New Report Uncovers Escalating Health Risks
By AMERICAN HEART ASSOCIATION
Research continues to unveil the health dangers associated with e-cigarette use, necessitating further studies on the potential long-term effects on the heart and lungs, reports a new scientific statement from the American Heart Association recently published in the journal Circulation.
The
new scientific statement outlines the most recent data and trends regarding
use, pinpoints current health impacts, underscores existing basic and clinical
scientific evidence related to e-cigarettes, and suggests research priorities
to gain deeper insight into the short- and long-term health repercussions of
using e-cigarettes.
Vaping
products, also known as e-cigarettes, are battery-operated systems that heat a
liquid solution, or e-liquid, to create an aerosol that is inhaled into the
lungs. Most e-liquid formulations deliver nicotine, which has been established
as having negative health effects as well as strong addictive properties.
The products may also contain other substances, most commonly tetrahydrocannabinol (THC), the psychoactive element of cannabis, as well as methamphetamine, methadone, or vitamins.
The liquids also include humectants (hygroscopic
carriers such as propylene glycol and vegetable glycerol) that act as solvents
and create a water aerosol or vapor, flavoring agents, cooling agents such as
menthol and sweeteners, in addition to metals from the heating coil and other
chemicals.
“E-cigarettes deliver numerous substances into the body that are potentially harmful, including chemicals and other compounds that are likely not known to or understood by the user. There is research indicating that nicotine-containing e-cigarettes are associated with acute changes in several hemodynamic measures, including increases in blood pressure and heart rate,” said the volunteer chair of the scientific statement writing committee Jason J. Rose, M.D., M.B.A., an associate professor of medicine and the associate dean of innovation and physician science development at the University of Maryland School of Medicine in Baltimore.
“There
has also been research indicating that even when nicotine is not present,
ingredients in e-cigarettes, particularly flavoring agents, independently carry
risks associated with heart and lung diseases in animals. Negative effects of
e-cigarettes have been shown through in vitro studies and in studies of
individuals exposed to chemicals in commercially available products.”
The
writing committee points to the significance of the clinical diagnosis of
“E-cigarette, or Vaping, product use Associated Lung Injury” (EVALI). EVALI was
first recognized as a condition by the U.S. Centers for Disease Control and
Prevention in 2019 when approximately 2,800 hospitalizations occurred among e-cigarette
users in less than a year.
This
is cited in the statement as one example that emphasizes the lack of knowledge
surrounding the risks of e-cigarettes and their ingredients. In the case of the
EVALI hospitalizations, vitamin E acetate has been implicated as the ingredient
likely causing illness. This substance is used as a thickening agent in some
e-cigarette liquids.
Studies
gauging the specific impact e-cigarettes have on heart attacks and strokes are
limited. Much research on e-cigarette use has been conducted on people who have
also used or are currently using traditional cigarettes.
Additionally,
large survey studies have focused on younger adults who have a low occurrence
of heart attacks and strokes. The writing committee says longer-term studies of
e-cigarette users of all ages are needed, including among people who already
have cardiovascular disease.
One
recent analysis of the adult Population Assessment of Tobacco and Health (PATH)
study found a statistically significant association between former or current
e-cigarette use at the time participants enrolled in the study and the
development of incident respiratory disease (chronic obstructive pulmonary
disease/COPD, chronic bronchitis, emphysema or asthma) within the next two
years.
The
PATH Study, an ongoing study that started in 2013, is one of the first large
tobacco research efforts undertaken by the National
Institutes of Health and the U.S. Food and Drug Administration.
Additional
studies cited in the statement indicate a rapid increase since 2010 in the
number of people who had ever used e-cigarettes or were currently using the
devices, and most of those users were current or former traditional cigarette
smokers. In addition, by 2016, data from the Behavioral Risk Factor
Surveillance System indicated about 1.2 million adults in the U.S. who had
never smoked combustible cigarettes before were currently using e-cigarettes.
The
writing committee noted that e-cigarettes are reported to be the most commonly
used tobacco product among youth, particularly high school and middle school
students. The statement cites data showing that almost 3 out of 4 young people
using e-cigarettes exclusively report using flavored e-cigarette products. This
high rate of use by youth makes it critical to assess the short- and long-term
health effects of these products, according to the statement.
“Young
people often become attracted to the flavors available in these products and
can develop nicotine dependence from e-cigarette use. There is significant
concern about young people assuming e-cigarettes are not harmful because they
are widely available and marketed to an age group that includes many people who
have never used any tobacco products,” Rose said.
“The
long-term risks of using e-cigarettes are unknown, but if the risks of chronic
use are like combustible cigarettes, or even if the risks are reduced but still
present, we may not observe them for decades. What is equally concerning is
that studies show that some youth who use e-cigarettes go on to use other tobacco
products, and there is also a correlation between e-cigarette use and substance
use disorders.”
Given
the established, high health risks of smoking combustible cigarettes,
e-cigarette products have been evaluated as smoking cessation tools. The writing
committee examined the limited research in this area and concluded that any
benefits e-cigarettes may offer to help people stop smoking or stop using
tobacco products need to be clearly balanced alongside the products’ known and
unknown potential health risks, including the known risk of long-term
dependence on these products.
“E-cigarette
companies have suggested that their products are a way to quit smoking
traditional cigarettes. There is no strong evidence to support this beyond any
short-term benefit. The lack of long-term scientific safety data on e-cigarette
use, along with the potential for the addiction to e-cigarette products seen
among youth, are among the reasons the American Heart Association does not
recommend e-cigarette use for cessation efforts,” said Rose Marie Robertson,
M.D., FAHA, the Association’s deputy chief science and medical officer and
co-director of the Association’s Tobacco Center of Regulatory Science.
“It’s
also important to note that e-cigarette products are not approved by the U.S.
Food and Drug Administration (FDA) for tobacco cessation. The Association
recommends a combination of multiple-episode cessation counseling accompanied
by personalized nicotine replacement therapy with FDA-approved doses and
formulations, as well as medications to help control cravings, to help people
who smoke combustible cigarettes with cessation. And all of this needs to be
undertaken with the understanding that quitting often takes many tries, and any
failures should be seen as just episodes to learn from on the road to finally
beating a powerful addiction for good.”
The
scientific statement writing committee emphasizes a critical need for
additional knowledge and research, specifically:
Future
research should focus on gaining knowledge about the serious and potentially
long-term effects of e-cigarettes on the heart, blood vessels, and lungs.
Studies
are needed that include patients with pre-existing cardiopulmonary disease,
such as coronary artery disease or chronic obstructive pulmonary disease, to
evaluate and compare outcomes among e-cigarette users in comparison to
traditional smokers, and those who use e-cigarettes along with traditional
cigarettes (referred to as dual users) and nonsmokers.
More
in-depth research is needed about the common chemical ingredients in
e-cigarettes and the effects they independently have on pulmonary and cardiac
health.
Clinical
studies are needed to study the risks and potential benefits of e-cigarettes as
alternatives to traditional combustible cigarettes.
Since
the long-term health impact of e-cigarettes may take decades to emerge, more
molecular and laboratory studies are needed in the interim to help determine
the biological implications of e-cigarette use.
“Because
e-cigarettes and other vaping systems have only been in the U.S. for about 15
years, we do not yet have enough information on their long-term health effects,
so we must rely on shorter-term studies, molecular experiments, and research in
animals to try to assess the true risk of using e-cigarettes,” Jason Rose
added. “It is necessary for us to expand this type of research since the
adoption of e-cigarettes has grown exponentially, especially in young people,
many of whom may have never used combustible cigarettes.”
Reference:
“Cardiopulmonary Impact of Electronic Cigarettes and Vaping Products: A
Scientific Statement From the American Heart Association” by Jason J. Rose,
Suchitra Krishnan-Sarin, Vernat J. Exil, Naomi M. Hamburg, Jessica L. Fetterman,
Fumito Ichinose, Miguel A. Perez-Pinzon, Mary Rezk-Hanna and Eric Williamson,
17 July 2023, Circulation.
DOI:
10.1161/CIR.0000000000001160
The
scientific statement was prepared by the volunteer writing group on behalf of
the American Heart Association’s Council on Cardiopulmonary, Critical Care,
Perioperative and Resuscitation; the Council on Epidemiology and Prevention;
the Council on Cardiovascular Radiology and Intervention; the Council on
Lifestyle and Cardiometabolic Health; the Council on Peripheral Vascular
Disease; the Stroke Council; and the Council on Arteriosclerosis, Thrombosis
and Vascular Biology. American Heart Association scientific statements promote
greater awareness about cardiovascular diseases and help facilitate informed
healthcare decisions. Scientific statements outline what is currently known
about a topic and what areas need additional research. While scientific
statements inform the development of guidelines, they do not make treatment
recommendations.