Background: The pandemic of new severe acute respiratory syndrome (SARS) due to coronavirus (CoV) 2 (SARS-CoV-2) has stressed the importance of effective diagnostic and prognostic biomarkers of clinical worsening and mortality. Epidemiological data showing a differential impact of SARS-CoV-2 infection on women and men have suggested a potential role for testosterone (T) in determining gender disparity in the SARS-CoV-2 clinical outcomes. Objectives: To estimate the association between T level and SARS-CoV-2 clinical outcomes (defined as conditions requiring transfer to higher or lower intensity of care or death) in a cohort of patients admitted in the respiratory intensive care unit (RICU). Materials and methods: A consecutive series of 31 male patients affected by SARS-CoV-2 pneumonia and recovered in the respiratory intensive care unit (RICU) of the "Carlo Poma" Hospital in Mantua were analyzed. Several biochemical risk factors (ie, blood count and leukocyte formula, C-reactive protein (CRP), procalcitonin (PCT), lactate dehydrogenase (LDH), ferritin, D-dimer, fibrinogen, interleukin 6 (IL-6)) as well as total testosterone (TT), calculated free T (cFT), sex hormone-binding globulin (SHBG), and luteinizing hormone (LH) were determined. Results: Lower TT and cFT were found in the transferred to ICU/deceased in RICU group vs groups of patients transferred to IM or maintained in the RICU in stable condition. Both TT and cFT showed a negative significant correlation with biochemical risk factors (ie, the neutrophil count, LDH, and PCT) but a positive association with the lymphocyte count. Likewise, TT was also negatively associated with CRP and ferritin levels. A steep increase in both ICU transfer and mortality risk was observed in men with TT < 5 nmol/L or cFT < 100 pmol/L. How to cite this article: RastrelliG, Di Stasi V, Inglese F, et al. Low testosterone levels predict clinical adverse outcomes in SARS-CoV-2 pneumonia patients.

By real-time RT-PCR and Western blot analysis, we found that phosphodiesterase type 5 (PDE5) mRNA and protein abundance was several fold higher in human male than in female reproductive tracts. The highest mRNA level (>1 x 10(7) molecules/microg total RNA) was detected in human corpora cavernosa (CC), where PDE5 protein was immunolocalized in both muscular and endothelial compartment. The possible role of androgens in regulating PDE5 expression was studied using a previously established rabbit model of hypogonadotropic hypogonadism. In this model, hypogonadism reduced, and testosterone (T) supplementation restored, CC PDE5 gene and protein expression. In addition, T supplementation completely rescued and even enhanced cyclic GMP conversion to metabolites, without changing IC(50) for sildenafil (IC(50) = 2.16 +/- 0.62 nm). In control CC strips, sildenafil dose-dependently increased relaxation induced by electrical field stimulation, with EC(50) = 3.42 +/- 1.7 nm. Hypogonadism reduced, and T increased, sildenafil effect on electrical field stimulation, again without changing their relative EC(50) values. CC sensitivity to the NO-donor NCX4040 was greater in hypogonadal rabbit strips than in control or T-treated counterparts. Moreover, sildenafil enhanced NCX4040 effect in eugonadal rabbit strips but not in hypogonadal ones. This suggests that androgens up-regulate PDE5 in rabbit penis. We also measured PDE5 gene expression and metabolic activity in human CC from male-to-female transsexual individuals, chronically treated with estrogens and cyproterone acetate. Comparing the observed values vs. eugonadal controls, PDE5 mRNA, protein, and functional activity were significantly reduced. In conclusion, we demonstrated, for the first time, that androgens positively regulate PDE5, thus providing a possible explanation about the highest abundance of this enzyme in male genital tract.

Introduction Metabolic syndrome (MetS) is a clustering of cardio-metabolic risk factors (hyperglycemia, hypertension, dyslipidemia, visceral fat accumulation) that is also associated with hypogonadism and erectile dysfunction (ED). Aim To clarify the relationships among MetS, hypogonadism, and ED, we developed an animal model of MetS. Methods Male rabbits fed a high-fat diet (HFD), with or without testosterone (T) supplementation, were compared with control rabbits (fed a standard chow) and with rabbits made hypogonadal by a single injection of a long-acting GnRH-analog, triptorelin. Main Outcome Measures Evaluation of metabolic disturbances (plasma glucose, cholesterol, triglycerides, testosterone, LH, FSH level, glucose tolerance, mean arterial pressure, visceral fat accumulation), and corpora cavernosa (CC) relaxant capacity (in vitro contractility study) in HFD animals as compared with control, GnRH analog-treated rabbits, and T-supplemented HFD rabbits. Results HFD rabbits showed all the features of MetS. HFD induced hypogonadotropic hypogonadism is characterized by a reduction of plasma T, FSH, LH levels, testis and seminal vesicles weight, and testicular steroidogenic enzymes. Such a phenotype is similar to that induced by triptorelin administration. A reduced GnRH immunopositivity in hypothalamus suggests a central origin of HFD-related hypogonadism. HFD also induced penile alterations, as demonstrated by a reduction of acetylcholine-and electrical field stimulation-induced CC relaxation, hyper-responsiveness to the NO donor, SNP, and unresponsiveness to PDE5 inhibitors. Similar penile alterations were observed in triptorelin treated rabbit. In HFD, as well as in triptorelin treated rabbits, PDE5 and eNOS mRNA expression quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) were significantly decreased. T administration prevented almost all penile alterations observed in HFD rabbits. T treatment dramatically reduced HFD-induced visceral obesity, partially ameliorating also the metabolic profile. Conclusion We have developed an animal model of MetS associated with hypogonadotropic hypogonadism and penile alterations including unresponsiveness to PDE5 inhibitors. T supplementation was able to partially revert HFD-induced phenotype.

Background Weight loss is a milestone in the prevention of chronic diseases associated with high morbility and mortality in industrialized countries. Very-low calorie ketogenic diets (VLCKDs) are increasingly used in clinical practice for weight loss and management of obesity-related comorbidities. Despite evidence on the clinical benefits of VLCKDs is rapidly emerging, some concern still exists about their potential risks and their use in the long-term, due to paucity of clinical studies. Notably, there is an important lack of guidelines on this topic, and the use and implementation of VLCKDs occurs vastly in the absence of clear evidence-based indications. Purpose We describe here the biochemistry, benefits and risks of VLCKDs, and provide recommendations on the correct use of this therapeutic approach for weight loss and management of metabolic diseases at different stages of life.