Laboratory measurement of testosterone

Impact of Lisinopril on Cardiometabolic Risk Factors in Sisters of Women With Polycystic Ovary Syndrome

Women with polycystic ovary syndrome (PCOS), the most common endocrinopathy in reproductive age, are characterized by increased cardiometabolic risk. Similar hormonal and metabolic changes were found in their siblings. The purpose of our study was to compare blood pressure-lowering and pleiotropic effects of lisinopril between sisters of women with PCOS and their unrelated peers. The study included two age-, body mass index-, and blood pressure-matched groups of women with grade 1 hypertension: 26 sisters of PCOS probands (Group 1) and 26 individuals without a family history of PCOS (Group 2), receiving 10-40 mg of lisinopril daily. Blood pressure, glucose homeostasis markers, plasma levels of lipids (androgens, estradiol, high-sensitivity C-reactive protein (hsCRP), homocysteine, fibrinogen, and uric acid), and urinary albumin-to-creatinine ratio (UACR) were measured before lisinopril treatment and 6 months later. At baseline, the study groups differed in insulin sensitivity, testosterone, free androgen index (FAI), hsCRP, homocysteine, and UACR. Blood pressure-lowering properties of lisinopril did not differ between the groups. The decrease in homocysteine and UACR, although observed in both groups, was stronger in Group 2 than in Group 1. Only in women without a family history of PCOS lisinopril improved insulin sensitivity and reduce hsCRP, fibrinogen, and uric acid. The remaining markers did not change throughout the study. Cardiometabolic effects of lisinopril correlated with testosterone, free androgen index, and changes in insulin sensitivity. The obtained results suggest that cardiometabolic effects of lisinopril may be slightly less pronounced in sisters of women with PCOS than in women without a family history of this disorder.

Impaired Prolactin-Lowering Effects of Metformin in Women with Polycystic Ovary Syndrome

The effect of metformin on prolactin concentration seems to be sex-dependent. The aim of this study was to determine whether the androgen status modulates the impact of metformin on plasma prolactin levels in women. This study included two matched groups of prediabetic women with hyperprolactinemia: 25 with PCOS and 25 control subjects with androgen levels within the reference range and with normal ovarian morphology. Glucose homeostasis markers, prolactin, the remaining anterior pituitary hormones, sex hormones, SHBG and IGF-1 were determined before and after six months of metformin treatment. At baseline, both groups differed in LH, LH/FSH ratio, testosterone, FAI, DHEA-S, androstenedione and estradiol. Although metformin improved insulin sensitivity and increased SHBG in both study groups, these effects were more pronounced in control subjects than in women with PCOS. In control subjects, the drug decreased total and monomeric prolactin and increased LH. In women with PCOS, metformin reduced LH, LH/FSH ratio, testosterone and FAI. In the control group, the impact on total and monomeric prolactin positively correlated with their baseline levels and with the degree of improvement in insulin sensitivity, as well as negatively correlated with testosterone and FAI. In women with PCOS, treatment-induced changes in testosterone and FAI positively correlated with the changes in LH and LH/FSH ratio. The obtained results suggest that the prolactin-lowering properties of metformin are less pronounced in women with coexisting PCOS than in women with elevated prolactin levels, probably owing to the increased production of endogenous testosterone.

The Impact of Atorvastatin on Cardiometabolic Risk Factors in Sisters of Women with Polycystic Ovary Syndrome

INTRODUCTION

Polycystic ovary syndrome (PCOS) is a frequent endocrinopathy in young women with significantly increased cardiometabolic risk. Siblings of women with this disorder are at increased risk of insulin resistance and androgen excess. The current study was aimed at investigating cardiometabolic effects of atorvastatin in sisters of women with PCOS.

METHODS

This prospective observational study compared two age-, body mass index-, blood pressure-, and plasma lipid-matched groups of women with hypercholesterolemia: sisters of PCOS probands (group A) and unrelated control subjects (group B), receiving atorvastatin (40 mg daily). Plasma lipids, glucose homeostasis markers, concentrations of sex hormones, high-sensitivity C-reactive protein (hsCRP), homocysteine, fibrinogen and uric acid, and the urinary albumin-to-creatinine ratio (UACR) were measured before entering the study and 6 months later.

RESULTS

Both groups differed in the degree of insulin resistance, testosterone, free androgen index (FAI), circulating levels of hsCRP and homocysteine, and UACR. There were no between-group differences in the impact of atorvastatin on plasma lipids. Despite reducing hsCRP and homocysteine in both groups of women, the effect on these biomarkers was stronger in group B than in group A. Only in group B, atorvastatin did reduce fibrinogen, uric acid, and UACR. Only in group A, atorvastatin did worsen insulin sensitivity and tended to reduce testosterone and FAI. The impact of atorvastatin on hsCRP, homocysteine, fibrinogen, uric acid, and UACR inversely correlated with testosterone and FAI.

CONCLUSION

The obtained results suggest that sisters of women with PCOS may benefit to a lesser degree from atorvastatin treatment than other women.

Sexual Function and Depressive Symptoms in Young Women with Euthyroid Hashimoto's Thyroiditis Receiving Vitamin D, Selenomethionine and Myo-Inositol: A Pilot Study

Thyroid autoimmunity is associated with an increased risk of sexual dysfunction. The aim of this study was to compare sexual functioning and depressive symptoms in women with Hashimoto's thyroiditis receiving different treatments. The study included euthyroid women with autoimmune thyroiditis, untreated or receiving vitamin D, selenomethionine, or myo-inositol. Apart from measuring antibody titers and hormone levels, all participants completed questionnaires evaluating female sexual function (FSFI) and depressive symptoms (BDI-II). In untreated women, the overall FSFI scores and domain scores for desire, arousal, lubrication, and sexual satisfaction were lower than in women receiving vitamin D, selenomethionine, and myo-inositol. In the vitamin D-treated women, the total FSFI scores and scores for desire and arousal were higher than in women receiving the remaining micronutrients. The BDI-II score was lowest in the vitamin D-treated women and highest in the untreated patients with thyroiditis. Vitamin D-treated women were also characterized by lower antibody titers and higher testosterone levels than the women receiving the remaining micronutrients. There were no differences in sexual functioning and depressive symptoms between the selenomethionine- and myo-inositol-treated women. The study results suggest that although all antibody-lowering treatments are associated with better sexual functioning and well-being in young women with euthyroid autoimmune thyroiditis, the greatest benefits are observed in patients receiving vitamin D.

A pilot study of the metabolic profiles of apheresis platelets modified by donor age and sex and in vitro short-term incubation with sex hormones

BACKGROUND

Platelets are part of innate immunity and comprise the cellular portion of hemostasis. Platelets express sex hormone receptors on their plasma membrane and sex hormones can alter their function in vitro. Little is known about how age and sex may affect platelet biology; thus, we hypothesized that platelets from males and females have different metabolomic profiles, which may be altered by age and in vitro treatment with sex hormones.

METHODS

Day 1 apheresis platelets were drawn from five 18-53-year-old, premenopausal younger females (YF), five ≥54-year-old, postmenopausal, older females (OF), five 18-44-year-old younger males (YM), and four ≥45-year-old older males (OM). Platelets were normalized to a standard concentration and metabolomics analyses were completed. Unsupervised statistical analyses and hierarchical clustering with principal component analyses were completed.

RESULTS

Platelets from OM had (1) elevated mono-, di- and tri-carboxylates, (2) increased levels of free fatty acids, acyl-carnitines, and free amino acids, and (3) increased purine breakdown and deamination products. In vitro incubation with sex hormones only affected platelets from OM donors with trends towards increased ATP and other high-energy purines and decreases in L-proline and other amino acids.

CONCLUSION

Platelets from OM's versus YF, OF, and YM have a different metabolome implying increased energy metabolism, more free fatty acids, acylcarnitines, and amino acids, and increased breakdown of purines and deamination products. However, only platelets from OM were affected by sex hormones in vitro. Platelets from OM are metabolically distinct, which may impart functional differences when transfused.

Effect of Human Cytochrome P450 2D6 Polymorphism on Progesterone Hydroxylation

BACKGROUND AND OBJECTIVES

Herein, hydroxylation activities at the 6β-position and 21-position of progesterone mediated by human cytochrome P450 (CYP) 2D6 and its variants and the effects of psychotropic drugs on these hydroxylation activities were compared to clarify whether CYP2D6 polymorphisms and psychotropic drugs impact neurosteroid levels in the brain.

METHODS

Progesterone was incubated with CYP2D6.1, CYP2D6.2 (Arg296Cys, Ser486Thr), CYP2D6.10 (Pro34Ser, Ser486Thr), and CYP2D6.39 (Ser486Thr) in the absence or presence of typical psychotropic drugs (fluvoxamine, fluoxetine, paroxetine, fluphenazine, and milnacipran) and endogenous steroids (testosterone and cortisol). Then, 6β- and 21-hydroxyprogesterone levels were determined by high-performance liquid chromatography.

RESULTS

Although the Michaelis-Menten constants (Km) for progesterone 6β- and 21-hydroxylation reactions mediated by the different CYP2D6 variants were similar, the maximal velocity (Vmax) values of the reactions mediated by CYP2D6.1 and CYP2D6.2 were the highest, followed by those mediated by CYP2D6.39 and CYP2D6.10. Thus, the of progesterone 6β- and/or 21-hydroxylation reactions mediated by CYP2D6.1 and CYP2D6.2 showed the highest Vmax/Km values, followed by the reactions mediated by CYP2D6.39. All investigated compounds inhibited progesterone 21-hydroxylation mediated by CYP2D6 variants at high concentrations. Interestingly, at low concentrations, fluoxetine increased progesterone 21-hydroxylation mediated by CYP2D6.1, but not that mediated by CYP2D6.2 or CYP2D6.10. In addition, the Km value for CYP2D6.2 was elevated in the presence of fluoxetine, whereas the value for CYP2D6.1 was unaltered; however, Vmax values of both CYP2D6.1 and CYP2D6.2 were increased. Paroxetine competitively inhibited CYP2D6.1- and CYP2D6.2-mediated progesterone 21-hydroxylation.

CONCLUSIONS

These results suggest that CYP2D6 polymorphism can affect the stimulation/inhibition of progesterone 21-hydroxylation.

Hormones, age, and sex affect platelet responsiveness in vitro

BACKGROUND

Female sex confers a survival advantage following severe injury in the setting of trauma-induced coagulopathy, with female platelets having heightened responsiveness likely due to estrogen. The effects of testosterone on platelet biology are unknown, and platelets express both estradiol and androgen receptors on the plasma membrane. We hypothesize testosterone decreases platelet responses in vitro, and there are baseline differences in platelet function and metabolism stratified by sex/age.

STUDY DESIGN AND METHODS

Apheresis platelets were collected from: older males (OM) ≥45 years, younger males (YM) <45 years, older females (OF) ≥54 years, and younger females (YF) <54 years, and testosterone and estradiol were measured. Platelets were incubated with testosterone (5.31 ng/ml), estradiol (105 pg/ml) or vehicle and stimulated with buffer, adenosine diphosphate (20 μM), platelet activating factor (2 μM), or thrombin (0.3 U/ml). Aggregation, CD62P surface expression, fibrinogen receptor surface expression, and platelet mitochondrial metabolism were measured.

RESULTS

Testosterone significantly inhibited aggregation in OF and OM (p < .05), inhibited CD41a expression in YF, YM, and OM (p < .05), and affected a few of the baseline amounts of CD62P surface expression but not platelet activation to platelet-activating factor and adenosine diphosphate, and variably changed platelet metabolism.

DISCUSSION

Platelets have sex- and age-specific aggregation, receptor expression, and metabolism. Testosterone decreases platelet function dependent on the stimulus, age, and sex. Similarly, platelet metabolism has varying responses to sex hormones with baseline metabolic differences dependent upon sex and age.

The role of testosterone in men's health: is it time for a new approach?

PURPOSE

Because of many unanswered questions regarding men's health, a literature review was performed to better understand the role of testosterone and testosterone replacement therapy (TRT) in the management of hypogonadism and aging related prostate gland diseases (ARPGD) including prostate cancer (PCa) and benign prostatic hyperplasia (BPH) with lower urinary tract symptoms (LUTS).

METHODS

The PubMed database was screened for pertinent peer reviewed articles published during the last four decades that culminated in the positions and recommendations in this paper.

RESULTS

Hypogonadism seriously impacts men's health, and the diagnosis remains controversial. The incidence of ARPGD is projected to increase worldwide and treatment still has significant limitations. There is compelling evidence that lower, not higher, testosterone levels trigger the development of PCa and BPH through androgen receptor over-expression. TRT was found to be safe and effective in treating hypogonadism including in PCa survivors and those harboring PCa. There is also evidence that TRT might reduce the incidence and prevalence of ARPGD.

CONCLUSIONS AND RECOMMENDATIONS

This review synthesizes a wide-ranging compendium of basic science and clinical research that strongly encourages altering the present approach to diagnosing and treating men with hypogonadism and ARPGD. These findings underscore the importance of avoiding significant testosterone decline and support the use of TRT. Ten recommendations are offered as a framework for the way forward. It is now time for clinicians, payers, researchers, funding agencies, professional associations, and patient advocacy groups to embrace this new paradigm to increase longevity and improve the quality of life.

Hypothalamic-pituitary-gonadal axis and sexual functioning in metformin-treated men after discontinuation of testosterone replacement therapy: A pilot study

WHAT IS KNOWN AND OBJECTIVE

Metformin was found to reduce elevated gonadotropin levels. The aim of the present study was to determine whether metformin modulates the impact of discontinuation of testosterone therapy on hypothalamic-pituitary-gonadal axis activity and sexual function in men with low testosterone levels.

METHODS

The study included 28 men with late-onset hypogonadism (defined according to the criteria of the European Male Aging Study group) receiving testosterone undecanoate (120 mg in three equal doses), 12 of whom had been treated with oral metformin (1.7-3 g daily). Both testosterone and metformin had been administered for at least six months before enrolment. In all patients, testosterone replacement required to be discontinued. The control group included 16 testosterone- and metformin-treated men with late-onset hypogonadism who during the entire study period continued their treatment. Glucose homeostasis markers, as well as plasma levels of insulin, gonadotropins, testosterone, calculated bioavailable testosterone, dehydroepiandrosterone-sulphate, oestradiol, thyrotropin, free thyroxine, prolactin, insulin-growth factor-1 and cortisol were measured at the beginning of the study and four months later. Moreover, at the beginning and the end of the study, all enrolled patients completed a questionnaire assessing their sexual functioning (IIEF-15).

RESULTS AND DISCUSSION

Discontinuation of testosterone therapy resulted in a decrease in total testosterone and bioavailable testosterone (by 42% and 45% in metformin-treated patients, and by 52% and 54% in metformin-naïve patients), as well as impaired all aspects of male sexual function. Changes in bioavailable testosterone, as well as in erectile function, orgasmic function and sexual desire were less pronounced if subjects received metformin. Only in metformin-naïve men, follow-up FSH and LH levels were higher than at baseline (by 75% and 62%). Moreover, discontinuation of testosterone therapy in metformin-naïve men increased glycated haemoglobin, as well as worsened insulin sensitivity. There were no differences between baseline and follow-up levels of the remaining hormones. In metformin-naïve subjects, the increase in gonadotropin levels correlated with the changes in testosterone levels and insulin sensitivity. No effect on glucose homeostasis markers, hormone levels and sexual functioning was observed in the control group.

WHAT IS NEW AND CONCLUSION

The obtained results suggest that metformin treatment mitigates the unfavourable effect of discontinuation of testosterone treatment on hypothalamic-pituitary-testicular axis activity and sexual function in men with late-onset hypogonadism.

Prognostic role of docetaxel-induced suppression of free testosterone serum levels in metastatic prostate cancer patients

To date, only few data concerning the biologically active, free form of testosterone (FT) are available in metastatic prostate cancer (mPC) and the impact of FT on disease, therapy and outcome is largely unknown. We retrospectively studied the effect of docetaxel on FT and total testosterone (TT) serum levels in 67 mPC patients monitored between April 2008 and November 2020. FT and TT levels were measured before and weekly during therapy. The primary endpoint was overall survival (OS). Secondary endpoints were prostate-specific antigen response and radiographic response (PSAR, RR), progression-free survival (PFS), FT/TT levels and safety. Median FT and TT serum levels were completely suppressed to below the detection limit during docetaxel treatment (FT: from 0.32 to < 0.18 pg/mL and TT: from 0.12 to < 0.05 ng/mL, respectively). Multivariate Cox regression analyses identified requirement of non-narcotics, PSAR, complete FT suppression and FT nadir values < 0.18 pg/mL as independent parameters for PFS. Prior androgen-receptor targeted therapy (ART), soft tissue metastasis and complete FT suppression were independent prognostic factors for OS. FT was not predictive for treatment outcome in mPC patients with a history of ART.

Impact of lisinopril on cardiometabolic risk factors in men with hypertension and early-onset androgenetic alopecia: a pilot study

ABSTRACT

Women with polycystic ovary syndrome are at high cardiometabolic risk. Early-onset male-pattern baldness is considered the phenotypic equivalent of polycystic ovary syndrome in men. The aim of the present study was to assess whether early-onset androgenetic alopecia modifies cardiometabolic effects of lisinopril in men with arterial hypertension. The study population consisted of 62 young men with grade 1 hypertension, 31 of whom were diagnosed with early-onset male-pattern baldness (group A). Thirty-one blood pressure-matched men with normal hair growth (group B) served as a control group. All participants were treated with lisinopril (10-40 mg daily). Blood pressure, glucose homeostasis markers, urinary albumin-to-creatinine ratio (UACR), as well as plasma levels of uric acid, high-sensitivity C-reactive protein (hsCRP), fibrinogen, homocysteine, total and calculated free testosterone, dehydroepiandrosterone-sulfate and estradiol were assessed before lisinopril treatment and six months later. At baseline, levels of all cardiometabolic risk factors were higher in group A than group B. Although lisinopril reduced systolic and diastolic blood pressure, UACR, hsCRP and fibrinogen in both study groups, these effects were stronger in group B than in group A. Only in group B, the drug decreased levels of uric acid and homocysteine, as well as improved insulin sensitivity. The impact of lisinopril on uric acid, hsCRP, fibrinogen, homocysteine and UACR correlated weakly with its hypotensive properties, androgen levels and insulin sensitivity. The obtained results suggest that cardiometabolic effects of lisinopril in men are less pronounced in case of coexisting early-onset androgenetic alopecia.

The impact of exogenous vitamin D on thyroid autoimmunity in euthyroid men with autoimmune thyroiditis and early-onset androgenic alopecia

Background

Early-onset androgenic alopecia is regarded as the phenotypic equivalent of polycystic ovary syndrome in men. Women with polycystic ovary syndrome are at high risk of autoimmune thyroiditis. The aim of the current study was to investigate whether early-onset androgenic alopecia determines the impact of exogenous vitamin D on thyroid autoimmunity and thyroid function in men with autoimmune thyroiditis.

Methods

The study included 67 young men with autoimmune thyroiditis, 25 of whom had early-onset androgenic alopecia (group A). All 25 men with alopecia and 23 out of the 42 men with no evidence of hair loss, matched for age, antibody titers and thyrotropin levels (group B), were then treated with vitamin D (100 μg daily). Serum titers of thyroid peroxidase and thyroglobulin antibodies, serum levels of thyrotropin, free thyroid hormones, total and calculated free testosterone, dehydroepiandrosterone-sulfate, estradiol, prolactin and 25-hydroxyvitamin D, as well as the calculated parameters of thyroid homeostasis were assessed before vitamin D treatment and 6 months later.

Results

At baseline, thyroid antibody titers were higher in subjects with than without alopecia and correlated with calculated free testosterone levels. Vitamin D reduced antibody titers in both groups but this effect was stronger in group B than group A. Only in group B, vitamin D increased SPINA-GT. The impact of vitamin D on antibody titers correlated with 25-hydroxyvitamin D levels, calculated free testosterone, treatment-induced increase in 25-hydroxyvitamin D levels and the improvement in insulin sensitivity.

Conclusion

This study suggests that euthyroid men with early-onset androgenic alopecia may benefit to a lesser degree from vitamin D treatment than other subjects with autoimmune thyroiditis.

Cardiometabolic Risk Factors in Rosuvastatin-Treated Men with Mixed Dyslipidemia and Early-Onset Androgenic Alopecia

Men with early-onset androgenetic alopecia are characterized by hormonal profiles similar to those observed in women with polycystic ovary syndrome. The purpose of this research was to investigate levels of cardiometabolic risk factors in 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA)-treated men with early-onset androgenic alopecia. We studied two matched rosuvastatin-treated groups of men with mixed dyslipidemia: subjects with early-onset androgenic alopecia (group A) and subjects with normal hair growth (group B). Plasma lipids, glucose homeostasis markers, and levels of sex hormones, uric acid, hsCRP, homocysteine, fibrinogen, and 25-hydroxyvitamin D were measured before entering the study and six months later. Both groups differed in insulin sensitivity and levels of calculated bioavailable testosterone, dehydroepiandrosterone-sulfate, uric acid, hsCRP, fibrinogen, and 25-hydroxyvitamin D. Though observed in both study groups, treatment-induced reductions in total cholesterol, LDL cholesterol, hsCRP, and fibrinogen were more pronounced in group B than group A. Moreover, only in group A did rosuvastatin deteriorate insulin sensitivity, and only in group B did the drug affect uric acid, homocysteine, and 25-hydroxyvitamin D. The impact of rosuvastatin on cardiometabolic risk factors correlated with insulin sensitivity, calculated bioavailable testosterone, and dehydroepiandrosterone-sulfate. The obtained results suggest that men with early-onset androgenic alopecia may benefit to a lesser degree from rosuvastatin treatment than their peers.

Olfactory Exposure to β-Caryophyllene Increases Testosterone Levels in Women's Saliva

INTRODUCTION

From previous studies, we hypothesized that olfactory exposure to β-caryophyllene stimulates women's libido. However, Japan's sex culture is so closed that it is difficult to test this possibility without accumulating scientific evidence. Therefore, it is necessary to measure the concentration of sex-related hormones in saliva, an experimental technique that is relatively easy to obtain research permission, and to obtain a scientific basis to convince ethics committee reviewers.

AIM

The aim of this study is to investigate whether β-caryophyllene increases salivary testosterone concentrations associated with libido and vaginal sensation during intercourse in women.

METHODS

19 women in the follicular phase of the menstrual cycle participated in the study. The subjects then sat in front of the odor exposure device we had created. Each subject was exposed to dipropylene glycol for 20 minutes, followed by 3% β-caryophyllene for 20 minutes. Saliva was collected 4 times: before and after control exposure, and before and after β-caryophyllene exposure.

MAIN OUTCOME MEASURE

Salivary testosterone and estrogen concentrations were measured with a competition ELISA.

RESULTS

β-caryophyllene significantly increased the salivary concentration of testosterone (control vs β-caryophyllene; 0.97 ± 0.05 vs 1.13 ± 0.03, P = .00, 95% confidence interval of control: 0.84-1.09, 95% confidence interval of β-caryophyllene: 1.04-1.20) but not estrogen (control vs β-caryophyllene; 1.05 ± 0.03 vs 1.07 ± 0.04, P = .69, 95% confidence interval of control: 0.96-1.12, 95% confidence interval of β-caryophyllene: 0.98-1.15).

STRENGTHS & LIMITATIONS

The personal preferences of the subjects and the order of exposure may have affected the results.

CONCLUSION

β-caryophyllene may be a remedy with fewer side effects for women with decreased libido. We believe that β-caryophyllene may be a remedy for women with decreased libido. However, this hypothesis must be tested by further clinical studies. Wataru Tarumi, Kazuyuki Shinohara. Olfactory Exposure to β-Caryophyllene Increases Testosterone Levels in Women's Saliva. J Sex Med 2020;8:525-531.

Comparison of steroid hormone hydroxylation mediated by cytochrome P450 3A subfamilies

Hydroxylation activity at the 6β-position of steroid hormones (testosterone, progesterone, and cortisol) by human cytochromes P450 (CYP) 3A4, polymorphic CYP3A5, and fetal CYP3A7 were compared to understand the catalytic properties of the major forms of human CYP3A subfamily. Testosterone, progesterone, and cortisol 6β-hydroxylation activities of recombinant CYP3A4, CYP3A5, and CYP3A7 were determined by liquid chromatography. Michaelis constants (K_m) for CYP3A7-mediated 6β-hydroxylation of testosterone, progesterone, and cortisol were similar to those of CYP3A4 and CYP3A5. The maximal velocity (k_cat) and k_cat/K_m values for CYP3A4 were the highest, followed by CYP3A5 and those for CYP3A7 were the lowest among three CYP3A subfamily members. A decrease in K_m values for progesterone 6β-hydroxylation by CYP3A4, CYP3A5, and CYP3A7 in the presence of testosterone was observed, and the k_cat values for CYP3A5 gradually increased with increasing testosterone. This indicated that testosterone stimulated progesterone 6β-hydroxylation by all three CYP3A subfamily members. However, progesterone inhibited testosterone 6β-hydroxylation mediated by CYP3A4, CYP3A5, and CYP3A7. In conclusion, the k_cat values, rather than K_m values, for 6β-hydroxylation of three steroid hormones mediated by CYP3A7 were different from those for CYP3A4 and CYP3A5. In addition, the inhibitory/stimulatory pattern of steroid-steroid interactions would be different among CYP3A subfamily members.

Assays of Serum Testosterone

The diagnosis of male hypogonadism depends on an assessment of the clinical signs and symptoms of hypogonadism and serum testosterone level. Current clinical laboratory testosterone assay platforms include immunoassays and mass spectrometry. Despite significant advances to improve the accuracy and precision of the currently available assays, limited comparability exists between assays at the lower and upper extremes of the testosterone range. Because of this lack of comparability, there is no current gold standard assay for the assessment of total testosterone levels.

"Linearity assessment methods for sex steroid hormones and carrier proteins among men in the National Health and Nutrition Examination Survey (NHANES III)"

INTRODUCTION

It has been hypothesized that racial disparities among several diseases are explained by differences in testosterone (T), 17-β estradiol (E), sex hormone binding globulin (SHBG) and albumin (A) levels, yet epidemiologic results have been mixed. Statistical advice regarding appropriate adjustment methods for carrier proteins of sex steroid hormones in the literature is scant. Therefore, we investigated different adjustment methods for carrier proteins.

METHODS

Data for 1496 men, >17 years from the Third National Health and Nutrition Examination Survey (NHANES III) 1988-91 were used to analyze linearity between sex hormones and carrier proteins by examining correlation, plots, and regression models. The statistical importance of age, body mass index (BMI), and race/ethnicity were examined for changes in results by the adjustment method.

RESULTS

T was weakly correlated with SHBG and A (r-squared, 0.25, 0.13, respectively) and E was weakly negatively correlated with A (p<0.0001), but not SHBG (p<0.1799). Based on the model residual plots and r-squared, the categorical model performed better than linear models. Regression coefficients for age, BMI, and race/ethnicity groups using quotient (e.g., T/A and E/A) models differed from continuous and categorical models.

CONCLUSION

Choosing an appropriate adjustment for carrier proteins is important to prevent bias in analyses and inconsistency in findings across studies. Linearity between variables should not be assumed when adjusting models, and should be conducted and reported. An independent categorical carrier protein variable is recommended in analysis exploring factors predicting sex hormone levels, although statistical testing should always be employed.

Genetic and environmental contributions to saliva testosterone levels in male and female infant twins

BACKGROUND

Testosterone is the key hormone for the development of male reproductive organs and secondary sexual characteristics. In addition, testosterone is associated with behavioural traits, including sexual behaviour and social dominance. The level of circulating testosterone in the human body is determined by genetic and environmental factors. Twin studies have shown moderate to high heritability in adolescence and adulthood, but heritability in early childhood has not been investigated. This study aimed at disentangling the genetic and environmental contributions to testosterone levels soon after birth.

METHODS

Using a sample of 314 twin pairs, saliva testosterone levels were measured at 5 months after birth. Quantitative genetic modelling was used to assess genetic and environmental contributions to the variation in testosterone levels.

RESULTS

Variation in testosterone levels was explained by common (56.6%) and unique (43.4%) environmental factors.

CONCLUSIONS

Taken together, these data from the largest study of twin testosterone levels suggest that, in contrast to findings in adulthood, environmental factors determine the interindividual variability in testosterone levels in early infancy. This may have consequences for the development of sex-related behaviour during childhood and calls for studies designed to unravel specific genetic and environmental factors involved in this process.

Modulating testosterone pathway: a new strategy to tackle male skin aging?

In men, the level of testosterone decreases with age. At the skin level, the result is observed as a decrease in density and in a lower elasticity. Identifying compounds that are able to increase the level of testosterone appears to be an attractive strategy to develop new antiaging bioactive ingredients for men. Reverse pharmacognosy was successfully applied to identify new natural compounds able to modulate testosterone levels. Among several in silico hits, honokiol was retained as a candidate as it has the greatest potential to become an active ingredient. This result was then validated in vitro on aromatase and 5-alpha-reductase type 1 and 2, which are two types of enzymes implicated in the degradation of free testosterone. Indeed, honokiol was identified as an inhibitor of aromatase, with a half-maximal inhibitory concentration (IC(50)) of about 50 μM. In addition, honokiol was shown to be an inhibitor of 5-alpha-reductase type 1, with an IC(50) of about 75 μM. Taken together, these data indicate that honokiol modulates testosterone levels, and its structure has the potential to serve as a lead for future designs of highly selective inhibitors of 5-alpha-reductase type 1.

Higher serum testosterone is associated with increased risk of advanced hepatitis C-related liver disease in males

Males have strikingly increased risk of advanced liver disease. However, the association between testosterone and risk of hepatitis C virus (HCV)-related advanced liver disease is unknown. We performed a cross-sectional study in male veterans with chronic HCV. Blood samples were obtained to measure total serum testosterone and perform the FibroSURE-ActiTest. Other risk-factor data were obtained through systematic questionnaires (e.g., alcohol), physical measurements (e.g., body mass index), and serological tests (e.g., viral load). The association between total testosterone and risk of advanced hepatic fibrosis (F3 and F3/F4) and inflammatory activity (A3 and A2/3) measured by the FibroSURE-ActiTest was evaluated with logistic regression. A total of 308 eligible study participants were prospectively recruited (mean age: 57; 52% African-American). There were 105 cases with advanced fibrosis and 203 mild fibrosis controls as well as 88 cases with advanced inflammatory activity and 220 mild activity controls. Mean total serum testosterone was significantly higher in advanced fibrosis cases as well as advanced inflammatory activity cases, compared to mild disease controls (6.0 versus 5.3 ng/mL and 5.9 versus 5.4 ng/mL, respectively). We observed a significant 25% increase in advanced fibrosis risk and 15% increase in advanced inflammatory activity risk for each 1-ng/mL increase in total serum testosterone. Total testosterone in the upper tertile was associated with an even greater excess risk of advanced fibrosis than advanced inflammatory activity (odds ratio [OR](adjusted advanced fibrosis) = 3.74; 95% CI: 1.86-6.54 versus OR(adjusted advanced inflammatory activity) = 2.23; 95% CI: 1.07-4.93, respectively).

CONCLUSIONS

Total serum testosterone is associated with an increased risk of both advanced hepatic fibrosis and advanced hepatic inflammatory activity in HCV-infected men. Testosterone may be important in the pathogenesis of HCV-related advanced liver disease in males.

A cross-sectional study of the association of age, race and ethnicity, and body mass index with sex steroid hormone marker profiles among men in the National Health and Nutrition Examination Survey (NHANES III)

OBJECTIVES

Since sex hormone markers are metabolically linked, examining sex steroid hormones singly may account for inconsistent findings by age, race/ethnicity and body mass index (BMI) across studies. First, these markers were statistically combined into profiles to account for the metabolic relationship between markers. Then, the relationships between sex steroid hormone profiles and age, race/ethnicity and BMI were explored in multinomial logistic regression models.

DESIGN

Cross-sectional survey.

SETTING

The US Third National Health and Nutrition Examination Survey (NHANES III).

PARTICIPANTS

1538 Men, >17 years.

PRIMARY OUTCOME MEASURE

Sex hormone profiles.

RESULTS

Cluster analysis was used to identify four statistically determined profiles with Blom-transformed T, E, sex hormone binding globulin (SHBG), and 3-α diol G. We used these four profiles with multinomial logistic regression models to examine differences by race/ethnicity, age and BMI. Mexican American men >50 years were associated with the profile that had lowest T, E and 3-α diol G levels compared to other profiles (p<0.05). Non-Hispanic Black, overweight (25-29.9 kg/m(2)) and obese (>30 kg/m(2)) men were most likely to be associated with the cluster with the lowest SHBG (p<0.05).

CONCLUSION

The associations of sex steroid hormone profiles by race/ethnicity are novel, while the findings by age and BMI groups are largely consistent with observations from single hormone studies. Future studies should validate these hormone profile groups and investigate these profiles in relation to chronic diseases and certain cancers.

Gonadal hormone status in highly trained sprinters and in untrained men

It is a common view that strength and sprint trained athletes are characterized by high plasma/serum testosterone (T) concentration, which is believed to be partly responsible for their performance level. This opinion, however, has poor scientific background. The aim of this study was to give evidence-based information on this issue. We examined gonadal hormone status at rest after overnight fasting in high and top-class track and field sprinters (n = 16) and in untrained men (n = 15). It was shown that basal T, free testosterone (fT), bioavailable testosterone (bio-T), and sex hormone-binding globulin concentrations were not significantly different (p > 0.05) in sprinters vs. untrained subjects. Further comparison of the results of the basal serum T concentration in 8 sprinters showed its significant changes during an annual training period. Significantly higher T concentration during a low-intensity training period (beginning of December) than during heavy sprint specific training period (end of March) was observed in these athletes (n = 8) (mean ± SD; 23.37 ± 5.28 vs. 20.99 ± 4.74 nmol · L(-1), respectively, p = 0.04). We have concluded that basal gonadal hormone concentration in high and top-class athletes (sprinters and jumpers) did not appear to be significantly different when compared with untrained subjects. Moreover, basal T concentration in sprinters can differ significantly during an annual training period. This fact should be taken into consideration when interpreting the results of gonadal hormone status in athletes at varied training stages.

Age-Related Androgen Deficiency and Type 2 Diabetes

There is a higher prevalence of low testosterone levels in males with type 2 diabetes compared to those without. Additionally, there is evidence that low testosterone levels may predict the development of type 2 diabetes. Symptoms of hypogonadism include decreased libido, decreased bone mineral density (BMD), and decreased lean muscle mass. The majority of the published cases in men with diabetes were attributed to age-related idiopathic hypogonadotropic hypogonadism. This paper reviews the link between type 2 diabetes and age-related hypogonadism and the treatment options for hypogonadism. Pharmacists who provide care for males with diabetes should be aware of the increased incidence of hypogonadism, know how to screen for it, and be able to recommend appropriate therapy.

Late-onset male hypogonadism: clinical and laboratory evaluation

Late-onset male hypogonadism (LOH) is a clinical and biochemical syndrome associated with advancing age and characterised by low serum testosterone concentrations. An understanding of the physiology of androgens in the ageing man is essential for the appropriate diagnosis of LOH. Clinical assessment of androgen status relevant to clinical biochemists and chemical pathologists is outlined in this review. Laboratory investigations of androgen status in men are not without pitfalls and the authors highlight problems associated with measuring and calculating serum testosterone and its fractions, the interpretation of which can be problematic. Current clinical guidelines and recommendations regarding the diagnosis and monitoring of LOH are also summarised.