Oestrogen may lessen the severity of Covid-19 symptoms, scientists claim

Women don’t seem to get Covid-19 as bad as men and it could be down to oestrogen, according to a new study that set out to explain the gender disparity. 

A number of studies show that men face a much greater chance of getting a severe case of Covid-19, and could be as much as twice as likely to die from the virus. 

In an effort to understand why this occurs, scientists at Wake Forest School of Medicine conducted a review of data on hormone activity, especially oestrogen.  

They found that the enzyme ACE2 that coronavirus attaches to in order to enter the heart, is reduced as a result of higher levels of oestrogen in women.

The enzyme is more prevalent in men due to the lack of oestrogen keeping numbers down –  which could account for why symptoms are worse in men, the team said.

In the UK, researchers studying 17 million adults found that men could face nearly twice the risk of death from the virus as women. 

According to the team, the reason men are more likely to die from the virus are ‘multi-fold’ including differences in lifestyle and an innate immunity in women. 

To get a deeper understanding of these differences, they assessed sex-specific hormone activity – particularly oestrogen, in COVID-19 patients.

‘We know that coronavirus affects the heart and we know that oestrogen is protective against cardiovascular disease in women,’ said Dr Leanne Groban.

‘So the most likely explanation seemed to be hormonal differences between the sexes,’ the lead author and professor of anaesthesiology explained.

Groban’s researchers looking through the published literature focused in on the angiotensin-converting enzyme2 (ACE2), which is attached to cell membranes in the heart, arteries, kidneys and intestines.

It is the cellular receptor of the coronavirus responsible for COVID-19 infections, and helps bring the virus into the cells of those organ systems, they explained.

The review, they said, also pointed to oestrogen’s lowering the level of ACE2 in the heart, which may modulate the severity of COVID-19 in women. 

Conversely, higher levels of ACE2 in tissues could account for why symptoms are worse in men than women, Groban said.

‘We hope that our review regarding the role of oestrogenic hormones in ACE2 expression and regulation may explain the gender differences in COVID-19 infection and outcomes,’ Groban said.

She added that it could help ‘serve as a guide for current treatment and the development of new therapies.’

There are two trials due to start soon aimed at discovering if short-term treatment of men with Covid-19 using an oestrogen patch could reduce severity of symptoms. 

An earlier, unrelated study, found that men may be more likely to suffer severe cases of coronavirus or die of the disease because they have weaker immune responses.

Researchers found that male patients had poor production of certain types of immune cells that kill the virus and fight off inflammation.  

However, women’s immune systems had a robust response that did not decrease with age as seen in men.

The team, from Yale University claim their findings offer some clues in the differences between the sexes and add that men and women may need separate types of vaccines and treatments.  

The oestrogen study is published in the journal Current Hypertension Reports.