scholarly journals The analog free testosterone assay: are the results in men clinically useful?

1998 ◽  
Vol 44 (10) ◽  
pp. 2178-2182 ◽  
Author(s):  
Stephen J Winters ◽  
David E Kelley ◽  
Bret Goodpaster

Abstract Men with low testosterone concentrations are usually hypogonadal. However, because variations in the testosterone transport protein, sex hormone-binding globulin (SHBG), directly influence the total testosterone concentration, confirmation of a low testosterone with a measurement of free testosterone or “bioavailable” testosterone (BAT) is recommended. In the present study, we examined the relationship of SHBG with free testosterone (Coat-A-Count assay, Diagnostic Products) and with BAT in men (n = 29) and women (n = 28) who participated in a study of the metabolic determinants of body composition. As expected, total testosterone was strongly positively correlated with SHBG among men (r = 0.68; P <0.01). Although the BAT was independent of SHBG in men (r = 0.02), SHBG was an important predictor of free testosterone (r = 0. 62; P <0.01). In contrast, in women serum concentrations of total testosterone (r = −0.26; P = 0.17), free testosterone (r = −0.30; P = 0.17), and BAT (r = −0.46; P = 0.013) all tended to be lower with increasing SHBG. Free testosterone was nearly perfectly positively correlated with total testosterone (r = 0.97) in men, among whom free testosterone represented a relatively constant percentage of the total testosterone (0.5–0.65%), and the percentage of free testosterone was unrelated to SHBG. Thus the Coat-A-Count free testosterone concentration in men, like the total testosterone concentration, is determined in part by plasma SHBG. Accordingly, androgen deficiency may be misclassified with this assay in men with low SHBG. Moreover, the previous findings of reduced free testosterone concentrations with hypertension or hyperinsulinemia or as a risk factor for developing type 2 diabetes, conditions in which SHBG is reduced, may have been methodology-related.

1991 ◽  
Vol 129 (3) ◽  
pp. 465-468 ◽  
Author(s):  
M. J. Wheeler ◽  
B. K. Toone ◽  
A. Dannatt ◽  
P. B. C. Fenwick ◽  
S. Brown

ABSTRACT There are several reports which state that male epileptics on anti-convulsant therapy have reduced sexual activity. We and others have shown that, although total testosterone is raised, the free testosterone concentration is reduced in this patient population. This could be a result of an increased metabolic clearance rate (MCR) of testosterone, inadequate secretion of LH to stimulate testosterone synthesis or inappropriately low testosterone production by the Leydig cells. We have examined these possibilities by measuring the MCR of testosterone in 15 male epileptics on anti-convulsant therapy. In this group of patients, the mean LH (9·3±5·9 IU/l) and sex-hormone binding globulin (SHBG) (54·5±22·9 nmol/l) concentrations were significantly greater than those of five normal control subjects (4·7±1·11 IU/l and 26·0 ±7·0 nmol/l respectively). Mean total testosterone concentrations of the two groups were not significantly different but the mean percentage of free testosterone and free testosterone concentration were significantly lower in the patient population (2·06±0·43 vs 2·98±0·27 and 0·56±1·1 vs 0·79±0·7 pmol/l). The MCR of testosterone was significantly lower in the patients (773±322 vs 1354±443 1/day) and showed a positive correlation with the percentage of free testosterone. Therefore, our results suggest that the lowered free testosterone in male epileptics on anti-convulsant therapy is not due to an increased MCR of testosterone. The increased LH concentration suggests primary hypogonadism. This, in turn, could be responsible for low free testosterone levels in the presence of normal testosterone. Journal of Endocrinology (1991) 129, 465–468


1983 ◽  
Vol 103 (2) ◽  
pp. 269-272 ◽  
Author(s):  
M. O. Pulkkinen ◽  
J. Mäenpää

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.


Author(s):  
E. Quiros-Roldan ◽  
T. Porcelli ◽  
L. C. Pezzaioli ◽  
M. Degli Antoni ◽  
S. Paghera ◽  
...  

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.


2007 ◽  
Vol 156 (5) ◽  
pp. 585-594 ◽  
Author(s):  
Bu B Yeap ◽  
Osvaldo P Almeida ◽  
Zoë Hyde ◽  
Paul E Norman ◽  
S A Paul Chubb ◽  
...  

Objective: An age-related decline in serum total and free testosterone concentration may contribute to ill health in men, but limited data are available for men > 70 years of age. We sought to determine the distribution and associations of reduced testosterone concentrations in older men. Design: The Health in Men Study is a community-representative prospective cohort investigation of 4263 men aged ≥ 70 years. Cross-sectional hormone data from 3645 men were analysed. Methods: Early morning sera were assayed for total testosterone, sex hormone binding globulin (SHBG) and LH. Free testosterone was calculated using the Vermeulen method. Results: Mean (± s.d.) serum total testosterone was 15.4 ± 5.6 nmol/l (444 ± 162 ng/dl), SHBG 42.4 ± 16.7 nmol/l and free testosterone 278 ± 96 pmol/l (8.01 ± 2.78 ng/dl). Total testosterone correlated with SHBG (Spearman’s r = 0.6, P < 0.0001). LH and SHBG increased with age (r = 0.2, P < 0.0001 for both). Instead of declining, total testosterone increased marginally (r = 0.04, P = 0.007) whilst free testosterone declined with age (r = −0.1, P < 0.0001). Free testosterone was inversely correlated with LH (r = −0.1, P < 0.0001). In multivariate analyses, increasing age, body mass index (BMI) and LH were associated with lower free testosterone. Conclusions: In men aged 70–89 years, modulation of androgen action may occur via an age-related increase in SHBG and reduction in free testosterone without a decline in total testosterone concentration. Increasing age, BMI and LH are independently associated with lower free testosterone. Further investigation would be required to assess the clinical consequences of low serum free testosterone, particularly in older men in whom total testosterone may be preserved.


Infection ◽  
2020 ◽  
Author(s):  
Letizia Chiara Pezzaioli ◽  
Eugenia Quiros-Roldan ◽  
Simone Paghera ◽  
Teresa Porcelli ◽  
Filippo Maffezzoni ◽  
...  

Abstract Purpose The prevalence of low testosterone and symptoms of hypogonadism in HIV-infected men is still debated. We aimed to estimate the prevalence and type of hypogonadism in HIV-infected males complaining about sexual symptoms, and to evaluate the role of calculated free testosterone (cFT) vs total testosterone (TT) for diagnosis. Furthermore, we evaluated relationship between sex hormone-binding globulin (SHBG), gonadal status and clinical and virologic parameters. Methods We retrospectively evaluated 169 HIV-infected men with sexual symptoms, with TT available. Among them, we selected 94 patients with TT, SHBG, cFT, and luteinizing hormone (LH) available, and classified hypogonadism into overt (low TT and/or low cFT) and compensated (high LH, normal TT and cFT). Comparison was performed by non-parametric Kruskal–Wallis test and Spearman’s correlation was calculated to verify the possible associations. Results Overt and compensated hypogonadism were found in 20.2% and 13.8% of patients, respectively. With reliance on TT alone, only 10.6% of patients would have met diagnosis. SHBG values were elevated in one third of patients, and higher in men with compensated hypogonadism. Significant positive correlation was found between SHBG and HIV infection duration, TT and LH. Conclusion Only a complete hormonal profile can properly diagnose and classify hypogonadism in HIV-infected men complaining about sexual symptoms. TT alone reliance may lead to half of diagnoses missing, while lack of gonadotropin prevents the identification of compensated hypogonadism. This largely comes from high SHBG, which seems to play a central role in the pathogenesis of hypogonadism in this population.


2008 ◽  
Vol 93 (5) ◽  
pp. 1834-1840 ◽  
Author(s):  
Mathis Grossmann ◽  
Merlin C. Thomas ◽  
Sianna Panagiotopoulos ◽  
Ken Sharpe ◽  
Richard J. MacIsaac ◽  
...  

Abstract Context: Low testosterone levels are common in men with type 2 diabetes and may be associated with insulin resistance. Objective: We investigated prevalence of testosterone deficiency and the relationship between testosterone and insulin resistance in a large cohort of men with type 2 and type 1 diabetes. Design: The study was a cross-sectional survey of 580 men with type 2 diabetes and 69 men with type 1 diabetes. A subgroup of 262 men with type 2 diabetes was then reassessed after a median of 6 months. Results: Forty-three percent of men with type 2 diabetes had a reduced total testosterone, and 57% had a reduced calculated free testosterone. Only 7% of men with type 1 diabetes had low total testosterone. By contrast, 20.3% of men with type 1 diabetes had low calculated free testosterone, similar to that observed in type 2 diabetes (age-body mass index adjusted odds ratio = 1.4; 95% confidence interval = 0.7–2.9). Low testosterone levels were independently associated with insulin resistance in men with type 1 diabetes as well as type 2 diabetes. Serial measurements also revealed an inverse relationship between changes in testosterone levels and insulin resistance. Conclusions: Testosterone deficiency is common in men with diabetes, regardless of the type. Testosterone levels are partly influenced by insulin resistance, which may represent an important avenue for intervention, whereas the utility of testosterone replacement remains to be established in prospective trials.


2019 ◽  
Vol 22 (2) ◽  
pp. 127-130
Author(s):  
Galina A. Melnichenko ◽  
Marina V. Shestakova ◽  
Roman V. Rozhivanov

BACKGROUND: Hypogonadism is a common complication in men with type 2 diabetes mellitus (DM), but its prevalence remains unknown. AIMS: To estimate the prevalence of hypogonadism in men with type 2 DM. MATERIALS AND METHODS: Male patients with type 2 DM were enrolled into a single-cohort contemporaneous multicenter non-interventional screening study. The study period was from November 2017 through August 2018. Assessments included total testosterone, luteinizing hormone (LH), sex hormone-binding globulin, HbA1c levels. Levels of free testosterone were calculated by Vermeullen method. RESULTS: TheThe median of age of 400 included men was 56 years [51; 58], total testosterone was 12.3 [9.2; 16.5] nmol/l, free testosterone 270 [217; 334] pmol/l, HbA1c 7,1% [6.1; 8.6]. Hypogonadism was found in 135 men (33.7%). The total testosterone level in that group was 7.9 [6.8; 9.8] nmol/l, and free testosterone 192 [164; 227] pmol/l. In hypogonadism-free men their levels were 15,1 [12,4; 18,6] nmol/l and 311 [270; 364] pmol/l, respectively. In most patients with hypogonadism LH level was low, but within normal ranges, and significantly lower than in men without hypogonadism 3.2 [2.1; 4.7] IU/L vs 3.8 [2.7; 4.9] IU/L, respectively (p=0.007). Most commonly hypogonadism was with normal LH levels (92,6%, median LH level 3.2 [2.2; 4.3] IU/L, p0,001). The frequency of hypogonadism with high LH level (10.2 [9.2; 14.7] IU/L) and low LH level (1.0 [0.6; 1.1] IU/L) was 4.4% and 3.0%, respectively. CONCLUSIONS: The prevalence of hypogonadism in men with type 2 DM was found to be 33.7%. Normal levels of LH are typical for this type of patients with hypogonadism.


Author(s):  
Dmitry S. Kuzichkin ◽  
Svetlana A. Chistokhodova

Introduction. Evaluation of the relationship between hemostasis and steroid hormones is an important area of research due to the high risk of hemorrhages and, especially, thromboembolic complications in their abnormal state, but this has not been practically studied in long-term isolation. The aim of study was to study the relationship between hemostasis and steroid hormones of participants in 120 - day isolation in a hermetic object. Materials and methods. Before, 3 times during and on the 7th day after 120-day isolation, venous blood samples were taken from the international crew members (3 men and 3 women) to measure the concentrations of cortisol, aldosterone, total testosterone, sex hormone-binding globulin, determine the free androgen index, and evaluate 9 hemostasis indicators. Results. In conditions of long-term isolation, the relationship of steroid hormones with the activity of the procoagulant hemostasis link and the state of the plasmin and antiplasmin systems was revealed. Conclusions. Anthropometric and hormonal parameters in isolation were significantly correlated with the dynamics of the international normalized ratio, activated partial thromboplastin time, fibrinogen, antithrombin III, plasminogen, α2-antiplasmin and protein C, and the gender of the subjects significantly affected only the activity of α2-antiplasmin, and the age of volunteers and the dynamics of testosterone had the most pronounced effect on hemostasis in isolation.


Author(s):  
Aleksandra Rył ◽  
Aleksandra Szylińska ◽  
Alina Jurewicz ◽  
Andrzej Bohatyrewicz ◽  
Tomasz Miazgowski ◽  
...  

Introduction: The purpose of this study was to analyze the relationship between the parameters of bone turnover and the levels of hormonal parameters, such as total testosterone (TT), bioavailable and free testosterone (FT), and estradiol (E2) in men. Material and methods: The study group included 63 men with testosterone deficiency syndrome (TDS). The control group consisted of 112 patients without TDS. Enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of osteocalcin (OC), parathyroid hormone (PTH), E2, sex hormone binding globulin (SHBG), dehydroepiandrosterone sulphate (DHEAS), insulin (I), Serum CrossLaps (CtX-I), human procollagen I N-terminal peptide (PINP), and TT. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry. Results: The groups with TSD and without TDS differed in terms of the following parameters: body weight (p = 0.001), BMI (p = 0.003), TT (p = 0.001), FT (p = 0.004), bioavailable testosterone (p = 0.001), E2 (p = 0.003), SHBG (p = 0.003), and PINP (p = 0.004). In the group without TDS, higher PINP levels were accompanied by higher levels of E2 (beta = 0.360, p = 0.002) and TT (beta = 0.389, p = 0.001). In the group without TDS, PINP was positively correlated with E2 (beta = 0.726, p <0.001). Patients with TDS had significantly lower PINP levels (p < 0.004). Conclusions: Analysis of sex hormones and biochemical bone markers in reflecting the quality of the bone tissue in men may suggest a relationship between these parameters. Nevertheless, further research based on a larger sample size is necessary to better describe this relationship.


Nutrients ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 4217
Author(s):  
Anna Bizoń ◽  
Sylwia Płaczkowska ◽  
Justyna Niepsuj ◽  
Marta Czwojdzińska ◽  
Marcin Leśniewski ◽  
...  

We investigated the relationship between selected body composition (BC) parameters and included 55 women diagnosed with PCOS and 29 women in which PCOS was excluded. Hormone concentration and BC parameters were assessed during hospitalization. Women with PCOS had higher concentration of luteinizing hormones, total testosterone, androstenedione, and Anti-Müllerian hormones compared to women that were not diagnosed with PCOS. We did not observe any significant differences in the BC parameters between both groups as well as between four PCOS phenotype subgroups. Only in the group of women with PCOS was the concentration of sex hormone binding globulin and free testosterone correlated with all investigated BC parameters. Correspondence analysis did not confirm unambiguously associations between phenotypes of PCOS and the value of BC parameters, while logistic regression revealed that increased Anti-Müllerian hormone concentration and the value of body mass index could be useful parameters in differentiating women with PCOS and women with other disorders. The ROC analysis performed on the entire group of women also confirmed that the concentration of Anti-Müllerian hormones could be a powerful parameter to categorize women as suffering from PCOS.


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