1/
As the #COVID19 pandemic progresses, exactly why men get infected more frequently, and with greater severity, than women is unknown.
This #tweetorial examines a theory (emphasis on theory) that might explain some of this difference.
#medthread #medtwitter
As the #COVID19 pandemic progresses, exactly why men get infected more frequently, and with greater severity, than women is unknown.
This #tweetorial examines a theory (emphasis on theory) that might explain some of this difference.
#medthread #medtwitter
2/
First, let's look at the gender distribution data for covid19.
It was noted early in the outbreak in China that more men than women were getting infected.
In this sample 58% of infections occurred in men (and they died at a slightly higher rate).
ncbi.nlm.nih.gov/pubmed/32109013
First, let's look at the gender distribution data for covid19.
It was noted early in the outbreak in China that more men than women were getting infected.
In this sample 58% of infections occurred in men (and they died at a slightly higher rate).
ncbi.nlm.nih.gov/pubmed/32109013
3/
A similar gender difference has emerged in Italy.
So far 59% of Italian cases have been in men.
statista.com/statistics/110…
A similar gender difference has emerged in Italy.
So far 59% of Italian cases have been in men.
statista.com/statistics/110…
4/
In Italy in particular, men seem to be dying of covid19 at a higher rate as well:
Men = 7.2% mortality
Women = 4.1% mortality
epicentro.iss.it/coronavirus/bo…
In Italy in particular, men seem to be dying of covid19 at a higher rate as well:
Men = 7.2% mortality
Women = 4.1% mortality
epicentro.iss.it/coronavirus/bo…
5/
Why would this be?
Some possibilities include that men and women seem to have different types of immune responses, levels of cardiovascular disease, even hand washing habits.
nytimes.com/2020/03/20/hea…
Why would this be?
Some possibilities include that men and women seem to have different types of immune responses, levels of cardiovascular disease, even hand washing habits.
nytimes.com/2020/03/20/hea…
6/
Another major difference between men and women is the rate of cigarette smoking.
Men smoke more frequently than women in general, including in Italy and China.
worldpopulationreview.com/countries/smok…
Another major difference between men and women is the rate of cigarette smoking.
Men smoke more frequently than women in general, including in Italy and China.
worldpopulationreview.com/countries/smok…
7/
On a simple level, smoking involves repetitive hand-to-face movements, which could put smokers at higher risk of contracting the virus.
This association is conjectural but plausible.
blogs.bmj.com/bmj/2020/03/20…
On a simple level, smoking involves repetitive hand-to-face movements, which could put smokers at higher risk of contracting the virus.
This association is conjectural but plausible.
blogs.bmj.com/bmj/2020/03/20…
8/
It's also established that smoking:
🔹Impairs immune responses in the lung
🔹Contributes to preexisting lung diseases/severity like asthma and COPD
🔹Associates with comorbidities like heart disease that increase the risk of death from covid19
ncbi.nlm.nih.gov/pubmed/32171067
It's also established that smoking:
🔹Impairs immune responses in the lung
🔹Contributes to preexisting lung diseases/severity like asthma and COPD
🔹Associates with comorbidities like heart disease that increase the risk of death from covid19
ncbi.nlm.nih.gov/pubmed/32171067
9/
For these reasons, if more men smoke, then perhaps that contributes to their risk of covid19 infection and severity.
But that may not be the whole story...
For these reasons, if more men smoke, then perhaps that contributes to their risk of covid19 infection and severity.
But that may not be the whole story...
10/
For reasons you'll see, let's take a closer look at Angiotensin Converting Enzyme II (ACE2):
🔹ACE2 is a peptidase on the surface of type 2 pneumocytes
🔹Covid19 binds it w/ high avidity
💥ACE2 is the receptor that allows covid19 to infect the body
ncbi.nlm.nih.gov/pubmed/32075877
For reasons you'll see, let's take a closer look at Angiotensin Converting Enzyme II (ACE2):
🔹ACE2 is a peptidase on the surface of type 2 pneumocytes
🔹Covid19 binds it w/ high avidity
💥ACE2 is the receptor that allows covid19 to infect the body
ncbi.nlm.nih.gov/pubmed/32075877
11/
A logical question:
Does smoking affect ACE2 (eg covid19 binding site) levels in the lung?
💥Preliminary data suggests that smokers do express higher levels of lung ACE2.
In effect, more smoking = more covid19 receptor
mdpi.com/2077-0383/9/3/…
A logical question:
Does smoking affect ACE2 (eg covid19 binding site) levels in the lung?
💥Preliminary data suggests that smokers do express higher levels of lung ACE2.
In effect, more smoking = more covid19 receptor
mdpi.com/2077-0383/9/3/…
12/
This pre-publication report found no differences in baseline lung ACE2 expression between genders but did find higher levels of ACE2 in those who smoke.
medrxiv.org/content/10.110…
This pre-publication report found no differences in baseline lung ACE2 expression between genders but did find higher levels of ACE2 in those who smoke.
medrxiv.org/content/10.110…
13/
One last point:
How vaping or marijuana smoking affects ACE2 levels in the lung is unknown.
One last point:
How vaping or marijuana smoking affects ACE2 levels in the lung is unknown.
14/
Let's summarize:
🔹There's a gender difference in covid19 infections/severity (men > women)
🔹Different smoking rates may account for some of this gap
🔹Covid19 binds ACE2 when infecting the airway
🔹Smoking increases ACE2 levels, ? increasing susceptibility to infxn
Let's summarize:
🔹There's a gender difference in covid19 infections/severity (men > women)
🔹Different smoking rates may account for some of this gap
🔹Covid19 binds ACE2 when infecting the airway
🔹Smoking increases ACE2 levels, ? increasing susceptibility to infxn
