Abstract
When heated by an electronic cigarette, propylene glycol and glycerol produce a nicotine-carrying-aerosol. This hygroscopic/hyperosmolar aerosol can deposit deep within the lung. Whether these deposits trigger local inflammation and disturb pulmonary gas exchanges is not known. The aim of this study was to assess the acute effects of high-wattage electronic cigarette vaping with or without nicotine on lung inflammation biomarkers, transcutaneous gas tensions, and pulmonary function tests in young and healthy tobacco smokers. Acute effects of vaping without nicotine on arterial blood gas tensions were also assessed in heavy smokers suspected of coronary artery disease. Using a single-blind within-subjects study design, 25 young tobacco smokers underwent three experimental sessions in random order: sham-vaping and vaping with and without nicotine at 60 W. Twenty heavy smokers were also exposed to sham-vaping (n = 10) or vaping without nicotine (n = 10) in an open-label, randomized parallel study. In the young tobacco smokers, compared with sham-vaping: 1) serum club cell protein-16 increased after vaping without nicotine (mean ± SE, −0.5 ± 0.2 vs. +1.1 ± 0.3 µg/l, P = 0.013) and vaping with nicotine (+1.2 ± 0.3 µg/l, P = 0.009); 2) transcutaneous oxygen tension decreased for 60 min after vaping without nicotine (nadir, −0.3 ± 1 vs. −15.3 ± 2.3 mmHg, P < 0.001) and for 80-min after vaping with nicotine (nadir, −19.6 ± 2.8 mmHg, P < 0.001). Compared with sham vaping, vaping without nicotine decreased arterial oxygen tension for 5 min in heavy-smoking patients (+5.4 ± 3.3 vs. −5.4 ± 1.9 mmHg, P = 0.012). Acute vaping of propylene glycol/glycerol aerosol at high wattage with or without nicotine induces airway epithelial injury and sustained decrement in transcutaneous oxygen tension in young tobacco smokers. Intense vaping conditions also transiently impair arterial oxygen tension in heavy smokers.
Highlights
Electronic cigarette (e-cigarette) liquid (e-liquid) is mainly constituted with propylene glycol (PG) and glycerol (GLY) in association with flavors and nicotine [15]
We examined the effect of pure PG/GLY vaping on arterial oxygen tension (PO2) in tobacco smokers suspected of coronary artery disease (CAD)
We found that serum levels of the anti-inflammatory protein CC16 increased acutely after vaping PG/GLY with and without nicotine
Summary
Electronic cigarette (e-cigarette) liquid (e-liquid) is mainly constituted with propylene glycol (PG) and glycerol (GLY) in association with flavors and nicotine [15]. GLY is an oily, hygroscopic liquid used as a humectant [19]. These molecules are “generally recognized as safe” (GRAS) for use as food additives [18, 19]. When heated by an electric resistance wire (as in an e-cigarette), PG and GLY aerosolize with other substances, such as flavoring compounds and nicotine [15]. This aerosol consists of a suspension mixture of gases, vapors, and aqueous particles. The latter elements condense in submicrometer to micrometer size droplets that can be inhaled into the lungs (i.e., “vaped”) [35, 52]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
