P3406Aortic stiffness is significantly increased in low-nicotine dependent smokers after the use of both combustible and electronic cigarettes

Abstract

Purpose: We sought to determine whether the magnitude of nicotine dependence, might have a differential effect on aortic stiffness after tobacco cigarette (TC) and electronic cigarette (EC) smoking. Methods: We studied 27 smokers (age: 30±8 years) otherwise free of cardiovascular risk factors on three separate occasions: a) TC over 5 minutes, b) EC for a period of 30 minutes, and c) nothing (sham procedure) for 60 minutes. Carotid-femoral pulse wave velocity (PWV) was used to assess aortic stiffness. All participants were asked to fill in the Fagerstrom Test for Nicotine Dependence (FTND) that is a standard instrument for assessing the intensity of nicotine dependence. Results: The mean (SD) FTND score of the study population was 3.6 (2.5). Of them, nine were highly nicotine dependent (FTND core>5). There were no significant differences in all baseline measurements between high and low nicotine dependence smokers at each of the three arms of the protocol. Higher increase in PWV response after TC was observed in low nicotine-dependent smokers compared to high nicotine-dependent smokers (peak effect at time zero point by 0.57 m/s vs. peak effect by 0.32 m/s, respectively, left plot). The interaction of the effect of TC smoking on PWV by nicotine dependence was statistically significant (P=0.009). Similarly, a higher increase in PWV after EC smoking was observed in low nicotine-dependent smokers (peak effect at time 15 minutes by 0.40 m/s vs. peak effect by 0.24 m/s, respectively, right plot). The interaction of the effect of EC on PWV by nicotine dependence was statistically significant (P=0.025). Importantly, the composite effect of both TC and EC smoking versus sham smoking throughout the study was statistically significant even among the high nicotinedependent smokers (P=0.002 and P=0.04, respectively). Conclusions: The study shows a harmful effect of both TC and EC smoking especially in low nicotine-dependent young smokers. This finding has clinically significant connotations given the nearly three times greater risk of ischemic heart disease in young adults who consume 1-4 cig/day than that of non-smokers (Figure Presented).