1. Introduction
illness, inflammation, infection, arterial vascular stiffness, arterial stiffness
CARDIOVASCULAR DISEASE, ENDOTHELIAL DYSFUNCTION, INFLAMMATION, FUNCTIONAL DISORDERS, INFECTION, INFLAMMATION, ARTERIAL STIFFNESS, ENDOTHELIAL DYSFUNCTION
In addition to the market launch of heated tobacco products (HTPs) and the JUUL as well as the EVALI, they caused a widespread discussion on the risk reduction compared to a combustible cigarette. Furthermore, first data showed harmful effects on the cardiovascular system. We, therefore, conducted investigations including a control group with a nicotine-free liquid. Forty active smokers were studied in two different approaches during and after consuming an HTP, a cigarette, a JUUL, or a typical electronic cigarette with or without nicotine in a partly double-blinded randomised, cross-over trial. Inflammation, endothelial dysfunction, and blood samples (full blood count, ELISA, multiplex immunoassay) were analysed, and arterial stiffness was measured. In addition to the cigarette, an increase in the white blood cell count but also in proinflammatory cytokines was shown for the various nicotine delivery systems. These correlated with the parameters of arterial vascular stiffness as a clinical parameter of endothelial dysfunction. It can be shown that even a single consumption of the different nicotine delivery system or cigarette leads to a significant inflammatory reaction followed by endothelial dysfunction and increased arterial stiffness causing cardiovascular disease. Inflammation, endothelial dysfunction, and arterial stiffness should be addressed in long-term observational studies.Cigarette smoking is one of the most frequent preventable causes of illness and premature mortality [The most frequent application is probably the inhalation of nicotine. Different possibilities and devices are distinguished. In this paper, the classic filter cigarette, the e-cigarette, the JUUL, and the IQOS, as a representative of HTPs, are compared. Both HTPs and e-cigarettes have been designed to release nicotine as an aerosol without the classic combustion and to make it available to the body via inhalation via the respiratory tract. In the HTPs made of specially prepared tobacco, the residual water is evaporated together with the nicotine. In the case of the e-cigarette, a liquid, which is a mixture of propylene glycol and/or glycerol as well as flavourings and possibly nicotine, is vapourised. In 2014, there were already more than 450 different e-cigarettes with now different generations and more than 8000 different liquids [Endothelial dysfunction refers to a functional disorder of the endothelium. The endothelium synthesises various vasoactive substances, such as nitric oxide (NO), which is a potent vasodilator. The intake of pollutants from tobacco smoke leads to a reduced release of NO. Due to increased concentrations of free radicals, oxidised low-density lipoprotein (LDL) is formed with a direct vascular damaging effect [The humoral factors of the non-specific immune response include proinflammatory cytokines, such as interleukin-6 (IL-6), and acute phase proteins, such as C-reactive protein (CRP). Both are considered to be easily detectable inflammatory parameters during an infection. Scott et al. and Higham et al. were able to demonstrate an increased production of IL-6 after exposure to cigarette smoke and e-cigarette vapour, respectively [Inflammation and endothelial dysfunction are not stand-alone parameters but interact directly with each other and with arterial stiffness. Therefore, we investigated the question of the effect of acute consumption of combustible cigarettes, e-cigarettes, and tobacco heaters on inflammation and arterial vascular stiffness in experimental approaches.