COVID-19: Study shows symptoms and testosterone levels in men are related

Low levels of testosterone could increase the severity of an illness.

A man receives a Covid-19 vaccine, at the Shaare Zedek hospital in Jerusalem, on January 3, 2021. (photo credit: YONATAN SINDEL/FLASH90)
A man receives a Covid-19 vaccine, at the Shaare Zedek hospital in Jerusalem, on January 3, 2021.
(photo credit: YONATAN SINDEL/FLASH90)
An imbalance in men's testosterone levels has been linked to the severity of their coronavirus case, a new study has found.
The experiment, led by Andrea Salonia MD of Milan's Urological Research Institute, compared levels of circulating total testosterone (tT) in confirmed and hospitalized male coronavirus patients to healthy male blood donors. 
The finds were published in the study called "Severely low testosterone in males with COVID‐19: a case‐control study" in the scientific journal American Society of Andrology and European Academy of Andrology on February 26.
Previous research identified a potential correlation between immune responses and biological sex; males are statistically more likely to catch the virus.
The virus enters and infects host cells via a glycoprotein called S, which passes through the cell membrane. This protein must be primed by proteins ACE2 and TMPRSS2, which are both steroid hormones responsible for managing masculine functions. Additionally, ACE2 levels are naturally higher in men. Researchers therefore hypothesized that COVID-19 would be related to male hormone levels.
The objective of the experiment was to test testosterone levels and the presence of hypogonadism, a dysfunction of sex hormone production, in male COVID-19 patients.
Some 286 ill patients were hospitalized with positive lab results to SARS-coV-2 and referrals from chest radiography or computed tomography. They were divided into four test groups: those discharged immediately, those admitted in relatively stable conditions, those under ICU ventilation who later recovered, and those who died in the ICU.
Of the four groups, 90% of the patients suffered from low levels of testosterone indicative of hypogonadism. Even more so, hypogonadism was six times more likely to be found in the coronavirus-groups than the healthy control group. Testosterone levels under 9.2 nmol/L were recorded in 257 corona patients (89.8%), whereas only 42 healthy men (14.9%) tested for such low levels. Overall, the lower testosterone levels predicted higher instances of mortality and critical conditions in the patients.
This study has many important implications for future medicine and research on virus pathology. Low levels of testosterone may increase the severity of an illness. It is clear that androgens, male sex hormones, including testosterone, are not as efficient in producing immune responses as female hormones, such as estrogen and progesterone.
Low testosterone levels affect as much as 20% of middle-aged and elderly men. The results of this study could mean male hormone levels contribute to health conditions and immune responses. Furthermore, viruses may be a factor in lowering male sex hormone levels and causing a collapse in the male endocrine system.