Persisting long term benefits of smoking abstinence and reduction in asthmatic smokers who have switched to electronic cigarettes

Background. Improvements in asthma outcomes have been recently reported in asthmatic smokers who have substantially reduced their tobacco consumption by switching to ECs. Confirmation of these preliminary findings is necessary to reassure patients, healthcare professionals and policy makers. Here, we present findings from long term prospective assessment of objective and subjective asthma outcomes as well as safety and tolerability in this group of EC users with asthma. Methods. We prospectively re-evaluated respiratory symptoms, lung function, airway hyperresponsiveness, asthma control, asthma exacerbations and tobacco consumption in adult daily ECs users with asthma who were previously studied in a retrospective study. Measurements recorded at baseline prior to switching were compared with those at the follow-up visits at 6, 12, and 24 months. Results. Eighteen ECs users with mild to moderate asthma were followed up prospectively. Complete data was obtained from sixteen EC users and two relapsers. Significant and stable improvements in respiratory symptoms, lung function, AHR, ACQ, and tobacco consumption were observed in the 16 ECs users with asthma, but no significant changes in exacerbation rates were reported. Similar findings were found in the dual users. Conclusion. This prospective study confirms that EC use ameliorates objective and subjective asthma outcomes and shows that these beneficial effects may persist in the long term. EC use can reverse harm from tobacco smoking in asthma patients who smoke. The evidence-based notion that substitution of conventional cigarettes with EC is unlikely to raise significant respiratory concerns, can improve counseling between physicians and their asthmatic patients who are using or intend to use ECs.