The use of electronic cigarettes significantly increases a person's risk of developing chronic lung diseases such as asthma, bronchitis, emphysema or chronic obstructive pulmonary disease, according to new research from the University of California San Francisco, in the first longitudinal study linking cigarettes with respiratory diseases in a representative sample of the entire American adult population.
The study also found that people who used electronic cigarettes and at the same time smoked tobacco, by far the most common pattern among adult users of electronic cigarettes, had an even greater risk of developing chronic lung disease than those who used only one of the two products.
The findings, which are published in the 'American Journal of Preventive Medicine', are based on an analysis of publicly available data from the Population Assessment of Tobacco and Health (PATH), which analyzed the habits of electronic cigarettes and tobacco, as well as new diagnoses of lung disease in more than 32,000 American adults from 2013 to 2016.
Although several previous population studies had found an association between the use of electronic cigarettes and lung disease at a single point in time, these so-called cross-sectional studies provided data that made it impossible for researchers to say whether lung disease was being caused by electronic cigarettes or if people with lung disease were more likely to use electronic cigarettes.
The study began with people who had no reported lung disease, who used electronic cigarettes and followed them up for three years. New longitudinal study offers stronger evidence of a causal link.
When starting with people who had no reported lung disease, taking into account the use of electronic cigarettes and smoking from the beginning, and then following them for three years, the new longitudinal study offers stronger evidence of a causal link between cigarette use electronics in adults and lung diseases than previous studies.
"What we found is that for users of electronic cigarettes the chances of developing lung disease increased by about a third, even after controlling their tobacco use and their clinical and demographic information," says lead author Stanton Glantz, professor of the UCSF of medicine and director of the Center for Research and Education for Tobacco Control of the UCSF.
"We conclude that electronic cigarettes are harmful by themselves, and the effects are independent of conventional tobacco smoking," Glantz adds.
Although current and former users of electronic cigarettes were 1.3 times more likely to develop chronic lung disease, tobacco smokers increased their risk by a factor of 2.6. For dual users, people who smoke and use electronic cigarettes at the same time, these two risks multiply, rather than triple the risk of developing lung disease.
"Dual users, the most common use pattern among people who use electronic cigarettes, have the combined risk of electronic cigarettes and conventional cigarettes, so they are actually worse than tobacco smokers," says Glantz.
This finding is particularly relevant as the debate continues on whether electronic cigarettes should be promoted as a harm reduction tool for smokers. While the authors found that switching from smoked tobacco to electronic cigarettes reduced the risk of developing lung disease, less than 1 percent of smokers who had completely switched to electronic cigarettes.
"Switching from conventional cigarettes to electronic cigarettes could only reduce the risk of lung disease, but very few people do," says Glantz. For most smokers, they simply add electronic cigarettes and become dual users, which significantly increases their risk of developing lung disease over those who only smoke tobacco. ”
Most smokers simply add electronic cigarettes and become dual users, which significantly increases their risk of developing lung disease over those who only smoke tobacco.
Importantly, the results reported in this study are not related to EVALI (Pulmonary Injury Associated with the Use of Electronic Cigarettes or Vaping), the acute lung disease that was first reported last summer, whose serious cases sent several users of electronic cigarettes to the hospital and others to premature death.
Although scientists are still working to determine the cause of EVALI, previous physiological studies in animals and humans found that electronic cigarettes suppress the immune system and increase levels of stress-related proteins in the lungs.
And, at the same time, chemical analyzes showed that electronic cigarettes contain higher levels of certain toxic chemicals than conventional cigarettes. But the new study shows that these are not the only health threats posed by electronic cigarettes.
"This study contributes to the growing case that electronic cigarettes have long-term adverse health effects and worsen the tobacco epidemic," Glantz concludes. . (tagsToTranslate) epoc (t) electronic cigarettes (t)