title: Short-term effects of a nicotine-free e-cigarette compared to a traditional cigarette in smokers and non-smokers.
abstract: BACKGROUND
  A few studies have assessed the short-term effects of low-dose nicotine e-cigarettes, while data about nicotine-free e-cigarettes (NF e-cigarettes) are scanty. Concerns have been expressed about the use of NF e-cigarettes, because of the high concentrations of propylene glycol and other compounds in the e-cigarette vapor.
  
  
  METHODS
  This laboratory-based study was aimed to compare the effects of ad libitum use of a NF e-cigarette or and a traditional cigarette for 5 min in healthy adult smokers (n = 10) and non-smokers (n = 10). The main outcome measures were pulmonary function tests, fraction of exhaled nitric oxide (FeNO) and fractional concentration of carbon monoxide (FeCO) in exhaled breath.
  
  
  RESULTS
  The traditional cigarette induced statistically significant increases in FeCO in both smokers and non-smokers, while no significant changes were observed in FeNO. In non-smokers, the traditional cigarette induced a significant decrease from baseline in FEF75 (81 % ± 35 % vs 70.2 % ± 28.2 %, P = 0.013), while in smokers significant decreases were observed in FEF25 (101.3 % ± 16.4 % vs 93.5 % ± 31.7 %, P = 0.037), FEV1 (102.2 % ± 9.5 % vs 98.3 % ± 10 %, P = 0.037) and PEF (109.5 % ± 14.6 % vs 99.2 % ± 17.5 %, P = 0.009). In contrast, the only statistically significant effects induced by the NF e-cigarette in smokers were reductions in FEV1 (102.2 % ± 9.5 % vs 99.5 ± 7.6 %, P = 0.041) and FEF25 (103.4 % ± 16.4 % vs 94.2 % ± 16.2 %, P =  .014).
  
  
  CONCLUSIONS
  The present study demonstrated that the specific brand of NF e-cigarette utilized did not induce any majoracute effects. In contrast, several studies have shown that both traditional cigarettes and nicotine-containing e-cigarettes have acute effects on lung function. Our study expands on previous observations on the effects of NF e-cigarettes, but also for the first time describes the changes induced by smoking one traditional cigarette in a group of never smokers.
  
  
  CONCLUSIONS
  The short-term use of the specific brand of NF e-cigarette assessed in this study had no immediate adverse effects on non-smokers and only small effects on FEV1 and FEF25 in smokers. The long-term health effects of NF e-cigarette use are unknown but worthy of further investigations.
  
  
  BACKGROUND
  Clinicaltrials.gov: NCT02102191.
authors.affiliation: Department of Specialistic, Diagnostic and Experimental Medicine, Respiratory and Critical Care Unit, Alma Mater Studiorum, Sant'Orsola Malpighi Hospital, University of Bologna, Bologna, Italy. ferrari.marco1984@gmail.com.
authors.forename: Marco
authors.initials: M
authors.lastname: Ferrari
authors.affiliation: Respiratory and Critical Care Unit, Sant'Orsola Malpighi Hospital, Via Massarenti 9, 40138, Bologna, Italy. alessandro.zanasi@aosp.bo.it.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Zanasi
authors.affiliation: Laboratory of Biostatistics, Department of Medical and Surgical Sciences (DIMEC), Alma Mater Studiorum, University of Bologna, Bologna, Italy. elena.nardi2@unibo.it.
authors.forename: Elena
authors.initials: E
authors.lastname: Nardi
authors.affiliation: Laboratory of Biostatistics, Department of Medical and Surgical Sciences (DIMEC), Alma Mater Studiorum, University of Bologna, Bologna, Italy. antonio.morselli@unibo.it.
authors.forename: Antonio Maria
authors.initials: AM
authors.lastname: Morselli Labate
authors.affiliation: Respiratory Unit, Fondazione S.Maugeri, IRCCS, Istituto Scientifico di Pavia, Pavia, Italy. piero.ceriana@fsm.it.
authors.forename: Piero
authors.initials: P
authors.lastname: Ceriana
authors.affiliation: Respiratory Unit, Fondazione S.Maugeri, IRCCS, Istituto Scientifico di Pavia, Pavia, Italy. antonella.balestrino@fsm.it.
authors.forename: Antonella
authors.initials: A
authors.lastname: Balestrino
authors.affiliation: Department of Specialistic, Diagnostic and Experimental Medicine, Respiratory and Critical Care Unit, Alma Mater Studiorum, Sant'Orsola Malpighi Hospital, University of Bologna, Bologna, Italy. larapisani81@gmail.com.
authors.forename: Lara
authors.initials: L
authors.lastname: Pisani
authors.affiliation: Department of Specialistic, Diagnostic and Experimental Medicine, Respiratory and Critical Care Unit, Alma Mater Studiorum, Sant'Orsola Malpighi Hospital, University of Bologna, Bologna, Italy. nadia.corcione@gmail.com.
authors.forename: Nadia
authors.initials: N
authors.lastname: Corcione
authors.affiliation: Department of Specialistic, Diagnostic and Experimental Medicine, Respiratory and Critical Care Unit, Alma Mater Studiorum, Sant'Orsola Malpighi Hospital, University of Bologna, Bologna, Italy. stefanava@gmail.com.|Respiratory and Critical Care Unit, Sant'Orsola Malpighi Hospital, Via Massarenti 9, 40138, Bologna, Italy. stefanava@gmail.com.
authors.forename: Stefano
authors.initials: S
authors.lastname: Nava
mesh_terms: D000328:Adult; D001944:Breath Tests; D002248:Carbon Monoxide / Q000032:analysis*; D066300:Electronic Nicotine Delivery Systems; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects; D006801:Humans; D008168:Lung / Q000187:drug effects* / Q000503:physiopathology; D008297:Male; D008450:Maximal Midexpiratory Flow Rate / Q000187:drug effects; D008875:Middle Aged; D009538:Nicotine / Q000494:pharmacology*; D018722:Nicotinic Agonists / Q000494:pharmacology*; D009569:Nitric Oxide / Q000032:analysis*; D010366:Peak Expiratory Flow Rate / Q000187:drug effects; D012907:Smoking; D062789:Tobacco Products
chemical_list: D018722:Nicotinic Agonists; D009569:Nitric Oxide; D009538:Nicotine; D002248:Carbon Monoxide