Despite becoming a replacement to using tobacco cigarettes, the effects of electronic cigarettes (EC) have yet to be thoroughly investigated. Authors of a study published in World Journal of Methodology evaluated potential correlations between changes in airway inflammation in patients with and without asthma after vaping 1 nicotine-containing EC.
For this study, 50 enrolled participants were divided into 1 of 2 groups: the asthma group, which consisted of 25 patients who had moderate persistent stable asthma well-controlled by receiving “step 3” treatment according to Global Initiative for Asthma (GINA) guidelines; or the control group, which consisted of 25 healthy participants. Participants were not considered for the asthma group if they were younger than 18 years of age, had an acute asthma exacerbation or a change in asthma medication within the month prior to enrollment, and had another acute or chronic disease other than asthma 2 weeks before enrollment. Control group enrollment was made after matching them with those of the asthma group for gender, age, body mass index, and smoking history (determined by number of pack-years).
All 50 participants were smokers and subjected to pulmonary function tests (PFTs), total respiratory resistances measurement with an impulse oscillometry system (IOS), fraction exhaled Nitric Oxide (FeNO) measurements, exhaled breathe condensate (EBC) gathering, and biomarker measurements before and after vaping 1 nicotine-containing EC. Additionally, concentrations of interleukins 1b, 4, 5, 6, 8, 10, 13, and 17A as well as tumor necrosis factor-alpha with flow cytometry and concentrations of 8-Isoprostane and leukotriene B4 were also assessed.
Participants all vaped using 1 EC that had the same concentration of nicotine in the cartridge (medium nicotine concentration) and was from the same company. Regardless of their assigned group, participants vaped the EC for 5 minutes that consisted of 10 puffs and 30-second intervals between puffs. Additionally, a new cartridge and atomizer were used for each participant.
Key Takeaways
- Airway Inflammation Linked to Electronic Cigarette Use in With Asthma Patients: The study found a direct association between airway inflammation and changes in respiratory mechanics in patients with asthma after using a nicotine-containing electronic cigarette (EC). These changes were observed even in patients whose asthma was well-controlled with inhaled corticosteroids, highlighting the potential respiratory risks associated with EC use in individuals with asthma.
- Significant Findings in Asthma Group vs. Control Group: While the control group—which consisted of healthy participants—showed no significant changes in airway inflammation or respiratory mechanics after EC use, the asthma group exhibited significant differences in key indicators such as fractional exhaled Nitric Oxide (FeNO) and respiratory impedance. These findings suggest that individuals with asthma may be more susceptible to the adverse effects of ECs.
- Study Limitations and Need for Further Research: The investigators acknowledged several limitations, including the small sample size, the use of only one brand of EC, and the assessment of biomarkers at a single time point. Despite these limitations, the study shows a need for more extensive research on the effects of ECs, particularly in individuals with respiratory conditions like asthma.
According to the investigators, 2 patients who had asthma presented mild cough and wheezing following EC inhalation, but after a few minutes, this resolved on its own and without the need for reliever medication use. Further, 15 minutes after vaping, all participants were again subjected to PFTs and IOS measurements, then after 30 minutes were subjected to a new FeNO measurement and EBC gathering.
In the control group, the investigators observed no significant correlations between the changes in FeNO and respiratory mechanics, both before and after EC use. Conversely, differences in FeNO before and after EC use in the asthma group was significantly associated with corresponding differences in residual volume, total lung capacity, and respiratory impedance at 5 Hz. In addition, the difference in FeNO before and after EC use in patients with asthma was also associated with corresponding differences in respiratory resistance at 5 and 20 Hz (R5Hz and R20Hz, respectively) at the limit of significance. In the total study population, there were no significant correlations found between the changes in the EBC biomarkers and the changes in respiratory mechanics both before and after EC use.
The investigators acknowledge that there are potential limitations to the study. They note that the small number of participants in each group may have resulted in the correlation between the difference in R5Hz and R20Hz at the limit of significance. Additionally, it could explain the lack of statistically significant correlation between the difference in FeNO and the differences in other key asthma biomarkers (eg, forced expiratory volume forced vital capacity, peak expiratory flow). Further, other limitations may include the measurements during follow-up being assessed only in 1 time point following EC use, only 1 specific brand of EC was used, and a presence of inhaled corticosteroids (ICS) may have hindered changes in lung function and airway inflammation. The investigators also note that only well-controlled patients with asthma of GINA “step 3” were evaluated.
The study findings demonstrate a direct association between airway inflammation and other respiratory mechanics in patients with asthma following EC use, even in patients who are receiving ICS. The investigators note that further research should continue to assess EC’s effects in human health, particularly in those with other respiratory conditions.
REFERENCE
Kotoulas, SC, Domvri, K, Tsantos, A, et al. Is there a correlation between the changes in airway inflammation and the changes in respiratory mechanics after vaping in patients with asthma? World J Methodol 2024;14(2):89284 [PMID: 38983659] doi:10.5662/wjm.v14.i2.89284]
