Oct. 6 (UPI) -- If teens are vaping nicotine, it's likely they're also using cannabis-based e-cigarettes and vice versa, according to a new analysis published Tuesday by JAMA Network Open.
The survey of more than 3,000 adolescents and teens from 10 high schools in the Los Angeles area found that older teens who identified as frequent users of nicotine vaping devices were 25% more likely than others to be moderate users of cannabis e-cigarettes.
Those who started using nicotine-based e-cigarettes in adolescence also were 46% more likely than others to become frequent cannabis vapers, the researchers said.
The trends suggest high levels of "poly-substance" use among teens who vape, according to the researchers. Poly-substance use is a term used in addiction medicine to describe dependence on two or more drugs.
"Poly-substance nicotine and cannabis vaping appears to be the norm, compared to nicotine-only or cannabis-only vaping for adolescents and young adults," study co-author H. Isabella Lanza told UPI.
"If your teen vapes one substance, it's highly likely they are or will vape other substances," said Lanza, an associate professor of human development at California State University-Long Beach.
E-cigarette use among teens has been seen as a significant public health challenge in recent years, with research indicating that as many as one in four teens vape.
In 2019, more than 2,500 teens suffered from e-cigarette- or vaping-associated lung injury, or EVALI, with one young person in Michigan even requiring a lung transplant to treat the potentially dangerous condition.
In their research, Lanza and her colleagues surveyed 3,322 high school students on their use of vaping products.
Among those surveyed, 17% reported infrequent -- one to two days per month -- nicotine use and 18% indicated that they vaped cannabis infrequently, the data showed.
Moderate use -- up to seven days per month -- of nicotine and cannabis vaping products was reported by 5% and 7% of the teen respondents, respectively, while approximately 6% indicated frequent use -- up to 19 days per month -- of both, according to the researchers.
In addition to the health risks associated with vaping, teens who use e-cigarettes are also more likely to transition to traditional cigarettes -- and possibly become heavy smokers -- as adults, data from the U.S. Centers for Disease Control and Prevention suggests.
A separate analysis, published Tuesday by JAMA Network Open, found that the percentage of young adults who started smoking in early adulthood -- aged 18 to 23 years -- has more than doubled to 43% in 2018 from 21% in 2002.
"Although prevention strategies focused on adolescent vaping should remain prominent, efforts specifically addressing young adult vaping use may be warranted to substantially reduce nicotine and cannabis vaping," Lanza said.