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. 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 dehydrogenase [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.