Little is known about the health risks to humans associated with smoking or “vaping” electronic cigarettes (EC). Based on the knowledge that the adverse effects of cigarette smoking are observed in the dysregulation of lung biology long before clinical abnormalities manifest, we assessed the hypothesis that acute exposure to EC vapors, with or without nicotine, modifies the biology of the lung of healthy never smokers. No significant changes in clinical parameters were observed following this brief exposure to EC vapors. However, marked changes were observed in the transcriptome of small airway epithelium and alveolar macrophage compared to baseline for both exposure groups with and without nicotine, and the group inhaling the nicotine containing vapors had elevated plasma endothelial microparticle levels. While additional studies are needed to ascertain long-term health risks of EC, this study provides preliminary in vivo data suggesting that EC vapors likely dysregulates normal human lung homeostasis, at least at the biologic level.
Overall design: Ten healthy never-smokers, with no history of exposure to any tobacco products or electronic cigarettes (EC), were assessed at baseline on day 1 with a questionnaire, chest X-ray, lung function, plasma levels of endothelial microparticles, and bronchoscopy with brushings to sample the small airway epithelium (10th–12th order bronchi) and bronchoalveolar lavage to obtain alveolar macrophages. One week later, subjects were trained how to use EC, and then inhaled 10 puffs of “Blu” brand EC, waited 30 min, then inhaled another 10 puffs. Of the n=10 subjects, n=7 were randomized to EC with nicotine and n=3 to EC without nicotine. Within 2 hr post-EC exposure, they were assessed with questionnaires, lung function, plasma EMP levels and repeat bronchoscopy with brushing and lavage.
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