New studies show the harmful effects of vaping and smoking on blood vessels and how combining e-cigarettes with regular cigarettes can increase health risks
Prolonged use of e-cigarettes can significantly impair the function of the body’s blood vessels, increasing the risk of cardiovascular disease. Additionally, using e-cigarettes and regular cigarettes can pose an even greater risk than using either product alone. these are the results of two new studies endorsed by the US National Heart, Lung and Blood Institute (NHLBI).
The results, published today in the journal Arteriosclerosis, Thrombosis, and Vascular Biology, add to the evidence that long-term use of e-cigarettes can harm people’s health. Researchers have known for years that smoking tobacco can damage blood vessels. However, the effects of e-cigarettes on cardiovascular health are poorly understood. The two new studies, one in humans and one in rats, were able to confirm the harmful effects.
Regular users of e-cigarettes may have a risk of cardiovascular disease similar to that of chronic smokers.
The human study found that chronic e-cigarette users had impaired blood vessel function, which could put them at greater risk for heart disease. That is, regular users of e-cigarettes may have a risk of cardiovascular disease similar to that of chronic smokers.
In this first study, blood samples were collected from a group of 120 volunteers that included long-term e-cigarette users, long-term cigarette smokers, and non-users. The researchers defined long-term e-cigarette use as more than five times a week for more than three months and defined long-term cigarette use as smoking more than five cigarettes a day.
They then exposed each of the blood samples to human blood vessel cells (endothelial cells) grown in the laboratory and measured the release of nitric oxide, a chemical marker used to assess the functioning of these cells. They also looked at cell permeability, that is, the ability of molecules to pass through one layer of cells and reach the other side. An excess of permeability makes the vessels permeable, impairing their function and increasing the risk of cardiovascular disease.
E-cigarettes have harmful cardiovascular effects differently than those caused by tobacco smoke
The researchers found that the blood of participants who used e-cigarettes and those who smoked caused a significantly greater decrease in nitric oxide production by blood vessel cells than the blood of non-users. Notably, the researchers found that the blood of e-cigarette users also caused more permeability in blood vessel cells than the blood of smokers and non-users. The blood of e-cigarette users also caused a greater release of hydrogen peroxide, an oxidative molecule, from blood vessel cells than the blood of non-users. Each of these three factors may contribute to impaired blood vessel function in people who use e-cigarettes, the researchers said.
The researchers found that e-cigarettes had deleterious cardiovascular effects different from those caused by tobacco smoke. Specifically, they found that the circulating biomarkers of cardiovascular risk were different in both cases. This means that the effects add up, and people who consume both products, of which there are many, are at even greater risk.
The damage is caused by irritation of the airways that triggers biological signals in the vagus nerve.
In the second study, researchers tried to find out whether specific components of cigarette smoke or e-cigarette vapor were responsible for the damage to blood vessels. In studies conducted with rats, they exposed the animals to various substances present in tobacco or electronic cigarette smoke. These included nicotine, menthol (a cigarette additive), the gases acrolein and acetaldehyde (two chemicals found in both tobacco smoke and e-cigarette vapours), and inert carbon nanoparticles to represent the nature of smoke and vapor particles. electronic cigarettes.
Using special measurements of arterial flow, the researchers showed that the damage to blood vessels does not appear to be caused by a specific component of cigarette smoke or e-cigarette vapor. Instead, they said, it appears to be caused by airway irritation that triggers biological signals in the vagus nerve, which somehow leads to blood vessel damage, possibly through an inflammatory process.
The vagus nerve is the longest in the body and extends from the brain through the airways, and plays a key role in heart rate, breathing, and other functions. The researchers showed that nerve disconnection in rats prevented blood vessel damage from tobacco smoke, demonstrating its key role in this process.
The researchers found that there was not a single component that could be removed to prevent the harmful effect of smoke or vapors on blood vessels. As long as there was an irritant in the airways, blood vessel function was impaired.
The finding has implications for efforts to regulate tobacco products and e-cigarettes, as it underscores how difficult it is to identify any ingredients that are responsible for blood vessel damage.
REFERENCE
Chronic e-cigarette use impairs endothelial function at both physiological and cellular levels
