The harm of nicotine: smoking has become an independent risk factor for the formation of atherosclerosis, and the addictiveness of nicotine is known to all. Nicotine induces the release of catecholamine and cortisol, and causes hemodynamic changes (increase in heart rate, rise in blood pressure, and the vasoconstriction) and adverse effects on blood lipids (leading to activation of adenylate cyclase in adipose tissue and decomposition of triglycerides. The study found that the total lipid composition of the rats exposed to E-cigarettes smoke increased significantly, the content of saturated fatty acids increased significantly, while the content of unsaturated fatty acids decreased significantly), as well as the induction of insulin resistance . Nicotine can also cause endothelial dysfunction, inhibit apoptosis, and enhance angiogenesis. This effect raises concerns with regard to nicotine promoting cancer development and accelerating atherosclerosis . Researchers at Danderyd Hospital in Sweden have found that inhaling E-cigarettes only 10 times can cause signs of damage to the blood vessels. Subsequently, they further studied the effects on healthy people of inhaling E-cigarettes 30 times. Magnus Rudbeck, a doctor at Danderyd Hospital who participated in the study, believes that E-cigarette users have poor vascular elasticity, and the poor vascular elasticity may lead to heart disease and stroke. Researchers believe that the nicotine in E-cigarettes may lead to poor vascular elasticity . The study of Flouris, A.D. et al. found that white blood cell count increased after smoking E-cigarettes, which reflected the inflammatory process of acute cardiovascular events . The health status of E-cigarette users was analyzed. It was found that, compared with non-smokers, the former had an enhancement in cardiac sympathetic nerve excitability, and they were more prone to oxidative stress reactions. Professor Choupo Perk from European Society of Cardiology explained that the stimulation of atomized nicotine on sympathetic nerves can cause irregular beating of the heart and elevated blood pressure, and may cause long-term harmful effects on the growth of the vascular wall . Vlachopoulos, C. et al. investigated cardiovascular risk factors among 24 young smokers in 4 different smoking scenarios, and used femoral artery to femoral pulse wave velocity (PWV) to assess aortic stiffness, finding that E-cigarette smoke increased young people’s arterial stiffness and blood pressure, and smoking E-cigarettes for over 30 min had an adverse effect on arterial stiffness that was similar to that of traditional cigarettes . The study of Battista, L. et al. also showed that nicotine inhalation vapors produced the same pathophysiological cardiovascular effects as traditional cigarettes . Farsalinos, K.E. et al. studied the acute effects of E-cigarette smoke on the cardiovascular system of exposed people, and the results showed that the cardiac output blood pressure of people exposed to E-cigarettes (11 mg/mL of nicotine content) increased slightly; when the heart of smokers contracted, cardiac output and heart rate were significantly increased. They also used the MTT test to authenticate that the atomized e-liquid has toxic effect on cultured myocardial cells .