One e-cigarette with nicotine leads to adrenaline changes in nonsmokers' hearts

September 20, 2017
Credit: CC0 Public Domain

A new UCLA study found that healthy nonsmokers experienced increased adrenaline levels in their heart after one electronic cigarette (e-cigarette) with nicotine but there were no increased adrenaline levels when the study subjects used an a nicotine-free or empty e-cig.

The findings are published in Journal of the American Heart Association, the Open Access Journal of the American Heart Association/American Stroke Association.

Unlike cigarettes, e-cigs have no combustion or tobacco. Instead, these electronic, handheld devices deliver nicotine with flavoring and other chemicals in a vapor instead of smoke.

"While e-cigarettes typically deliver fewer carcinogens than are found in the tar of tobacco cigarette smoke, they also usually deliver nicotine. Many believe that the tar—not the nicotine—is what leads to increased cancer and heart attack risks," said Dr. Holly R. Middlekauff, senior study author and professor of medicine (cardiology) and physiology at the David Geffen School of Medicine at UCLA. "So, we asked the question, are e-cigarettes safe?"

The researchers had previously reported that chronic e-cig users have elevated sympathetic nerve activity which increases adrenaline directed to the heart and are more susceptible to oxidative stress. Both are risks factors for heart attack. This study aimed to find out if nicotine caused these events.

Middlekauff and her team used a technique called "heart rate variability" obtained from a prolonged, non-invasive heart rhythm recording. Heart rate variability is calculated from the degree of variability in the time between heartbeats. This variability may be indicative of the amount of adrenaline on the heart.

Credit: UCLA Health

Prior studies have used a heart rate variability test to link increased adrenaline activity in the heart with increased . People with known heart disease and people without known heart disease who have this pattern of high adrenaline levels in the heart have increased risk of death, Middlekauff said.

In the first study to separate the nicotine from the non-nicotine components when looking at the heart impact of e-cigarettes on humans, researchers studied 33 healthy adults who were not current or tobacco cigarette smokers. On different days, each participant used an e-cigarette with nicotine, an e-cigarette without nicotine or an empty 'sham' device. Researchers measured cardiac adrenaline activity by assessing heart rate variability and oxidative stress in blood samples by measuring the enzyme plasma paraoxonase (PON1).

They found:

  • Exposure to e-cigarettes with nicotine, but not e-cigarettes without nicotine, led to increased adrenaline levels to the heart, as indicated by abnormal .
  • Oxidative stress, which increases risks for atherosclerosis and , showed no changes after exposure to e-cigarettes with and without nicotine. The number of markers they studied for oxidative stress were minimal, however and more studies are warranted, according to Middlekauff.

"While it's reassuring that the non-nicotine components do not have an obvious effect on adrenaline levels to the , these findings challenge the concept that inhaled nicotine is benign, or safe. Our study showed that acute electronic cigarette use with increases cardiac levels. And it's in the same pattern that is associated with increased cardiac risk in patients who have known cardiac disease, and even in patients without known cardiac disease," Middlekauff said. "I think that just seeing this pattern at all is very concerning and it would hopefully discourage nonsmokers from taking up electronic cigarettes."

Future studies should look more closely at and e-cigarette use, using a broader number of cardiac markers, in a larger population of people, researchers said.

Explore further: Habitual e-cigarette use associated with risk factors linked to increased cardiovascular risk

Related Stories

Habitual e-cigarette use associated with risk factors linked to increased cardiovascular risk

February 1, 2017
In a study published online by JAMA Cardiology, Holly R. Middlekauff, M.D., of the David Geffen School of Medicine, University of California, Los Angeles, and colleagues examined whether habitual users of electronic cigarettes ...

E-cigarettes linked to increased arterial stiffness, blood pressure and heart rate in humans

September 11, 2017
New research has shown for the first time that e-cigarettes with nicotine cause a stiffening of the arteries in humans. This has important implications for the use of e-cigarettes, as arterial stiffness is associated with ...

How safe is vaping?

July 7, 2017
On the heels of another damning statistic against tobacco—it kills more than 7 million people each year, the World Health Organization said recently—come questions about whether vaping is a healthier substitute.

Human heart cells respond less to e-cig vapour than tobacco smoke

May 4, 2016
New research has showed substantial differences in the way human heart cells respond to e-cigarette smoke and conventional cigarette smoke.

FDA to target addictive levels of nicotine in cigarettes

July 28, 2017
For the first time, the federal government is proposing cutting the nicotine level in cigarettes so they aren't so addictive.

New method measures nicotine delivery from e-cigarettes

March 22, 2016
The effectiveness of e-cigarettes as a smoking substitute will likely rely on whether they can consistently provide the amount of nicotine a smoker needs to resist the desire to return to traditional cigarettes.

Recommended for you

Regular takeaways linked to kids' heart disease and diabetes risk factors

December 14, 2017
Kids who regularly eat take-away meals may be boosting their risk factors for heart disease and diabetes, suggests research published online in the Archives of Disease in Childhood.

Simulation model finds Cure Violence program and targeted policing curb urban violence

December 14, 2017
When communities and police work together to deter urban violence, they can achieve better outcomes with fewer resources than when each works in isolation, a simulation model created by researchers at the UC Davis Violence ...

One in five patients report discrimination in health care

December 14, 2017
Almost one in five older patients with a chronic disease reported experiencing health care discrimination of one type or another in a large national survey that asked about their daily experiences of discrimination between ...

Your pets can't put your aging on 'paws'

December 14, 2017
(HealthDay)—In a finding that's sure to ruffle some fur and feathers, scientists report that having a pet doesn't fend off age-related declines in physical or mental health.

Healthy eating linked to kids' happiness

December 13, 2017
Healthy eating is associated with better self-esteem and fewer emotional and peer problems, such as having fewer friends or being picked on or bullied, in children regardless of body weight, according to a study published ...

Searching for a link between achy joints and rainy weather in a flood of data, researchers come up dry

December 13, 2017
Rainy weather has long been blamed for achy joints. Unjustly so, according to new research from Harvard Medical School. The analysis, published Dec. 13 in BMJ, found no relationship between rainfall and joint or back pain.

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

Thnder
not rated yet Sep 20, 2017
Sounds like risk of cancer dropped to all but nothing vs Cigarettes. We should encourage smokers that won't quit, to swap to vaping.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.