What's the link between testosterone and COVID-19?

The question of why men are dying of coronavirus at twice the rate of women has been raised again by scientists after they noted that prostate cancer patients given androgen deprivation therapy, which reduces testosterone levels, were four times less likely to die of COVID-19 than those not on them.

This follows on from separate research programmes which have started to look at the potential of the possible protective properties of oestrogen.

Could blocking testosterone be the answer for coronavirus?

London’s Institute for Cancer Research (ICR) are analysing the role testosterone plays in COVID-19 and the University of California, Los Angeles, are studying whether blocking testosterone could potentially be a therapy.

Testosterone drives up levels of a protein called TMPRSS2, which is implicated in prostate cancer. Researchers looking into COVID 19 have recently found that the coronavirus also uses this protein to ‘unlock’ cells.

Professor Nick James, of London’s ICR, is analysing data from around 8,000 NHS prostate cancer patients in a trial he runs, to see if those on hormone reduction therapy have been less likely to be hospitalised with Covid-19.

Using such drugs as a coronavirus treatment is a possibility, he said, but not one to be taken lightly due to their serious side effects.

‘Being on these drugs is the male equivalent of going through the menopause,’ he said, believing using them as a large-scale preventative measure was a non-starter. ‘You would almost certainly cause more harm than good,’ he explained. 

Is ACE2 the missing part of the COVID-19 puzzle?

Differences in the make-up of men’s blood and tissue has also been suggested as a reason for the sex disparity in death rates and severity of COVID-19. The University Medical Center (UMC) Groningen, has published a study in the European Heart Journal.

The study was started before the pandemic began; it focussed on the effects of ACE-inhibitor heart drugs, but researchers quickly realised their findings could shed light on COVID-19’s sex divide.

ACE2 is a receptor on the surface of cells which binds to the new coronavirus and allows it to enter and infect cells. It’s found in the heart, kidneys, in tissues lining blood vessels, and in particularly high levels in the testes. Far smaller amounts are found in ovarian tissue, consequently women have low levels of ACE2.

Iziah Sama, a doctor at UMC Groningen who also helped lead the study, said: 'When we found that one of the strongest biomarkers, ACE2, was much higher in men than in women, I realised that this had the potential to explain why men were more likely to die from COVID-19 than women.'

But low testosterone can cause COVID-19 complications ...

The link between testosterone and COVID-19 is likely to be more complex. A small study from University Medical Center Hamburg-Eppendorf looked at the first 45 COVID-19 patients admitted to the intensive care unit.

From this group of 35 men and 10 women, nine men and three women died. Seven of the patients needed oxygen and a further 33 were placed onto ventilators.

More than two thirds of the men (68.6 per cent) recorded low levels of testosterone while 60 per cent of female patients had raised testosterone levels.

Researchers have a theory that low levels of testosterone can weaken the body’s ability to successfully fight off the virus causing a ‘cytokine storm’, an extreme immune response to COVID-19.

Swansea University experts have supported this theory by showing that men who have low testosterone levels are at more at risk of Covid-19 than other men, after looking at the data of 200,000 people in 41 countries 

Scientists are hoping these research projects will soon start to yield answers to save lives in the future.