδάκτωρ Πανεπιστημίου Αθηνών
Introduction: Electronic cigarette (e-cig) has been proposed as a bridge to smoking cessation. In this study we examined its effects a) on aortic elasticity, b) endothelial glycocalyx thickness, c) exhaled CO concentration, and d) oxidative stress acutely.
Aim: The purpose of this study is the potential effects of using the electronic cigarette on arterial wall function parameters.
Material and methods: We studied 70 current smokers without diagnosed cardiovascular disease. In the acute phase the subjects were randomized to either smoke a single conventional or vape an electronic cigarette for 7 min (simulating the duration of a normal cigarette smoking), and after a 40 minute washout period were crossed over to the alternative cigarette. Of the 70 subjects, 35 used nicotine-free electronic cigarette fluid during the acute phase protocol, while the remaining 35 electronic cigarette fluid with nicotine concentration of 12 mg/dL. All subjects underwent sham smoking for 7 min before randomization. In both groups, we measured: a) the velocity of pulse wave propagation in the aortic wall (PWV) and the amplification index (AIx) by Arteriograph and Complior, b) the diameter of the endothelial infiltration area of sublingual arterial microcirculation through Sideview, Darkfield image (Microscan, Glycochech) as an endothelial glycosylase integrity marker; (c) Exposure to CO (parts per million-ppm) as a smoking activity index and (d) Oxidative stress load, as estimated by the concentration of malonic aldehyde in the plasma. Results :
In the acute phase, both conventional cigarette and electronic cigarette showed an increase in arterial stiffness and a burden of oxidative stress. Comparing these two, however, the price levels of PWV, AIX, CO and MDA were lower after using the electronic cigarette than the conventional cigarette.
(PWV, baseline: 10±0.2 vs e-cig: 10.5±0.2 vs con-cig: 11±0.2 m/s, p<0.05; Aix, baseline: 29.5±7 vs e-cig: 30.2±8 vs con-cig: 33.1±8%, p<0.05; CO, baseline: 12.9±0.7 vs e-cig: 12±0.6 vs con-cig: 14.9±0.7 ppm, p<0.001; MDA, baseline: 1.09±0.1 vs e-cig: 1.17±0.1 vs con-cig:1.28±0.1 μmol/L, p<0.001).
In addition, the nicotine-free electronic cigarette showed a significantly lower increase in PWV and MDA values from the electronic cigarette containing nicotine replacement liquid.
(nicotine free PWV: 10.2±0.3 to 10.5±0.3 m/s vs nicotine containing PWV: 9.8±0.4 to 10.6±0.3 m/s, ΔPWV=+0.3 vs +0.8 m/s, p<0.05 nicotine free MDA: 1.23±0.2 to 1.26±0.2 μmol/L vs nicotine containing MDA: 1.09±0.3 to 1.46±0.4 μmol/L, p<0.05).
Changes between baseline and false smoking were lower than the corresponding changes after the use of an electronic cigarette (with or without nicotine) as well as that of the conventional cigarette. (p <0.01).
The use of electronic cigarette causes less increase in arterial stiffness and oxidative stress load compared to smoking a single conventional cigarette.
Electronic cigarette, Endothilium, Glykokalikas,
Arterial stifness, Arteriograph