Poll finds higher risk of stroke in electronic cigarette users

The use of electronic cigarettes is badociated with an increased risk of heart attack, heart disease and stroke, according to a study that is expected to be presented Feb. 6 at the International Conference on Stroke Diseases. American Stroke Association in Honolulu.

The concern over the effects of the use of the electronic cigarette on health has increased over the last few years, fueled by soaring popularity and the belief that these are safe alternatives to normal cigarettes.

Electronic cigarette consumption among high school students increased by 900% between 2011 and 2015. In 2018, more than 3.6 million young people in the United States, including one in five high school students, were cigarette consumers. according to the Center for Disease Control and Prevention.

"There is some notion that electronic cigarettes are harmless," says Dr. Paul Ndunda, author of the study and an badistant professor at the University of Kansas Medical School in Wichita. "But this study and other previous studies show that although they are less harmful than normal cigarettes, their use still involves risks."

Researchers used data collected by the 2016 Behavioral Risk Factor Surveillance System, a telephone survey sponsored by several federal agencies, including the CDC. The survey includes people in the 50 states surveyed about health risk behaviors, such as smoking, and whether respondents were diagnosed with health problems.

Of the more than 400,000 people surveyed in 2016, 66,795 reported having ever used e-cigarettes at least once. Compared to non-users, e-cigarette users had a 71% higher stroke risk, an increased risk of heart attack by 40% and heart disease.

Ndunda says the nature of the badysis has prevented the research team from accurately calculating the absolute risk of heart attack and stroke from the database.

The results have not been published in a peer-reviewed scientific journal, but the researchers plan to submit their results soon, according to Ndunda.

"These findings are important because they match qualitatively and quantitatively with previous studies," says Stanton Glantz, researcher on tobacco and e-cigarettes at the University of California, San Francisco, who did not participate in this work but published another study linking the use of cigarettes with increased risk of heart attack. "The fact that the risk factors for stroke and heart attack are not so different is also identical to that seen with smoking, which adds extra weight to this study."

However, many users of electronic cigarettes also smoke conventional cigarettes. In other words, users of electronic cigarettes are twice as likely to smoke conventional cigarettes as non-consumers.

Ndunda and her colleague, Dr. Tabitha Muutu, compared people who used only electronic cigarettes – not conventional cigarettes – to non-smokers.

"Even in this group, the risk of stroke and the risk of heart attack were 29% higher," said Ndunda. Taken together, these two badyzes suggest an additive effect of the use of the electronic cigarette and the conventional cigarette.

"So, if you're a dual user, which is the case for many e-cigs, your situation is worse," says Glantz, who discovered a similar additive effect in his study.

Scientists do not know very well how electronic cigarettes carry this higher risk.

Smoking electronic cigarettes can contribute to the gradual accumulation of fatty deposits in the arteries, says Glantz. But he thinks that researchers could detect a link between an increased risk of heart attacks and strokes and the use of electronic cigarettes because of a more immediate effect on the cardiovascular system.

Glantz says: "You can then have this pre-existing buildup" and then use the electronic cigarette, which triggers a series of inflammatory processes, the release of oxidizing agents and other things that hinder the normal functioning of blood and blood vessels. and this triggers a heart attack or stroke. "

"This study certainly has limits," says Ndunda. On the one hand, this study did not make it possible to distinguish between the occasional use of electronic cigarettes and people who spray more frequently. "It probably depends on your consumption, and we can not evaluate that here," says Ndunda.

Electronic cigarettes can provide a range of nicotine concentrations and a wide variety of chemical flavors, further complicating the badysis. The design of the study also means that it can only show a connection between the use of the e-cigarette and the risk, and not a cause-and-effect.

Ndunda added that a study that identifies electronic cigarette users at an early stage, and then tracks their health status over time, would provide a clearer picture of the consequences of vaping.

Dr. Chitra Dinakar, Clinical Professor of Pulmonary Medicine and Critical Care Medicine at the Stanford University School of Medicine, who has studied the harmful effects of electronic cigarettes on health, says that these works, which are not only on adults 18 years and older, stroke in young users. "Nevertheless," she says, "this is an important subject that deserves a thorough examination."

Jonathan Lambert is an intern at NPR's Science Desk. You can follow him on Twitter: @evolambert.

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