A Reappraisal of Testosterone's Binding in Circulation: Physiological and Clinical Implications

Assessment of the endocrine-disrupting effects of organophosphorus pesticide triazophos and its metabolites on endocrine hormones biosynthesis, transport and receptor binding in silico

Triazophos (TAP) was a widely used organophosphorus insecticide in developing countries. TAP could produce specific metabolites triazophos-oxon (TAPO) and 1-phenyl-3-hydroxy-1,2,4-triazole (PHT) and non-specific metabolites diethylthiophosphate (DETP) and diethylphosphate (DEP). The objective of this study involved computational approaches to discover potential mechanisms of molecular interaction of TAP and its major metabolites with endocrine hormone-related proteins using molecular docking in silico. We found that TAP, TAPO and DEP showed high binding affinity with more proteins and enzymes than PHT and DETP. TAP might interfere with the endocrine function of the adrenal gland, and TAP might also bind strongly with glucocorticoid receptors and thyroid hormone receptors. TAPO might disrupt the normal binding of androgen receptor, estrogen receptor, progesterone receptor and adrenergic receptor to their natural hormone ligands. DEP might affect biosynthesis of steroid hormones and thyroid hormones. Meanwhile, DEP might disrupt the binding and transport of thyroid hormones in the blood and the normal binding of thyroid hormones to their receptors. These results suggested that TAP and DEP might have endocrine disrupting activities and were potential endocrine disrupting chemicals. Our results provided further reference for the comprehensive evaluation of toxicity of organophosphorus chemicals and their metabolites.

Aging and the Male Reproductive System

This narrative review presents an overview of current knowledge on fertility and reproductive hormone changes in aging men, the factors driving and modulating these changes, their clinical consequences, and the benefits and risks of testosterone (T) therapy. Aging is accompanied by moderate decline of gamete quality and fertility. Population mean levels show a mild total T decline, an SHBG increase, a steeper free T decline, and a moderate LH increase with important contribution of comorbidities (e.g., obesity) to these changes. Sexual symptoms and lower hematocrit are associated with low T and are partly responsive to T therapy. The relationship of serum T with body composition and metabolic health is bidirectional; limited beneficial effects of T therapy on body composition have only marginal effects on metabolic health and physical function. Skeletal changes are associated primarily with estradiol and SHBG. Cognitive decline is not consistently linked to low T and is not improved by T therapy. Although limited evidence links moderate androgen decline with depressive symptoms, T therapy has small beneficial effects on mood, depressive symptoms, and vitality in elderly patients with low T. Suboptimal T (and/or DHT) has been associated with increased risk of stroke, but not of ischemic heart disease, whereas an association with mortality probably reflects that low T is a marker of poor health. Globally, neither severity of clinical consequences attributable to low T nor the nature and magnitude of beneficial treatment effects justify the concept of some broadly applied "T replacement therapy" in older men with low T. Moreover, long-term safety of T therapy is not established.

Obesity and male hypogonadism: Tales of a vicious cycle

Obesity prevalence, particularly in children and young adults, is perilously increasing worldwide foreseeing serious negative health impacts in the future to come. Obesity is linked to impaired male gonadal function and is currently a major cause of hypogonadism. Besides signs and symptoms directly derived from decreased circulating testosterone levels, males with obesity also present poor fertility outcomes, further evidencing the parallelism between obesity and male reproductive function. In addition, males with androgen deficiency also exhibit increased fat accumulation and reduced muscle and mineral bone mass. Thus, compelling evidence highlights a vicious cycle where male hypogonadism can lead to increased adiposity, while obesity can be a cause for male hypogonadism. On the opposite direction, sustained weight loss can attain amelioration of male gonadal function. In this scenario, a thorough evaluation of gonadal function in men with obesity is crucial to dissect the causes from the consequences in order to target clinical interventions towards maximized improvement of reproductive health. This review will address the causes and consequences of the bidirectional relationship between obesity and hypogonadism, highlighting the implicit male reproductive repercussions.

Male Obesity-related Secondary Hypogonadism - Pathophysiology, Clinical Implications and Management

The single most significant risk factor for testosterone deficiency in men is obesity. The pathophysiological mechanisms involved in male obesity-related secondary hypogonadism are highly complex. Obesity-induced increase in levels of leptin, insulin, proinflammatory cytokines and oestrogen can cause a functional hypogonadotrophic hypogonadism with the defect present at the level of the hypothalamic gonadotrophin-releasing hormone (GnRH) neurons. The resulting hypogonadism by itself can worsen obesity, creating a self-perpetuating cycle. Obesity-induced hypogonadism is reversible with substantial weight loss. Lifestyle-measures form the cornerstone of management as they can potentially improve androgen deficiency symptoms irrespective of their effect on testosterone levels. In selected patients, bariatric surgery can reverse the obesity-induced hypogonadism. If these measures fail to relieve symptoms and to normalise testosterone levels, in appropriately selected men, testosterone replacement therapy could be started. Aromatase inhibitors and selective oestrogen receptor modulators are not recommended due to lack of consistent clinical trial-based evidence.

Breast levonorgestrel concentrations in women using a levonorgestrel-releasing intrauterine system

OBJECTIVE

To measure breast tissue and serum LNG concentrations in women using a LNG-IUS.

STUDY DESIGN

This pilot study was performed in 25 healthy women undergoing breast surgery at the Ghent University hospital. LNG concentrations were measured in serum and microdissected breast tissue samples using a validated ultra-performance liquid chromatography/tandem mass spectrometry assay.

RESULT(S)

The mean LNG concentration in the 18 LNG-IUS users was 0.18±0.16 ng/mL in serum and 0.26±0.28 ng/g in breast tissue. For four women without any form of hormonal contraceptive (the negative controls), the mean concentrations were below the limit of quantification, i.e., 0.15 ng/mL and 0.20 ng/g, for serum and breast tissue, respectively. For the three positive controls the concentrations in the serum (20.5 and 3.4 ng/ml) and the breast (3.74 and 1.24 ng/g) were respectively for the 20 μg EE/100 μg users and 315 pg/ml in the serum and 1.17 ng/g in the breast for the minipill user. The intracellular free fraction of LNG may be as low as 0.008 ng/g.

CONCLUSION(S)

The concentration of LNG in breast epithelium cells in women using the LNG-IUS is very low.

IMPLICATIONS

The relationship between the serum and breast tissue levels of LNG was studied in women using a LNG-IUS or oral LNG-containing contraception. Compared to oral contraception, the tissue levels of LNG in LNG-IUS users are much lower in the breast. It is not known what level of LNG exposure in the breast would stimulate RANKL and WNT4 expression; such information is needed.

Contribution of Liver Fat to Weight Loss-Induced Changes in Serum Hepatokines: A Randomized Controlled Trial

CONTEXT

Hepatokines have emerged as potential mediators of obesity-associated comorbidities, such as type 2 diabetes, cardiovascular disease, fractures, and central hypogonadism.

OBJECTIVE

To assess whether weight loss-induced changes in hepatokines are mediated by intrahepatic triglyceride (IHTG) content.

DESIGN

Cross-sectional study and randomized controlled trial.

SETTING

General community.

PARTICIPANTS

Metabolically healthy, lean men (waist <94 cm; n = 25) and men with abdominal obesity (waist 102 to 110 cm; n = 52).

INTERVENTION

Men with abdominal obesity were randomized to 8-week dietary weight loss or no weight loss.

MAIN OUTCOME MEASURES

IHTG and serum hepatokines, that is, serum IGF1, IGF binding protein 1 (IGFBP1), SHBG, fibroblast growth factor 21 (FGF21), fetuin A, and plasma fetuin B.

RESULTS

All hepatokines, except for fetuin B, were significantly different between lean men and men with obesity. After the weight-loss intervention (-10.3 kg; 95% CI, -11.4 to-9.2), serum IGF1, IGFBP1, SHBG, and fetuin A approached the values observed in lean men. Cross-sectional associations were observed between IHTG and IGF1 (β = -0.51; 95% CI, -0.82 to -0.20), IGFBP1 (β = -4.2; 95% CI, -7.7 to -0.7), and FGF21 (β = 2.1; 95% CI, 1.3 to 2.9) in lean men and men with abdominal obesity combined. Weight loss resulted in a reduction of IHTG (treatment effect, -2.2%; 95% CI, -3.4% to -1.2%) that was associated with a change in IGF1 (β = -0.9; 95% CI, -1.3 to -0.4), IGFBP1 (β = -0.17; 95% CI, -0.31 to -0.03), and SHBG levels (β = -0.18; 95% CI, -0.29 to -0.07). Mediation analyses showed that only the weight loss-induced change in serum IGF1 was mediated by IHTG (mediated effect, 32.7%; 95% CI, 4.6% to 79.2%).

CONCLUSIONS

Dietary weight loss has differential effects on hepatokines. This study shows that the change in serum IGF1 levels after dietary weight loss is mediated by the change in IHTG content.

Female Pattern Hair Loss and Androgen Excess: A Report From the Multidisciplinary Androgen Excess and PCOS Committee

OBJECTIVE

To determine the current state of knowledge and provide evidence-based recommendations that could be valid for all specialists taking care of female pattern hair loss (FPHL), a common form of hair loss in women that is characterized by the reduction of hair density in the central area of the scalp, whereas the frontal hairline is generally well conserved.

PARTICIPANTS

An expert task force appointed by the Androgen Excess and PCOS Society, which included specialists from dermatology, endocrinology, and reproductive endocrinology.

DESIGN

Levels of evidence were assessed and graded from A to D. Peer-reviewed studies evaluating FPHL published through December 2017 were reviewed. Criteria for inclusion/exclusion of the published papers were agreed on by at least two reviewers in each area and arbitrated by a third when necessary.

CONCLUSIONS

(i) The term "female pattern hair loss" should be used, avoiding the previous terms of alopecia or androgenetic alopecia. (ii) The two typical patterns of hair loss in FPHL are centrifugal expansion in the mid scalp, and a frontal accentuation or Christmas tree pattern. (iii) Isolated FPHL should not be considered a sign of hyperandrogenism when androgen levels are normal. (iv) The assessment of patients with FPHL is primarily clinical. (v) In all patients with FPHL, assessment of a possible androgen excess is mandatory. Measurement of vitamin D, iron, zinc, thyroid hormones, and prolactin are optional but recommended. (vi) Treatment of FPHL should start with minoxidil (5%), adding 5α-reductase inhibitors or antiandrogens when there is severe hair loss or hyperandrogenism.

Assessment of free testosterone concentration

Testosterone (T) is strongly bound to sex hormone binding globulin and measurement of free T may be more appropriate than measuring total serum T, according to the free hormone theory. This view remains controversial and it has its detractors who claim that little extra benefit is gained than simply measuring total T, but it is endorsed by recent clinical practice guidelines for investigation of androgen disorders in both men and women. Free T measurement is very challenging. The gold standard equilibrium dialysis methods are too complex for use in routine clinical laboratories, assays are not harmonized and consequently there are no common reference intervals to aid result interpretation. The algorithms derived for calculating free T are inaccurate because they were founded on faulty models of testosterone binding to SHBG, however they can still give clinically useful results. To negate the effects of differences in binding protein constants, some equations for free T have been derived from accurate measurement of testosterone in large population studies, however a criticism is that the equations may not hold true in different patient populations. The free androgen index is not recommended for use in men because of inaccuracy at extremes of SHBG concentration, and in women it can also give inaccurate results when SHBG concentrations are low. If the free hormone hypothesis is to be believed, then calculated free testosterone may offer the best way forward but better equations are needed to improve accuracy and these should be derived from detailed knowledge of testosterone binding to SHBG. There is still much work to be done to improve harmonization of T and SHBG assays between laboratories because these can have a profound effect on the equations used to calculate free testosterone.

Validity of free testosterone calculation in pregnant women

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.

Paediatric and adult-onset male hypogonadism

The hypothalamic-pituitary-gonadal axis is of relevance in many processes related to the development, maturation and ageing of the male. Through this axis, a cascade of coordinated activities is carried out leading to sustained testicular endocrine function, with gonadal testosterone production, as well as exocrine function, with spermatogenesis. Conditions impairing the hypothalamic-pituitary-gonadal axis during paediatric or pubertal life may result in delayed puberty. Late-onset hypogonadism is a clinical condition in the ageing male combining low concentrations of circulating testosterone and specific symptoms associated with impaired hormone production. Testosterone therapy for congenital forms of hypogonadism must be lifelong, whereas testosterone treatment of late-onset hypogonadism remains a matter of debate because of unclear indications for replacement, uncertain efficacy and potential risks. This Primer focuses on a reappraisal of the physiological role of testosterone, with emphasis on the critical interpretation of the hypogonadal conditions throughout the lifespan of the male individual, with the exception of hypogonadal states resulting from congenital disorders of sex development.

Pharmacokinetics of the 1.5 mg levonorgestrel emergency contraceptive in women with normal, obese and extremely obese body mass index

OBJECTIVE

To assess the pharmacokinetics (PK) of levonorgestrel after 1.5 mg oral doses (LNG-EC) in women with normal, obese and extremely obese body mass index (BMI).

STUDY DESIGN

The 1.5 mg LNG dose was given to healthy, reproductive-age, ovulatory women with normal BMI (mean 22.0), obese (mean 34.4), and extremely obese (mean 46.6 kg/m2) BMI. Total serum LNG was measured over 0 to 96 h by radioimmunoassay while free and bioavailable LNG were calculated. The maximum concentration (Cmax), time to maximum concentration (Tmax), and area under the curve (AUC) of LNG were assessed. Pharmacokinetic parameters calculated included half-life (t1/2), clearance (CL) and volume of distribution (Vss).

RESULTS

Ten normal-BMI, 11 obese-BMI, 5 extremely obese-BMI women were studied. After LNG-EC, mean total LNG metrics were lower in the obese and extremely obese groups compared to normal (Cmax 10.5 and 10.5 versus 16.2 ng/mL, both p<.01; AUC 208 and 197 versus 360 h × ng/mL, both p<.05). Mean bioavailable LNG Cmax was lower in obese (7.03 ng/mL, p<.05) and extremely obese (7.53 ng/ml, p=.198) compared to normal BMI (9.39 ng/mL). Mean bioavailable LNG AUC values were lower in obese and extremely obese compared to normal (131.6 and 127.5 vs 185.0 h × ng/mL, p<.05 for both).

CONCLUSIONS

Obese and extremely obese women were exposed to lower total and bioavailable LNG than normal BMI women.

IMPLICATIONS

Lower 'bioavailable' (free plus albumin bound) LNG AUC in obese women may play a role in the purported reduced efficacy of LNG-EC in obese users.

Longitudinal changes in serum vitamin D binding protein and free 25-hydroxyvitamin D in a multiracial cohort of pregnant adolescents

Serum free 25-hydroxyvitamin D (25(OH)D) rather than total 25(OH)D may better indicate vitamin D status during pregnancy given the pregnancy-associated increase in serum vitamin D binding protein (DBP) concentration. Our aims were to assess changes in DBP and free 25(OH)D across gestation and to determine whether free compared with total 25(OH)D more strongly correlates with markers of vitamin D and calcium metabolism during pregnancy. This ancillary study included 58 pregnant adolescents (53% African American, 47% White) who completed a vitamin D3 supplementation study in Rochester, NY. Blood was collected at entry, mid-study, and delivery (median 17, 29, and 40 weeks' gestation). Mixed-effects regression was used to test for differences in DBP, directly measured free 25(OH)D, and other serum markers by study visit and race. Free and total 25(OH)D were evaluated in relation to serum PTH, 1,25(OH)2D, 24,25(OH)2D, and calcium. The mean DBP concentration was above nonpregnant reference values at entry and increased across gestation (P < 0.0001). Total 25(OH)D explained most of the variance in free 25(OH)D (r ≥ 0.67; P < 0.0001). Holding total 25(OH)D constant, each 100 mg/L increase in DBP was associated with a 0.4 pg/mL decrease in free 25(OH)D (P < 0.01). The percent free 25(OH)D was inversely related to both DBP and total 25(OH)D at each visit. Regardless of race or visit, total 25(OH)D was a stronger correlate of PTH, 1,25(OH)2D, and 24,25(OH)2D, and neither total nor free 25(OH)D was related to serum calcium. African Americans had lower total 25(OH)D (P <  0.0001), but free 25(OH)D did not significantly differ by race (P =  0.2). In pregnant adolescents, DBP concentration was elevated and inversely associated with percent free 25(OH)D, but measured free 25(OH)D provided no advantage over total 25(OH)D as a predictor of PTH, 1,25(OH)2D, 24,25(OH)2D, or calcium. The clinical relevance of the small racial difference in percent free 25(OH)D requires further investigation.

Clinical practice update on testosterone therapy for male hypogonadism: Contrasting perspectives to optimize care

US Endocrine Society (ES) published a clinical practice guideline on testosterone therapy in men with hypogonadism, and Endocrine Society of Australia (ESA) a position statement on management of male hypogonadism. Both emphasize the importance of diagnosing men who are androgen deficient due to organic (classical or pathological) hypogonadism arising from disorders of the hypothalamus, pituitary or testes, who assuredly benefit from testosterone therapy. Both recognize that men with an intact gonadal axis may have low testosterone concentrations, for instance older men or men with obesity or other medical comorbidities. ES guidelines classify such symptomatic men as having organic (advanced age) or functional (obesity, medical comorbidities) hypogonadism, giving an option for testosterone therapy as a shared decision between clinicians and individual patients. ESA did not recommend testosterone therapy in these men. ES offers a reference range for total testosterone established in young men, while ESA cites age-standardized reference ranges. ES recommends using free testosterone as well as total testosterone to identify men with hypogonadism in conditions where sex hormone-binding globulin (SHBG) is altered, or when total testosterone is borderline. ESA recommends confirmatory biochemical testing with total testosterone, recognizing that this may be lower than expected if SHBG concentrations are low. Both emphasize the importance of identifying pre-existing prostate and cardiovascular disease prior to initiating testosterone therapy, with ES providing specific recommendations for PSA measurement, deferring testosterone therapy after major cardiovascular events and indications for pituitary imaging. These contrasting approaches highlight gaps in the evidence base where individualized patient management is required.

Testosterone, sex hormone-binding globulin and risk of cardiovascular events: A report from the Outcome Reduction with an Initial Glargine Intervention trial

Aims: Testosterone and its binding protein sex hormone-binding globulin have been associated with cardiovascular disease and dysglycaemia. However, information on the prognostic implication in patients at high cardiovascular risk with dysglycaemia is inconsistent. The study objective was to determine whether testosterone and/or sex hormone-binding globulin predict cardiovascular events or death in dysglycaemic patients.

Methods: Dysglycaemic males at high cardiovascular risk ( n = 5553) who participated in the Outcome Reduction with an Initial Glargine Intervention (ORIGIN) trial and provided baseline blood samples were studied. Testosterone and sex hormone-binding globulin were measured at baseline and used to estimate free testosterone. Low levels of total and free testosterone were defined as ≤300 ng/dl and ≤7 ng/dl, respectively. Patients were followed for six years for cardiovascular events (defined as the composite of cardiovascular death, non-fatal myocardial infarction or stroke) and all-cause mortality.

Results: The mean total and free testosterone levels were 416.6 ng/dl and 8.4 ng/dl, and low levels were present in 13% and 37% of the patients. The median sex hormone-binding globulin level was 35 nmol/l. In Cox regression models adjusted for age, previous diseases and pharmacological treatment, neither total nor free testosterone predicted cardiovascular events. However, a one-standard-deviation increase in sex hormone-binding globulin predicted both cardiovascular events (hazard ratio 1.07; 95% confidence interval 1.00–1.14; p = 0.03) and all-cause mortality (hazard ratio 1.13; 95% confidence interval 1.06–1.21; p < 0.01).

Conclusion: Sex hormone-binding globulin, but not total testosterone, predicts cardiovascular disease and all-cause mortality in dysglycaemic males at high cardiovascular risk.

Certified testosterone immunoassays for hyperandrogenaemia

BACKGROUND

Testosterone (T) measurement in women is problematic leading to initiatives aiming to improve laboratory standardization of commercial assays. We assessed the impact on the clinical diagnosis of functional hyperandrogenic disorders of a total T immunoassay recently certified by the Centers for Diseases Control and Prevention (CDC).

METHODS

We conducted a cross-sectional study including 263 consecutive adult premenopausal women presenting with functional ovarian hyperandrogenism-including polycystic ovary syndrome (PCOS)-and 73 nonhyperandrogenic female volunteers who served to define reference ranges. Total T was measured by a local routine direct radioimmunoassay and by a CDC-certified immunochemiluminescence assay. The main outcome measures were total and calculated free T concentrations and percentage of patients with hyperandrogenaemia.

RESULTS

Both assays showed a poor concordance for total and calculated free T measurements. Hence, 147 (56%) and 109 (41%) of women had hyperandrogenaemia with the routine and CDC-certified assays, respectively [κ (95%CI): 0.538 (0.441-0.634)]. Free T levels calculated from total T using both assays showed similar correlations with metabolic variables. Women showing hyperandrogenaemia by both methods had the worst metabolic profiles, yet women presenting with hyperandrogenaemia only when using the CDC-certified assay did not show any significant difference compared to nonhyperandrogenic women in anthropometric or metabolic variables. Those women with hyperandrogenaemia only when using the routine assay were more obese and insulin resistant than normoandrogenaemic hirsute patients.

CONCLUSIONS

An isolated androgen measurement, even a very specific one, is unlikely to identify the hyperandrogenic milieu that characterizes patients with functional ovarian hyperandrogenism and PCOS.

Low Free Testosterone and Prostate Cancer Risk: A Collaborative Analysis of 20 Prospective Studies

BACKGROUND

Experimental and clinical evidence implicates testosterone in the aetiology of prostate cancer. Variation across the normal range of circulating free testosterone concentrations may not lead to changes in prostate biology, unless circulating concentrations are low. This may also apply to prostate cancer risk, but this has not been investigated in an epidemiological setting.

OBJECTIVE

To examine whether men with low concentrations of circulating free testosterone have a reduced risk of prostate cancer.

DESIGN, SETTING, AND PARTICIPANTS

Analysis of individual participant data from 20 prospective studies including 6933 prostate cancer cases, diagnosed on average 6.8 yr after blood collection, and 12 088 controls in the Endogenous Hormones, Nutritional Biomarkers and Prostate Cancer Collaborative Group.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Odds ratios (ORs) of incident overall prostate cancer and subtypes by stage and grade, using conditional logistic regression, based on study-specific tenths of calculated free testosterone concentration.

RESULTS AND LIMITATIONS

Men in the lowest tenth of free testosterone concentration had a lower risk of overall prostate cancer (OR=0.77, 95% confidence interval [CI] 0.69-0.86; p<0.001) compared with men with higher concentrations (2nd-10th tenths of the distribution). Heterogeneity was present by tumour grade (phet=0.01), with a lower risk of low-grade disease (OR=0.76, 95% CI 0.67-0.88) and a nonsignificantly higher risk of high-grade disease (OR=1.56, 95% CI 0.95-2.57). There was no evidence of heterogeneity by tumour stage. The observational design is a limitation.

CONCLUSIONS

Men with low circulating free testosterone may have a lower risk of overall prostate cancer; this may be due to a direct biological effect, or detection bias. Further research is needed to explore the apparent differential association by tumour grade.

PATIENT SUMMARY

In this study, we looked at circulating testosterone levels and risk of developing prostate cancer, finding that men with low testosterone had a lower risk of prostate cancer.

Testosterone Levels in Third Trimester in Polycystic Ovary Syndrome: Odense Child Cohort

BACKGROUND

Polycystic ovary syndrome (PCOS) is characterized by hyperandrogenism. In pregnancy, testosterone levels may be higher in women with PCOS compared with controls.

AIMS

To compare total testosterone (TT), free testosterone (FT), and sex hormone-binding globulin (SHBG) levels in third-trimester pregnant women with PCOS and controls and to establish reference ranges for TT, FT, and SHBG in PCOS and controls.

METHODS

The study was part of the prospective study, Odense Child Cohort. PCOS was diagnosed by questionnaires and/or patient records. Fasting blood samples were collected at gestational week 28 and plasma TT was measured by liquid chromatography-tandem mass spectrometry in women with PCOS (n = 145) and in women without PCOS (controls, n = 1341).

RESULTS

Levels of TT (mean, 2.4 vs 2.0 nmol/L) and FT (mean, 0.005 vs 0.004 nmol/L) were higher, whereas SHBG levels (mean, 447 vs 477 nmol/L) were lower in women with PCOS vs controls (all P < 0.001). Reference intervals for TT, FT, and SHBG in women with PCOS and controls were overlapping, and partitioning of reference intervals was an ambiguous decision. In multiple regression analyses, TT and FT levels were positively associated with PCOS status and BMI and inversely associated with age and parity. Offspring sex did not predict maternal TT and FT.

CONCLUSIONS

TT and FT levels were higher in third-trimester pregnant women with PCOS compared with controls. Separate reference interval for FT in women with PCOS should be considered.

A Dose-Escalating Study With the Fetal Estrogen Estetrol in Healthy Men

CONTEXT

Luteinizing hormone-releasing hormone (LHRH) agonists have replaced estrogens for endocrine treatment of advanced prostate cancer (PC) because of cardiovascular side effects. The fetal estrogen estetrol (E4) may be safer for PC treatment and is expected to decrease testosterone (T) and prevent estrogen deficiency.

OBJECTIVE

To investigate the safety and T-suppressive effect of E4 in healthy men.

DESIGN

Double-blind, randomized, placebo-controlled, dose-escalating study.

SETTING

The study was conducted at a phase I clinical unit (QPS, Netherlands).

PARTICIPANTS

Healthy male volunteers aged 40 to 70 years.

INTERVENTION(S)

Three treatment cohorts of 15 volunteers with placebo (n = 5) and E4 (n = 10). Estetrol doses tested were 20, 40, and 60 mg/d. Subjects were treated for 4 weeks.

MAIN OUTCOME MEASURES

Subjective side effects, pharmacodynamic effects on hemostatic variables, lipids, glucose, bone parameters, and endocrine parameters related to T metabolism.

RESULTS

Total and free T decreased dose-dependently and significantly. Nipple tenderness occurred in 40% and decrease of libido occurred in 30% of E4-treated men. The unwanted estrogenic effects on hemostasis were small, dose dependent, and in some cases significant. Lipid and bone parameters showed a favorable trend.

CONCLUSION

The effect of E4 on testosterone levels is insufficient for standalone PC treatment. Taking all clinical and pharmacodynamic variables into consideration, a daily dose of 40 mg E4 seems safe for further evaluation of endocrine PC treatment in combination with LHRH analogs.

Reproductive Hormones and Subclinical Cardiovascular Disease in Midlife Women

CONTEXT

Reproductive hormones are important to the pathophysiology of cardiovascular disease (CVD) in women. However, standard estradiol (E2) and testosterone (T) assays lack sensitivity at the levels of postmenopausal women.

OBJECTIVE

Investigate relations of mass spectrometry-assessed estrone (E1), E2, and T and SHBG and subclinical CVD in women.

DESIGN, SETTING, AND PARTICIPANTS

Three hundred and four perimenopausal and postmenopausal women aged 40 to 60 years underwent subclinical CVD measurements. E1, E2, and T were assayed using liquid chromatography-tandem mass spectrometry; free T (FT) was estimated using ensemble allostery models. Regression models were adjusted for CVD risk factors.

MAIN OUTCOME MEASURES

Carotid artery intima media thickness, interadventitial diameter (IAD), and plaque; brachial flow mediated dilation (FMD).

RESULTS

Higher E1 was related to higher FMD [β(SE) = 0.77 (0.37), P = 0.04], indicating better endothelial function. Higher E2 was related to lower IAD [β(SE) = -0.07 (0.02), P = 0.004], indicating less carotid remodeling. Higher SHBG was related to higher FMD [β(SE) = 1.31 (0.40), P = 0.001], yet higher IAD [β(SE) = 0.15 (0.06), P = 0.02] and plaque [OR (95% CI) = 1.84 (1.16 to 2.91), P = 0.009]; FT showed a similar yet inverse pattern of relations as SHBG. Thus, higher SHBG and lower FT were associated with better endothelial function, yet greater carotid remodeling and plaque.

CONCLUSIONS

Endogenous E1 levels were related to endothelial function and E2 to vascular remodeling, suggesting distinct roles of these estrogens. SHBG and FT have complex roles depending on the vessel under study.

Soy protein supplementation is not androgenic or estrogenic in college-aged men when combined with resistance exercise training

It is currently unclear as to whether sex hormones are significantly affected by soy or whey protein consumption. Additionally, estrogenic signaling may be potentiated via soy protein supplementation due to the presence of phytoestrogenic isoflavones. Limited also evidence suggests that whey protein supplementation may increase androgenic signaling. Therefore, the purpose of this study was to examine the effects of soy protein concentrate (SPC), whey protein concentrate (WPC), or placebo (PLA) supplementation on serum sex hormones, androgen signaling markers in muscle tissue, and estrogen signaling markers in subcutaneous (SQ) adipose tissue of previously untrained, college-aged men (n = 47, 20 ± 1 yrs) that resistance trained for 12 weeks. Fasting serum total testosterone increased pre- to post-training, but more so in subjects consuming WPC (p < 0.05), whereas serum 17β-estradiol remained unaltered. SQ estrogen receptor alpha (ERα) protein expression and hormone-sensitive lipase mRNA increased with training regardless of supplementation. Muscle androgen receptor (AR) mRNA increased while ornithine decarboxylase mRNA (a gene target indicative of androgen signaling) decreased with training regardless of supplementation (p < 0.05). No significant interactions of supplement and time were observed for adipose tissue ERα/β protein levels, muscle tissue AR protein levels, or mRNAs in either tissue indicative of altered estrogenic or androgenic activity. Interestingly, WPC had the largest effect on increasing type II muscle fiber cross sectional area values (Cohen's d = 1.30), whereas SPC had the largest effect on increasing this metric in type I fibers (Cohen's d = 0.84). These data suggest that, while isoflavones were detected in SPC, chronic WPC or SPC supplementation did not appreciably affect biomarkers related to muscle androgenic signaling or SQ estrogenic signaling. The noted fiber type-specific responses to WPC and SPC supplementation warrant future research.

Association between Low Testosterone Levels and Sarcopenia in Cirrhosis: A Cross-sectional Study

INTRODUCTION AND AIM

Sarcopenia is an independent predictor of mortality in cirrhosis. Hypogonadism is common in cirrhosis and has been associated with sarcopenia in non-cirrhotic chronic liver disease populations. The aim of this study is to investigate if sarcopenia is associated with low testosterone levels in patients with cirrhosis.

MATERIAL AND METHODS

This is a retrospective analysis of prospectively collected data of 211 cirrhotic patients undergoing evaluation for liver transplantation. Sarcopenia was defined by computed tomography (CT) scan using specific cutoffs of the 3rd lumbar vertebra skeletal muscle index (L3 SMI). Morning testosterone levels were obtained in all patients.

RESULTS

Of the 211 patients, sarcopenia was noted in 94 (45%). Testosterone levels were lower in sarcopenic patients (10.7 ± 1.1 vs. 13.7 ± 1.4 nmol/L, p = 0.03) and hypotestosteronemia was more frequent in them too (34 vs. 16%, p = 0.004). In males, those with sarcopenia had lower testosterone levels (14.6 ± 1.4 vs. 21.9 ± 1.8, p = 0.002), and the corresponding frequency of hypotestosteronemia (42 vs. 19%, p = 0.006) was also higher. There were no significant differences in female patients. There was a weak correlation between L3 SMI and testosterone levels (r 0.37, p &lt; 0.001). On multivariable regression analysis including sex, body mass index (BMI), hypotestosteronemia, MELD and etiology of cirrhosis, only hypotestosteronemia (RR 2.76, p = 0.005) and BMI (RR 0.88, p &lt; 0.001) were independently associated with sarcopenia.

CONCLUSION

Low testosterone levels are associated with sarcopenia in male cirrhotic patients. The potential therapeutic effect of testosterone to reverse sarcopenia in these patients warrants evaluation in future trials.

Sex hormone-binding globulin is a biomarker associated with nonvertebral fracture in men on dialysis therapy

Gonadal hormones impact bone health and higher values of sex hormone-binding globulin (SHBG) have been independently associated with fracture risk in men without chronic kidney disease. People with chronic kidney disease have a greatly increased fracture risk, and gonadal dysfunction is common in men receiving dialysis treatment. Nevertheless, in these men the effect of gonadal steroids and SHBG on bone mineral density (BMD) and fracture risk is unknown. Here we investigate relationships between gonadal steroids, SHBG, BMD and fracture in men on long-term dialysis therapy, awaiting kidney or simultaneous pancreas kidney transplantation. Results of serum biochemistry, SHBG, gonadal steroids (total testosterone, calculated free testosterone and estradiol), BMD by dual-energy X-ray absorptiometry and thoracolumbar X-rays were obtained. Multivariable regression models were used to examine associations between SHBG, gonadal steroids, BMD and fracture of 321 men with a mean age of 47 years. Diabetes mellitus was present in 45% and their median dialysis vintage was 24 months. Prior fractures occurred in 42%, 18% had vertebral fracture on lateral spine X-ray, 17% had non-vertebral fragility fracture within 10 years and 7% had both. After adjustment for age, body mass index and dialysis vintage, higher SHBG levels were significantly associated with nonvertebral fractures [odds ratio 1.81 (1.30-2.53)] and remained significant after adjustment for BMD. Calculated free testosterone and estradiol values were not associated with fracture. Prevalent fracture rates were high in relatively young men on dialysis awaiting transplantation. Thus, SHBG is a novel biomarker associated with fracture, which warrants investigation in prospective studies.

Reassessing Free-Testosterone Calculation by Liquid Chromatography-Tandem Mass Spectrometry Direct Equilibrium Dialysis

CONTEXT

Assessment of free testosterone (FT) might help evaluate androgen status in patients with borderline total testosterone (T) and/or altered sex hormone-binding globulin (SHBG) levels. However, the validity of different methods to measure FT is debatable.

METHODS

Serum from 183 women and 146 men was analyzed using equilibrium dialysis (ED), with FT directly measured by liquid chromatography-tandem mass spectrometry. FT calculation was re-evaluated for the mass action law-based equation according to Vermeulen (cFT-V), empirical equations according to Ly (cFT-L), and a proposed calculation based on a multistep, dynamic, allosteric model according to Zakharov (cFT-Z).

RESULTS

FT level analyzed by ED [median,13 pmol/L (1.2% of T) in women; 248 pmol/L (1.5% of T) in men] was strongly inversely correlated to SHBG level, significantly to albumin level in women, and only weakly to SHBG level in men. The median [percentile (p) range, 2.5 to 97.5] ratios of calculated FT (cFT) over ED-FT (from European Male Aging Study samples) were 1.19 (0.9 to 1.47), 1.00 (0.69 to 1.42), and 2.05 (1.26 to 3.26) for cFT-V, cFT-L, and cFT-Z, respectively. The ratio for cFT-V was not significantly affected by SHBG, T, or albumin levels (ρ range, 0.17 to -0.01); ratios for cFT-L and cFT-Z were affected (P < 0.05 and P < 0.001, respectively) and strongly correlated with SHBG levels (ρ = 0.72 and 0.75, respectively). Rank correlations between cFT% and ED-FT% (for men) were 0.62, 0.74, and 0.89 for cFT-Z, cFT-L, and cFT-V, respectively.

CONCLUSION

FT results by direct ED confirm prior FT data from indirect ED and ultrafiltration methodologies. Calculations have inherent limitations, with clinically important differences among evaluated equations: cFT-V, although overestimating FT level, appears the most robust approximation, largely independent of SHBG, albumin, and T levels.

Testosterone Therapy in Men With Hypogonadism: An Endocrine Society Clinical Practice Guideline

OBJECTIVE

To update the "Testosterone Therapy in Men With Androgen Deficiency Syndromes" guideline published in 2010.

PARTICIPANTS

The participants include an Endocrine Society-appointed task force of 10 medical content experts and a clinical practice guideline methodologist.

EVIDENCE

This evidence-based guideline was developed using the Grading of Recommendations, Assessment, Development, and Evaluation approach to describe the strength of recommendations and the quality of evidence. The task force commissioned two systematic reviews and used the best available evidence from other published systematic reviews and individual studies.

CONSENSUS PROCESS

One group meeting, several conference calls, and e-mail communications facilitated consensus development. Endocrine Society committees and members and the cosponsoring organization were invited to review and comment on preliminary drafts of the guideline.

CONCLUSIONS

We recommend making a diagnosis of hypogonadism only in men with symptoms and signs consistent with testosterone (T) deficiency and unequivocally and consistently low serum T concentrations. We recommend measuring fasting morning total T concentrations using an accurate and reliable assay as the initial diagnostic test. We recommend confirming the diagnosis by repeating the measurement of morning fasting total T concentrations. In men whose total T is near the lower limit of normal or who have a condition that alters sex hormone-binding globulin, we recommend obtaining a free T concentration using either equilibrium dialysis or estimating it using an accurate formula. In men determined to have androgen deficiency, we recommend additional diagnostic evaluation to ascertain the cause of androgen deficiency. We recommend T therapy for men with symptomatic T deficiency to induce and maintain secondary sex characteristics and correct symptoms of hypogonadism after discussing the potential benefits and risks of therapy and of monitoring therapy and involving the patient in decision making. We recommend against starting T therapy in patients who are planning fertility in the near term or have any of the following conditions: breast or prostate cancer, a palpable prostate nodule or induration, prostate-specific antigen level > 4 ng/mL, prostate-specific antigen > 3 ng/mL in men at increased risk of prostate cancer (e.g., African Americans and men with a first-degree relative with diagnosed prostate cancer) without further urological evaluation, elevated hematocrit, untreated severe obstructive sleep apnea, severe lower urinary tract symptoms, uncontrolled heart failure, myocardial infarction or stroke within the last 6 months, or thrombophilia. We suggest that when clinicians institute T therapy, they aim at achieving T concentrations in the mid-normal range during treatment with any of the approved formulations, taking into consideration patient preference, pharmacokinetics, formulation-specific adverse effects, treatment burden, and cost. Clinicians should monitor men receiving T therapy using a standardized plan that includes: evaluating symptoms, adverse effects, and compliance; measuring serum T and hematocrit concentrations; and evaluating prostate cancer risk during the first year after initiating T therapy.

Testosterone, frailty and physical function in older men

INTRODUCTION

Age-related decline in serum testosterone (T) has been suggested in some studies to be associated with individual components of frailty: diminished energy, muscle strength and physical function.

AREAS COVERED

The aim of this study is to comprehensively review evidence from observational and interventional studies on the relationship of T to frailty in older men. We reviewed observational studies exploring the relationship between circulating T and its potent metabolite dihydrotestosterone (DHT) with frailty. We further reviewed the effects of T treatment on lean mass, muscle strength and physical function in both frail and non-frail older men.

EXPERT COMMENTARY

T treatment may provide modest improvements in lean mass among both frail and non-frail older men, but current evidence on the T effect on muscle strength is conflicting and the effect on physical function is weak.

Mitochondria, glycogen, and lipid droplets in skeletal muscle during testosterone treatment and strength training: a randomized, double-blinded, placebo-controlled trial

Low testosterone levels in aging men are associated with insulin resistance. Mitochondrial dysfunction, changes in glycogen metabolism, and lipid accumulation are linked to insulin resistance in skeletal muscle. In this randomized, double-blinded, placebo-controlled study, we investigated the effects of six-month testosterone replacement therapy (TRT) and strength training (ST) on mitochondrial, glycogen, and lipid droplet (LD) content in skeletal muscle of aging men with subnormal bioavailable testosterone (BioT) levels. Mitochondrial, glycogen, and LD volume fractions in muscle biopsies were estimated by transmission electron microscopy. Insulin sensitivity (insulin-stimulated Rd) and body composition were assessed by euglycemic-hyperinsulinemic clamp and dual X-ray absorptiometry, respectively. TRT significantly increased total testosterone levels, BioT, and lean body mass (LBM) (p < 0.05), whereas percent body fat decreased (p < 0.05), and insulin sensitivity was unchanged. Baseline mitochondrial volume fraction correlated inversely with percent body fat (ρ = -0.43; p = 0.003). Δ-mitochondrial fraction correlated positively with Δ-total testosterone (ρ = 0.70; p = 0.02), and Δ-glycogen fraction correlated inversely with Δ-LBM (ρ = -0.83; p = 0.002) during six-month TRT, but no significant changes were observed in mitochondrial, glycogen, and LD volume fractions during TRT and ST. In conclusion, in this exploratory small-scale study, the beneficial effects of six-month TRT on total testosterone, LBM, and percent body fat were not followed by significant changes in fractions of mitochondria, glycogen, or lipid in skeletal muscle of aging men with lowered testosterone levels. Six-month ST or combined three-month ST+TRT did not change intramyocellular mitochondria, glycogen, and LD fractions compared to placebo. However, further studies with a larger sample size are needed.

Evaluation and Treatment of Hirsutism in Premenopausal Women: An Endocrine Society Clinical Practice Guideline

OBJECTIVE

To update the "Evaluation and Treatment of Hirsutism in Premenopausal Women: An Endocrine Society Clinical Practice Guideline," published by the Endocrine Society in 2008.

PARTICIPANTS

The participants include an Endocrine Society-appointed task force of seven medical experts and a methodologist.

EVIDENCE

This evidence-based guideline was developed using the Grading of Recommendations, Assessment, Development, and Evaluation system to describe the strength of recommendations and the quality of evidence. The task force commissioned two systematic reviews and used the best available evidence from other published systematic reviews and individual studies.

CONSENSUS PROCESS

Group meetings, conference calls, and e-mail communications facilitated consensus development. Endocrine Society committees, members, and cosponsoring organizations reviewed and commented on preliminary drafts of the guidelines.

CONCLUSION

We suggest testing for elevated androgen levels in all women with an abnormal hirsutism score. We suggest against testing for elevated androgen levels in eumenorrheic women with unwanted local hair growth (i.e., in the absence of an abnormal hirsutism score). For most women with patient-important hirsutism despite cosmetic measures (shaving, plucking, waxing), we suggest starting with pharmacological therapy and adding direct hair removal methods (electrolysis, photoepilation) for those who desire additional cosmetic benefit. For women with mild hirsutism and no evidence of an endocrine disorder, we suggest either pharmacological therapy or direct hair removal methods. For pharmacological therapy, we suggest oral combined estrogen-progestin contraceptives for the majority of women, adding an antiandrogen after 6 months if the response is suboptimal. We recommend against antiandrogen monotherapy unless adequate contraception is used. We suggest against using insulin-lowering drugs. For most women who choose hair removal therapy, we suggest laser/photoepilation.

MANAGEMENT OF ENDOCRINE DISEASE Hyperandrogenic states in women: pitfalls in laboratory diagnosis

Measuring total testosterone level is the first-line approach in assessing androgen excess in women. The main pitfalls in measuring testosterone relate to its low concentration and to the structural similarity between circulating androgens and testosterone, requiring accurate techniques with high specificity and sensitivity. These goals can be achieved by immunoassay using a specific anti-testosterone monoclonal antibody, ideally after an extraction step. Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) will be commonly used for measuring testosterone, providing optimal accuracy with a low limit of detection. Yet, the pitfalls of these two techniques are well identified and must be recognized and systematically addressed. In general, laboratories using direct testosterone immunoassay and mass spectrometry need to operate within a quality framework and be actively engaged in external quality control processes and standardization, so as to ensure appropriate interpretation irrespective of the particular laboratory. Circulating testosterone is strongly bound to sex-hormone-binding globulin (SHBG), and SHBG levels are typically low in overweight hyperandrogenic patients. Thus, low SHBG may decrease circulating testosterone to normal values, which will mask androgen excess status. One way to avoid this pitfall, awaiting direct free testosterone assays that are yet to be developed, is to measure SHBG and calculate free testosterone. A few other pitfalls will be discussed in this review, including those of adrenal androgen exploration, with the aim of helping clinicians to better handle laboratory investigation of androgen excess disorders in women.