Reproducibility of Serum Sex Steroid Assays in Men by RIA and Mass Spectrometry

Androgen deficiency in hypopituitary women: its consequences and management

Women with hypopituitarism have various degrees of androgen deficiency, which is marked among those with combined hypogonadotrophic hypogonadism and secondary adrenal insufficiency. The consequences of androgen deficiency and the effects of androgen replacement therapy have not been fully elucidated. While an impact of androgen deficiency on outcomes such as bone mineral density, quality of life, and sexual function is plausible, the available evidence is limited. There is currently no consensus on the definition of androgen deficiency in women and it is still controversial whether androgen substitution should be used in women with hypopituitarism and coexisting androgen deficiency. Some studies suggest beneficial clinical effects of androgen replacement but data on long-term benefits and risk are not available. Transdermal testosterone replacement therapy in hypopituitary women has shown some positive effects on bone metabolism and body composition. Studies of treatment with oral dehydroepiandrosterone have yielded mixed results, with some studies suggesting improvements in quality of life and sexual function. Further research is required to elucidate the impact of androgen deficiency and its replacement treatment on long-term outcomes in women with hypopituitarism. The lack of transdermal androgens for replacement in this patient population and limited outcome data limit its use. A cautious and personalized treatment approach in the clinical management of androgen deficiency in women with hypopituitarism is recommended while awaiting more efficacy and safety data.

Comparison of assay methods for quantifying sex hormone concentrations across the menstrual cycle in rhesus macaques

Immunoassays have been the preferred method for steroid hormone analysis for more than 50 years. Automated immunoassays (AIAs) offer high-throughput, rapid data turnaround, and low cost for measuring steroid hormone concentrations. The application of liquid chromatography-tandem mass spectrometry (LC-MS/MS) for steroid quantification provides greater specificity and selectivity for individual steroids, the ability to simultaneously analyze multiple steroids, and high-throughput and automation. We compared AIA and LC-MS/MS for analysis of 17β-estradiol (E2) and progesterone (P4) over the course of several menstrual cycles in 12 rhesus macaques (Macaca mulatta). Serum samples were collected every four days across four menstrual cycles from each monkey. AIAs were performed on a Roche cobas e411 analyzer. Analysis of E2 and P4 was performed by LC-MS/MS on a Shimadzu-Nexera-LCMS-8060 instrument. Scatter plots with Passing-Bablok regression showed excellent agreement between AIA and LC-MS/MS for both E2 and P4. Bland-Altman plots revealed no bias for either method; however, AIA overestimated E2 at concentrations >140 pg/ml and underestimated P4 at concentrations >4 ng/ml compared to LC-MS/MS. A comparison of testosterone (T) concentrations measured by AIA and LC-MS/MS in the same samples was also performed. In contrast to E2 and P4, AIA and LC-MS/MS yielded significantly different results for T concentrations, with AIA consistently underestimating concentrations relative to those obtained by LC-MS/MS. Well-characterized AIAs are an excellent tool for daily monitoring of monkey menstrual cycles or providing single data points requiring fast turnaround. In certain situations where AIA may provide inaccurate estimations of E2 and P4 concentrations, LC-MS/MS assays are preferable.

Serum DHEA and Testosterone Levels Associate Inversely With Coronary Artery Calcification in Elderly Men

CONTEXT

Epidemiological and preclinical data support cardiovascular, mainly protective, effects of sex steroids in men, but the mechanisms underlying the cardiovascular actions of sex steroids are poorly understood. Vascular calcification parallels the development of atherosclerosis, but is increasingly recognized as a diversified, highly regulated process, which itself may have pathophysiological importance for clinical cardiovascular events.

OBJECTIVE

To investigate the association between serum sex steroids and coronary artery calcification (CAC) in elderly men.

METHODS

We used gas chromatography tandem mass spectrometry to analyze a comprehensive sex steroid profile, including levels of dehydroepiandrosterone (DHEA), androstenedione, estrone, testosterone, estradiol, and dihydrotestosterone, in men from the population-based AGES-Reykjavik study (n = 1287, mean 76 years). Further, sex hormone-binding globulin (SHBG) was assayed and bioavailable hormone levels calculated. CAC score was determined by computed tomography. The main outcome measures were cross-sectional associations between dehydroepiandrosterone, androstenedione, estrone, testosterone, dihydrotestosterone, and estradiol and quintiles of CAC.

RESULTS

Serum levels of DHEA, androstenedione, testosterone, dihydrotestosterone, and bioavailable testosterone showed significant inverse associations with CAC, while estrone, estradiol, bioavailable estradiol, and SHBG did not. DHEA, testosterone, and bioavailable testosterone remained associated with CAC after adjustment for traditional cardiovascular risk factors. In addition, our results support partially independent associations between adrenal-derived DHEA and testes-derived testosterone and CAC.

CONCLUSION

Serum levels of DHEA and testosterone are inversely associated with CAC in elderly men, partially independently from each other. These results raise the question whether androgens from both the adrenals and the testes may contribute to male cardiovascular health.

Verification of sex- and age-specific reference intervals for 13 serum steroids determined by mass spectrometry: evaluation of an indirect statistical approach

OBJECTIVES

Conventionally, reference intervals are established by direct methods, which require a well-characterized, obviously healthy study population. This elaborate approach is time consuming, costly and has rarely been applied to steroid hormones measured by mass spectrometry. In this feasibility study, we investigate whether indirect methods based on routine laboratory results can be used to verify reference intervals from external sources.

METHODS

A total of 11,259 serum samples were used to quantify 13 steroid hormones by mass spectrometry. For indirect estimation of reference intervals, we applied a "modified Hoffmann approach", and verified the results with a more sophisticated statistical method (refineR). We compared our results with those of four recent studies using direct approaches.

RESULTS

We evaluated a total of 81 sex- and age-specific reference intervals, for which at least 120 measurements were available. The overall agreement between indirectly and directly determined reference intervals was surprisingly good as nearly every fourth reference limit could be confirmed by narrow tolerance limits. Furthermore, lower reference limits could be provided for some low concentrated hormones by the indirect method. In cases of substantial deviations, our results matched the underlying data better than reference intervals from external studies.

CONCLUSIONS

Our study shows for the first time that indirect methods are a valuable tool to verify existing reference intervals for steroid hormones. A simple "modified Hoffmann approach" based on the general assumption of a normal or lognormal distribution model is sufficient for screening purposes, while the refineR algorithm may be used for a more detailed analysis.

Serum Androgen Metabolites Correlate with Clinical Variables in African and European American Men with Localized, Therapy Naïve Prostate Cancer

Dihydrotestosterone (DHT) and testosterone (T), which mediate androgen receptor nuclear translocation and target gene transcription, are crucial androgens and essential molecular triggers required for the proliferation and survival of prostate cancer cells. Therefore, androgen metabolism is commonly targeted in the treatment of prostate cancer. Using a high-pressure liquid chromatographic assay with tandem mass spectral detection, we determined the serum levels of metabolites produced during DHT/T biosynthesis in African American (AA) and European American (EA) men with localized, therapy naïve prostate cancer. Serum progesterone and related metabolites were significantly lower in AA men than in EA men, and these differences were associated with rapid disease progression. Multivariate analysis revealed significant differences between a subset of intermediate androgen metabolites between AA and EA men and between men with <=3 + 4 and >=4 + 3 Gleason score disease. AA men have a significantly higher frequency of single nucleotide polymorphisms in CYP11B1 and CYP11B2, enzymes that regulate corticosterone-aldosterone conversion. Finally, higher levels of T and pregnenolone were associated with a lower risk of progression-free survival only in AA men. This work provides new insight into androgen metabolism and racial disparities in prostate cancer by presenting evidence of dysregulated androgen biosynthesis in therapy naïve disease that correlates with clinical variables.

Sex-dependent effects of multiple acute concurrent stresses on memory: a role for hippocampal estrogens

Memory disruption commonly follows chronic stress, whereas acute stressors are generally benign. However, acute traumas such as mass shootings or natural disasters—lasting minutes to hours and consisting of simultaneous physical, social, and emotional stresses—are increasingly recognized as significant risk factors for memory problems and PTSD. Our prior work has revealed that these complex stresses (concurrent multiple acute stresses: MAS) disrupt hippocampus-dependent memory in male rodents. In females, the impacts of MAS are estrous cycle-dependent: MAS impairs memory during early proestrus (high estrogens phase), whereas the memory of female mice stressed during estrus (low estrogens phase) is protected. Female memory impairments limited to high estrogens phases suggest that higher levels of estrogens are necessary for MAS to disrupt memory, supported by evidence that males have higher hippocampal estradiol than estrous females. To test the role of estrogens in stress-induced memory deficits, we blocked estrogen production using aromatase inhibitors. A week of blockade protected male and female mice from MAS-induced memory disturbances, suggesting that high levels of estrogens are required for stress-provoked memory impairments in both males and females. To directly quantify 17β-estradiol in murine hippocampus we employed both ELISA and mass spectrometry and identified significant confounders in both procedures. Taken together, the cross-cycle and aromatase studies in males and females support the role for high hippocampal estrogens in mediating the effect of complex acute stress on memory. Future studies focus on the receptors involved, the longevity of these effects, and their relation to PTSD-like behaviors in experimental models.

Determination of testosterone in serum by magnetic molecularly imprinted polymer-coupled nano-ESI-MS

Monitoring clinical biomarkers, such as testosterone in serum, is important for disease assessment. Due to the very low concentration of testosterone in serum, we have developed a new strategy for its enrichment in serum samples by magnetic molecularly imprinted polymers (MMIPs) technology and detection by nano-electrospray ionization mass spectrometry (Nano-ESI-MS). Testosterone was selectively extracted and enriched by the imprinted polymers on the surface of magnetic particles and the complex matrix was eliminated from the serum. The linear calibration curve was in the range of 0.1-10 μg/L and the limit of detection was 11.4 ng/L. The recovery and repeatability of the spiked serum were satisfactory. These results demonstrate that the proposed method is a promising approach for quantitative analysis of testosterone in serum.

Low Progesterone and Low Estradiol Levels Associate With Abdominal Aortic Aneurysms in Men

CONTEXT

Male sex is a major risk factor for abdominal aortic aneurysms (AAA) but few studies have addressed associations between sex hormone levels and AAA.

OBJECTIVE

We aimed to describe the associations between serum sex steroids and early, screening-detected AAA in men.

METHODS

We validated a high-sensitivity liquid chromatography-tandem mass spectrometry assay for comprehensive serum sex hormone profiling. This assay was then employed in a case-control study including 147 men with AAA (infrarenal aorta ≥ 30 mm) and 251 AAA-free controls recruited at the general population-based ultrasound screening for AAA in 65-year-old Swedish men.

OUTCOMES INCLUDED

associations between dehydroepiandrosterone, progesterone, 17α-hydroxyprogesterone, androstenedione, estrone, testosterone, dihydrotestosterone, and estradiol and AAA presence.

RESULTS

Dehydroepiandrosterone, progesterone, 17α-hydroxyprogesterone, testosterone, and estradiol, but not the other hormones, were lower in men with AAA. In models with adjustments for known AAA risk factors and comorbidity, only progesterone (odds ratio per SD decrease 1.62 [95% CI, 1.18-2.22]) and estradiol (1.40 [95% CI, 1.04-1.87]) remained inversely associated with the presence of AAA. Progesterone and estradiol contributed with independent additive information for prediction of AAA presence; compared with men with high (above median) levels, men with low (below median) levels of both hormones had a 4-fold increased odds ratio for AAA (4.06 [95% CI, 2.25-7.31]).

CONCLUSION

Measured by a high-performance sex steroid assay, progesterone and estradiol are inversely associated with AAA in men, independent of known risk factors. Future studies should explore whether progesterone and estradiol, which are important reproductive hormones in women, are protective in human AAA.

Androgen Glucuronidation in Mice: When, Where, and How

Simple Summary

Hormone metabolism can vary from one species to another. In humans, specific UDP-glucuronosyltransferase (UGT) enzymes transform androgens (the male hormones) into glucuronide derivatives, which are easier to eliminate. Whether a similar mechanism also takes place in mice has never been ascertained. This study aimed at addressing this question. Organs and pure Ugt2b enzymes from mice were assayed for their ability to transform several androgens into their glucuronide derivatives. Results show that, as in humans, both murine organs and enzymes are reactive with androgen molecules, and glucuronide derivatives are formed with substrate-, organ- and enzyme-specific manner. In conclusion, these observations revealed that glucuronosyltransferase enzymes from mice works in a similar manner as their human counterparts.

Abstract

Glucuronidation, catalyzed by UDP-glucuronosyltransferase UGT2B enzymes, is a major inactivating and elimination pathway for androgen hormones in humans. Whether Ugt2b enzymes from mice are also reactive with these hormones have never been investigated. The present study aimed at evaluating the capability of murine tissues and Ugt2b enzymes to glucuronidated androgens. The 7 murine Ugt2b (Ugt2b1, 2b5, 2b34, 2b35, 2b36, 2b37 and 2b38) enzymes were cloned and stably expressed into HEK293 cells. In vitro glucuronidation assays were performed with microsomal proteins or homogenates from mice tissues (liver, kidney, intestine, adipose, testis, prostate, epididymis, bulbo, seminal vesicle, mammary glands, uterus, and ovary) and from Ugt2b-HEK293 cells. Male and female livers, as well as male kidneys, are the major sites for androgen glucuronidation in mice. The male liver is highly efficient at glucuronidation of dihydrotestosterone (DHT) and testosterone and is enriched in Ugt2b1 and 2b5 enzymes. Androsterone and 3α-Diol are conjugated in the male kidney through an Ugt2b37-dependent process. Interestingly, castration partially abolished hepatic Ugt2b1 expression and activity, while Ugt2b37 was totally repressed. DHT injection partially corrected these changes. In conclusion, these observations revealed the substrate- and tissue-specific manner in which murine Ugt2b enzymes conjugate androgens. They also evidence how androgens modulate their own glucuronide conjugation in mice.

Skeletal muscle wasting: the estrogen side of sexual dimorphism

The importance of defining sex differences across various biological and physiological mechanisms is more pervasive now than it has been over the past 15-20 years. As the muscle biology field pushes to identify small molecules and interventions to prevent, attenuate, or even reverse muscle wasting, we must consider the effect of sex as a biological variable. It should not be assumed that a therapeutic will affect males and females with equal efficacy or equivalent target affinities under conditions where muscle wasting is observed. With that said, it is not surprising to find that we have an unclear or even a poor understanding of the effects of sex or sex hormones on muscle wasting conditions. Although recent investigations are beginning to establish experimental approaches that will allow investigators to assess the impact of sex-specific hormones on muscle wasting, the field still needs rigorous scientific tools that will allow the community to address critical hypotheses centered around sex hormones. The focus of this review is on female sex hormones, specifically estrogens, and the roles that these hormones and their receptors play in skeletal muscle wasting conditions. With the overall review goal of assembling the current knowledge in the area of sexual dimorphism driven by estrogens with an effort to provide insights to interested physiologists on necessary considerations when trying to assess models for potential sex differences in cellular and molecular mechanisms of muscle wasting.

A developed HPLC-MS/MS method to quantitate 5 steriod hormones in clinical human serum by using PBS as the surrogate matrix

Steroid hormones play an essential role in regulating physiological and reproductive development throughout the lifetime of an individual. One of the difficulties in determining endogenous substances is the lack of a blank matrix. Especially when the level of analytes is lower than the level in the so-called blank matrix. In the present study, an optimized HPLC-MS/MS method was developed and validated to quantify androstenedione (ASD), testosterone (Ts), dehydroepiandrosterone (DHEA), 5α-dihydrotestosterone (DHT), and progesterone (P) in serum samples from healthy people using PBS (pH = 7.4) as the blank surrogate matrix. Simultaneously, the method investigated the characteristics of NaCl, bull serum albumin, pure water as surrogate matrices for the analysis of steroid hormones. The data showed that the matrix effects of ASD, Ts, DHEA, DHT, and P in the same groups were not significantly different between PBS and twice charcoal-stripped serum (CS₂S) as a blank surrogate matrix. Furthermore, the LLOQ using PBS as the blank matrix was up to 0.005 ng/mL for ASD, Ts, and P and 0.05 ng/mL for DHEA and DHT. The reference ranges of concentration (C_PBS) of 5 steroid hormones were provided. Compared to the concentration with CS₂S (C_CSS) as the blank surrogate matrix, the relative biases (RBs) of Ts, DHT, P, and DHEA were finally stabilized at approximately -0.7%, -15%, -1.2%, and 9.2%, respectively. The results suggest that, in the cases of special required, the developed HPLC-MS/MS method can be used to determine the absolute concentration of 5 hormones in biological samples with PBS as the blank surrogate matrix.

Association of Genetically Predicted Serum Estradiol With Risk of Thromboembolism in Men: A Mendelian Randomization Study

CONTEXT

An association was recently reported between genetic markers related to high testosterone and increased risk of thromboembolism in men, but a possible causal role of estradiol for risk of thromboembolism in men remains unknown.

OBJECTIVE

This work aimed to determine whether endogenous estradiol has a causal role in thromboembolism in men.

METHODS

A 2-sample mendelian randomization study using gene-based genetic instruments assessed the association between endogenous estradiol genetically predicted by 22 variants in the aromatase CYP19A1 gene region and the risk of thromboembolism (5815 cases) in 170 593 unrelated men of White ancestry in the UK Biobank. The main outcome measure included thromboembolism based on self-reports, hospital episodes, and death.

RESULTS

Endogenous estradiol genetically predicted by variants in the CYP19A1 gene region was inversely associated with the risk of thromboembolism (odds ratio per SD increase in estradiol 0.74; 95% CI, 0.62-0.90). In contrast, genetic variants in the JMJD1C gene, used as a predictor of high endogenous testosterone, were associated with an increased risk of thromboembolism (odds ratio per SD increase in testosterone 1.39; 95% CI, 1.12-1.72). Subsequent explorative analyses evaluating potential repercussions of thromboembolism revealed that endogenous estradiol genetically predicted by variants in the CYP19A1 gene region was inversely associated with the risk of ischemic stroke (0.68; 95% CI, 0.49-0.95) but not myocardial infarction (0.97; 95% CI, 0.84-1.13).

CONCLUSION

Genetically predicted estradiol was inversely associated with the risk of thromboembolism and ischemic stroke in men. The ratio between testosterone and estradiol, determined by CYP19A1 activity, may contribute to the overall impact of sex steroids on thromboembolism in men.

Profiling of Steroid Metabolic Pathways in Human Plasma by GC-MS/MS Combined with Microwave-Assisted Derivatization for Diagnosis of Gastric Disorders

Steroid hormones are associated in depth to cellular signaling, inflammatory immune responses, and reproductive functions, and their metabolism alterations incur various diseases. In particular, quantitative profiling of steroids in plasma of patients with gastric cancer can provide a vast information to understand development of gastric cancer, since both sex hormones and glucocorticoids might be correlated with the pathological mechanisms of gastric cancer. Here, we developed a gas chromatography-tandem mass spectrometry-dynamic multiple reaction monitoring (GC-MS/MS-dMRM) method combined with solid-phase extraction (SPE) and microwave-assisted derivatization (MAD) to determine 20 endogenous steroids in human plasma. In this study, MAD conditions were optimized with respect to irradiation power and time. The SPE enabled effective cleanup and extraction for profiling of steroid hormones in human plasma samples. The MAD could improve laborious and time-consuming derivatization procedure, since dielectric heating using microwave directly increase molecular energy of reactants by penetrating through medium. Furthermore, dMRM method provided more sensitive determination of 20 steroids, compared to traditional MRM detection. The limits of quantification of steroids were below 1.125 ng/mL and determination coefficients of calibration curves were higher than 0.9925. Overall precision and accuracy results were below 19.93% and within ±17.04%, respectively. The developed method provided sufficient detection sensitivities and reliable quantification results. The established method was successfully applied to profile steroid metabolism pathways in plasma of patients with chronic superficial gastritis (CSG), intestinal metaplasia (IM), and gastric cancer. Statistical significances of steroid plasma levels between gastric disorder groups were investigated. In conclusion, this method provided comprehensive profiling of 20 steroids in human plasma samples and will be helpful to discover potential biomarkers for the development of gastric cancer and to further understand metabolic syndrome.

Circulating sex-steroids and Staphylococcus aureus nasal carriage in a general female population

OBJECTIVE

Staphylococcus aureus is a major human pathogen, and nasal carriers have an increased risk for infection and disease. The exploration of host determinants for nasal carriage is relevant to decrease infection burden. Former studies demonstrate lower carriage prevalence in women and among users of progestin-only contraceptives. The aim of this study was to investigate the possible associations between circulating sex-steroid hormones and nasal carriage of Staphylococcus aureus in a general population.

METHODS

In the population-based sixth Tromsø study (2007-2008) nurses collected nasal swab samples from 724 women aged 30-87 not using any exogenous hormones, and 700 of the women had a repeated nasal swab taken (median interval 28 days). We analysed a panel of serum sex-steroids by liquid chromatography tandem mass spectrometry, and collected information about lifestyle, health and anthropometric measures. Multivariable logistic regression was used to study the association between circulating sex-steroids and Staphylococcus aureus carriage (one swab) and persistent carriage (two swabs), while adjusting for potential confounding factors. Women in luteal phase were excluded in the analysis of androgens.

RESULTS

Staphylococcus aureus persistent nasal carriage prevalence was 22%. One standard deviation increase in testosterone and bioavailable testosterone was associated with lower odds of persistent nasal carriage, (OR = 0.57; 95% CI = 0.35-0.92 and OR = 0.52, 95% CI = 0.30-0.92) respectively. Analysis stratified by menopause gave similar findings. Persistent carriers had lower average levels of androstenedione and DHEA, however, not statistically significant.

CONCLUSION

This large population-based study supports that women with lower levels of circulating testosterone may have increased probability of Staphylococcus aureus persistent carriage.

Reproductive dysfunction linked to alteration of endocrine activities in zebrafish exposed to mono-(2-ethylhexyl) phthalate (MEHP)

This study aimed to investigate the effect of mono-(2-ethylhexyl) phthalate (MEHP), one of the major phthalate metabolites that are widespread in aquatic environments, on reproductive dysfunction, particularly on endocrine activity in adult male and female zebrafish. For 21 days, the zebrafish were exposed to test concentrations of MEHP (0, 2, 10, and 50 μg/mL) that were determined based on the effective concentrations (ECx) for zebrafish embryos. Exposure to 50 μg/mL MEHP in female zebrafish significantly decreased the number of ovulated eggs as well as the hepatic VTG mRNA abundance when those of the control group. Meanwhile, in female zebrafish, the biosynthetic concentrations of 17β-estradiol (E2) and the metabolic ratio of androgen to estrogen were remarkably increased in all MEHP exposed group compared with those in the control group, along with the elevated levels of cortisol. However, no significant difference was observed between these parameters in male zebrafishes. Therefore, exposure to MEHP causes reproductive dysfunction in female zebrafishes and this phenomenon can be attributed to the alteration in endocrine activities. Moreover, the reproductive dysfunction in MEHP-exposed female zebrafishes may be closely associated with stress responses, such as elevated cortisol levels. To further understand the effect of MEHP on the reproductive activities of fish, follow-up studies are required to determine the interactions between endocrine activities and stress responses. Overall, this study provides a response biomarker for assessing reproductive toxicity of endocrine disruptors that can serve as a methodological approach for an alternative to chronic toxicity testing.

Associations Between Prediagnostic Concentrations of Circulating Sex Steroid Hormones and Liver Cancer Among Postmenopausal Women

BACKGROUND AND AIMS

In almost all countries, incidence rates of liver cancer (LC) are 100%-200% higher in males than in females. However, this difference is predominantly driven by hepatocellular carcinoma (HCC), which accounts for 75% of LC cases. Intrahepatic cholangiocarcinoma (ICC) accounts for 12% of cases and has rates only 30% higher in males. Hormones are hypothesized to underlie observed sex differences. We investigated whether prediagnostic circulating hormone and sex hormone binding globulin (SHBG) levels were associated with LC risk, overall and by histology, by leveraging resources from five prospective cohorts.

APPROACH AND RESULTS

Seven sex steroid hormones and SHBG were quantitated using gas chromatography/tandem mass spectrometry and competitive electrochemiluminescence immunoassay, respectively, from baseline serum/plasma samples of 191 postmenopausal female LC cases (HCC, n = 83; ICC, n = 56) and 426 controls, matched on sex, cohort, age, race/ethnicity, and blood collection date. Odds ratios (ORs) and 95% confidence intervals (CIs) for associations between a one-unit increase in log₂ hormone value (approximate doubling of circulating concentration) and LC were calculated using multivariable-adjusted conditional logistic regression. A doubling in the concentration of 4-androstenedione (4-dione) was associated with a 50% decreased LC risk (OR = 0.50; 95% CI = 0.30-0.82), whereas SHBG was associated with a 31% increased risk (OR = 1.31; 95% CI = 1.05-1.63). Examining histology, a doubling of estradiol was associated with a 40% increased risk of ICC (OR = 1.40; 95% CI = 1.05-1.89), but not HCC (OR = 1.12; 95% CI = 0.81-1.54).

CONCLUSIONS

This study provides evidence that higher levels of 4-dione may be associated with lower, and SHBG with higher, LC risk in women. However, this study does not support the hypothesis that higher estrogen levels decrease LC risk. Indeed, estradiol may be associated with an increased ICC risk.

Acute Valproate Exposure Induces Sex-Specific Changes in Steroid Hormone Metabolism in the Cerebral Cortex of Juvenile Mice

Valproic acid (VPA), an antiepileptic and mood stabilizer, modulates neurotransmission and gene expression by inhibiting histone deacetylase activity. It is reported that VPA may affects the steroid hormone level. In this study, VPA-induced acute metabolic alterations were investigated using liquid chromatography-tandem mass spectrometry in prepubertal mice brain. In VPA-treated (400 mg/kg in saline solution, intraperitoneal) mice, cortisol levels were increased (female: P < 0.004, male: P < 0.003) and 17β-estradiol levels were decreased (Both P < 0.03). Furthermore, in the VPA-treated male mice, dihydrotestosterone levels were increased (P < 0.02) and testosterone were decreased (P < 0.002). The 4-hydroxylase activity was upregulated in the female VPA-treated mice (P < 0.01) and the 5α-reductase activity was increased in the male VPA-treated mice (P < 0.003). These results indicate sex specific differences in VPA-induced steroid metabolism in the brain cortex.

Associations of plasma androgens with suicidality among men and women: A 9-year longitudinal cohort study

BACKGROUND

Testosterone has been implicated in suicidality in cross-sectional studies. Stress that coincides with a suicide attempt may alter androgen levels, so prospective studies are needed to exclude reverse causation. We aimed to examine the associations of plasma androgens with concurrent and future suicidality, and if present, whether these associations were mediated by a behavioral trait like reactive aggression.

METHODS

Baseline plasma levels of total testosterone, 5α-dihydrotestosterone, and androstenedione were determined with liquid chromatography-tandem mass spectrometry, and dehydroepiandrosterone-sulphate with a radioimmunoassay. Suicidality was assessed using the Suicidal Ideation Scale at baseline and after 2-, 4-, 6-, and 9-year follow-up. Men and women were analyzed separately, and potential confounders were considered.

RESULTS

Participants (N = 2861; 66.3% women) had a mean age of 42.0 years (range 18-65) and almost half (46.9%) fulfilled criteria for a major depressive or anxiety disorder. At baseline 13.2% of men and 11.2% of women reported current suicidal ideation. In participants who were non-suicidal at baseline, slightly more men than women reported suicidal ideation during follow-up (14.7% vs. 12.5%), whereas the reverse pattern was observed for suicide attempts (3.6% vs. 4.2%). None of the associations between androgens and current and future suicidality were significant.

LIMITATIONS

Androgens were determined once, which may have been insufficient to predict suicidality over longer periods.

DISCUSSION

The lack of associations between plasma levels of androgens determined by 'gold-standard' laboratory methods with suicidality do not support previous cross-sectional and smaller studies in adult men and women with values within the physiological range.

Advancements in the gold standard: Measuring steroid sex hormones by mass spectrometry

Sex hormones, such as testosterone and estrogens, play an essential role in regulating physiological and reproductive development throughout the lifetime of the individual. Although variation in levels of these hormones are observed throughout the distinct stages in life, significant deviations from reference ranges can result in detrimental effects to the individual. Alterations, by either an increase or decrease, in hormone levels are associated with physiological changes, decreased reproductive capabilities, and increased risk for diseases. Hormone therapies (HTs) and assisted reproductive technologies (ARTs) are commonly used to address these factors. In addition to these treatments, gender-affirming therapies, an iteration of HTs, are also a prominent treatment for transgender individuals. Considering that the effectiveness of these treatments relies on achieving therapeutic hormone levels, monitoring of hormones has served as a way of assessing therapeutic efficay. The need for reliable methods to achieve this task has led to great advancements in methods for evaluating hormone concentrations in biological matrices. Although immunoassays are the more widely used method, mass spectrometry (MS)-based methods have proven to be more sensitive, specific, and reliable. Advances in MS technology and its applications for therapeutic hormone monitoring have been significant, hence integration of these methods in the clinical setting is desired. Here, we provide a general overview of HT and ART, and the immunoassay and MS-based methods currently utilized for monitoring sex hormones. Additionally, we highlight recent advances in MS-based methods and discuss future applications and considerations for MS-based hormone assays.

Associations Between Prediagnostic Concentrations of Circulating Sex Steroid Hormones and Esophageal/Gastric Cardia Adenocarcinoma Among Men

Background

Esophageal adenocarcinoma (EA) and gastric cardia adenocarcinoma (GCA) are characterized by a strong male predominance. Concentrations of sex steroid hormones have been hypothesized to explain this sex disparity. However, no prospective population-based study has examined sex steroid hormones in relation to EA/GCA risk. Thus, we investigated whether prediagnostic circulating sex steroid hormone concentrations were associated with EA/GCA in a nested case-control study drawn from participants in three prospective cohort studies.

Methods

Using gas chromatography-mass spectrometry (GC-MS) and electrochemiluminescence immunoassay, we quantitated sex steroid hormones and sex hormone binding globulin, respectively, in serum from 259 EA/GCA male case participants and 259 matched male control participants from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study, and Cancer Prevention Study II Nutrition Cohort. Multivariable conditional logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for associations between circulating hormones and EA/GCA risk. All statistical tests were two-sided.

Results

Higher concentrations of dehydroepiandrosterone (DHEA) were associated with a 38% decreased risk of EA/GCA (OR per unit increase in log2 DHEA = 0.62, 95% CI = 0.47 to 0.82, Ptrend = .001). Higher estradiol concentrations were associated with a 34% reduced risk of EA/GCA (OR = 0.66, 95% CI = 0.45 to 0.98, Ptrend = .05), and the association with free estradiol was similar. No other associations between baseline hormone concentrations and future EA/GCA risk were observed.

Conclusions

This study provides the first evidence that higher concentrations of circulating DHEA, estradiol, and free estradiol may be associated with lower risks of EA/GCA in men.

Serum Testosterone and Cortisol Concentrations After Single-Dose Administration of 100-Mg Transdermal Testosterone in Healthy Men

The growing interest in testosterone's effects on men's social behaviors, in particular aggressive, risk-taking, or status maintenance behaviors, is accompanied by a paucity of dose-dependent pharmacokinetic data. Examining the neurophysiological effects of transdermal testosterone typically includes a 4h delay before further brain-behavior measurements. Nevertheless, high heterogeneity regarding the timing of follow-up measurements and dosage remains. In a double-blind placebo-controlled design, we examined the short-term pharmacokinetic profile of 100-mg transdermal testosterone (Testotop^®) to determine the optimal time for detecting testosterone-mediated effects. Across two studies, 35 healthy men received a single dose of testosterone and placebo in two separate sessions. In study one (n = 16), serum testosterone and cortisol were assessed serially every 30 min up to 2 h posttreatment. In study two (n = 19), we assessed serum testosterone and cortisol at baseline, 2 h, and 4.15 h (255 min) posttreatment. Relative to baseline and placebo, transdermal testosterone significantly increased total serum testosterone concentrations 90 min posttreatment, reaching maximum concentration between 2 h and 3 h posttreatment. Albeit elevated, serum testosterone levels gradually decreased between 2 h and 4 h following treatment. Transdermal testosterone did not suppress cortisol release. Instead, cortisol concentrations decreased according to cortisol's known circadian rhythm. Unlike previous findings showing significant testosterone concentration increases as soon as 60 min and as late as 3 h post 150-mg testosterone treatment, our 100-mg testosterone manipulation significantly increased testosterone concentrations 90 min following treatment. These pharmacokinetic data are important in facilitating the optimization of timing parameters for future testosterone challenge studies.

Measuring urinary cortisol and testosterone levels in male Barbary macaques: A comparison of EIA and LC-MS

The development of methods to quantify hormones from non-invasively collected samples such as urine or feces has facilitated endocrinology research on wild-living animals. To ensure that hormone measurements are biologically meaningful, method validations are strongly recommended for each new species or sample matrix. Our aim was to validate three commonly used enzyme immunoassays (EIA), one for analysis of cortisol and two for analysis of testosterone, to assess adrenocortical and gonadal endocrine activity, respectively, from the urine of male Barbary macaques. We compared EIA and liquid chromatography-mass spectrometry (LC-MS) results to determine if the EIA measurements truly reflect levels of the target hormone and to determine if antibody cross-reactivities with other steroids were potentially confounding results. Furthermore, we conducted a biological validation of testosterone to ensure that both EIA and LC-MS were able to capture physiologically meaningful differences in hormone levels. We found that cortisol measured by EIA correlated strongly with cortisol measured by LC-MS in both adult and immature males, without the need for deconjugation of steroids in the urine. Both testosterone EIAs correlated strongly with LC-MS in adult males, but only if steroids in the urine were deconjugated by enzymatic hydrolysis prior to analysis. However, in immature males, EIA and LC-MS results did not correlate significantly. Further correlation analyses suggest this is likely due to cross-reactivity of the testosterone antibodies with other adrenal steroids such as cortisol, DHEA, and likely others, which are present at much higher concentrations relative to testosterone in immature males. Testosterone levels were significantly higher in adult compared to immature males as measured by LC-MS but not as measured by EIA. Taken together, our results suggest that the testosterone EIAs are suitable to assess gonadal activity in adult but not immature males, and only if a hydrolysis of the urine is conducted prior to analysis.

Relative hyperestrogenism in Klinefelter Syndrome: results from a meta-analysis

OBJECTIVE

Klinefelter Syndrome (KS) is classically described as characterized by hyperestrogenism, although solid evidence is lacking. This study aims to test the hypothesis that men with KS have higher serum estradiol than normal controls.

DESIGN

Meta-analysis of all studies extracted by MEDLINE from 1942 to 31 January 2018. All studies reporting serum estradiol measurement were considered, among them only case-control studies were included in the meta-analysis.

METHODS

Meta-analysis was conducted according to the PRISMA statement using RevMan.

RESULTS

Out of 4120 articles, 23 case-control studies, 14 case series, and 19 case reports reported data on serum estradiol. A total of 707 KS and 1019 controls were included in the meta-analysis. Serum estradiol was slightly, but significantly higher in KS than controls (mean difference 4.25 pg/mL; CI: 0.41, 8.10 pg/mL; p = 0.030). This difference was lost considering only studies using estradiol assays with good accuracy (5.48 pg/mL, CI: -2.11, 13.07 pg/mL; p = 0.160). Serum testosterone and estradiol/testosterone ratio were significantly lower and higher in KS than controls, respectively. Data from KS case series and case reports confirmed that serum estradiol is within the normal ranges.

CONCLUSIONS

Serum estradiol is not increased in KS although slightly higher than controls. However, the meta-analysis that included only studies using a serum estradiol assay with good accuracy showed no difference in serum estradiol between KS and controls. The traditional belief that KS is associated with elevated serum estradiol should be reconsidered. This meta-analysis shows that men with KS have relative hyperestrogenism (increased estradiol/testosterone ratio) compared to controls.

Effects of transdermal testosterone treatment on inflammatory markers in elderly males

OBJECTIVE

During the male aging process, testosterone (T) levels progressively fall and inflammatory biomarkers increase. Although a relationship between these 2 phenomena has been tested in previous clinical trials, there is inconclusive evidence about the potential anti-inflammatory action of T.

METHODS

A total of 108 healthy males >65 years with serum T concentration <475 ng/dL were recruited by direct mailings to alumni of the University of Pennsylvania and Temple University and randomized to 60-cm2 T or a placebo patch for 36 months. Ninety-six subjects completed the trial. Information and stored serum specimens from this trial were used to test the hypothesis of the inhibitory effect of T on inflammation. We evaluated 70 males (42 in the T group) who had banked specimens from multiple time points available for assays of T, C-reactive protein (CRP), tumor necrosis factor (TNF)-α, soluble TNF-α receptor-1 (TNFR1), interleukin-6 (IL-6), and soluble IL-6 receptors (sIL6r and sgp130).

RESULTS

The mean age ± SD at baseline was 71.8 ± 4.9 years. Testosterone replacement therapy for 36 months did not induce significant decreases in inflammatory markers. A trend toward a significant increase was observed in the placebo group for TNF-α (P = .03) and sgp130 (P = .01). Significant differences in estimated means of TNFR1 (but not other inflammatory markers), with lower levels in the T group, were observed at the 36-month time point. In T-treated subjects we found an almost significant treatment x time interaction term TNFR1 (P = .02) independent of total body fat content as assessed by dual energy X-ray absorptiometry (DXA). No serious adverse effect was observed.

CONCLUSIONS

Transdermal T treatment of older males for 36 months is not associated with significant changes in inflammatory markers.

Comparison of isotope pattern deconvolution and calibration curve quantification methods for the determination of estrone and 17β-estradiol in human serum

A Liquid Chromatography coupled to tandem mass spectrometry (LC-MS/MS) based method have been developed for the determination of the main estrogen compounds -estrone (E1) and 17β-estradiol (E2)- in human serum. Two isotope dilution mass spectrometry (IDMS) quantification procedures have been used: a classical calibration curve-based method were compared to a recently developed isotope pattern deconvolution (IPD) method. IPD is based on isotopic abundance measurements and multiple linear regression. Validation was performed in terms of intra-assay repeatability (n = 5), inter-assay reproducibility (n = 9) and accuracy using spiked steroid-free serum at 5 concentration levels and 3 certified reference materials. Both methodologies meet EMEA requirements yielding recoveries between 79-106% and coefficient of variations of 1.7-8.3% along all experiments. Limits of quantification as low as 5 ng/L were achieved. 40 real samples were analysed for comparison purposes showing a great correlation between calibration and IPD concentration values. Real samples were also quantified by routine immunoassay analysis, which showed a significant proportional bias of 2.55 for E1 and good correlation for E2. While methods were considered suitable for routine or countercheck analysis within the context of hospital's needs, IPD has demonstrated to be faster and cost saving.

Establishment of reference intervals for serum concentrations of androstanediol glucuronide by a newly developed LC-MS/MS method

BACKGROUND

Androstanediol glucuronide is linked to a range of disorders of peripheral androgen formation and action, such as in hirsutism and acne. Nowadays its accurate quantification is still challenging and there are just a few LC-MS/MS methods available. Besides, their reference intervals for normal European populations by LC-MS/MS, including prepubertal and pubertal children, have not been reported yet.

METHODS

Validation of the proposed new methodology was performed at 3 levels in triplicate during 3 different days. Calibration curve concentration ranged from 0.1 to 25 µg/L. For method comparison between ELISA and the newly developed LC-MS/MS method, 43 patient samples were tested. A reference interval study was performed with 264 healthy Belgian individuals (108 male and 156 female).

RESULTS

Validation of the proposed LC-MS/MS method was satisfactorily achieved, with mean imprecision values lower than 7.4%, mean recoveries within 99-108% and a limit of quantification of 0.059 µg/L. Compared to LC-MS/MS, ELISA showed a positive bias in serum samples, providing results 43% higher for the same sample. As a consequence, new reference intervals based on age and gender have been calculated.

CONCLUSION

An easy, fast and straightforward LC-MS/MS method for the determination of androstanediol glucuronide has been developed and fully validated. Besides, reference interval for normal European populations, including prepubertal and pubertal children has been established for the first time.

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.

Lower Circulating Androgens Are Associated with Overall Cancer Risk and Prostate Cancer Risk in Men Aged 25-84 Years from the Busselton Health Study

Androgens, notably testosterone (T), have been implicated in development of several common cancers and prostate cancer; however, precise mechanisms remain unclear. This study assessed prospective associations of serum T, dihydrotestosterone (DHT) and estradiol (E2) with overall cancer (excluding skin cancer), prostate, colorectal and lung cancer risk in 1574 community-dwelling men aged 25-84 years. Sex hormones were assayed using mass spectrometry and men were followed for 20 years with outcomes ascertained using data linkage. Over 20 years, there were 289, 116, 48 and 22 men who developed any cancer, prostate cancer, colorectal cancer and lung cancer, respectively. Androgens in the lowest quartile were associated with an increased overall cancer risk (HR = 1.36, 95% CI 1.05-1.76, p = 0.020 for T; and HR = 1.30, 95% CI 1.00-1.69, p = 0.049 for DHT comparing the lowest vs other quartiles). T in the lowest quartile was associated with an increased risk of prostate cancer (HR = 1.53, 95% CI 1.02-2.29, p = 0.038 comparing the lowest vs other quartiles). The association between androgens and overall cancer risk remained similar after excluding prostate cancer outcomes; however, results were not significant. There were no associations of T, DHT or E2 with colorectal or lung cancer risk; however, LH in the highest quartile was associated with an increased risk of lung cancer (HR = 4.55, 95% CI 1.70-12.19, p = 0.003 for the highest vs other quartiles). Whether T is a biomarker of poor health in men with any cancer or prostate cancer requires further confirmation as does the nature and mechanism of the association of a high LH with future lung cancer.

Behavioral evidence for sex steroids hypersensitivity in castrated male canaries

In seasonally breeding songbirds such as canaries, singing behavior is predominantly under the control of testosterone and its metabolites. Short daylengths in the fall that break photorefractoriness are followed by increasing daylengths in spring that activate singing via both photoperiodic and hormonal mechanisms. However, we observed in a group of castrated male Fife fancy canaries maintained for a long duration under a short day photoperiod a large proportion of subjects that sang at high rates. This singing rate was not correlated with variation in the low circulating concentrations of testosterone. Treatment of these actively singing castrated male canaries with a combination of an aromatase inhibitor (ATD) and an androgen receptor blocker (flutamide) only marginally decreased this singing activity as compared to control untreated birds and did not affect various measures of song quality. The volumes of HVC and of the medial preoptic nucleus (POM) were also unaffected by these treatments but were relatively large and similar to volumes in testosterone-treated males. In contrast, peripheral androgen-sensitive structures such as the cloacal protuberance and syrinx mass were small, similar to what is observed in castrates. Together these data suggest that after a long-term steroid deprivation singing behavior can be activated by very low concentrations of testosterone. Singing normally depends on the activation by testosterone and its metabolites of multiple downstream neurochemical systems such as catecholamines, nonapeptides or opioids. These transmitter systems might become hypersensitive to steroid action after long term castration as they probably are at the end of winter during the annual cycle in seasonally breeding temperate zone species.

Corrigendum to "Validation of a testosterone and dihydrotestosterone liquid chromatography tandem mass spectrometry assay: interference and comparison with established methods" [Steroids Volume 73, Issue 13, 12 December 2008, Pages 1345-1352]

Testosterone (T) and its metabolite dihydrotestosterone (DHT) are androgens with different biologic profiles. T and DHT measurements are required for assessment of patients with ambiguous genitalia, hirsutism, during 5 alpha reductase treatment of prostate disorders, and new androgen formulations. Our laboratory has developed and validated a method to simultaneously measure serum T and DHT with liquid chromatography tandem mass spectrometry (LC-MS/MS) for use in a clinical chemistry laboratory. Analysis of sera from blood collected in tubes containing clot activator gave results of T that were four fold higher than blood collected in plain tubes. Changing the ion pair selected for monitoring eliminated this interference by clot activators. Blood collected in fluoride coated tubes gave serum T and DHT levels that were 20 and 15 percent lower respectively than levels measured in blood collected in plain tubes (no additives). Addition of T enanthate to blood collected in plain tubes caused a dose related increase serum T levels due to the action of non-specific esterases in the red cells. This esterase activity could be avoided by using fluoride tubes for blood collection. Serum DHT levels were consistently lower when measured by LC-MS/MS versus radioimmunoassay. The differences were concentration dependent and the variance for the difference was large when serum DHT concentration was low. Celite chromatograph prior to radioimmunoassay reduced the differences between the two methods, thus confirming that higher levels of DHT obtained by immunoassays were probably due to interfering substances which were partially removed by Celite chromatography.

Dihydrotestosterone and cancer risk

PURPOSE OF REVIEW

Androgens have been implicated in prostate growth; however, the role of androgens in prostate cancer development is not clear. Furthermore, studies suggest a role for androgens in female-hormone-dependent cancers and common nonhormone dependent cancers. This study aims to review key studies and more recent studies of dihydrotestosterone (DHT) and cancer risk.

RECENT FINDINGS

Epidemiological studies are reassuring as they have not associated endogenous androgens with prostate cancer risk. Intraprostatic regulation of DHT is becoming recognized as an important area of research to clarify the role of DHT in prostate cancer development. In females, further understanding of intracrine regulation of sex hormones and interactions between androgens and estrogens in influencing breast and endometrial cancer risk are required. Studies show a signal for DHT in modulating lung and colorectal cancer growth; however, research in this area is relatively scarce and further studies are required to clarify these associations.

SUMMARY

Although concerns of prostate cancer risk remain, there is also potential for androgens to modulate the growth and development of other common cancers. Further research is required as this may have clinical implications.

Fat Mass Follows a U-Shaped Distribution Based on Estradiol Levels in Postmenopausal Women

OBJECTIVE

Estradiol (E2) regulates adipose tissue resulting in increased fat mass (FM) with declining E2. However, increased visceral fat and hyperestrogenemia are features of obese individuals. It is possible that adipocytes in obese individuals are less sensitive to E2 resulting in higher FM. Our objective is to identify the range of serum E2 for which postmenopausal women have the lowest FM and best body composition.

METHODS

Cross-sectional data from 252 community-dwelling postmenopausal women, 42-90 years old. Subjects were stratified into categories of E2 (pg/ml): (1) ≤10.5; (2) 10.6-13.9; (3) 14.0-17.4; and (4) ≥17.5. Body composition by dual-energy X-ray absorptiometry. Serum E2 by radioimmunoassay. Between-group comparisons by analysis of covariance.

RESULTS

E2 linearly increased with increasing body weight and body mass index (r = 0.15 and p = 0.01 for both), but not with total FM (kg) or % FM (r = 0.07, p = 0.34 and r = -0.04, p = 0.56, respectively). However, total FM (kg) followed a U-shaped distribution and was significantly lower in group 3 (27.6 ± 10.6), compared with groups 1: (34.6 ± 12.5), 2: (34.0 ± 12.4), and 4: (37.0 ± 10.6), p = 0.005. % FM was also lowest in group 3. While fat-free mass (FFM, kg) increased with increasing E2 (p < 0.001), % FFM was highest in group 3.

CONCLUSION

In our population of postmenopausal women, FM followed a U-shaped distribution according to E2 levels. E2 between 14.0 and 17.4 pg/ml is associated with the best body composition, i.e., lowest total and % FM and highest % FFM. Given the role of E2 in regulating body fat, high FM at the high end of the E2 spectrum may suggest reduced E2 sensitivity in adipocytes among obese postmenopausal women.

CLINICAL TRIALS

ClinicalTrials.gov identifier: NCT00146107.

Clinical and biochemical correlates of male hypogonadism in type 2 diabetes

The origin of hypogonadism, a condition including both symptoms and biochemical criteria of androgen deficiency, in type 2 diabetes is poorly known. In a cross-sectional study of 267 unselected patients, we analyzed the potential correlation of several clinical and biochemical variables as well as chronic micro- and macrovascular diabetic complications with hypogonadism. Hypogonadism was present in 46 patients (17.2%) using a cutoff of total testosterone 10.4 nmol/L and in 31 (11.6%) with a cutoff of 8 nmol/L. Among these patients, hypogonadotropic hypogonadism was the most prevalent form (82.6%). Compared to eugonadal subjects, hypogonadal men had significantly lower glomerular filtration rate (67.1 ± 23.4 vs. 78.4 ± 24.6 mL/min/1.73 m² , p = 0.005) and higher prevalence of chronic kidney disease (43.5% vs. 20.4%, p = 0.002), abnormal liver function tests (26.7% vs. 12%, p = 0.019), and psychiatric treatment (23.9% vs. 10.4%, p = 0.025). Total testosterone levels correlated inversely with age (R = -0.164, p = 0.007), fasting blood glucose (R = -0.127, p = 0.037), and triglycerides (R = -0.134, p = 0.029) and directly with glomerular filtration rate (R = 0.148, p = 0.015). Calculated free testosterone and bioavailable testosterone correlated directly with hemoglobin (R = 0.171, p = 0.015 and R = 0.234, p = 0.001, respectively). Multivariate logistic regression analysis, after adjusting for relevant confounding variables, showed that age >60 years (OR = 3.58, CI 95% = 1.48-8.69, p = 0.005), body mass index >27 kg/m² (OR = 2.85, CI 95% = 1.14-7.11, p = 0.025), hypertriglyceridemia (OR = 2.16, CI 95% = 1.05-4.41, p = 0.035), glomerular filtration rate <60 mL/min/1.73 m² (OR = 2.51, CI 95% = 1.19-5.29, p = 0.015), and abnormal liver function tests (OR = 3.57, CI 95% = 1.48-8.60, p = 0.005) were independently associated with male hypogonadism. Although older age, body mass index, and hypertriglyceridemia have been previously related to hypogonadism, our results describe that chronic kidney disease and abnormal liver function tests are independently correlated with hypogonadism in type 2 diabetic men.

Relationships between Circulating and Intraprostatic Sex Steroid Hormone Concentrations

Background: Sex hormones have been implicated in prostate carcinogenesis, yet epidemiologic studies have not provided substantiating evidence. We tested the hypothesis that circulating concentrations of sex steroid hormones reflect intraprostatic concentrations using serum and adjacent microscopically verified benign prostate tissue from prostate cancer cases.Methods: Incident localized prostate cancer cases scheduled for surgery were invited to participate. Consented participants completed surveys, and provided resected tissues and blood. Histologic assessment of the ends of fresh frozen tissue confirmed adjacent microscopically verified benign pathology. Sex steroid hormones in sera and tissues were extracted, chromatographically separated, and then quantitated by radioimmunoassays. Linear regression was used to account for variations in intraprostatic hormone concentrations by age, body mass index, race, and study site, and subsequently to assess relationships with serum hormone concentrations. Gleason score (from adjacent tumor tissue), race, and age were assessed as potential effect modifiers.Results: Circulating sex steroid hormone concentrations had low-to-moderate correlations with, and explained small proportions of variations in, intraprostatic sex steroid hormone concentrations. Androstane-3α,17β-diol glucuronide (3α-diol G) explained the highest variance of tissue concentrations of 3α-diol G (linear regression r2 = 0.21), followed by serum testosterone and tissue dihydrotestosterone (r2 = 0.10), and then serum estrone and tissue estrone (r2 = 0.09). There was no effect modification by Gleason score, race, or age.Conclusions: Circulating concentrations of sex steroid hormones are poor surrogate measures of the intraprostatic hormonal milieu.Impact: The high exposure misclassification provided by circulating sex steroid hormone concentrations for intraprostatic levels may partly explain the lack of any consistent association of circulating hormones with prostate cancer risk. Cancer Epidemiol Biomarkers Prev; 26(11); 1660-6. ©2017 AACR.

The association of testosterone, sex hormone-binding globulin, and insulin-like growth factor-1 with bone parameters in Korean men aged 50 years or older

Testosterone and insulin-like growth factor-1 (IGF-1) are essential factors for the maintenance of bone health in men. However, the results for the association of testosterone and IGF-1 with bone parameters were not consistent in prior studies. We evaluated the relationship of testosterone, sex hormone-binding globulin (SHBG), and IGF-1 with bone mineral density (BMD) and bone turnover markers (BTMs) in Korean men. We enrolled 1227 men aged ≥50 years in this cross-sectional study. Serum levels of total testosterone (TT), SHBG, IGF-1, osteocalcin, and C-terminal cross-linking telopeptide of type I collagen (CTX) were measured. Free testosterone (FT) was calculated using Vermeulen's method. BMD was measured by dual-energy X-ray absorptiometry. TT level was not related to BMD or BTMs in the unadjusted model; however, after adjusting for SHBG and IGF-1, the association between TT and BTMs was significant (β = -0.139 for osteocalcin and β = -0.204 for CTX). SHBG levels were negatively associated with lumbar BMD, and positively associated with BTMs in all models. As SHBG level increased, the prevalence of osteopenia or osteoporosis defined by BMD significantly increased (OR of 1SD change, 1.24). IGF-1 levels were significantly related with BMD, but not with BTMs. Meanwhile, FT levels were positively associated with BMD and negatively associated with BTMs. In conclusion, SHBG levels were independently related with bone parameters and osteopenia in men aged ≥50 years. IGF-1 levels were positively associated with BMD, but not with BTMs. SHBG may play a role in regulating age-related bone loss in men after middle-age.

Role of Mass Spectrometry in Clinical Endocrinology

The advent of mass spectrometry into the clinical laboratory has led to an improvement in clinical management of several endocrine diseases. Liquid chromatography tandem mass spectrometry found some of its first clinical applications in the diagnosis of inborn errors of metabolism, in quantitative steroid analysis, and in drug analysis laboratories. Mass spectrometry assays offer analytical sensitivity and specificity that is superior to immunoassays for many analytes. This article highlights several areas of clinical endocrinology that have witnessed the use of liquid chromatography tandem mass spectrometry to improve clinical outcomes.

Umbilical cord blood androgen levels in girls and boys assessed by gas chromatography-tandem mass spectrometry

Androgen exposure of the fetus during gestation plays an important role in human physiology and pathophysiology, but assessment of androgens, in particular dihydrotestosterone (DHT), in human umbilical cord blood is technically challenging. The aim of this study was to assess umbilical cord androgen levels, including DHT, at birth by a highly sensitive assay, and study their association with sex of the infant, sex-hormone-binding globulin (SHBG) levels, and gestational age at delivery. Swedish infants (27 girls, 26 boys) were recruited at maternity care clinics in Southern Sweden. Umbilical cord blood levels of dehydroepiandrosterone (DHEA), androstenedione, testosterone and DHT at delivery were assessed by a gas chromatography-tandem mass spectrometry assay. Cord blood levels of DHT were 2.4-fold higher in boys (median 27.8pg/mL) than in girls (11.5pg/mL), while the sex difference was less pronounced for testosterone (1.3-fold higher in boys) and non-significant for DHEA and androstenedione. Gestational age at delivery associated inversely with DHT levels in boys and with DHEA levels in girls. There was a strong inverse correlation between SHBG and DHEA in both sexes, while there were no associations between SHBG and testosterone or DHT levels. In conclusion, using state of the art technology, we report that there is a pronounced sexual dimorphism in human umbilical cord blood DHT levels. The possibility to assess a complete androgen profile in human cord blood opens up for future increased understanding of the biological impact of the fetal androgen milieu.

Dihydrotestosterone: Biochemistry, Physiology, and Clinical Implications of Elevated Blood Levels

Benefits associated with lowered serum DHT levels after 5α-reductase inhibitor (5AR-I) therapy in men have contributed to a misconception that circulating DHT levels are an important stimulus for androgenic action in target tissues (e.g., prostate). Yet evidence from clinical studies indicates that intracellular concentrations of androgens (particularly in androgen-sensitive tissues) are essentially independent of circulating levels. To assess the clinical significance of modest elevations in serum DHT and the DHT/testosterone (T) ratio observed in response to common T replacement therapy, a comprehensive review of the published literature was performed to identify relevant data. Although the primary focus of this review is about DHT in men, we also provide a brief overview of DHT in women. The available published data are limited by the lack of large, well-controlled studies of long duration that are sufficiently powered to expose subtle safety signals. Nonetheless, the preponderance of available clinical data indicates that modest elevations in circulating levels of DHT in response to androgen therapy should not be of concern in clinical practice. Elevated DHT has not been associated with increased risk of prostate disease (e.g., cancer or benign hyperplasia) nor does it appear to have any systemic effects on cardiovascular disease safety parameters (including increased risk of polycythemia) beyond those commonly observed with available T preparations. Well-controlled, long-term studies of transdermal DHT preparations have failed to identify safety signals unique to markedly elevated circulating DHT concentrations or signals materially different from T.

Low Testosterone, but Not Estradiol, Is Associated With Incident Falls in Older Men: The International MrOS Study

Fracture risk is determined by bone strength and the risk of falls. The relationship between serum sex steroids and bone strength parameters in men is well known, whereas the predictive value of sex steroids for falls is less studied. The aim of this study was to assess the associations between serum testosterone (T) and estradiol (E2) and the likelihood of falls. Older men (aged ≥65 years) from the United States (n = 1919), Sweden (n = 2495), and Hong Kong (n = 1469) participating in the Osteoporotic Fractures in Men Study had baseline T and E2 analyzed by mass spectrometry. Bioavailable (Bio) levels were calculated using mass action equations. Incident falls were ascertained every 4 months during a mean follow-up of 5.7 years. Associations between sex steroids and falls were estimated by generalized estimating equations. Fall rate was highest in the US and lowest in Hong Kong (US 0.50, Sweden 0.31, Hong Kong 0.12 fall reports/person/year). In the combined cohort of 5883 men, total T (odds ratio [OR] per SD increase = 0.88, 95% confidence interval [CI] 0.86-0.91) and BioT (OR = 0.86, 95% CI 0.83-0.88) were associated with incident falls in models adjusted for age and prevalent falls. These associations were only slightly attenuated after simultaneous adjustment for physical performance variables (total T: OR = 0.94, 95% CI 0.91-0.96; BioT: OR = 0.91, 95% CI 0.89-0.94). E2, BioE2, and sex hormone-binding globulin (SHBG) were not significantly associated with falls. Analyses in the individual cohorts showed that both total T and BioT were associated with falls in MrOS US and Sweden. No association was found in MrOS Hong Kong, and this may be attributable to environmental factors rather than ethnic differences because total T and BioT predicted falls in MrOS US Asians. In conclusion, low total T and BioT levels, but not E2 or SHBG, are associated with increased falls in older men. © 2017 American Society for Bone and Mineral Research.

Ethnic differences in male reproductive hormones and relationships with adiposity and insulin resistance in older men

OBJECTIVES

To assess ethnic differences in male reproductive hormone levels and to determine whether any differences are explained by adiposity, insulin resistance (IR) or comorbidities in older men.

DESIGN

Multi-ethnic cross-sectional observational study.

PARTICIPANTS

Community dwelling middle-aged and elderly men residing in the UK aged 40-84 years of South Asian (SA; n = 180), White European (WE; n = 328) or African Caribbean (AC; n = 166) origin.

OBSERVATIONS

Measured testosterone (T), calculated free T (cFT), sex hormone-binding globulin and LH in SA, WE and AC men along with an assessment of body composition, IR, lifestyle factors and medical conditions.

RESULTS

Age-adjusted mean T and cFT levels were lower in SA men when compared to WE and AC men (mean (SEM) T: SA: 14·0 ± 0·4; WE: 17·1 ± 0·3; AC: 17·2 ± 0·5 nmol/l, P < 0·001; cFT: SA: 283 ± 7; WE: 313 ± 5; AC: 314 ± 8 pmol/l, P < 0·006). Compared to WE and AC men, SA men had higher levels of body fat, IR, comorbidities and diabetes. After adjusting for body fat, IR and other confounders, T levels in SA men remained lower than in WE men (P = 0·04) but ethnic differences in cFT became nonsignificant. LH levels were higher in SA than WE men in age-adjusted and fully adjusted models.

CONCLUSIONS

T and cFT are lower in SA men than in WE and AC men. Whether ethnic-specific reference ranges for T and cFT might be appropriate in clinical practice requires further investigation. Ethnic differences in cFT, but not T, appear to be, more readily, explained by ethnic differences in adiposity, thus providing insights into potential pathophysiological mechanisms.

Testosterone in human studies: Modest associations between plasma and salivary measurements

Testosterone is involved in many processes like aggression and mood disorders. As it may easily diffuse from blood into saliva, salivary testosterone is thought to reflect plasma free testosterone level. If so, it would provide a welcome noninvasive and less stressful alternative to blood sampling. Past research did not reveal consensus regarding the strength of the association, but sample sizes were small. This study aimed to analyse the association in a large cohort. In total, 2,048 participants (age range 18-65 years; 696 males and 1,352 females) were included and saliva (using cotton Salivettes) and plasma were collected for testosterone measurements. Levels were determined by enzyme-linked immunosorbent assay and radioimmunoassay respectively. Free testosterone was calculated by the Vermeulen algorithm. Associations were determined using linear regression analyses. Plasma total and free testosterone showed a significant association with salivary testosterone in men (adjusted β = .09, p = .01; and β = .15, p < .001, respectively) and in women (adjusted β = .08, p = .004; and crude β = .09, p = .002 respectively). The modest associations indicate that there are many influencing factors of both technical and biological origin.

Stress-induced changes of neurosteroid profiles in rat brain and plasma under immobilized condition

In this study, various neurosteroids in brain and plasma were simultaneously determined using liquid chromatography-tandem mass spectrometry and their profile changes in a stress-induced rats were investigated. The investigated neurosteroids are as follows: progesterone (P4), 5α-dihydroprogesterone (5α-DHP), 5β-dihydroprogesterone, estrone, androstenedione (AE), cortisol, cortisone, corticosterone (CORT), dehydroepiandrosterone (DHEA), pregnanolone (3α,5β-THP), allopregnanolone (ALLO), 11-deoxycorticosterone (DOC), 11-deoxycortisol, pregnenolone (PREG), and 5α/5β-tetrahydrodeoxycorticosterone (5α/5β-THDOC). Brain and plasma samples were processed using solid-phase extraction with methanol and acetic acid (99:1), and derivatized with a hydroxylamine reagent. Separation was achieved within 13min at a flow rate of 0.4mL/min with a C18 column (3.0×50mm, 2.7μm). The triple quadrupole mass spectrometer was operated in the positive electrospray ionization mode. Using this method, the neurosteroid level variation was quantitated and investigated in the brain and plasma upon immobilization stress in rats. As a result, AE, CORT, DOC, P4, 5α-DHP, 5α/5β-THDOC, DHEA, 3α,5β-THP, ALLO, and PREG levels were significantly altered in both the brain and plasma samples when stress was induced. These findings demonstrated that stress leads to the alteration of the GABAergic neurosteroid profile. The present results will be helpful for furthering an understanding of the role of neurosteroids in stressed conditions.

Multiplex assay reliability and long-term intra-individual variation of serologic inflammatory biomarkers

BACKGROUND

Circulating cytokines, chemokines, and soluble cytokine receptors can serve as biomarkers of inflammation and immune dysregulation. Good reliability of multiplex platforms, which allow for simultaneous, comprehensive biomarker assessment, is critical for their utility in epidemiologic studies. We examined the reliability of the Meso-Scale Discovery (MSD) platform to simultaneously quantitate 15 cytokines and chemokines and the Luminex platform (R&D Systems) to quantitate 5 soluble receptors and 2 chemokines and cytokines and evaluated long-term within-person correlation of these biomarkers.

METHODS

The detectability and reliability of these assay systems were assessed using the same external controls across plates and archived sera from 250 HIV^- men in the Multicenter AIDS Cohort Study. Using up to four visits per person from 1984 to 2009, age-adjusted intraclass correlation coefficients (ICC) of biomarkers with >80% detectability (CCL11, CXCL8, CXCL10, CCL2, CCL4, CCL13, CCL17, CXCL13, IL-10, IL-12p70, IL-6, TNF-α, BAFF, sCD14, sCD27, sgp130, sIL-2Rα, and sTNF-R2) were obtained using linear mixed models.

RESULTS

Most biomarkers were detectable in 80% of control samples; IFN-γ, GM-CSF, and IL-2 were undetectable in >20% of samples. Among the HIV-uninfected men, most biomarkers showed fair to strong within-person correlation (ICC>0.40) up to 15years. The ICC for CXCL8 was good in the short term but decreased with increasing time between visits, becoming lower (ICC<0.40) after 8years.

CONCLUSIONS

These multiplexed assays showed acceptable reliability for use in epidemiologic research, despite some technical variability and limitations in cytokine quantitation. Most biomarkers displayed moderate-to-excellent intra-individual variability over the long term, suggesting their utility in prospective studies investigating etiologic associations with diverse chronic conditions.

The androgen receptor gene CAG repeat in relation to 4-year changes in androgen-sensitive endpoints in community-dwelling older European men

CONTEXT

The androgen receptor (AR) gene exon 1 CAG repeat length has been proposed to be a determinant of between-individual variations in androgen action in target tissues, which might regulate phenotypic differences of human ageing. However, findings on its phenotypic effects are inconclusive.

OBJECTIVE

To assess whether the AR CAG repeat length is associated with longitudinal changes in endpoints that are influenced by testosterone (T) levels in middle-aged and elderly European men.

DESIGN

Multinational European observational prospective cohort study.

PARTICIPANTS

A total of 1887 men (mean ± s.d. age: 63 ± 11 years; median follow up: 4.3 years) from centres of eight European countries comprised the analysis sample after exclusion of those with diagnosed diseases of the hypothalamic-pituitary-testicular (HPT) axis.

MAIN OUTCOME MEASURES

Longitudinal associations between the AR CAG repeat and changes in androgen-sensitive endpoints (ASEs) and medical conditions were assessed using regression analysis adjusting for age and centre. The AR CAG repeat length was treated as both a continuous and a categorical (6-20; 21-23; 24-39 repeats) predictor. Additional analysis investigated whether results were independent of baseline T or oestradiol (E₂) levels.

RESULTS

The AR CAG repeat, when used as a continuous or a categorical predictor, was not associated with longitudinal changes in ASEs or medical conditions after adjustments. These results were independent of T and E₂ levels.

CONCLUSION

Within a 4-year time frame, variations in the AR CAG repeat do not contribute to the rate of phenotypic ageing, over and above, which might be associated with the age-related decline in T levels.