Exposure to electronic cigarettes impairs vascular and microvascular function.

Background: The prevalence of e-cigarette use has increased in recent years, driven by the perception that e-cigarettes are less harmful compared to traditional tobacco smoking. Nevertheless, conflicting data exists regarding the potential impact of e-cigarettes on vascular health. Present study aimed to elucidate whether markers of vascular/microvascular function differs between e-cigarette and tobacco smokers, especially following acute exposure.

Methods: The study population consisted of 108 participants, including 39 e-cigarette users, 39 tobacco smokers and 30 never-smokers. Tobacco smokers smoked 1 cigarette in 7 min, and e-cigarette users used their device for 15 min. Coronary flow reserve (CFR), flow-mediated dilatation (FMD), and pulse wave velocity (PWV) were measured before and after smoking.

Results: Baseline CFR was significantly lower in both e-cigarette users and tobacco smokers as compared to controls (p < 0.001), while neither PWV (p = 0.925) nor FMD (p = 0.243) differed across groups. Compared to baseline, exposure to e-cigarettes led to a significant decrease in CFR (p < 0.001) and increase in PWV (p = 0.001), while there was a nonsignificant reduction in FMD (p = 0.053). Exposure to tobacco smoking was related to a significant decrease in CFR (p < 0.001) and FMD (p < 0.001), but not in PWV (p = 0.077). There were no interactions between the type of exposure (i.e. e-cigarette or tobacco) and changes in markers of vascular/microvascular dysfunction (P nonsignificant for all).

Conclusions: Both e-cigarette users and tobacco smokers show findings compatible with coronary microvascular dysfunction at baseline. Acute exposure to either e-cigarettes or tobacco is associated with further vascular and microvascular dysfunction.