By: Jamie Turner, BS, BSW and Julia C. Basso, PhD
As we write this, the coronavirus or the COVID-19 disease continues to spread throughout the world in an exponential fashion. This pandemic is at the forefront of everyone’s minds and is fundamentally changing our everyday lives. Fortunately, scientists are scrambling to obtain data on this novel virus and publish the findings with speeds that are unheard of in the scientific community. There are many unknowns and one area of inquiry is the factors that put us at an increased risk for catching this disease.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) produces a respiratory illness primarily indicated by dry cough, fever, and shortness of breath much like pneumonia. The virus has affected mostly individuals who are age 30 or older with an increasing percentage of fatalities as age increases. Individuals who are most at risk include those with chronic health conditions, such as heart or lung disease, diabetes, asthma, or immunodeficiency. Additionally, new research is emerging that there may be yet another risk factor for acquiring COVID-19 – SMOKING.
Take home point: Being a smoker may put you at an increased risk for contracting COVID-19.
WHAT IS THE EVIDENCE SUPPORTING THIS CONCLUSION?
The predominant evidence comes from a study out of China that investigated 78 patients with COVID-19 and studied their disease progression over the course of 2 weeks. At the end of the 2 weeks, 67 (85.9%) of the patients had improved or stabilized whereas 11 (14.1% ) had deteriorated. The factors that led to the progression of COVID-19 were age, history of smoking, maximum body temperature at admission, presence of respiratory failure, low levels of albumin, and elevation of C-reactive protein. Of those, smoking had the highest odds ratio, indicating that of those factors, smoking had the strongest association to progression of the disease. Other research from China has shown a sex discrepancy in the prevalence of disease, with more men contracting COVID-19 than women, which the authors  relate to the fact that significantly more men smoke than women (48.4% versus 1.9%).
WHY WOULD SMOKING PUT ME AT A HIGHER RISK FOR CONTRACTING THE CORONAVIRUS?
Though data is continually emerging, the newest evidence shows at least a correlational association between smoking and risk for contracting the coronavirus. Additionally, if you contract the coronavirus and are a current or former smoker, the likelihood of COVID-19 symptom severity increases. One primary reason for this association may be that smokers generally have poorer overall health than non-smokers, which makes them more vulnerable to viral attack. Similarly, smoking contributes to several chronic health conditions including heart disease, lung diseases, and cancers, again making those individuals especially vulnerable. Finally, smokers tend to engage in more risky or maladaptive health behaviors, which in this case could be going out to a bar or restaurant when these behaviors are ill advised.
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Take home point: Smoking may put you at an increased risk for acquiring COVID-19 because of compromised health due to smoking.
WHAT IS THE BIOLOGY BEHIND THIS?
Smoking is related to a higher expression of ACE2, which is the receptor for SARS-CoV-2. What is a receptor you say? Viruses are intracellular parasites. That is, they enter cells and hijack normal cellular function to promote the replication and spread of the virus. The first step to this process is viral entry. To do this, the virus enters the body and acts by binding to receptors on our cells; in this case, SARS-CoV-2 binds to ACE2. This is why it is so important to wash those hands for the full 20 seconds, so the virus doesn’t enter the body in the first place. The virus can then gain entry to the cell and begin to replicate itself. This process is known as receptor-mediated endocytosis. If you smoke, your body expresses more ACE2 receptors, which means that the virus has more entry points and a greater ability to infect you. Please note that this data is preliminary and these effects may be different in different populations (e.g., Asians versus Caucasians).
Interested to learn more about how viruses work, check out this article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4488714/
Take home point: Smokers may be more susceptible to COVID-19 because their cells express higher levels of the coronavirus receptor (ACE2).
OK, BUT QUITTING SMOKING IS ONE OF THE MOST DIFFICULT THINGS TO DO AND YOU REALLY EXPECT ME TO DO IT NOW?
Quitting smoking is certainly not easy. Most people find that they experience increased appetite, irritability, anger, depressed mood, anxiety, nausea, and many other symptoms from nicotine withdrawal. Right now, many people are worried about if they can go to work, pay the bills, take care of their children who are out of school, and are fearing for their elderly or at-risk family members. Quitting smoking might feel like a bad idea when being faced with stressful situations such as these. The main thing to keep in mind is that quitting smoking will be beneficial in protecting oneself by reducing the development or worsening of chronic health conditions. In turn this could potentially decrease the risk of severe outcomes when it comes to infectious diseases. This will not be an overnight process, and we know that maintaining one’s health is a lifelong process full of everyday choices.
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Overall message: Quitting smoking right now will have several benefits for your overall health and help your ability to fight off all infectious diseases and protect you against this novel virus.
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To find quit and recovery resources, check out our resources page here. If you are in recovery, you can become a member of the International Quit and Recovery Registry by registering here. During this unexpected time inside, you can take our monthly assessments, earn rewards, and get support from our online recovery community. We would love to have you as part of our recovery team.
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References:
Boulant, S., Stanifer, M., & Lozach, P. Y. (2015). Dynamics of virus-receptor interactions in virus binding, signaling, and endocytosis. Viruses, 7(6), 2794-2815. https://www.ncbi.nlm.nih.gov/pubmed/26043381
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Cai, H. (2020). Sex difference and smoking predisposition in patients with COVID-19. The Lancet Respiratory Medicine. https://www.thelancet.com/journals/lanres/article/PIIS2213-2600(20)30117-X/fulltext
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Liu, W., Tao, Z. W., Lei, W., Ming-Li, Y., Kui, L., Ling, Z., ... & Ming, Y. (2020). Analysis of factors associated with disease outcomes in hospitalized patients with 2019 novel coronavirus disease. Chinese Medical Journal. https://www.ncbi.nlm.nih.gov/pubmed/32118640
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Additional preprints: