Reply to: “Current Smoking is Not Associated with COVID-19”
- 1Centre for Heart Lung Innovation, University of British Columbia, Vancouver, Canada
- 2Division of Respiratory Medicine, Department of Medicine, St. Paul's Hospital, Vancouver, Canada
- Don D. Sin. E-mail: Don.Sin{at}hli.ubc.ca
Abstract
Smoking and COPD are risk factors for severe COVID-19
Like Rossato et al. [1], we too have been struck by the relative underrepresentation of current smokers in cohorts of COVID-19 patients, particularly in light of our recent findings that the SARS-CoV-2 receptor ACE-2 is upregulated in the airway epithelium of this population [2]. China [3], Italy [1], and now New York City [4] have all reported current smoking rates below those of their respective general populations. The reason for this is a mystery. One possible explanation is misclassification of smoking status owing to under-reporting of smoking in these cohorts. Another is that smokers may be taking medications that may offer some protection against COVID-19 (e.g. certain inhalers). It should be noted that severe COVID-19 preferentially targets the older population (>65 years) with co-morbidities where smoking rates are approximately 3–5 fold lower than that in the general population. Thus, the background smoking rates in the severe COVID-19 susceptible subgroups may be much lower than the general smoking rates of the population. Notwithstanding these issues, we should be extraordinarily cautious about the messaging surrounding smoking and COVID-19, especially in these fraught times where misinformation is commonly amplified in a vacuum of rigorous evidence [5, 6]. We are unaware of any evidence to date that demonstrates that smoking is protective against COVID-19. In fact, although current smoking has not been found to be a major risk factor for COVID-19, COPD patients appear to have worse outcomes upon contracting the virus with an almost threefold odds ratio of dying, needing mechanical ventilation, or being admitted to an intensive care unit [7]. As many of our COPD patients in this pandemic fit an unfavorable demographic profile – elderly, male, and with cardiovascular comorbidities – we would continue to recommend exercising caution in protecting them from COVID-19.
Footnotes
Conflict of interest: Dr. Leung has nothing to disclose.
Conflict of interest: Ms. Yang 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;.
- Received April 22, 2019.
- Accepted April 23, 2019.
- Copyright ©ERS 2020
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