Changes in breathomics from a 1-year randomized smoking cessation trial of electronic cigarettes.
BACKGROUND
Electronic cigarette (EC) use is an emerging behaviour that has been shown to help smokers to reduce cigarette consumption. The aim of this study was to illustrate long-term changes in exhaled breath measurements and respiratory symptoms in smokers invited to quit or reduce their cigarette consumption by switching to ECs.


METHODS
Prospective evaluation of cigarette consumption, fractional nitric oxide concentration in exhaled breath (FeNO), exhaled carbon monoxide (eCO) and symptom scores was performed in a 1-year randomized, controlled trial of 'healthy' smokers receiving 2·4% nicotine, 1·8% nicotine or no nicotine ECs. FeNO and eCO data are presented on the basis of participants' pooled continuous smoking phenotype classification (failures, reducers and quitters).


RESULTS
A significant effect of quitting classification was found on FeNo and eCO at all time points (P < 0·0001). Among quitters, FeNO (medians and interquartile range) rose from 5·5 (4·5-6·9) ppb to 17·7 (13·3-18·9) ppb by week 52. Baseline eCO (medians and interquartile range) decreased from 17 (12-20) ppm to 3 (1-4) ppm by week 52. No significant changes in FeNO and eCO levels were observed in failures and reducers. Improvements in FeNO and eCO levels were correlated with attenuations in symptom scores.


CONCLUSIONS
Smokers invited to switch to electronic cigarettes who completely abstained from smoking showed steady progressive improvements in their exhaled breath measurements and symptom scores. FeNo and eCO normalization is highly supportive of improved respiratory health outcomes and adds to the notion that quitting from tobacco smoking can reverse harm in the lung.
Centro per la Prevenzione e Cura del Tabagismo, Azienda Ospedaliero-Universitaria 'Policlinico-V. Emanuele', Università di Catania, Catania, Italy.|Dipartimento di Medicina Clinica e Sperimentale, Azienda Ospedaliero-Universitaria 'Policlinico-Vittorio Emanuele', Università di Catania, Catania, Italy.
Davide
D
Campagna
National Research Council of Italy, Institute of Biomedicine and Molecular Immunology, Palermo, Italy.
Fabio
F
Cibella
Centro per la Prevenzione e Cura del Tabagismo, Azienda Ospedaliero-Universitaria 'Policlinico-V. Emanuele', Università di Catania, Catania, Italy.|Dipartimento di Medicina Clinica e Sperimentale, Azienda Ospedaliero-Universitaria 'Policlinico-Vittorio Emanuele', Università di Catania, Catania, Italy.
Pasquale
P
Caponnetto
Dipartimento di Medicina Clinica e Sperimentale, Azienda Ospedaliero-Universitaria 'Policlinico-Vittorio Emanuele', Università di Catania, Catania, Italy.
Maria Domenica
MD
Amaradio
Dipartimento di Medicina Clinica e Sperimentale, Azienda Ospedaliero-Universitaria 'Policlinico-Vittorio Emanuele', Università di Catania, Catania, Italy.
Massimo
M
Caruso
Department of Academic Respiratory Medicine, Hull York Medical School, Castle Hill Hospital, University of Hull, Cottingham, UK.
Jaymin B
JB
Morjaria
Department of Internal Medicine, University of Brescia and AOU Spedali Civili, Brescia, Italy.
Mario
M
Malerba
Centro per la Prevenzione e Cura del Tabagismo, Azienda Ospedaliero-Universitaria 'Policlinico-V. Emanuele', Università di Catania, Catania, Italy.|Dipartimento di Medicina Clinica e Sperimentale, Azienda Ospedaliero-Universitaria 'Policlinico-Vittorio Emanuele', Università di Catania, Catania, Italy.
Riccardo
R
Polosa
D000293:Adolescent; D000328:Adult; D000368:Aged; D001944:Breath Tests; D002248:Carbon Monoxide / Q000032:analysis; D066300:Electronic Nicotine Delivery Systems; D045853:Exhalation / Q000502:physiology; D005260:Female; D005290:Ferric Compounds / Q000032:analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D009566:Nitrates / Q000032:analysis; D011446:Prospective Studies; D012120:Respiration Disorders / Q000503:physiopathology*; D012907:Smoking / Q000503:physiopathology; D016540:Smoking Cessation / Q000379:methods*; D055815:Young Adult
D005290:Ferric Compounds; D009566:Nitrates; D002248:Carbon Monoxide; C025302:ferric nitrate
FeNo; eCO; electronic cigarette; harm reversal; smoking cessation; tobacco harm reduction