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The use of e-cigarettes is associated with an increased risk of heart attack, heart disease and stroke, according to research that will be presented on February 6 at the American Stroke Association International Conference on Stroke in Honolulu.
Concerns over the influence of e-cigarette on health have risen in recent years, driven by an increase in their popularity and the belief that they are safe alternatives to normal cigarettes.
The use of e-cigarettes among high school students increased by 900 percent 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 e-cigarette users, according to Control Centers and disease prevention.
"There is a certain perception that e-cigarettes are harmless," says Dr. Paul Ndunda, author of the study and assistant at the University of Kansas, Wichita Medical School. "But this study and other previous studies show that although they are less harmful than normal cigarettes, their use still comes with risks."
Researchers used data collected by a behavioral risk factor monitoring system in 2016, a telephone poll sponsored by several federal agencies, including CDC. Research involves people in all 50 countries, wondering about risky health-related behaviors, such as smoking, and whether any health problem is diagnosed with the respondents.
Of over 400,000 people in 2016, 66,795 said they used e-cigarettes at least once, and compared to those who did not use e-cigarettes, they had 71 percent higher risk of stroke, 59 percent higher risk of heart attack, and 40 a higher risk of heart disease.
Ndunda says the nature of the analysis has prevented the research team from accurately calculating the absolute risk of heart and brain stroke from the database.
The findings are not published in a scientific-professional journal, but Ndunda says researchers are planning to submit their results soon.
"These results are important because they qualitatively and quantitatively agree with the previous research," says Stanton Glantz, a tobacco researcher and e-cigarette researcher at the University of California at San Francisco, who was not involved in this business, but published another study linking e-cigarettes. – use of cigarettes at higher risk of heart attack. "The fact that the risk factors for stroke and heart attack are different is also the same pattern you see with cigarette smoking, which adds extra weight to this study."
However, many e-cigarette users also smoke conventional cigarettes.
In fact, Ndund has revealed that e-cigarette users are twice as likely to smoke conventional cigarettes as compared to those who do not use e-cigarettes.
To see only the effects of e-cigarette on health, Ndund and his colleague Dr. Tabitha Altriu compared people who used only e-cigarettes – not conventional cigarettes – non-smokers.
"Even in this group there was 29 percent higher risk of stroke and 25 percent higher risk of heart attack," says Ndunda. Taken together, these two analyzes point to the aditive effect of e-cigarettes and the conventional use of cigarettes.
"So if you're a double user, many of you e-cigarette users, you're actually worse off," says Glantz, who found a similar additive effect in his study.
Scientists are not quite sure how e-cigarettes lead to this greater risk.
Smoking of e-cigarettes can contribute to the gradual accumulation of fat deposits in the arteries, says Glantz. But researchers believe that researchers can detect the link between increased risk of heart attack and stroke and the use of e-cigarettes due to the current effect on the cardiovascular system.
It could happen that the existing bundles, says Glantz, "and then use an e-cigarette and it causes a pile of inflammatory processes, release of oxidizing agents and things that interfere with normal functioning of the blood and blood vessels, causing a heart attack or stroke stroke. "
"This study certainly has limitations," says Ndunda. First of all, this study could not differentiate the occasional use of e-cigarettes and those that are more frequent. "It's probably as important as you use, and we could not estimate it here," says Ndunda.
E-cigarettes can deliver a range of nicotine concentrations and a wide range of chemical aromas, adding further complications to the analysis. Design of a study also means that it can only show the link between the use of e-cigarettes and the risk, not the cause and the consequences.
Ndunda added that a study that early identifies e-cigarette users, and then tracked their health, gave a clearer picture of the consequences of steaming.
Dr. Chitra Dinakar, clinical professor of pulmonary and critical medicine at the Stanford University Medical School, who studied the effects of e-cigarette on health, says that this study, which only examines adults 18 and over, "does not reflect the risk of stroke in younger patients. "Still, he says," this is an important topic that deserves constant supervision ".
Jonathan Lambert is a trainee at the NPR Scientific Office. You can track it on Twitter: @evolambert.