Screening for low testosterone is needed for early identification and treatment of men at high risk of mortality from Covid-19

Sex hormones and the total testosterone:estradiol ratio as predictors of severe acute respiratory syndrome coronavirus 2 infection in hospitalized men

BACKGROUND

The predictive ability of the early determination of sex steroids and the total testosterone:estradiol ratio for the risk of severe coronavirus disease 2019 or the potential existence of a biological gradient in this relationship has not been evaluated.

OBJECTIVES

To assess the relationship of sex steroid levels and the total testosterone:estradiol ratio with the risk of severe acute respiratory syndrome coronavirus 2 infection in men, defined as the need for intensive care unit admission or death, and the predictive ability of each biomarker.

MATERIALS AND METHODS

This was a prospective observational study. We included all consecutive adult men with severe acute respiratory syndrome coronavirus 2 infections in a single center admitted to a general hospital ward or to the intensive care unit. Sex steroids were evaluated at the centralized laboratory of our hospital.

RESULTS

We recruited 98 patients, 54 (55.1%) of whom developed severe coronavirus disease in 2019. Compared to patients with nonsevere coronavirus disease 2019, patients with severe coronavirus disease 2019 had significantly lower serum levels of total testosterone (111 ± 89 vs. 191 ± 143 ng/dL; p < 0.001), dehydroepiandrosterone (1.69 ± 1.26 vs. 2.96 ± 2.64 ng/mL; p < 0.001), and dehydroepiandrosterone sulfate (91.72 ± 76.20 vs. 134.28 ± 98.261 μg/dL; p = 0.009), significantly higher levels of estradiol (64.61 ± 59.35 vs. 33.78 ± 13.78 pg/mL; p = 0.001), and significantly lower total testosterone:estradiol ratio (0.28 ± 0.31 vs. 0.70 ± 0.75; p < 0.001). The lower the serum level of androgen and the lower the total testosterone:estradiol ratio values, the higher the likelihood of developing severe coronavirus disease 2019, with the linear trend in the adjusted analyses being statistically significant for all parameters except for androstenedione (p = 0.064). In the receiver operating characteristic analysis, better predictive performance was shown by the total testosterone:estradiol ratio, with an area under the curve of 0.77 (95% confidence interval 0.68-0.87; p < 0.001).

DISCUSSION AND CONCLUSION

Our results suggest that men with severe acute respiratory syndrome coronavirus 2 infection, decreased androgen levels and increased estradiol levels have a higher likelihood of developing an unfavorable outcome. The total testosterone:estradiol ratio showed the best predictive ability.

Understanding Covid-19: Digit ratios and duration of oxygen therapy in hospitalized Covid-19 patients

BACKGROUND

Covid-19 severity shows a sex difference (males>females) and progressive hypoxia among the most seriously affected. Digit ratios are sexually dimorphic and may be negatively-related to prenatal (2nd-to-4th digits' ratio; 2D:4D) and pubertal (3rd-to-5th digits' ratio; 3D:5D) testosterone. Oxygen therapy is important in Covid-19 treatment and low 2D:4D is linked to efficient oxygen metabolism. We consider relationships between digit ratios and duration of oxygen treatment in hospitalized Covid-19 patients.

METHODS

Digit lengths were measured from photographs of the patient's hands. Age, Sex, BMI, vaccination status and number of days of O2 treatment, were recorded.

RESULTS

There were 100 (58 women) patients. Sex differences (males

CONCLUSION

We have found that high (feminized) 2D:4D of males and females is positively related to duration of oxygen therapy. This adds to the evidence for links between severity of Covid-19 and national and individual level variation in foetal androgen (as measured by 2D:4D). We discuss our finding in the light of the "low-androgen-driven COVID-19 pandemic theory".

Collapse

Key Words

• COVID-19
• Digit ratio
• Oxygen therapy

Collapse

MESH Headings

• Humans
• Male
• Female
• Androgens
• Fingers/anatomy & histology
• Digit Ratios
• COVID-19/therapy
• Pandemics
• COVID-19 Drug Treatment
• Sex Characteristics
• Oxygen/therapeutic use

Collapse

Grants Collapse

Affiliation(s)

Anna Kasielska-Trojan Plastic, Reconstructive and Aesthetic Surgery Clinic, Institute of Surgery, Medical University of Lodz, Lodz, Poland.
Maciej Jabłkowski Department of Infectious and Liver Diseases, Medical University of Lodz, Lodz, Poland
Jolanta Białkowska-Warzecha Department of Infectious and Liver Diseases, Medical University of Lodz, Lodz, Poland
Oliwia Kwaśniewska Medical University of Lodz, Lodz, Poland
Bogusław Antoszewski Plastic, Reconstructive and Aesthetic Surgery Clinic, Institute of Surgery, Medical University of Lodz, Lodz, Poland

Collapse

Sex hormones in SARS-CoV-2 susceptibility: key players or confounders?

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has a clear sex disparity in clinical outcomes. Hence, the interaction between sex hormones, virus entry receptors and immune responses has attracted major interest as a target for the prevention and treatment of SARS-CoV-2 infections. This Review summarizes the current understanding of the roles of androgens, oestrogens and progesterone in the regulation of virus entry receptors and disease progression of coronavirus disease 2019 (COVID-19) as well as their therapeutic value. Although many experimental and clinical studies have analysed potential mechanisms by which female sex hormones might provide protection against SARS-CoV-2 infectivity, there is currently no clear evidence for a sex-specific expression of virus entry receptors. In addition, reports describing an influence of oestrogen, progesterone and androgens on the course of COVID-19 vary widely. Current data also do not support the administration of oestradiol in COVID-19. The conflicting evidence and lack of consensus results from a paucity of mechanistic studies and clinical trials reporting sex-disaggregated data. Further, the influence of variables beyond biological factors (sex), such as sociocultural factors (gender), on COVID-19 manifestations has not been investigated. Future research will have to fill this knowledge gap as the influence of sex and gender on COVID-19 will be essential to understanding and managing the long-term consequences of this pandemic.

Insights into the Scenario of SARS-CoV-2 Infection in Male Reproductive Toxicity

COVID-19 has become a significant public health concern that has catastrophic consequences for society. Some preliminary evidence suggests that the male reproductive system may be an infection target for SARS-CoV-2. SARS-CoV-2 may be transmitted sexually, according to preliminary research. Testicular cells exhibit a high level of the angiotensin-converting enzyme 2 (ACE2) receptor, which enhances the entry of the SARS-CoV-2 into host cells. Some instances of COVID-19 have been documented to exhibit hypogonadism during the acute stage. Furthermore, systemic inflammatory reactions triggered by SARS-CoV-2 infection may cause oxidative stress (OS), which has been shown to have profoundly deleterious consequences on testicular functioning. This work gives a clear picture of how COVID-19 may affect male reproductive systems and calls attention to the many unanswered questions about the mechanisms by which this virus can be linked to men's health and fertility.

Estrogens as a Possible Therapeutic Strategy for the Management of Neuroinflammation and Neuroprotection in COVID-19

The Coronavirus disease 2019 (COVID-19) affects several tissues, including the central and peripheral nervous system. It has also been related to signs and symptoms that suggest neuroinflammation with possible effects in the short, medium, and long term. Estrogens could have a positive impact on the management of the disease, not only due to its already known immunomodulator effect, but also activating other pathways that may be important in the pathophysiology of COVID-19, such as the regulation of the virus receptor and its metabolites. In addition, they can have a positive effect on neuroinflammation secondary to pathologies other than COVID-19. The aim of this study is to analyze the molecular mechanisms that link estrogens with their possible therapeutic effect for neuroinflammation related to COVID-19. Advanced searches were performed in scientific databases as Pub- Med, ProQuest, EBSCO, the Science Citation index, and clinical trials. Estrogens have been shown to participate in the immune modulation of the response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In addition to this mechanism, we propose that estrogens can regulate the expression and activity of the Angiotensin-converting enzyme 2 (ACE2), reestablishing its cytoprotective function, which may be limited by its interaction with SARS-CoV-2. In this proposal, estrogens and estrogenic compounds could increase the synthesis of Angiotensin-(1-7) (Ang-(1-7)) that acts through the Mas receptor (MasR) in cells that are being attacked by the virus. Estrogens can be a promising, accessible, and low-cost treatment for neuroprotection and neuroinflammation in patients with COVID-19, due to its direct immunomodulatory capacity in decreasing cytokine storm and increasing cytoprotective capacity of the axis ACE2/Ang (1-7)/MasR.

Relationship of inflammatory mediators and sex-related parameters in Jordanian adult men patients with Covid-19

BACKGROUND

Recent epidemiological data suggest that Co - ro navirus disease 2019 (COVID-19) has a gender predisposition, with men being more seriously affected than women. Furthermore, older men accounting for most deaths. Therefore, this study aimed to investigate the serum testosterone, inhibin B, intrleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-a) levels in different age groups of Jordanian males with SARS-CoV2 infection and to evaluate the correlation of these markers in male patients with COVID-19.

METHODS

This study was performed on 157 selected individuals divided into two groups; COVID-19 patients and healthy controls. The participants of each group were further divided into two subgroups based on the age (20-50 years and 51-80 years age groups). The biochemical tests that were performed in this research are testosterone, inhibin-B, TNF-a, and IL-6.

RESULTS

The levels of IL-6 were significantly higher in COVID-19 patients than healthy individuals (7.63 ± 6.30 vs. 5.54 ± 2.10, P=0.006). Similarly, the difference between the levels of TNF-a in the study groups were statistically significant (P=0.001). The mean testosterone levels in COVID-19 patients and healthy controls were 1.53 ± 1.24 and 3.87 ± 1.44, respectively (P<0.001), whereas the mean inhibin B levels in COVID-19 patients (54.29 ± 7.33) were lower than in healthy controls (64.14 ± 37.66) with P = 0.011. TNF-a was significantly and positively correlated with age (r = 0.263, P=0.018) and IL-6 (r = 0.245, P=0.027). Inhibin B had a significant, but negative correlation with TNF-a (r = -0.326, P = 0.003).

CONCLUSIONS

It can be concluded that most men seeking medical attention with symptomatic COVID-19 had low testosterone and inhibin B levels with increased both IL-6 and TNF-a, which are independent of age conforming the deleterious effects of SARS-CoV-2 infection on testicular function and immune response induction.

Examining Male Predominance of Severe COVID-19 Outcomes: A Systematic Review

Although not universal, many epidemiological data sources signal that a higher proportion of males than females with confirmed Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infections have adverse outcomes, such as intensive care unit (ICU) admission and death. Though likely multifactorial, the various hypotheses that have been proposed as underlying factors behind this trend are related to greater smoking prevalence among males, testosterone (T) deficiency causing an inflammatory storm, androgen-driven pathogenesis of SARS-CoV-2, a protective effect of estrogen in females, and inborn errors of cytokine immunity. This review aims at examining the evidence and at assessing the likelihood that the factors being investigated are contributory to the reported trend of male predominance of severe COVID-19 cases. Sources were obtained using the PubMed database and were selected based on their relevance to one of the primary hypotheses attempting to explain the strong male sex bias of severe SARS-CoV-2 infections. Emphasis was placed on meta-analyses and population-based studies. Sources are current through February 22, 2022. A severe COVID-19 case or outcome is defined in this review as a progression of the SARS-CoV-2 virus that results in either admission to an ICU for management of symptoms and clinical stabilization or which leads to death. Although the trend of male predominance of severe COVID-19 cases is likely multifactorial, the hypothesis of T deficiency causing an inflammatory storm has support from many studies with limited conflicting evidence. An inborn error in cytokine immunity is also well supported, but it needs more studies to add support to the hypothesis. The immunologic protective effect of estrogen is supported by multiple studies, but it also has conflicting evidence. It appears less likely that the trend is caused solely by an increased prevalence of smoking among males or an androgen-driven pathogenesis, based on the extent of conflicting evidence.

Association Between Sex Hormone Levels and Clinical Outcomes in Patients With COVID-19 Admitted to Hospital: An Observational, Retrospective, Cohort Study

Understanding the cause of sex disparities in COVID-19 outcomes is a major challenge. We investigate sex hormone levels and their association with outcomes in COVID-19 patients, stratified by sex and age. This observational, retrospective, cohort study included 138 patients aged 18 years or older with COVID-19, hospitalized in Italy between February 1 and May 30, 2020. The association between sex hormones (testosterone, estradiol, progesterone, dehydroepiandrosterone) and outcomes (ARDS, severe COVID-19, in-hospital mortality) was explored in 120 patients aged 50 years and over. STROBE checklist was followed. The median age was 73.5 years [IQR 61, 82]; 55.8% were male. In older males, testosterone was lower if ARDS and severe COVID-19 were reported than if not (3.6 vs. 5.3 nmol/L, p =0.0378 and 3.7 vs. 8.5 nmol/L, p =0.0011, respectively). Deceased males had lower testosterone (2.4 vs. 4.8 nmol/L, p =0.0536) and higher estradiol than survivors (40 vs. 24 pg/mL, p = 0.0006). Testosterone was negatively associated with ARDS (OR 0.849 [95% CI 0.734, 0.982]), severe COVID-19 (OR 0.691 [95% CI 0.546, 0.874]), and in-hospital mortality (OR 0.742 [95% CI 0.566, 0.972]), regardless of potential confounders, though confirmed only in the regression model on males. Higher estradiol was associated with a higher probability of death (OR 1.051 [95% CI 1.018, 1.084]), confirmed in both sex models. In males, higher testosterone seems to be protective against any considered outcome. Higher estradiol was associated with a higher probability of death in both sexes.

Androgens in SARS-CoV-2 coronavirus infections

Recent molecular biology findings have shown that for the penetration of the SARS-CoV-2 coronavirus into host cells, a key role is played by protease serine 2, the activity of which is dependent on androgens. The important role of androgens is also evidenced by clinical observations that men in some age categories are infected by this novel coronavirus up to two times more frequently than women. In addition, men with androgenic alopecia tend to have more serious clinical courses, while men with androgen deprivation as a result of prostate cancer treatments tend to have milder courses. This is in line with the fact that preadolescent children are only rarely sickened with serious forms of SARS-CoV-2 infections. Even though these observations may be explained by other factors, many authors have hypothesized that lowered androgen levels and blocking their activity using anti-androgen medication may moderate the course of the viral infection in intermediately- to critically-affected cases. Clearly, it would be important for androgen deprivation to block not just gonadal androgens, but also adrenal androgens. On the other hand, low androgen levels are considered to be a risk factor for the course of SARS-CoV-2 infections, either because low androgen levels have a general effect on anabolic-catabolic equilibrium and energy metabolism, or because of the ability of testosterone to modify the immune system. It is not yet clear if infection with this novel coronavirus might induce hypogonadism, leading to undesirable side effects on male fertility.

Immunoreactivity of the SARS-CoV-2 entry proteins ACE-2 and TMPRSS-2 in murine models of hormonal manipulation, ageing, and cardiac injury

Previous work indicates that SARS-CoV-2 virus entry proteins angiotensin-converting enzyme 2 (ACE-2) and the cell surface transmembrane protease serine 2 (TMPRSS-2) are regulated by sex hormones. However, clinical studies addressing this association have yielded conflicting results. We sought to analyze the impact of sex hormones, age, and cardiovascular disease on ACE-2 and TMPRSS-2 expression in different mouse models. ACE-2 and TMPRSS-2 expression was analyzed by immunostaining in a variety of tissues obtained from FVB/N mice undergoing either gonadectomy or sham-surgery and being subjected to ischemia-reperfusion injury or transverse aortic constriction surgery. In lung tissues sex did not have a significant impact on the expression of ACE-2 and TMPRSS-2. On the contrary, following myocardial injury, female sex was associated to a lower expression of ACE-2 at the level of the kidney tubules. In addition, after myocardial injury, a significant correlation between younger age and higher expression of both ACE-2 and TMPRSS-2 was observed for lung alveoli and bronchioli, kidney tubules, and liver sinusoids. Our experimental data indicate that gonadal hormones and biological sex do not alter ACE-2 and TMPRSS-2 expression in the respiratory tract in mice, independent of disease state. Thus, sex differences in ACE-2 and TMPRSS-2 protein expression observed in mice may not explain the higher disease burden of COVID-19 among men.

High estradiol and low testosterone levels are associated with critical illness in male but not in female COVID-19 patients: a retrospective cohort study

Male sex was repeatedly identified as a risk factor for death and intensive care admission. However, it is yet unclear whether sex hormones are associated with disease severity in COVID-19 patients. In this study, we analysed sex hormone levels (estradiol and testosterone) of male and female COVID-19 patients (n = 50) admitted to an intensive care unit (ICU) in comparison to control non-COVID-19 patients at the ICU (n = 42), non-COVID-19 patients with the most prevalent comorbidity (coronary heart diseases) present within the COVID-19 cohort (n = 39) and healthy individuals (n = 50). We detected significantly elevated estradiol levels in critically ill male COVID-19 patients compared to all control cohorts. Testosterone levels were significantly reduced in critically ill male COVID-19 patients compared to control cohorts. No statistically significant differences in sex hormone levels were detected in critically ill female COVID-19 patients, albeit similar trends towards elevated estradiol levels were observed. Linear regression analysis revealed that among a broad range of cytokines and chemokines analysed, IFN-γ levels are positively associated with estradiol levels in male and female COVID-19 patients. Furthermore, male COVID-19 patients with elevated estradiol levels were more likely to receive ECMO treatment. Thus, we herein identified that disturbance of sex hormone metabolism might present a hallmark in critically ill male COVID-19 patients.

Testosterone, free, bioavailable and total, in patients with COVID-19

BACKGROUND

Low Testosterone (mainly total testosterone; TTe) has been noted in patients with COVID-19. Calculated free testosterone (FTe) and bioavailable testosterone (BavTe) may reflect more accurately this hormone's levels. In this study, we sought to assess TTe, FTe as well as BavTe in male patients with COVID-19.

SUBJECTS/METHODS

Sera were collected upon admission from 65 men (10 in the intensive care units [ICU] and 55 in the wards) with polymerase chain reaction - proven COVID-19. A group of age-matched COVID-19-negative men (n=29) hospitalized in general medical wards served as controls. Age, body mass index (BMI) and 28-day mortality were noted. Measurements included TTe, sex-hormone binding globulin, albumin (the latter two for calculating FTe and BavTe) and laboratory markers of inflammation (white blood cell count [WBC], D-Dimers [D-D], lactate dehydrogenease [LDH], ferritin [Fer] and C-reactive protein [CRP]).

RESULTS

Profoundly low TTe, FTe and BavTe were noted in most patients, and were associated with disease severity/outcome (being the lowest in COVID-19 patients in the ICU and overall being lower in non-survivors; analysis of covariance p<0.05). Pearson's correlations for logTe, logFTe or logBavTe versus WBC, D-D, LDH, Ferr or CRP were negative, ranging from -0.403 to -0.293 (p=0.009 to 0.014).

CONCLUSIONS

TTe, FTe and BavTe are prone to be low in patients with COVID-19, are negatively associated with disease severity and may be considered to have prognostic value.

COVID-19 susceptibility variants associate with blood clots, thrombophlebitis and circulatory diseases

Epidemiological studies suggest that individuals with comorbid conditions including diabetes, chronic lung, inflammatory and vascular disease, are at higher risk of adverse COVID-19 outcomes. Genome-wide association studies have identified several loci associated with increased susceptibility and severity for COVID-19. However, it is not clear whether these associations are genetically determined or not. We used a Phenome-Wide Association (PheWAS) approach to investigate the role of genetically determined COVID-19 susceptibility on disease related outcomes. PheWAS analyses were performed in order to identify traits and diseases related to COVID-19 susceptibility and severity, evaluated through a predictive COVID-19 risk score. We utilised phenotypic data in up to 400,000 individuals from the UK Biobank, including Hospital Episode Statistics and General Practice data. We identified a spectrum of associations between both genetically determined COVID-19 susceptibility and severity with a number of traits. COVID-19 risk was associated with increased risk for phlebitis and thrombophlebitis (OR = 1.11, p = 5.36e-08). We also identified significant signals between COVID-19 susceptibility with blood clots in the leg (OR = 1.1, p = 1.66e-16) and with increased risk for blood clots in the lung (OR = 1.12, p = 1.45 e-10). Our study identifies significant association of genetically determined COVID-19 with increased blood clot events in leg and lungs. The reported associations between both COVID-19 susceptibility and severity and other diseases adds to the identification and stratification of individuals at increased risk, adverse outcomes and long-term effects.

Testosterone in males with COVID-19: A 7-month cohort study

Background

Circulating testosterone levels have been found to be reduced in men with severe acute respiratory syndrome coronavirus 2 infection, COVID‐19, with lower levels being associated with more severe clinical outcomes.

Objectives

We aimed to assess total testosterone levels and the prevalence of total testosterone still suggesting for hypogonadism at 7‐month follow‐up in a cohort of 121 men who recovered from laboratory‐confirmed COVID‐19.

Materials and methods

Demographic, clinical, and hormonal values were collected for all patients. Hypogonadism was defined as total testosterone ≤9.2 nmol/L. The Charlson Comorbidity Index was used to score health‐significant comorbidities. Descriptive statistics and multivariable linear and logistic regression models tested the association between clinical and laboratory variables and total testosterone levels at follow‐up assessment.

Results

Circulating total testosterone levels increased at 7‐month follow‐up compared to hospital admittance (p < 0.0001), while luteinizing hormone and 17β‐estradiol levels significantly decreased (all p ≤ 0.02). Overall, total testosterone levels increased in 106 (87.6%) patients, but further decreased in 12 (9.9%) patients at follow‐up, where a total testosterone level suggestive for hypogonadism was still observed in 66 (55%) patients. Baseline Charlson Comorbidity Index score (OR 0.36; p = 0.03 [0.14, 0.89]) was independently associated with total testosterone levels at 7‐month follow‐up, after adjusting for age, BMI, and IL‐6 at hospital admittance.

Conclusions

Although total testosterone levels increased over time after COVID‐19, more than 50% of men who recovered from the disease still had circulating testosterone levels suggestive for a condition of hypogonadism at 7‐month follow‐up. In as many as 10% of cases, testosterone levels even further decreased. Of clinical relevance, the higher the burden of comorbid conditions at presentation, the lower the probability of testosterone levels recovery over time.

An overview of sex hormones in relation to SARS-CoV-2 infection

Aim: Sex differences in COVID-19 outcomes might be explained from a sex hormones (SexHs) perspective. Materials & methods: PubMed, Scopus, Web of Science, EMBASE and Google Scholar were searched up to March 2021. Results: Based on the literature review, the crosstalk between SexHs (estrogens, progesterone and testosterone), their receptors (estrogen α and β, androgen, and progesterone) and the immune system shaped the sex-related differences in immune responses against COVID-19. Differential production of SexHs over the lifespan (during pregnancy, reproductive years, menopause and andropause) and over different seasons may result in disparities in body response toward COVID-19. Moreover, SexHs-specific differences might affect vaccine efficacy and response to treatment. Conclusion: The roles of SexHs need to be considered in vaccine development and even treatment of COVID-19.

Novel inhibitors of the main protease enzyme of SARS-CoV-2 identified via molecular dynamics simulation-guided in vitro assay

For the COVID-19 pandemic caused by SARS-CoV-2, there are currently no effective drugs or vaccines to treat this coronavirus infection. In this study, we focus on the main protease enzyme of SARS-CoV-2, 3CLpro, which is critical for viral replication. We employ explicit solvent molecular dynamics simulations of about 150 compounds docked into 3CLpro's binding site and that had emerged as good main protease ligands from our previous in silico screening of over 1.2 million compounds. By incoporating protein dynamics and applying a range of structural descriptors, such as the ability to form specific contacts with the catalytic dyad residues of 3CLpro and the structural fluctuations of the ligands in the binding site, we are able to further refine our compound selection. Fourteen compounds including estradiol shown to be the most promising based on our calculations were procured and screened against recombinant 3CLpro in a fluorescence assay. Eight of these compounds have significant activity in inhibiting the SARS-CoV-2 main protease. Among these are corilagin, a gallotannin, and lurasidone, an antipsychotic drug, which emerged as the most promising natural product and drug, respectively, and might thus be candidates for drug repurposing for the treatment of COVID-19. In addition, we also tested the inhibitory activity of testosterone, and our results reveal testosterone as possessing moderate inhibitory potency against the 3CLpro enzyme, which may thus provide an explanation why older men are more severely affected by COVID-19.

Modeling the Contribution of Male Testosterone Levels to the Duration of Positive COVID Testing among Hospitalized Male COVID-19 Patients

Background: A growing body of evidence is emerging suggesting testosterone can affect all cells involved in the immune response to both bacterial and viral infections, and the testosterone effect on the immune response could explain the greater susceptibility of men to infections including COVID-19. We aimed to explore the predictive role of male serum total testosterone (TT) levels on the time till viral negativity testing among hospitalized COVID-19 patients. Methods: The univariate effect of risk factors for the duration of COVID-19 viral positivity was evaluated using the log-rank test and Kaplan-Meier estimates. A multivariable Cox regression model was developed to test the role of TT levels and the subsequent odds for shorter viral positivity intervals. Results: Increasing serum TT levels and the need for an oxygen administration strategy were independently predictive for respectively reduced and increased days to negativization (Hazard Ratio [HR]: 1.39, 95% CI: 0.95-2.03 and HR: 0.19, 95% CI: 0.03-1.18). Conclusion: Baseline higher TT levels for male COVID-19 patients at hospital admission are associated with shorter durations of positive COVID-19 testing and thus viral clearance. Our preliminary findings might play a relevant to help pandemic control strategies if these will be verified in future larger multicentric and possibly randomized trials.

Sex-based differences in severity and mortality in COVID-19

The current coronavirus disease (COVID‐19) pandemic caused by novel severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) has a male bias in severity and mortality. This is consistent with previous coronavirus pandemics such as SARS‐CoV and MERS‐CoV, and viral infections in general. Here, we discuss the sex‐disaggregated epidemiological data for COVID‐19 and highlight underlying differences that may explain the sexual dimorphism to help inform risk stratification strategies and therapeutic options.

Sex- or Gender-specific Differences in the Clinical Presentation, Outcome, and Treatment of SARS-CoV-2

This review describes the sex and gender differences in COVID-19 presentation, treatment, and outcomes. We discuss the differences between the sexes in susceptibility to infection, the role of sex chromosomes on the body's immunologic response and the influence of hormones on the body's response to the virus. Additionally, the sex differences in clinical and laboratory presentation, complications of infection and outcomes, as well as differences in response to treatment and prevention are reviewed.

Testosterone target therapy: focus on immune response, controversies and clinical implications in patients with COVID-19 infection

The pandemic acute respiratory syndrome coronavirus 2 (SARS-CoV-2) named COVID-19 is causing a severe health emergency, and an individual's hormonal milieu may play an important role in both susceptibility to infection and severity of clinical course. We analyzed the role of testosterone in the immune response, and we hypothesized possible mechanisms to explain the high incidence of COVID-19 infection and a worse clinical course in elderly male patients. Testosterone may impair the immune response, and this effect could explain the greater susceptibility of men to infection. Transmembrane serine protease 2 (TMPRSS2) plays a crucial role in the entry of the virus into the respiratory epithelial cells, leading to COVID-19 disease. It is crucial to emphasize that testosterone levels and chemical castration (e.g. by androgen deprivation therapy for prostate cancer) may have contrasting roles in the phases of COVID-19 infection. Whereas low testosterone levels may be protective against the initial susceptibility (due to a restoration of immunological functions and a block of TMPRSS2), low testosterone may stimulate a worse clinical course in the advanced COVID-19 infection as it could exacerbate or activate the cytokine storm. If testosterone levels play these different roles, it is necessary to carefully identify patients for any indicated testosterone manipulation.

Role of testosterone in COVID-19 patients - A double-edged sword?

COVID-19 affects males twice as frequently as females with significantly increased severity and mortality. Current data suggest a direct correlation between the lower level of serum testosterone, inflammatory cytokines, disease severity, and poor clinical outcomes among male patients with COVID-19. The gradual decline in total and free testosterone levels has a direct correlation with serious pulmonary complications requiring advanced care (ICU, ventilators, ECMO, etc.). SARS-CoV-2 utilizes Angiotensin-Converting Enzyme II (ACE2) for entry in the host cell, and Transmembrane Protease, Serine 2 (TMPRSS2) to prime spike protein of SARS-CoV-2. Testosterone induces ACE-2 expression, a critical pulmonary protective enzyme. Low testosterone levels in males have a direct correlation with the high probability of ICU admission and the worse disease outcome (ARDS, duration of ICU stay, mortality). On the contrary, however, high testosterone levels can lead to thrombosis which is also one of the fatal manifestations in COVID-19 patients. A critical evaluation of the serum testosterone and its relevance to COVID-19 is warranted to re-evaluate strategies to effectively triage, prioritize, and manage high-risk patients for ICU admission, survival outcomes, targeted solutions, and operational algorithms.