In patients with chronic obstructive pulmonary disease (COPD), passive vape exposure from e-cigarettes has been shown to be potentially harmful by exerting acute small inflammatory responses in the lungs and blood, as well as throat irritation. Results of the analysis were published in the European Clinical Respiratory Journal.
The researchers sought to explore the local and systemic effects of short-term passive vape exposure among individuals with mild or moderate COPD. A randomized, controlled, double-blind, crossover study on the topic was conducted in Denmark. All of the participants were subjected to 2 exposure sessions. Each of the sessions lasted for 4 hours, containing either air mixed with aerosol from e-cigarette users or clean filtered air, and occurred 2 weeks apart, in order to eliminate any carryover effects. Other than the air quality, the filtered clean air and e-cigarette vape sessions were identical. The exposure sessions took place in an exposure chamber, whereas the exposure generation occurred in an adjacent chamber. All of the particles were measured via use of an ultrafine particle counter and a scanning mobility particle sizer.
All of the recruited participants were nonsmokers who had mild or moderate COPD. Their COPD diagnosis was established by symptoms and spirometry (using forced expiratory volume in 1 second [FEV1]/forced vital capacity [FVC] below the lower limit of normal, Medical Research Council [MRC] score of ≥2, and COPD Assessment Test score of ≥10). Any patients who were on long-acting bronchodilators and inhaled corticosteroids were switched to short-acting bronchodilators 1 week prior to study participation. All participants were required to be free of any signs of infection or airway symptoms for ≥1 week and not to have taken any medication for ≥48 hours.
The primary outcomes of interest included surfactant protein-A (SP-A) and albumin in exhaled air. Secondary study outcomes included spirometry, fractional exhaled nitric oxide, plasma proteins, and self-reported symptoms. A total of 16 individuals (6 females and 10 males) participated in the study. The mean participant age was 67.6 years.
The peak number of particles on the days of vape exposure ranged from approximately 30 to 40 nm. Although it was minor, another peak was observed for larger particles (ie, 200 to 500 nm), which coincided with information from the vapers on the coil overheating. Thus, these particles could be derived from combustion. When the particle size was around 300 to 500 nm, the particle mass peaked.
Results of the study showed that SP-A in exhaled air was negatively impacted by exposure to vape, with the levels of several plasma proteins increasing significantly. Throat irritation was more prominent during passive vape exposure, whereas FEV1 and FVC values decreased, although not significantly.
Limitations of the study included low power due to few participants, and additionally, not all participants were able to complete all health examinations resulting in missing data.
The investigators concluded that additional studies on passive vape exposure in sensitive subgroups of patients are warranted, along with future studies of individuals who are chronically exposed to passive vaping, with such studies currently almost nonexistent.
Rosenkilde Laursen K, Bønløkke JH, et al. An RCT of acute health effects in COPD-patients after passive vape exposure from e-cigarettes. Eur Clin Respir J. 2020;8(1):1861580. doi:10.1080/20018525.2020.1861580