September 2019

Vaping: How Smoking E-Cigarettes Affects Physiology and Athletic Performance

Editor’s Note: As of press time, the US Centers for Disease Control has reported 1299 cases of e-cigarette- or vaping-associated lung injury (EVALI) and issued interim guidance to assist with assessment, evaluation, management, and followup. The cases have been reported in 49 states and the Distric of Columbia, with 26 deaths reported across 21 states.

By Nicole Wetsman

For the past few years, popular conversation has pointed to e-cigarettes and vaporizers as a safer way to consume tobacco than other products, like cigarettes. But research on that method of tobacco consumption, and a spate of recent illnesses, has complicated that narrative: more than 1200 people have been affected by respiratory illnesses associated with e-cigarettes and vaping, and nearly a dozen people have died.

The Centers for Disease Control has determined that the majority of the illnesses are from illicit vaporizer products that contain THC, the psychoactive ingredient in marijuana. However, the standard, legally available products containing nicotine also have health effects, according to research conducted over the past few years. Nicotine’s well-documented effects on the way the adolescent brain forms synapses can harm the parts of the brain that control attention, learning, mood, and impulse control. (See “E-Cigarette, Vaping, Terminology and Facts,” page 30.)

Like other forms of tobacco, these products are sometimes used by athletes, both adult and adolescent. As a result, it’s important to identify the factors that may contribute to harm specific to athletes, as well as the patterns of use in that population.

“Coaches believe that their athletes are already healthier than others. They believe they’re not using substances, but it’s sometimes a dirty secret in athletic communities,” said Philip Veliz, PhD, associate director of the Sport, Health, and Activity Research and Policy Center at the University of Michigan. “We can’t turn a blind eye. It’s something that has to be addressed in sports organizations.”

Use Among Athletes

Because vaping only emerged as a popular trend a few years ago, there still isn’t much specific research on how and which types of athletes might be most likely to engage in this behavior, Veliz explained. However, the work that’s been done so far points to some key differences between vaping and other types of tobacco use in adolescent athletes, in particular.

Research on cigarette smoking indicates that adolescents who participate in physical activities, such as sports, are less likely to smoke. Some sports, though, are less protective against cigarette smoking than others: kids who play contact sports, like football, are at a higher risk than kids who run cross country, for example.1

Veliz analyzed data from the 2014 and 2015 Monitoring the Future survey, which collects information on drug use and attitudes among around 15,000 high school students.2 A subset of that year’s survey completed additional questions about e-cigarette use. Veliz compared reported sports participation with e-cigarette or cigarette use. As in previous work, this dataset showed that kids who played sports—especially those who played 3 or more sports—were less likely to use cigarettes. However, he found no difference between athletes and non-athletes with regards to their reported e-cigarette use over the 30 days before taking the survey.

Wrestlers were at the greatest risk of using all tobacco products, including e-cigarettes. Baseball and softball players also had a notably higher risk of using e-cigarettes.

“There isn’t a protective effect of sports participation against vaping, not the way that there is for cigarette use,” Veliz said. “The idea might be that kids think vaping or e-cigarettes are safer than cigarettes. Athletes might also see that is the case, and that it wouldn’t impact their sports the same way.”

However, he noted, the research into vaping, e-cigarettes, and athletes is still in early stages. The survey did not explicitly ask about any use of Juul, a brand that is particularly popular with teens and adolescents. Many young people, when asked if they vape, will say that they do not, even if they use Juul—it’s thought of as distinct. Because vaping only became popular among teens and adolescents recently, and also only recently emerged into the public consciousness, data on the groups who do and do not vape is still not available. “We still have to wait,” Veliz said. “It’s going to probably be another year or year and a half before we see anything new.”

Propylene glycol and glycerol, two common components of the liquids vaporized in these products, can be irritants when inhaled…
Alessandra Caporale, PhD

Vascular Effects

Although data on the demographics of athletes and vape and e-cigarette use are limited, research into the physical effects of using those products reveal potential impacts that might be particularly harmful to and impede performance in people participating in sports.

For example, research shows that vaping can affect blood flow and blood vessels. Nicotine is a known vasoconstrictor, regardless of delivery method. One study, published in the journal Chest in 2016, found that e-cigarettes and traditional cigarettes containing the same levels of nicotine both increased levels of oxidative stress and negatively affected flow-mediated dilation, the widening of arteries as blood flow increases.3 Flow-mediated dilation is a measure of blood vessel health.

However, nicotine is not the only component of e-cigarettes that can affect vascular health, according to Alessandra Caporale, PhD, a post-doctoral researcher in the Laboratory for Structural, Physiologic, and Functional Imaging at the University of Pennsylvania School of Medicine. Caporale led a study that examined vascular function following use of nicotine-free vaping and e-cigarette products. “We initially thought the major effect would be nicotine. But inside the e-cigarette aerosol are other components,” she said. Propylene glycol and glycerol, two common components of the liquids vaporized in these products, can be irritants when inhaled, she noted, adding that tiny particles of metals, smaller than 100 nanometers, have been detected as being released by e-cigarettes. Such small particles can cause vascular inflammation, as well as other effects.

Using an MRI, Caporale’s study measured vascular function in 31 non-smokers before and after they inhaled e-cigarette vapor that did not contain nicotine.4 “We imaged the femoral artery,” Caporale said. “We used a cuff, the same type of cuff used to measure blood pressure, around the upper thigh, and inflated it. Then we monitored the response of the artery after the cuff was released.” In a normal, healthy vessel, when the cuff is released, the artery should dilate to allow more oxygenated blood to return to the tissue. “There should be vasodilation to allow more blood through,” she said.

After the participants inhaled the e-cigarette vapor, however, dilation was reduced by around 34%, indicating changes to the inner lining of the vessels, which controls dilation. “The endothelium was not functioning properly,” Caporale said, adding that these findings should be extrapolatable to other vessels in the body, although those were not examined in this specific study.

Those effects on vessels are imperceptible, she said, so e-cigarette users would not notice that anything was different. Those effects on a single use also resolve after around 4 to 6 hours. However, when the vapor is inhaled consistently, it has the potential to cause long term, lingering vascular problems.

Even transient changes in blood vessels might affect athletes, though, Caporale said. “When you go to the gym, your muscles need a boost of oxygenated blood. They need reactive and healthy vessels to dilate as needed. If the ability of vessels is impaired, it means the whole system is down, and doesn’t work as well.”

Wound Healing

Vascular impairment might also contribute to another way early research shows vaping impacts health. Patients are warned to stop smoking traditional cigarettes before they have surgery, because the evidence shows that smokers have a higher chance of complications and their wounds take longer to heal.

Over the past few years, Jeffery Spiegel, MD, professor of otolaryngology, head and neck surgery at Boston University School of Medicine, said he started to have patients ask about vaping. “They would say, I know smoking is unsafe around surgery, but is vaping ok?” In response, he conducted a study to see if e-cigarettes affected wounds in the same way that traditional cigarettes do.5

“Wound healing is a pretty good model for physical health in general,” Spiegel explained. “You need good nutrition, good blood flow to heal an injury.”

The study exposed 15 rats to traditional cigarette smoke and 15 rats to e-cigarette vapor for 30 minutes twice a day for 30 days.5 Fifteen rats were left as controls, with no cigarette exposure. After 30 days, a piece of tissue was removed from the rodents’ backs and surgically reattached to simulate a surgical procedure. Rodents exposed to cigarettes and e-cigarettes saw more tissue death in the wound than controls, indicating that the wound healing process was impaired. Changes in vascular function and blood flow to the wound, likely caused by the nicotine in both products, might have contributed to that complication.

While this study was conducted on rodents, and it’s unclear how vaping and e-cigarettes affect wound healing in humans, Spiegel said he would expect the impairment would remain. “You can’t be certain,” he said,. “but it’s a compelling argument. I think the detrimental effects of cigarettes are similiar, so it crosses over.”

If vaping impacts wound healing, that would also have repercussions for athletic performance, Spiegel noted. Sports injuries may take longer to heal if the impairment proves significant, such as fractures, muscle tears, or other problems. In addition, working to build muscle is a constant cycle of micro-injuries. Exercise causes microscopic tears in muscle fibers, which heal to regrow stronger. “If vaping interferes with the body’s ability to heal, it would interfere with the athlete’s ability to train well or reap the benefits of training,” Spiegel said. “It’s the same way for people with bad diabetes, or an autoimmune disease, or anything that interferes with their ability to heal. We can’t expect them to be able to reach the types of performance of an elite athlete.”

Research on vaping is still in early stages, Spiegel noted, and there are still open questions about the product’s impact on human health and performance. Continued regulatory and legislative action on vaporizer products and e-cigarettes, however, might restrict their use significantly. “It may be that additional research into vaping becomes less valuable, because it’s going to be uncommon soon,” he said.

But until that point, athletic organizations and experts working with young athletes need to keep an eye on their use, according to Veliz. “I don’t know if it’s 100% on their radar. It took a while for them to, for example, start thinking about prescription painkillers. But I do think it’s starting to pick up traction.”

REFERENCES
  1. Veliz PT, Boyd CJ, McCabe SE. Competitive sport involvement and substance use among adolescents: a nationwide study. Subst Use Misuse. 2015;50:156-65.
  2. Veliz P et al. Adolescent sports participation, e-cigarette use, and cigarette smoking. Am J Prev Med. 2017;53:e175-e183.
  3. Carnevale R, et al. Acute impact of tobacco vs electronic cigarette smoking on oxidative stress and vascular function. Chest. 2016;150:606-12.
  4. Caporale A, et al. Acute effects of electronic cigarette aerosol inhalation on vascular function detected at quantitative MRI. Radiology. 2019;293:1-10.
  5. Troiano C, Jaleel Z, Spiegel JH. Association of electronic cigarette vaping and cigarette smoking with decreased random flap viability in rats. JAMA Facial Plast Surg. 2019;21:5-10.

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