scholarly journals Analog-Based Free Testosterone Test Results Linked to Total Testosterone Concentrations, Not Free Testosterone Concentrations

2008 ◽  
Vol 54 (3) ◽  
pp. 512-516 ◽  
Author(s):  
Kristofer S Fritz ◽  
Alastair J S McKean ◽  
Jerald C Nelson ◽  
R Bruce Wilcox
Keyword(s):  
Serum Proteins ◽  
Equilibrium Dialysis ◽  
Serum Testosterone ◽  
Free Testosterone ◽  
Sex Hormone Binding Globulin ◽  
Normal Male ◽  
Total Testosterone ◽  
Test Results ◽  
Experimental Conditions ◽  
Serum Free

Abstract Background: Analog-based free testosterone test results, sex hormone binding globulin (SHBG) concentrations, and total testosterone concentrations are somehow related. This study used new experiments to clarify these relationships. Methods: An analog-based free testosterone immunoassay and a total testosterone immunoassay were applied to well-defined fractions of serum testosterone. First, they were applied to the 2 fractions (retentate and dialysate) of normal male serum obtained by equilibrium dialysis. Second, they were applied to covaried concentrations of SHBG and total testosterone. Third, they were applied to decreasing concentrations of SHBG and protein-bound testosterone, offset by increasing concentrations of protein-free testosterone, while total testosterone was held constant. Results: The analog-based free testosterone assay and the total testosterone assay detected and reported serum testosterone test results from serum retentate, whereas neither assay detected the free testosterone in serum dialysate. Test results reported by the analog-based free testosterone assay followed varied concentrations of SHBG and total testosterone. When total testosterone was held constant, however, analog-based free testosterone test results did not follow varied concentrations of serum proteins or of free testosterone. Conclusion: An analog-based free testosterone immunoassay reported free testosterone test results that were related to total testosterone concentrations under varied experimental conditions. This alleged free testosterone assay did not detect serum free testosterone (the test results it reported were nonspecific) and should not be used for this purpose.

Simultaneous determination of free testosterone and testosterone bound to non-sex-hormone-binding globulin by equilibrium dialysis

1993 ◽  
Vol 39 (6) ◽  
pp. 938-941 ◽  
Author(s):  
A Barini ◽  
I Liberale ◽  
E Menini
Keyword(s):  
Simultaneous Determination ◽  
Equilibrium Dialysis ◽  
Free Testosterone ◽  
Sex Hormone ◽  
Sex Hormone Binding Globulin ◽  
Hormone Binding ◽  
Experimental Conditions ◽  
Normal Men ◽  
Fractional Distribution

Abstract We describe a procedure based on equilibrium dialysis that allows the simultaneous determination of free testosterone and testosterone bound to non-sex-hormone-binding globulin (non-SHBG) in plasma. After saturating SHBG with 5 alpha-dihydrotestosterone (DHT) according to a technique recently described, the percentage of free testosterone in the treated and the untreated samples is measured by equilibrium dialysis with use of a semiautomated instrument that allows rigorous standardization of the experimental conditions. The present method is simpler and faster than the previously described technique in which, after the saturation of SHBG with DHT, the unbound fractions were measured by centrifugal ultrafiltration dialysis. The method is also reproducible and suited for the analysis of a large number of samples. The technique has been applied to the determination of the fractional distribution of testosterone in plasma pools from normally menstruating, pregnant, and postmenopausal women and from normal men.

Decrease in serum testosterone concentration during treatment with tetracycline

1983 ◽  
Vol 103 (2) ◽  
pp. 269-272 ◽  
Author(s):  
M. O. Pulkkinen ◽  
J. Mäenpää
Keyword(s):  
Binding Capacity ◽  
Serum Testosterone ◽  
Free Testosterone ◽  
Sex Hormone Binding Globulin ◽  
Total Testosterone ◽  
Serum Concentrations ◽  
Hormone Binding ◽  
Testosterone Concentration ◽  
Tetracycline Treatment ◽  
Cessation Of Treatment

Abstract. Serum concentrations of testosterone and the binding capacity of sex hormone binding globulin (SHBG) were measured on 2 days immediately preceding tetracycline treatment, on 3 days of treatment and on 2 days immediately after cessation of treatment. On the treatment days serum mean testosterone concentrations were significantly lower than on the control days (17 ± 0.9 vs 21 ± 0.8 nmol/l, P < 0.01). There were no differences in the SHBG. The 'free testosterone index' behaved like the total testosterone.

In women, no significant variances of calculated free testosterone (cFT) are observed when a fixed value of albumin (Alb: 4.3 g/dL) is used instead of measured albumin values

2014 ◽  
Vol 20 (3) ◽  
Author(s):  
Dinamarie Garcia-Banigan ◽  
Andre Guay ◽  
Abdul Traish ◽  
Gheorghe Doros ◽  
John Gawoski
Keyword(s):  
Equilibrium Dialysis ◽  
Free Testosterone ◽  
Sex Hormone Binding Globulin ◽  
Total Testosterone ◽  
Hormone Binding ◽  
R Software ◽  
Significant Variance ◽  
Clinical Evaluations ◽  
Data Points ◽  
Two Measures

AbstractCalculated free testosterone (cFT) is determined from the values of total testosterone (TT), sex hormone binding globulin (SHBG), and albumin (Alb) using mathematical formulae. We evaluated any potential cFT variance when determined with fixed Alb (4.3 g/dL) compared to measured Alb, and the point at which low SHBG and Alb combinations produced significant cFT variance.We analyzed 2050 data points in 1222 women. cFT values with fixed vs. the actual measured Alb values were evaluated and contrasted. cFT levels were determined theoretically for all possible combinations of TT, SHBG, and Alb.Agreement between the two measures was assessed with Lin’s concordance coefficient. Statistical analyses were performed using R software version 2.12.1.Mean Alb was 4.05±0.30 g/dL. Mean SHBG 73.0±53.3 nmol/L. A fixed Alb of 4.3 g/dL produced no significant variance for most evaluations of cFT. The accuracy decreased with Alb ≤3.5 g/dL in combination with SHBG ≤30 nmol/L and exists in 1.0% of the samples.A fixed Alb of 4.3 g/dL is acceptable for most clinical evaluations. If Alb is ≤3.5 g/dL, along with SHBG ≤30 nmol/L, the variance increases and a free testosterone (FT) measurement by equilibrium dialysis is warranted for better accuracy.

scholarly journals Prevalence and Influence of Diagnostic Criteria in the Assessment of Hypogonadism in Intrathecal Opioid Therapy Patients

2013 ◽  
Vol 1;16 (1;1) ◽  
pp. 9-14 ◽  
Author(s):  
Rui V. Duarte
Keyword(s):  
Diagnostic Criteria ◽  
Alternative Assessment ◽  
Serum Testosterone ◽  
Free Testosterone ◽  
Opioid Therapy ◽  
Sex Hormone Binding Globulin ◽  
Total Serum ◽  
Total Testosterone ◽  
Bioavailable Testosterone

Background: Hypogonadism is frequently diagnosed based on total testosterone (TT) levels alone. However, 99% of testosterone is bound to the sex hormone-binding globulin (SHBG) with only 1% free testosterone. Alternative assessment methods consist of assay of free testosterone (FT) or bioavailable testosterone (BT) by equilibrium dialysis, calculation of FT and BT through the Vermeulen equations, and calculation of the free androgen index (FAI). Objectives: The aim of this study was to investigate the prevalence of hypogonadism in male chronic non-cancer pain patients undertaking long-term intrathecal opioid therapy and the existence of diagnostic discrepancies according to the criteria used. Study design: Prospective observational study. Setting: Department of Pain Management, Russells Hall Hospital, Dudley, United Kingdom. Methods: Twenty consecutive male patients undertaking long-term intrathecal opioid therapy had the gonadal axis evaluated by assays of luteinising hormone (LH), follicle stimulating hormone (FSH), TT, SHBG and by calculating the FT, BT and FAI. Results: Hypogonadism was present in 17 (85%) of the patients based on TT; 17 (85%) according to FT and BT calculations; and 14 (70%) when calculating FAI. Based on either TT or FT being low or borderline/low, 19 (95%) of the investigated patients were biochemically hypogonadal. Significant differences were observed between diagnosis based on FT and FAI (P < 0.05). No significant differences were observed between diagnosis based on TT and FT (P = 0.40) or TT and FAI (P = 0.20). Conclusion: Hypogonadism is common in patients undertaking intrathecal opioid therapy for the management of chronic non-malignant pain; however, diagnostic criteria can influence the diagnosis of this side effect. The assessment of the hypothalamic-pituitarygonadal axis should include evaluation of total serum testosterone, free testosterone, or bioavailable testosterone. Key words: Diagnostic criteria, free testosterone, hypogonadism, implantable drug delivery systems, total serum testosterone

Effects of Androstenedione-Herbal Supplementation on Serum Sex Hormone Concentrations in 30- to 59-Year-old Men

2001 ◽  
Vol 71 (5) ◽  
pp. 293-301 ◽  
Author(s):  
Gregory A. Brown ◽  
Matthew D. Vukovich ◽  
Emily R. Martini ◽  
Marian L. Kohut ◽  
Warren D. Franke ◽  
...  
Keyword(s):  
Specific Antigen ◽  
Serum Testosterone ◽  
Free Testosterone ◽  
Nutritional Supplement ◽  
Total Testosterone ◽  
Tribulus Terrestris ◽  
Herbal Products ◽  
Serum Free ◽  
Supplementation Period ◽  
Old Men

The effectiveness of a nutritional supplement designed to enhance serum testosterone concentrations and prevent the formation of dihydrotestosterone and estrogens from the ingested androgens was investigated in healthy 30- to 59-year old men. Subjects were randomly assigned to consume DION (300 mg androstenedione, 150 mg dehydroepiandrosterone, 540 mg saw palmetto, 300 mg indole-3-carbinol, 625 mg chrysin, and 750 mg Tribulus terrestris per day; n = 28) or placebo (n = 27) for 28 days. Serum free testosterone, total testosterone, androstenedione, dihydrotestosterone, estradiol, prostate-specific antigen (PSA), and lipid concentrations were measured before and throughout the 4-week supplementation period. Serum concentrations of total testosterone and PSA were unchanged by supplementation. DION increased (p < 0.05) serum androstenedione (342%), free testosterone (38%), dihydrotestosterone (71%), and estradiol (103%) concentrations. Serum HDL-C concentrations were reduced by 5.0 mg/dL in DION (p < 0.05). Increases in serum free testosterone (r2 = 0.01), androstenedione (r2 = 0.01), dihydrotestosterone (r2 = 0.03), or estradiol (r2 = 0.07) concentrations in DION were not related to age. While the ingestion of androstenedione combined with herbal products increased serum free testosterone concentrations in older men, these herbal products did not prevent the conversion of ingested androstenedione to estradiol and dihydrotestosterone.

Screening for Hypogonadism in Primary Healthcare: How to do this Effectively

2018 ◽  
Vol 126 (03) ◽  
pp. 176-181
Author(s):  
Mark Livingston ◽  
Richard Jones ◽  
Geoff Hackett ◽  
Gemma Donnahey ◽  
Gabriela Moreno ◽  
...  
Keyword(s):  
Primary Healthcare ◽  
Testosterone Level ◽  
Serum Testosterone ◽  
Free Testosterone ◽  
Sex Hormone Binding Globulin ◽  
Serum Prolactin ◽  
Total Testosterone ◽  
Male Hypogonadism ◽  
The Uk ◽  
Secondary Hypogonadism

Abstract Background Testosterone, the most important androgen produced by the testes, plays an integral role in male health. Testosterone levels are increasingly being checked in primary healthcare as awareness of the risks of male hypogonadism grows. Aim To investigate what tests are performed to screen for hypogonadism and to exclude secondary hypogonadism. Design and Setting All participants attended general practices in the UK. Methods Data search was performed using the EMIS® clinical database (provider of the majority of GP operating systems in Cheshire). The anonymised records of male patients aged 18–98 years who had undergone a check of serum testosterone during a 10-year period were analysed. Results Overall screening rate was 4.3%. Of 8 788 men with a testosterone result, 1 924 men (21.9%) had a total testosterone level <10 nmol/L. Just 689 of 8 788 men (7.8%) had a sex hormone-binding globulin (SHBG) result, corresponding to 30.5% of those potentially hypogonadal. Estimated free testosterone was negatively associated with BMI (Spearman’s rho -0.2, p<0.001) as was total testosterone in the over 50 s. Of 1 924 potentially hypogonadal men with a serum testosterone <10 nmol/L, 588 of 1 924 (30.6%) had a check of serum prolactin. 46.3% and 41.7% had LH and FSH measured, respectively. Only 19.1% of 1 924 men with a hypogonadal total testosterone level were subsequently put on testosterone replacement. The percentage of men in the relatively socially disadvantaged category was similar for both eugonadal and hypogonadal men with a much higher rate of screening for hypogonadism in more socially advantaged men. Conclusions Screening in primary healthcare identified a significant minority of men who had potential hypogonadism. Interpretation of a low serum testosterone requires measurement of serum prolactin, LH and FSH in order to rule out secondary hypogonadism. We suggest that this becomes part of routine screening with a balanced screening approach across the socioeconomic spectrum.

Simultaneous Determination of Free Testosterone and Testosterone Bound to Non-Sex-Hormone-Binding Globulin by Equilibrium Dialysis

1993 ◽  
Vol 39 (6) ◽  
pp. 936-941 ◽  
Author(s):  
Angela Barini ◽  
Italiana Liberale ◽  
Edoardo Menini
Keyword(s):  
Simultaneous Determination ◽  
Equilibrium Dialysis ◽  
Free Testosterone ◽  
Sex Hormone ◽  
Sex Hormone Binding Globulin ◽  
Hormone Binding ◽  
Experimental Conditions ◽  
Normal Men ◽  
Fractional Distribution

Abstract We describe a procedure based on equilibrium dialysis that allows the simultaneous determination of free testosterone and testorerone bound to non-sex-hormone-binding globulin (non-SHBG) in plasma. After saturating SHBG with 5α-dihydrotestosterone (DHT) according to a technique recently described, the percentage of free testosterone in the treated and the untreated samples is measured by equilibrium dialysis with use of a semiautomated instrument that allows rigorous standardization of the experimental conditions. The present method is simpler and faster than the previously described technique in which, after the saturation of SHBG with DHT, the unbound fractions were measured by centrifugal ultrafiltration dialysis. The method is also reproducible and suited for the analysis of a large number of samples. The technique has been applied to the determination of the fractional distribution of testosterone in plasma pools from normally menstruating, pregnant, and postmenopausal women and from normal men.

scholarly journals Validity of free testosterone calculation in pregnant women

2019 ◽  
Vol 8 (6) ◽  
pp. 672-679
Author(s):  
M P Schuijt ◽  
C G J Sweep ◽  
R van der Steen ◽  
A J Olthaar ◽  
N M M L Stikkelbroeck ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Equilibrium Dialysis ◽  
Free Testosterone ◽  
Sex Hormone Binding Globulin ◽  
Total Testosterone ◽  
Testosterone Concentration ◽  
Testosterone Levels ◽  
Liquid Chromatography Tandem Mass ◽  
Highly Correlated ◽  
Design And Methods

Objective Increased maternal testosterone concentration during pregnancy may affect the fetus. Therefore it is clinically relevant to have a quick and reliable method to determine free testosterone levels. Current calculators for free testosterone are suspected to perform poorly during pregnancy due to suggested competition between high levels of estradiol and free (bio-active) testosterone for sex hormone-binding globulin (SHBG) binding. Therefore, it is claimed that reliable calculation of free testosterone concentration is not possible. However, recent evidence on SHBG-binding sites questions the estradiol effect on the testosterone-SHBG binding during pregnancy. In this study, we investigated whether the free testosterone concentration can be calculated in pregnant women. Design and methods Free testosterone was measured with a specially developed equilibrium dialysis method combined with liquid chromatography tandem mass spectrometry (LC-MS/MS). Free testosterone was also calculated with the formulas of Vermeulen et al. and Ross et al. Results Total and free testosterone measured in healthy men and women were in good agreement with earlier reports. In pregnant women, total testosterone values were higher than in non-pregnant women, whereas free testosterone values were comparable. Calculated free testosterone levels in pregnant women were highly correlated, but marginally higher, compared to measured free testosterone levels. Conclusions We developed an equilibrium dialysis–LC-MS/MS method for the measurement of free testosterone in the low range of pregnant and non-pregnant women. Although during pregnancy total testosterone is increased, this is not the case for free testosterone. The free testosterone formulas perform well in pregnant women.

A simple method for estimating equilibrium constants for serum testosterone binding resulting in an optimal free testosterone index for use in elderly men

2005 ◽  
Vol 43 (6) ◽  
Author(s):  
H. Alec Ross ◽  
Eric J. Meuleman ◽  
Fred C. G. J. Sweep
Keyword(s):  
Equilibrium Constants ◽  
Reference Method ◽  
Serum Testosterone ◽  
Free Testosterone ◽  
Sex Hormone Binding Globulin ◽  
Elderly Men ◽  
Simple Method ◽  
Serum Free ◽  
Healthy Elderly ◽  
Affinity Constants

AbstractAn algorithm was developed to evaluate equilibrium constants for testosterone (Te) and sex hormone-binding globulin (SHBG) or albumin from serum free testosterone (FTe) measurements performed in a panel of 30 healthy elderly men by means of a near-reference method, i.e., symmetric dialysis (affinity constants: SHBG-Te, 1.13×10

scholarly journals Hypogonadism and liver fibrosis in HIV-infected patients

2021 ◽  
Author(s):  
E. Quiros-Roldan ◽  
T. Porcelli ◽  
L. C. Pezzaioli ◽  
M. Degli Antoni ◽  
S. Paghera ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Univariate Analysis ◽  
Free Testosterone ◽  
Sex Hormone Binding Globulin ◽  
Total Testosterone ◽  
Cross Sectional ◽  
Pituitary Dysfunction ◽  
Consequent Reduction ◽  
Secondary Hypogonadism ◽  
The Relationship

Abstract Purpose Hypogonadism is frequent in HIV-infected men and might impact on metabolic and sexual health. Low testosterone results from either primary testicular damage, secondary hypothalamic-pituitary dysfunction, or from liver-derived sex-hormone-binding-globulin (SHBG) elevation, with consequent reduction of free testosterone. The relationship between liver fibrosis and hypogonadism in HIV-infected men is unknown. Aim of our study was to determine the prevalence and type of hypogonadism in a cohort of HIV-infected men and its relationship with liver fibrosis. Methods We performed a cross-sectional retrospective study including 107 HIV-infected men (median age 54 years) with hypogonadal symptoms. Based on total testosterone (TT), calculated free testosterone, and luteinizing hormone, five categories were identified: eugonadism, primary, secondary, normogonadotropic and compensated hypogonadism. Estimates of liver fibrosis were performed by aspartate aminotransferase (AST)-to-platelet ratio index (APRI) and Fibrosis-4 (FIB-4) scores. Results Hypogonadism was found in 32/107 patients (30.8%), with normogonadotropic (10/107, 9.3%) and compensated (17/107, 15.8%) being the most frequent forms. Patients with secondary/normogonadotropic hypogonadism had higher body mass index (BMI) (p < 0001). Patients with compensated hypogonadism had longer HIV infection duration (p = 0.031), higher APRI (p = 0.035) and FIB-4 scores (p = 0.008), and higher HCV co-infection. Univariate analysis showed a direct significant correlation between APRI and TT (p = 0.006) and SHBG (p = 0.002), and between FIB-4 and SHBG (p = 0.045). Multivariate analysis showed that SHBG was independently associated with both liver fibrosis scores. Conclusion Overt and compensated hypogonadism are frequently observed among HIV-infected men. Whereas obesity is related to secondary hypogonadism, high SHBG levels, related to liver fibrosis degree and HCV co-infection, are responsible for compensated forms.

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