The study titled, “E-Cigarette Use, Small Airway Fibrosis, and Constrictive Bronchiolitis,” followed the cases of four patients with lung disease who had been vaping regularly between 3 to 8 years.
The research team found fibrosis and damage in the small airways of the participants, similar to the damage typically caused by chemical inhalation. Since the same type of lung damage was found in all four patients, while an improvement in symptoms was observed after usage was stopped, the research team concluded that vaping was the most likely cause of the damage.
“All four individuals we studied had injury localized to the same anatomic location within the lung, manifesting as small airway-centered fibrosis with constrictive bronchiolitis, which was attributed to vaping after thorough clinical evaluations excluded other possible causes,” said lead study author Lida Hariri, MD, Ph.D., a pathologist and physician investigator at MGH. “We also observed that when patients ceased vaping, they had a partial reversal of the condition over one to four years, though not complete due to residual scarring in the lung tissue.”
Reading between the lines
Discussing the study, renowned respiratory and tobacco harm reduction expert Dr. Ricardo Polosa, told Vaping Post that there are other important factors to consider. “These four cases describe severe symptoms after vaping (please note some vapers had autoimmune disease that can explain symptoms per se). More importantly he highlighted, all the participants were previous smokers. “All were former smokers (previous smoking is an important confounder).
He explained that given the available information, it is difficult to ascertain casualty from vaping. “Not clear the frequency of exposure to EC aerosols. There is limited information about the vaping product use to establish any form of causality. Obviously, a problem with a certain ingredient in a susceptible users can happen. The same happens with medications and other consumer products in some individuals.”
On this note, the respiratory expert directed us to a study indicating “a rare case of generalized urticaria after using a certain e-liquid containing an unusual flavoring that can elicit adverse effects in susceptible individuals.”
“Of course, case series like this one do not establish causality but can be hypothesis-generating and therefore argue in favor of large-scale epidemiologic studies (more request for research grant to support investigation in rare adverse effect of EC users). The latter may show significant associations, but even large epidemiological studies do not definitively establish causality,” he added.
An association between vaping and asthma
Another recent study published in Preventative Medicine reported finding a significant link between vaping and Asthma among teens. The study “Association between e-cigarette use and asthma among US adolescents: Youth Risk Behavior Surveillance System 2015–2019,” used data from the CDC’s Youth Risk Behavior Surveillance System, from 3,000 adolescents in Texas, aged between 13 and 17.
The researchers compared the results from this cohort, with responses from more than 32,000 teens across the United States. The respondents were asked whether they had ever used a vape, how often they vaped and whether they had ever been diagnosed with asthma.
The responses highlighted that teens were more likely to vape if they suffered from depression or used cigarettes, alcohol and other substances. More importantly, the study found an association found between vaping and asthma among those who had never smoked combustible products, indicting that vaping increased the risk of asthma independently of other tobacco use. However, added the researchers, this still cannot prove a direct cause-and-effect relationship.
Study author Dr. Taehyun Roh, told Vaping Post that the research team did take into account that vapers could be former or current smokers, hence did not include such participants in the study. “When studying the association between e-cigarette usage and smoking, there arises curiosity about whether the elevated risk of asthma is solely attributable to e-cigarette use or if it could be influenced by regular combustible products. Our focus was on individuals who had never used regular combustible products, and our findings indicated that e-cigarette use increases the risk of asthma, independently from regular combustible products.”
Vaping’s positive effect on blood flow in the lungs
Meanwhile, a functional MRI-based study conducted in Switzerland and published in Radiology, found that cigarette smoke inhibits pulmonary perfusion while nicotine-containing e-cigarettes actually increase blood flow in the lungs.
The study titled, “MRI Shows Lung Perfusion Changes after Vaping and Smoking,” was conducted by a research team from Bern University Hospital. A total of 44 healthy adults of which 13 were vapers, 12 smokers, 9 were former smokers and 10 were non-users were sent for unenhanced lung fMRI and functional lung tests.
The tests indicated that current and past tobacco users experienced a significant decrease in lung perfusion/blood flow after smoking vs. baseline, while interestingly, vapers experienced an increase in lung perfusion following vaping. “MRI showed a decrease of lung perfusion after exposure to tobacco smoke and an increase of lung perfusion after use of electronic nicotine delivery systems,” concluded the study.
