Are smokers prone to COVID 19?
Are smokers prone to COVID 19? What’s the current evidence/ The deleterious effects of tobacco are well documented in literature. Its usage in cigarettes and cigars all over the world, across all strata of society, results in approximately 8 million deaths every year from various causes such as cardiovascular diseases, lung disorders and cancers of the lung, oesophagus, throat and mouth due to the prolonged exposure to, not only nicotine but over 5000+ other toxic and carcinogenic compounds present in cigarette smoke.
Smoking has been found to increase the severity of respiratory diseases from any cause including colds, influenza, pneumonia of various causes, and tuberculosis and there is no reason to believe that the COVID 19 infection is any different. Are smokers prone to COVID 19? logic says they are. However whats the evidence?
Are smokers prone to COVID 19 – what’s the current evidence?
It must however be stated that at this particular point in time there are no prospective, randomized, double blind, placebo controlled trials (that could lead upto level 1a evidence) or other meta-analyses to conclusively prove that smokers are more prone to severe infection with COVID 19 compared to nonsmokers. This is understandable as COVID 19 is a recently discovered zoonotic (transmitted from infected animals to humans) viral illness. Studies regarding its infectivity are still “work in progress”. These studies will shortly establish is
More time is needed before high powered, convincing, evidence, based on robust analyses of good data can emerge from well designed scientific studies. There are however many observational and cohort studies to support the hypothesis that smokers are more prone to COVID 19 than nonsmokers. As this pandemic is relatively recent and is an ongoing one, more time is needed to conclusively prove this hypothesis beyond reasonable doubt.
Tobacco smoking and ciliary dysfunction.
Tobacco smoke is a toxic cocktail of numerous (more than 5000), very damaging, chemicals. In addition to nicotine, other components of cigarette smoke such as carbon monoxide and other polycyclic aromatic hydrocarbons also cause significant damage to the various organs in the human body especially the lungs.
Smoking also causes a severe dysfunction of the small hair like cilia in the major airways whose brush like oscillatory movements help to push particulate matter and droplets from deep inside the respiratory tract, back towards the glottis (voice box) so that they can be coughed out and expelled. Ciliary dysfunction is a major cause of retention of particulate matter and droplets in the respiratory tract which predispose to lung infections subsequently.
Smoking also “drys” the lining of the respiratory tract by causing a thickening of secretions in the respiratory tract which are difficult to expel while coughing. A gradual accumulation of thick secretions in the lungs is a potent risk factor for all lung infections. Smokers who have recently stopped smoking often complain of a “paradoxical cough”.
This paradoxical cough is due to the resumption of the previously inactive ciliary mechanism which restarts pushing particulate matter / debris / droplets back towards the glottis for expulsion via the glottis during coughing. A recurrence of cough just after cessation of smoking is therefore a sign that the protective ciliary mechanism of the lungs has started functioning again. Its thus easy to deduce the answer to the question – are smokers prone to COVID 19.
Smokers and ACE2 receptor upregulation.
Are smokers prone to COVID 19? A close look at the ACE2 receptor suggests they are. Smokers also have an increase in the number of ACE2 protein secretory cells. The ACE2 protein is the coupling device which causes the COVID 19 virus to attach to the cells of the respiratory tract and subsequently penetrate into them. The more the number of ACE2 receptors, the easier it is for the virus to attach to a cell.
Are smokers prone to COVID 19? A look at the the ACE2 receptor protein seems to suggest they are. Apart from facilitating attachment onto a host cell, this protein also triggers an “inflammatory response” in the lung which is thought to cause thrombosis (blood clot formation) in the small and microscopic blood vessels of the lung – a finding which is clinching evidence of a severe COVID 19 infection. The inflammation in the lung results in the characteristic “cytokine storm” which is common in severe COVID 19 infections.
Smoking also causes a lot of other co-morbidities in the lungs (including asthma, pulmonary hypertension, and chronic bronchitis), and other organ such as the heart (high blood pressure and accelerated coronary artery disease). Maternal smoking is known to be detrimental to the unborn fetus in utero. These co-morbidities also contribute to overall mortality in smokers during a COVID 19 infection. Smoking can indirectly affect the heart as well.
Are smokers prone to COVID 19 when they use e-cigarettes as well? The use of e-cigarettes, engaging in passive smoking or vaping is as detrimental as conventional smoking as far as susceptibility to the COVID 19 virus is concerned.
Does smoking protect from COVD 19? The misleading French study.
Are smokers prone to COVID 19? A French study done at the Pitie-Salpetriere University Hospital in Paris, lead by professor of internal medicine, Zahir Amoura, claimed that nicotine in cigarette smoke may prevent the COVID 19 virus from latching on to the host cell. The study looked at 343 inpatients treated for COVID 19 infection between February 28th 2020 to March 30th 2020, and 139 outpatients treated between March 23rd 2020 to April 9th 2020.
The study found that 4.4% of inpatients and 5.3% of patients with COVID 19 infection were current smokers. This was much lower than the prevalence of the disease amongst the general population in France. The authors claimed that nicotine in cigarette smoke attached to the ACE2 protein on the cell surface and thus blocked the attachment of the COVID 19 virus by competing with the virus for the ACE2 receptor protein. This study cast a shadow on the hypothesis – are smokers prone to COVID 19.
A critical analysis of the methodology used in the study however revealed several flaws that could have biased the results. This study was also not peer reviewed and its publication was allegedly “fast tracked” to leverage its surprising findings and a persisting doubt, – are smokers prone to COVID 19.
The critique of the study was lead by Amine Benyamina, the president of the French Federation of Addiction. Another top French health official Jerome Salomon also weighed in, stating that nonsmokers should not use nicotine patches to protect from COVID 19 infection.
Lastly the act of smoking involves contact between (potentially contaminated) fingers, cigarettes (potentially contaminated) and lips. A cigarette is sometimes shared between pals / buddies as well! All these dangerous acts could increase the risk of transmission of COVID 19. Apart from the COVID 19 risks, smoking has numerous other deleterious effects. Are smokers prone to CIVID 19. The above observations certainly seem to suggest they are.
Its never too late to quit.
Are smokers prone to COVID 19? of course they are. Its never ever too late to quit! Within 20 minutes of quitting, elevated heart rates and blood pressures start normalising. After about 12 hours, the carbon monoxide levels in the blood normalise. After 4-12 weeks, the vital capacity of the lungs increase. The list of beneficial effects of quitting is a long one! If you are still smoking after reading this, QUIT NOW! Save yourself and your loved ones.