Extract
Three recently published letters by Lutchman [1], McAlinden [2], and Farsalinos [3] together capture the divergence in opinion on the impact of smoking on COVID-19 and whether the angiotensin converting enzyme-2 (ACE-2) receptor mediates this relationship. At the heart of this controversy is whether smoking reduces or increases the risk of contracting COVID-19. Farsalinos et al. through analysis of the pooled prevalence of current smoking across 11 case series determined that current smoking status was significantly lower than expected gender and age-adjusted prevalence in COVID-19 patients [3]. That smoking could potentially be protective against COVID-19 has not gone unnoticed by the public. Since late April, multiple media outlets have reported on this possibility, prompting the World Health Organisation (WHO) to release a warning on May 4, 2020, on tobacco use during this pandemic [4]. While we do not dispute that the prevalence of smoking in COVID-19 cases has been surprisingly low across the world, we would echo the WHO's advice based on emerging evidence that outcomes in COVID-19 are worse in patients who do smoke. Mehra et al.'s analysis of 8910 COVID-19 patients across three continents, for instance, demonstrated that current smoking was an independent risk factor for in-hospital death, carrying an odds ratio of 1.79 (95% confidence interval 1.29–2.47) [5]. A recent meta-analysis has also shown that smokers have a relative risk of 1.45 (95% confidence interval 1.03–2.04) of having more severe disease [6]. While smoking may not necessarily increase one's risk for contracting COVID-19, the biologic and inflammatory cascade that occurs upon SARS-CoV-2 infection may be particularly devastating for a smoker.
Abstract
Smoking increases severity of COVID-19
Footnotes
Conflict of interest: Dr. Leung has nothing to disclose.
Conflict of interest: Dr. Sin reports grants from Merck, personal fees from Sanofi-Aventis, personal fees from Regeneron, grants and personal fees from Boehringer Ingelheim, grants and personal fees from AstraZeneca, personal fees from Novartis, outside the submitted work;.
- Copyright ©ERS 2020
This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial Licence 4.0.