Significantly decreased elasticity and elevated stiffness of ascending aorta was observed after smoking, confirming previous studies. However, no adverse effects were observed after using the EC(electronic cigarette). Research on ECs(ecigs) should be intensified since they may be potentially useful in reducing the adverse vascular effects associated with smoking.
Cigarette smoking has well-documented acute and chronic adverse effects on the vascular wall. It has been found to reduce distensibility and increasing stiffness of the aorta. Electronic cigarettes have been marketed in recent years as substitutes to smoking. Research has found that they release by far less toxic chemicals compared to cigarette smoke. However, clinical studies on their effects are relatively low. The purpose of this study was to evaluate the acute effects of electronic cigarette (EC) use on the elastic properties of the ascending aorta and compare them with the effects of tobacco cigarette smoking.
We recruited 108 healthy participants, aged 20-55 years; 51 smokers, and 57 daily EC users who had stopped smoking since 10.5 ± 8.7 months. Smokers were asked to smoke 2 cigarettes (0.7mg nicotine) and use an EC with nicotine-containing liquid (18mg/ml) for 10 minutes in a randomized cross-over design. Two-dimensional guided M-mode evaluation of systolic (AoS) and diastolic (AoD) diameters of the ascending aorta, 3cm above the aortic valve, was performed at baseline (8 hours abstinence from smoking, alcohol and caffeine), 20 minutes after smoking and 20 minutes after using the EC. Blood pressure and heart rate were also measured. For EC users, examinations were performed at baseline and 20 minutes after using the same EC device and liquid as smokers. The following aortic elasticity indices were measured: aortic strain = 100 (AoS – AoD)/AoD aortic distensibility (DIS) = 2(AoS – AoD)/(AoD x pulse pressure) aortic stiffness index (SI) = ln(SBP/DBP)/[(AoS – AoD)/AoD]
Both groups had similar characteristics. Blood pressure and heart rate were similar at baseline and 20 minutes after use of tobacco or EC. No difference was observed in aortic elasticity indices at baseline. In smokers, significantly decreased aortic strain (from 10.48 ± 4.49% to 8.47 ± 3.49%, P < 0.001) and DIS (from 3.24 ± 1.57 to 2.69 ± 1.25, P = 0.001), and elevated SI (from 5.73 ± 2.34 to 7.01 ± 3.75, P = 0.004) was observed after cigarette smoking compared to baseline. On the contrary, no difference from baseline was observed after using the EC (aortic strain: 10.32 ± 4.44%, P = 0.694; DIS: 3.26 ± 1.49, P = 0.873; SI: 5.86 ± 2.76, P = 0.655). In EC users, no difference was observed between baseline and post-use measurements (aortic strain: 10.85 ± 3.99% vs. 11.05 ± 3.77%; DIS: 3.39 ± 1.39 vs. 3.29 ± 1.16; SI: 5.37 ± 2.58 vs. 5.24 ± 1.84, P = NS for all). Conclusions
CONCLUSIONS. Significantly decreased elasticity and elevated stiffness of ascending aorta was observed after smoking, confirming previous studies. However, no adverse effects were observed after using the EC. Research on
ECs should be intensified since they may be potentially useful in reducing the adverse vascular effects associated with smoking.