Reference ranges for serum and salivary testosterone in young men of Mediterranean region

Abstract

Background and aims: The interassay variability found in the measurement of testosterone (T) levels warrants the need for laboratories to validate their methods to establish trustworthy cut-off points for diagnosis of male hypogonadism. The aims of this study were to validate measurement of total T (TT) at our laboratory in order to obtain reference ranges for TT, calculated free T (CFT), calculated bioavailable T (CBT), and salivary T (ST) in healthy young men from the Mediterranean region, and to evaluate the potential clinical value of ST by establishing its correlation with serum T. Methods: An observational, cross-sectional study with sequential sampling. Inclusion criteria: men aged 18---30 years with body mass index (BMI) < 30. Exclusion criteria: chronic diseases, hepatic insufficiency or use of drugs altering circulating T levels. Main outcome measures TT (chemiluminescent immunoassay UniCell DXI 800 [Access T Beckman Coulter]), CFT and CBT (Vermeulen's formula), and ST (radioimmunoassay for serum TT modified for saliva [Coat-A-Count, Siemens]). Descriptive statistical analyses and correlation by Spearman's rho (SPSS 19.0 Inc., Chicago) were used. Results: One hundred and twenty-one subjects aged 24 ± 3.6 years with BMI 24 ± 2.5 kg/m 2 were enrolled. Hormone study: TT, 19 ± 5.5 nmol/L (reference range [rr.] 9.7---33.3); CFT, 0.38 nmol/L (rr. 0.22---0.79); CBT, 9.7 nmol/L (rr. 4.9---19.2); and ST, 0.35 nmol/L (rr. 0.19---0.68). Correlation between ST and CFT was 0.46. Testosterona; Valores de referencia; Área mediterránea; Hipogonadismo masculino Valores de referencia de testosterona sérica y salivar en varones jóvenes del área Mediterránea ResumenAntecedentes y objetivos: La variabilidad interensayo existente en la determinación de testosterona (T) justifica la necesidad de que cada laboratorio valide su método y establezca puntos de corte fiables para el diagnóstico del hipogonadismo masculino. Los objetivos del estudio fueron validar la determinación de T total (TT) en nuestro laboratorio para obtener los valores de referencia de TT, T libre calculada (TLC), T biodisponible calculada (TBC) y T salivar (TS) en varones jóvenes sanos del área mediterránea y evaluar la posible utilidad clínica de la TS. Material y métodos: Estudio observacional transversal. Muestreo secuencial. Criterios de inclusión: varones, 18---30 años de edad, índice de masa corporal (IMC) < 30. Criterios de exclusión: enfermedades crónicas, insuficiencia hepática o uso de medicamentos que alteran las concentraciones circulantes de T. Metodología: TT (inmunoanálisis de quimioluminiscencia UniCell DXI800 [Acces T Beckman Coulter]), TLC y TBC (fórmula de Vermeulen), TS (radioinmunoensayo para TT sérica modificado para la saliva [Coat-A-Count, Siemens]). Análisis estadísticos: descriptivos y correlación rho de Spearman (SPSS 19,0 Inc.,Chicago). Resultados: Se incluyeron 121 individuos de 24 ± 3,6 años e IMC 24 ± 2,5 kg/m 2 . Estudio hormonal TT, 19 ± 5,5 nmol/L (intervalo de confianza 95% 9,7---33,3); TLC, 0,38 nmol/L ([P 2,5 ---P 97,5 ]...

Male pituitary–gonadal axis dysfunction in post‐acute COVID‐19 syndrome—Prevalence and associated factors: A Mediterranean case series

“… a Defined as total testosterone (TT) < 2 ng/ml (6.9 nmol/l) or in those with borderline TT levels 2–4 ng/ml (6.9–13.9 nmol/l) as calculated free testosterone (CFT) <6.36 ng/dl (<0.22 nmol/L), lower than the normal range for healthy young males in our laboratory 13,14 …”

“… Low serum testosterone was defined as total testosterone (TT) < 2 ng/ml (6.9 nmol/L) or in those with borderline TT levels 2–4 ng/ml (6.9–13.9 nmol/l) as a calculated free testosterone (CFT) < 6.36 ng/dl (<0.22 nmol/L), according to the normal range for healthy young males in our laboratory 13,14 . CFT was calculated by determining TT, sex hormone binding globulin (SHBG) and albumin from the equation described by Vermeulen et al 15 Sertoli cell dysfunction, spermatogenesis disruption, was defined as inhibin‐B < 89 pg/ml (89 ng/L), cutoff derived from 2.5 percentile inhibin‐B in a cohort of young men unbiased with regard to fertility 16 .…”

Biological markers of fertility (inhibin‐B) in HIV‐infected men: influence of HIV infection and antiretroviral therapy

“…. Hypogonadism was defined as calculated free testosterone (CFT) < 0.22 nmol/L (< 6.36 ng/dL), lower than the normal range for healthy young men . The concentration of luteinizing hormone (LH) (UI/L; rr 2–11.2 UI/L) was determined by ECLIA (Modular Analytics E170; Roche Diagnostics).…”

Transfer of Topical Testosterone to Subcutaneous Microdialysate, Blood and Saliva in Healthy Young Men

“…Saliva contains the free unbound testosterone which is lipid soluble and can therefore be transferred more rapidly than hydrophilic molecules from blood into saliva by passive diffusion along a concentration gradient. When comparing salivary testosterone with serum free testosterone levels in studies without previous administration of testosterone, correlations of different intensity were found with correlation coefficients ranging from r = 0.46 [15] to r = 0.97 [16]. The reasons for the differences are varied and may be based on different sampling and determination methods of total and free testosterone in saliva and blood such as immunoassays (RIA, ELISA), liquid or gas chromatography with tandem mass spectrometry, or calculation of free testosterone.…”