[cutty]

I remember seeing similar articles. While I don't understand the science behind these findings, my understanding is that smokers are less likely to catch COVID, but if they do, then their symptoms are significantly more severe than those of nonsmokers.

[nyolfen]

incorrect; smokers are shown to be substantially less susceptible to both catching covid and developing severe symptoms, a finding that has been demonstrated independently in (at least) france, china, and the USA:

> Conclusions and relevance: Our cross sectional study in both COVID-19 out- and inpatients strongly suggests that daily smokers have a very much lower probability of developing symptomatic or severe SARS-CoV-2 infection as compared to the general population.

> Very recently, the US Center of Disease Control reported an analysis of current smoker rate among US COVID-19 patients which was found to be 1.3% for the whole population of COVID-19 patients, 1% for outpatients, 2% for patients, not hospitalized in an ICU, and 1% in intensive care unit (ICU)-admitted patients

https://www.qeios.com/read/WPP19W.3

in all of the mentioned countries, only about 1% of ICU cases are smokers. this has (perhaps unsurprisingly) not been widely reported.

[antognini]

Both SARS-Cov-2 and nicotine bind to the ACE2 receptor. One hypothesis is that because SARS-Cov-2 has to compete with nicotine for the receptor it ends up being less effective. Another hypothesis is that smokers tend to do better because of nicotine's effect of reducing inflammation.

[hwillis]

Seems more likely to me they're just lying about being smokers- 60% admit to being former smokers. Inpatient hospitalizations also almost all suffer from serious comorbid conditions like hypertension or diabetes, which probably causes many to smoke less. Less so with the outpatients (<20%) but I would not be surprised if it was because unhealthy people getting sick, and those unhealthy people don't smoke because it would be bad for them.

[Supermancho]

> Seems more likely to me they're just lying about being smokers

Being a smoker has been a standard part of your medical history for a long time now for obvious reasons. There's no reason to think there is a coordinated strategy for lying about smoking in the context of a pandemic (much less revising patient medical histories, which would be the medical service industry lying).

50%+ lying about smoking in the face of potential (or actual) respiratory failure is laughable.

[hwillis]

The study isn't talking about history, it's talking about current smokers and many of the comments on the paper bring up concerns with how specific that is, and how many could have quit days before going to the hospital.

I don't know where you got 50%+. The outpatient group was 5.3% current smokers vs expected (adjusted for age and sex) 26.9%. For inpatient it was 4.4% vs expected 17.9%. The fact that both groups had the same reported rate of current smokers (within experimental error) but very different expected rates says to me that you're only getting the people who are honest or simply incapable of quitting even while sick.

Also, see this concern brought up:

> Finally, and I believe this to be the most significant piece of data supporting the null hypothesis, the prevalence of never-smokers in the general population is approximately 0.75, if one subtracts the smoking incidence rate from 100. In your patient groups, non-smokers are strongly under-represented by about a factor of 2 relative to the general population, with 31% of outpatient and 32% of inpatient being labeled as never-smokers. This suggests to me that any amount of smoking actually puts one at risk for contracting COVID-19 as defined by this paper.

[tripletao]

I'm not sure I understand the quoted concern? The study they referenced[1] showed that France was ~37% never smokers average over all ages (nowhere near 75%), and their in- and out-patients were about the same fraction (Table 2) for male, a little lower for female. The big discrepancy is under-representation of current smokers, and over-representation of former smokers. But their patients are old, and I'd expect older people to have more former smokers, since they've had more time to start and stop and since the general trend in smoking is down. I don't see that broken down by age in the paper they linked though. Maybe we'd have to dig in to the raw data, or maybe it's just not available?

In any case, many other studies of COVID-19 have found similar results, and studies of different respiratory diseases have not. I'd initially just thought people were lying too, but at some point the evidence becomes overwhelming--if the protective behavior were anything but smoking, then people would have accepted it long ago.

Of course smoking is far deadlier on average than the coronavirus, per my calculation elsewhere in this thread. No one should start smoking because of this, but I do see enough evidence e.g. that a nursing home patient (who's at very high risk of death from coronavirus, and likely to die of something else before smoking-related diseases could develop) shouldn't quit. Vaping probably gets any benefit with almost none of the health risk, though that's speculative.

1. http://beh.santepubliquefrance.fr/beh/2019/15/pdf/2019_15_1....

[dec0dedab0de]

Maybe they're lying on the paper work because they're afraid their insurance rates will go up.

[shim2k]

The studies are not being conducted in the US alone.

[thewhitetulip]

As said by the Dr Gregory House on 'House MD' series, 'everybody lies'

[titzer]

Maybe they just drop dead immediately in their homes? /s

Seriously though, it's baffling because smoking causes so many underlying health problems that don't go well with COVID. Also, smokers have a depressed immune system compared to nonsmokers, so it would seem to suggest they'd be less likely to fight off an infection like this.

[zaarn]

In a lot of cases, COVID-19 symptoms involve an immunesystem overreaction, which causes massive inflammation and organ damage all over, so having a depressed immunesystem might help there.

[lazyasciiart]

That is contradicted by the studies in the linked article

>smokers with a positive Covid-19 test were more than twice as likely as non-smokers with coronavirus to be hospitalised.

> This aligns with research from the US which found hospitalised smokers with coronavirus were 1.8 times more likely to die.

[nyolfen]

i don't think it is a contradiction; "a very small fraction of smokers contract covid or end up in the hospital due to it; those that do are more likely to die"

[lazyasciiart]

This sentence: "smokers are shown to be substantially less susceptible to both catching covid and developing severe symptoms"

is contradicted by the study showing that smokers with covid are more likely to have severe symptoms than non-smokers with covid.

[lol636363]

Also in countries like India and Pakistan with very high percentage of smokers, we are seeing very low COVID19 cases.

While a lot of people are skeptical of the official numbers from these countries, I think they have free media and if cases were high, we would have known.

[mytherin]

I haven't read this article in-depth, but at a glance I did not see this discussed there: can't this simply be explained by smokers generally having a lower life expectancy than non-smokers?

If most people that have severe COVID complications and end up on the ICU are aged 80+, and generally smokers die before that age from smoking-related complications, doesn't it naturally follow that most people on the ICU will be non-smokers? Smoking will have killed the smokers before they become part of the high-risk group, after all.

[488643689]

Weird sentiment to think the researchers wouldn't identify and correct for such an obvious factor.

[mytherin]

Correcting for something is much easier said than done, and it is very often done incorrectly. Blindly trusting researchers to do so is a mistake.

Here is a quote from the abstract of the paper linked above:

> Results: The inpatient group was composed of 343 patients, median age 65 yr: 206 men (601%, median age 66 years) and 137 women (39.9%, median age 65 years) with a rate of daily smokers of 4.4% (5.4% of men and 2.9% of women).The outpatient group was composed of 139 patients, median age 44 years: 62 men (44.6 %, median age 43 years, and 77 women (55.4 %, median age 44 years). The daily smokers rate was 5.3% (5.1% of men and 5.5 % of women). In the French population, the daily smokers rate was 25.4% (28.2% of men and 22.9% of women).

The average daily smoker rate is taken as-is over the whole population, and compared to the smoking rate of people of age around ~66 years, despite the article itself stating that the percentage of daily smokers is lower for old people and higher for young people.

So already in the abstract they have made a mistake and forgot to correct for age. I have not read the rest of the article in enough depth to judge fully, but I would absolutely not blindly trust researchers to always do this correction in an appropriate way.

[fab1an]

Most of these studies correct for age because of that.

[Gibbon1]

I saw an analysis from a epidemiologist who said the result is due to naive over adjustment for confounding variables. Specifically if you treat related confounding variables as if they are independent you end up with garbage.

They also said elsewhere that a lot of researchers from outside epidemiology are running really bad studies and publishing papers.

[himinlomax]

He's almost certainly wrong, the effect size on this one is astounding. See for example this: https://www.qeios.com/read/WPP19W.3

Even with conservative assumptions, smokers in this French study were 4 to 5 times less likely to be infected.

Keep in mind that drugs being tested are considered good when they reduce mortality by 10%. We're talking 75% reduction in infection rate here, and no increased mortality in those who are infected. It's really really hard to imagine what sort of confounding factor that could be at play here that would make the effect insignificant.

[sharken]

If the facts speak against what an epidemiologist says, then perhaps we should also use critical thinking there.

[numpad0]

Makes me wonder if tobacco in eras of tuberculosis improved chances of individual survival...

[sudosysgen]

Almost certainly not. Nicotine is known to downregulate the recptor that SARS-CoV-2 uses for entry.

[xwolfi]

They are just as likely to catch it, but the symtoms are less severe in more cases than non-smoker.

They give nicotine patches to nurses in pilot studies, how ironical :D

[jnkl]

Do you have source?

[metrokoi]

Smoking decreases the amount of certain enzymes that COVID binds to in order to infect the lungs. Less enzymes means a lesser chance of catching the virus, but if caught, the person will likely have a more severe case due to the decreased lung capability.[0][1] The figures that I have seen previously did show a very significantly decreased risk of catching COVID, and I'm surprised it hasn't been investigated far more.

Edit: I had that wrong, it seems nicotine increases ACE2, but also binds with ACE2 decreasing the amount of available enzymes overall that COVID could bind to.[2]

[0]https://en.wikipedia.org/wiki/Angiotensin-converting_enzyme_... [1]https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7191112/ [2]https://arxiv.org/abs/2004.14943