There is a growing mood of jubilance in England and for good reason – on 19 July the UK will press ahead and remove all remaining coronavirus restrictions. The vaccine campaign has severely weakened the link between transmission and hospitalisation, even as deadly new variants such as the Delta variant have entered our shores. Nonetheless, the vaccines are not a silver-bullet – the virus can still breach the immune system’s defences. Meanwhile, new research has identified a major risk factor in men.
Men with symptomatic COVID-19, who were found to have low testosterone following admittance to hospital, were more likely to become severely ill and die from the disease, new research has found.
The study, carried out in Milan during the first wave of coronavirus in 2020, found that the lower the levels of testosterone, the higher the likelihood that male patients would need intensive care, be intubated on a ventilator and remain in hospital over a longer period.
Their likelihood of dying increased six-fold.
Professor Andrea Salonia and his colleagues at the San Raffaele University Hospital in Milan compared 286 male Covid patients, who came to the emergency department, with 305 healthy male volunteers, who attended hospital to give blood between Feb and May 2020.
Those patients who had mild symptoms or were admitted to hospital had slightly higher testosterone levels (between 3-4 nmol/l) than those admitted to ICU or those who died of the disease (just 0.7-1.0 nmol/l).
Even when age, pre-existing conditions and body mass index (BMI) – the universally recognised measure of healthy weight – were taken into account, the differences in hormonal profiles and clinical outcomes were still stark.
Commenting on the findings, Professor Salonia, a specialist in urology and endocrinology at San Raffaele Hospital, said: “At the start of the Covid pandemic, we were seeing far more men than women coming to hospital and suffering very severe forms of the disease. We immediately thought this might be related to male hormone levels, particularly testosterone.
“But we never expected to see such a high proportion of Covid patients with these extremely low levels of testosterone, in comparison to a similar group of healthy men.”
Prof Salonia added: “The relationship is very clear: the lower the testosterone, the higher the severity of the condition and likelihood of death. I’ve never seen anything like it in my 25 years in the field.”
Because the team does not have data on the testosterone levels in the patients before they contracted COVID-19, they cannot say whether low testosterone was a pre-existing long-term condition that exacerbated the disease or whether it was caused by the SARS-COV2 virus (the virus that causes COVID-19).
However, other research has shown that some receptors for the virus, including the enzyme TMPRSS2, are linked to male hormones and that the virus reduces the number of Leydig cells in the body, which produce testosterone.
“We simply don’t have the data to know which came first in these patients, the low testosterone levels or the Covid,” explained Professor Salonia.
“Testosterone does play a role in protecting men from disease. However, it’s also possible that the virus itself is able to induce an acute reduction in testosterone levels, which then predisposes these men to a worse outcome. We’re now following up these patients over a longer time period, to see how their hormone levels change over time, so we can try and answer these questions.”
Professor Jens Sonksen, an executive member of the EAU (Europe’s biggest urology conference), said: “The SARS-CoV-2 pandemic has had a tremendous impact on global health since the virus first started spreading in early 2020. We have learned a lot about the virus and possible health consequences from COVID-19 since those early days, but there is much still to learn.
“This is highlighted by this new research, which found a surprisingly low level of total testosterone in men with COVID-19 compared to healthy controls.
“Symptomatic COVID-19 patients with low testosterone were also more likely to become critically ill from COVID-19. Additional research on potential impacts from COVID-19 on men’s health is definitely needed.”
Low testosterone levels – how to tell
The American Urology Association (AUA) identifies low blood testosterone symptoms as the following:
- Low sex drive
- Reduced lean muscle mass
- Erectile dysfunction
The health body adds: “There are many other possible reasons for these symptoms, such as: opioid use, some congenital conditions (medical conditions you are born with), loss of or harm to the testicles, diabetes, and obesity (being overweight). See your doctor if you have any of these symptoms.”