Health effects in COPD smokers who switch to electronic cigarettes: a retrospective-prospective 3-year follow-up

Riccardo Polosa,1–3,* Jaymin Bhagwanji Morjaria,4,5,* Umberto Prosperini,6 Cristina Russo,7 Alfio Pennisi,8 Rosario Puleo,1–3 Massimo Caruso,1,2 Pasquale Caponnetto1,2 1Department of Clinical & Experimental Medicine, University of Catania, Catania, Italy; 2Centre for the Prevention and Treatment of Tobacco Addiction (CPCT), Teaching Hospital “Policlinico – V. Emanuele”, University of Catania, Catania, Italy; 3Institute of Internal and Emergency Medicine, Teaching Hospital “Policlinico – V. emanuele”, University of Catania, Catania, Italy; 4Department of Respiratory Medicine, Royal Brompton & Harefield Hospital Foundation Trust, Harefield Hospital, Harefield, UK; 5Imperial College, Harefield, UK; 6Hospital “San Vincenzo”, Taormina, Italy; 7Emergency Department, Hospital “Arnas Garibaldi”, Catania, Italy; 8Department of Respiratory Medicine, Private clinics “Musumeci-Gecas”, Catania, Italy *These authors contributed equally to this work Background: Health effects of electronic cigarette (EC) use in patients with chronic obstructive pulmonary disease (COPD) are largely unexplored.Aim: We present findings from a long-term prospective assessment of respiratory parameters in a cohort of COPD patients who ceased or substantially reduced conventional cigarette use with ECs.Methods: We prospectively re-evaluated COPD exacerbations, spirometric indices, subjective assessments (using the COPD Assessment Tool [CAT] scores), physical activity (measured by the 6-minute walk distance [6MWD]), and conventional cigarette use in EC users with COPD who were retrospectively assessed previously. Baseline measurements prior to switching to EC use were compared to follow-up visits at 12, 24, and 36 months. Age- and sex-matched regularly smoking COPD patients who were not using ECs were included as reference (control) group.Results: Complete data were available from 44 patients. Compared to baseline in the EC-user group, there was a marked decline in the use of conventional cigarettes. Although there was no change in lung function, significant improvements in COPD exacerbation rates, CAT scores, and 6MWD were observed consistently in the EC user group over the 3-year period (p