Top Things to Know: Cardiopulmonary Consequences of Vaping in Adolescents

1. E-cigarette, or electronic nicotine delivery system (ENDS) use has increased substantially in the last decade, yet the exact composition of the e-liquids within the devices is not publicly known, making it difficult to predict their health effects, including on the lungs and heart.
2. Since their introduction to the market in the early 2000s, overall e-cigarette use has increased exponentially, including increased use in youth and young adult populations; in 2019 self-reported past 30-day use of e-cigarettes was 27.5% in adolescents (grades 9-12, n = 10,097) and 10.5% in early adolescents (grades 6-8, n = 8837)¹ reversing years of decreasing combustible tobacco use. Despite this, there is limited knowledge about the cardiopulmonary consequences of e-cigarette use in adolescents.
3. The goal of this scientific statement is to provide background information on the effects of e-cigarettes on adolescent cardiopulmonary health, and to guide strategies for therapies and for future research directions, as well as inform public policy makers on the short- and long-term risks of e-cigarettes.
4. The development of small ENDS devices in that contain nicotine in salt form rather than freebase, allowed higher nicotine delivery at lower power, coincident with increased popularity among adolescents. While sometimes marketed as smoking cessation aids, e-cigarettes are not FDA-approved for this purpose and their effectiveness in reducing nicotine consumption is around four-fold less than nicotine patches.
5. The toxicity of e-cigarettes remains poorly understood. Other than nicotine, e-liquids contain vegetable glycerin and propylene glycol, which are on the FDA’s generally recognized as safe (GRAS) list but were not intended to be inhaled thus have not been tested for inhalation toxicology. When heated these compounds break down into acetaldehyde, acrolein, diacetyl and formaldehyde. Acrolein and formaldehyde are potent irritants and known carcinogens.
6. Studies have found higher rates of wheezing in e-cigarette users, greater prevalence of asthma in youth, and increased incidence of respiratory disease. Changes in gene expression indicative of immunosuppression have been detected, and e-cigarette exposure has been demonstrated to alter bronchial epithelia and airway secretions, all suggesting e-cigarette users have increased susceptibility to pulmonary infections.
7. In young adults, e-cigarette use is associated with higher arterial stiffness, impaired endothelial function, increases in blood pressure, heart rate and sympathetic tone, increased levels of oxidative stress biomarkers, and pro-inflammatory white blood cells, increasing the risk of cardiovascular disease. Thus, e-cigarette use is like to increase cardiovascular disease risk in adolescents as well.
8. Lung development continues into the early 20s, and adolescents who vape are at risk for stunting or altering their lung development and may not reach full lung function. Available studies indicate that adolescents who vape, smoke or are exposed to secondhand smoke will likely become symptomatic at a lower threshold for asthma, chronic obstructive pulmonary disease (COPD), pneumonia, or interstitial lung disease.
9. The FDA has taken action against some flavored e-liquids, which are known to appeal to youth, but many flavored e-cigarettes remain on the market as of this writing, and there is currently no regulatory standard limiting nicotine concentration. Healthcare stakeholders such as medical schools and hospitals should develop anti-vaping curricula and offer e-cigarette-cessation programs for adolescents and adults.
10. Although e-cigarettes may be able to help some regular cigarette smokers switch from combustible tobacco, their appeal among adolescents has grown substantially, with limited knowledge of their cardiopulmonary and other long-term health consequences. This field is clearly of great public health concern and intensive research is needed to determine the long- and short-term consequences of vaping in adolescents, especially those that are likely to be present for many years in the future.

¹Cullen KA, Gentske AS, Sawdey MD, Chang JT, Anic GM, Wang TW, Creamer MLR, Jamal A, Ambrose BK, King BA. E-Cigarette Use among Youth in the United States, 2019. JAMA. 2019;332:2095-2103. Doi:10.1001/jama.2019.18387.