Smoking and COVID-19: Adding Fuel to the Flame

Abstract

The coronavirus disease 2019 (COVID-19) pandemic, an infection caused by the severe acute respiratory syndrome coronavirus (SARS-CoV-2), has led to more than 771,000 deaths worldwide. Tobacco smoking is a major known risk factor for severe illness and even death from many respiratory infections. The effects of smoking on COVID-19 are currently controversial. Here, we provide an overview of the current knowledge on the effects of smoking on the clinical manifestations, disease progression, inflammatory responses, immunopathogenesis, racial ethnic disparities, and incidence of COVID-19. This review also documents future directions of smoking related research in COVID-19. The current epidemiological finding suggests that active smoking is associated with an increased severity of disease and death in hospitalized COVID-19 patients. Smoking can upregulate the angiotensin-converting enzyme-2 (ACE-2) receptor utilized by SARS-CoV-2 to enter the host cell and activate a ‘cytokine storm’ which can lead to worsen outcomes in COVID-19 patients. This receptor can also act as a potential therapeutic target for COVID-19 and other infectious diseases. The COVID-19 pandemic sheds light on a legacy of inequalities regarding gender, racial, and ethnic health disparities associated with active smoking, thus, smoking cessation may help in improving outcomes. In addition, to flatten the COVID-19 curve, staying indoors, avoiding unnecessary social contact, and bolstering the immune defense system by maintaining a healthy diet/living are highly desirable.

A qualitative study exploring older smokers' attitudes and motivation toward quitting during the COVID-19 pandemic

“…The understanding of the relationship between COVID-19 and smoking is evolving ( CDC, 2020 ), with preliminary studies showing associations between smoking and COVID-19 infection ( Engin et al, 2020 ), progression ( Lowe et al, 2021 ), and severity ( Patanavanich and Glantz, 2020 , Paleiron et al, 2021 , Kashyap et al, 2020 ). Smokers may be more susceptible to bacterial and viral infections ( Berlin et al, 2020 ) that may be more likely to progress compared to non-smokers ( Lowe et al, 2021 , Patanavanich and Glantz, 2020 ), possibly due to older age ( Liu et al, 2020 ) and certain chronic conditions ( Engin et al, 2020 , CDC, 2020 ).…”

Combination of Angiotensin (1-7) Agonists and Convalescent Plasma as a New Strategy to Overcome Angiotensin Converting Enzyme 2 (ACE2) Inhibition for the Treatment of COVID-19

“…In this context, it has been reported that long term smokers express high levels of ACE2 receptor ( 78 ), namely in type-2 pneumocytes and alveolar macrophages ( 79 ), making them at high risk of infection by SARS-CoV-2 ( 78 ). This elevated expression occurs through activation of the α7 subtype of the nicotine acetylcholine receptor (α7-nAChR) ( 80 ).…”

Telemedicine for Tobacco Cessation and Prevention to Combat COVID-19 Morbidity and Mortality in Rural Areas

“…Despite limitations of the rapidly emerging available data, such as relying on electronic medical record data for smoking status, it is likely that combustible and non-combustible tobacco product use influences COVID-19 progression and negative health outcomes including death. Thus, a recent review concluded that smoking cessation is expected to reduce COVID-19-related risks and severe complications, and acknowledged telemedicine as one tool that can be employed to promote quitting smoking ( 36 ).…”