The relative role of gonadal sex steroids and gonadotropin-releasing hormone pulse frequency in the regulation of follicle-stimulating hormone secretion in men

Body composition and testosterone in men: a Mendelian randomization study

Background

Testosterone is an essential sex hormone that plays a vital role in the overall health and development of males. It is well known that obesity decreases testosterone levels, but it is difficult to determine the causal relationship between body composition and testosterone.

Methods

To investigate potential causal associations between body composition and testosterone levels by a first time application of Mendelian randomization methods. Exposure variables in men included body composition (fat mass, fat-free mass, and body mass index). In addition to whole body fat and fat-free mass, we examined fat and fat-free mass for each body part (e.g., trunk, left arm, right arm, left leg and right leg) as exposures. Instrumental variables were defined using genome-wide association study data from the UK Biobank. Outcome variables in men included testosterone levels (total testosterone [TT], bioavailable testosterone [BT], and sex hormone-binding globulin [SHBG]). A one-sample Mendelian randomization analysis of inverse-variance weighted and weighted median was performed.

Results

The number of genetic instruments for the 13 exposure traits related to body composition ranged from 156 to 540. Genetically predicted whole body fat mass was negatively associated with TT (β=-0.24, P=5.2×10-33), BT (β=-0.18, P=5.8×10-20) and SHBG (β=-0.06, P=8.0×10-9). Genetically predicted whole body fat-free mass was negatively associated with BT (β=-0.04, P=2.1×10-4), but not with TT and SHBG, after multiple testing corrections. When comparing the causal effect on testosterone levels, there was a consistent trend that the effect of fat mass was more potent than that of fat-free mass. There were no differences between body parts.

Conclusion

These results show that reducing fat mass may increase testosterone levels.

Leflutrozole in male obesity-associated hypogonadotropic hypogonadism: Ph 2b double-blind randomised controlled trial

OBJECTIVE

Assessment of the efficacy and safety/tolerability of the aromatase inhibitor leflutrozole to normalise testosterone in Obesity-associated Hypogonadotropic Hypogonadism (OHH).

DESIGN

Placebo-controlled, double-blind, RCT, in 70 sites in Europe/USA.

METHODS

Patient inclusion criteria: men with BMI of 30-50 kg/m2, morning total testosterone (TT) < 10.41 nmol/L, and two androgen deficiency symptoms (at least one of sexual dysfunction). Patients randomised to weekly leflutrozole (0.1/0.3/1.0 mg) or placebo for 24 weeks. Primary endpoint: normalisation of TT levels in ≥75% of patients after 24 weeks. Secondary endpoints (included): time to TT normalisation and change in LH/FSH. Safety was assessed through adverse events and laboratory monitoring.

RESULTS AND CONCLUSIONS

Of 2103 screened, 271 were randomised, 81 discontinued. Demographic characteristics were similar across groups. Mean BMI was 38.1 kg/m2 and TT 7.97 nmol/L. The primary endpoint was achieved in all leflutrozole-treated groups by 24 weeks with a dose-tiered response; mean TT 15.89; 17.78; 20.35 nmol/L, for leflutrozole 0.1 mg, 0.3 mg, and 1.0 mg groups respectively, vs 8.04 nmol/L for placebo. LH/FSH significantly increased in leflutrozole vs placebo groups. No improvements in body composition or sexual dysfunction were observed. Semen volume/total motile sperm count improved with leflutrozole vs placebo. Treatment-emergent adverse events, more common in leflutrozole-treated groups included, raised haematocrit, hypertension, increased PSA, and headache. Some reduction in lumbar bone density was observed with leflutrozole (mean -1.24%, -1.30%, -2.09%) and 0.66% for 0.1 mg, 0.3 mg, 1.0 mg, and placebo, respectively, without change at the hip. This RCT of leflutrozole in OHH demonstrated normalisation of TT in obese men. FSH/LH and semen parameter changes support that leflutrozole may preserve/improve testicular function.

CLINICAL TRIAL REGISTRATION NUMBER

NCT02730169.

Endoscopic Enucleation of Prostate Could Increase Testosterone Levels in Hypotestosteronemic Patients with Bladder Outlet Obstruction

Background: We evaluated the impact of endoscopic enucleation of the prostate on testosterone levels in hypotestosteronemic patients with bladder outlet obstruction. Methods: We enrolled 294 men with lower urinary tract symptoms (LUTS) who received surgery between January 2019 and December 2020 in simple tertiary centre. The inclusion criteria were as follows: being a male patient aged 45−95 years and having recurrent urinary tract infection, having previously failed medical treatment for LUTS or urine retention, and undergoing bipolar or thulium laser enucleation of the prostate. The preoperative and postoperative data were retrospectively reviewed. Results: This study included 112 men with a mean age of 69.4 years. The mean preoperative and postoperative testosterone levels were 4.8 and 4.98, respectively. Of the patients, 88 (78.6%) received ThuLEP and 24 received BipolEP. We divided the patients into two groups according to preoperative serum testosterone levels: normal-testosterone (≥3 ng/mL) and low-testosterone (<3 ng/mL) groups. A significant change in testosterone levels (p = 0.025) was observed in the low-testosterone group. In contrast, no significant difference in testosterone levels was noted in the normal-testosterone group (p = 0.698). Conclusions: Endoscopic enucleation surgery of the prostate could improve postoperative testosterone levels in hypotestosteronemic patients with bladder outlet obstruction.

GnRH replacement rescues cognition in Down syndrome

At the present time, no viable treatment exists for cognitive and olfactory deficits in Down syndrome (DS). We show in a DS model (Ts65Dn mice) that these progressive nonreproductive neurological symptoms closely parallel a postpubertal decrease in hypothalamic as well as extrahypothalamic expression of a master molecule that controls reproduction-gonadotropin-releasing hormone (GnRH)-and appear related to an imbalance in a microRNA-gene network known to regulate GnRH neuron maturation together with altered hippocampal synaptic transmission. Epigenetic, cellular, chemogenetic, and pharmacological interventions that restore physiological GnRH levels abolish olfactory and cognitive defects in Ts65Dn mice, whereas pulsatile GnRH therapy improves cognition and brain connectivity in adult DS patients. GnRH thus plays a crucial role in olfaction and cognition, and pulsatile GnRH therapy holds promise to improve cognitive deficits in DS.

Prevalence and Characteristics of Erectile Dysfunction in Obstructive Sleep Apnea Patients

BACKGROUND

Obstructive sleep apnea (OSA) is a common and severe social problem. Erectile dysfunction (ED) is an important health concern. The prevalence of OSA with ED is increasing, which significantly affects the quality of life and work efficiency of patients. However, the mechanism underlying the comorbidity of these two diseases remains unclear.

OBJECTIVES

(1) Investigate the prevalence of OSA with ED; (2) analyze the correlation between OSA and ED; and (3) explore the treatment response to and possible mechanism of uvulapalatopharyngoplasty (UPPP) in patients with OSA and ED. This study aims to provide a theoretical basis for the clinical diagnosis and comprehensive treatment of OSA with ED and improve prevention and treatment strategies.

MATERIALS AND METHODS

In total, 135 subjects were enrolled in the study. Clinical data, polysomnography, the ESS score, Beck anxiety score, Beck depression score, IIEF-5 score and ASEX score were recorded before UPPP and 6 months after UPPP. Sex hormones were measured for all subjects using a Roche electrochemiluminescence analyzer.

RESULT

The prevalence of OSA with ED was 64.52%, and the prevalence of severe OSA with ED was 73.02%. The prevalence of OSA with ED increased with age, BMI and apnea-hypopnea index (AHI) value. Among polysomnography indicators, minimum oxygen saturation and average oxygen saturation may predict the occurrence of OSA with ED. Improving the patient's anxiety and depression is very important for treating OSA with ED. Sex hormone levels were not significantly correlated with the occurrence of OSA with ED.

CONCLUSION

ED is a common symptom of OSA patients. This study showed that sex hormone levels in OSA patients with ED were not significantly correlated with the condition, but further investigation of this relationship is worthwhile. It is recommended that the free and combined types of sex hormones be further distinguished during testing because the free type is the active form. UPPP surgical treatment is effective for OSA with ED, and its possible mechanism is protection of the peripheral nerves of the sex organs by improving nighttime hypoxia and arousal.

Testosterone replacement therapy in men with type 2 diabetes mellitus and functional hypogonadism -an Integrated Diabetes and Endocrine Academy (IDEA) consensus guideline

BACKGROUND

Though testosterone replacement therapy in men with organic hypogonadism is established, its role in men with type 2 diabetes mellitus (T2DM) and functional hypogonadism is unclear.

METHODS

Thirteen experts addressed ten topic-specific questions after an in-depth review of literature, where all relevant issues were critically evaluated.

RESULTS

Ten recommendations concerning diagnosis and management of men with T2DM and functional hypogonadism have been put forward.

CONCLUSION

Routine measurement of serum testosterone in all, and inappropriate replacement of testosterone in asymptomatic T2DM men with functional hypogonadism and borderline low serum testosterone values, is not recommended.

Prevalence of hypogonadism in patients with type 2 diabetes mellitus among the Indian population

OBJECTIVES

To determine the prevalence of hypogonadism among Indian men with and without type 2 diabetes mellitus (T2DM) and evaluate its association with various metabolic parameters.

METHODS

One hundred fifty consecutive men with T2DM, aged 25-70 years, and one hundred age-matched healthy men without diabetes were included. The free testosterone (FT) level was calculated using the total testosterone (TT), sex hormone-binding globulin (SHBG), and albumin levels in serum. Patients with a calculated FT level <6.35 ng/dL and a positive response on the androgen deficiency in aging male questionnaire (ADAM) were diagnosed with hypogonadism.

RESULTS

The prevalence of hypogonadism was 17.3% and 10% in men with and without T2DM, respectively. The body mass index (BMI) and the mean levels of follicle-stimulating hormone (FSH), TT, SHBG, Triglycerides (TG), and FT were significantly different between the groups. The mean BMI and TG levels were significantly higher in patients with T2DM than in those without. Both groups showed a significant negative correlation between the BMI and SHBG level.

CONCLUSION

The hypogonadism prevalence was higher in patients with T2DM than in those without, although the difference did not reach statistical significance.

Androgens' effects on cerebrovascular function in health and disease

Androgens affect the cerebral vasculature and may contribute to sex differences in cerebrovascular diseases. Men are at a greater risk for stroke and vascular contributions to cognitive impairment and dementia (VCID) compared to women throughout much of the lifespan. The cerebral vasculature is a target for direct androgen actions, as it expresses several sex steroid receptors and metabolizing enzymes. Androgens’ actions on the cerebral vasculature are complex, as they have been shown to have both protective and detrimental effects, depending on factors such as age, dose, and disease state. When administered chronically, androgens are shown to be pro-angiogenic, promote vasoconstriction, and influence blood-brain barrier permeability. In addition to these direct effects of androgens on the cerebral vasculature, androgens also influence other vascular risk factors that may contribute to sex differences in cerebrovascular diseases. In men, low androgen levels have been linked to metabolic and cardiovascular diseases including hypertension, diabetes, hyperlipidemia, and obesity, which greatly increase the risk of stroke and VCID. Thus, a better understanding of androgens’ interactions with the cerebral vasculature under physiological and pathological conditions is of key importance.

Estrogens in Human Male Gonadotropin Secretion and Testicular Physiology From Infancy to Late Puberty

Several reports in humans as well as transgenic mouse models have shown that estrogens play an important role in male reproduction and fertility. Estrogen receptor alpha (ERα) and beta (ERβ) are expressed in different male tissues including the brain. The estradiol-binding protein GPER1 also mediates estrogen action in target tissues. In human testes a minimal ERα expression during prepuberty along with a marked pubertal up-regulation in germ cells has been reported. ERβ expression was detected mostly in spermatogonia, primary spermatocytes, and immature spermatids. In Sertoli cells ERβ expression increases with age. The aromatase enzyme (cP450arom), which converts androgens to estrogens, is widely expressed in human tissues (including gonads and hypothalamus), even during fetal life, suggesting that estrogens are also involved in human fetal physiology. Moreover, cP450arom is expressed in the early postnatal testicular Leydig cells and spermatogonia. Even though the aromatase complex is required for estrogen synthesis, its biological relevance is also related to the regulation of the balance between androgens and estrogens in different tissues. Knockout mouse models of aromatase (ArKO) and estrogen receptors (ERKOα, ERKOβ, and ERKOαβ) provide an important tool to study the effects of estrogens on the male reproductive physiology including the gonadal axis. High basal serum FSH levels were reported in adult aromatase-deficient men, suggesting that estrogens are involved in the negative regulatory gonadotropin feedback. However, normal serum gonadotropin levels were observed in an aromatase-deficient boy, suggesting a maturational pattern role of estrogen in the regulation of gonadotropin secretion. Nevertheless, the role of estrogens in primate testis development and function is controversial and poorly understood. This review addresses the role of estrogens in gonadotropin secretion and testicular physiology in male humans especially during childhood and puberty.

Vascular Dysfunction among Malaysian Men with Increased BMI: An Indication of Synergistic Effect of Free Testosterone and Inflammation

Background and objectives: Obesity is associated with poor vascular function and may lead to future cardiovascular disease (CVD). Obesity is also related to increased inflammation and a low testosterone level. This study was conducted to determine the relationship between inflammation, testosterone level, and vascular function among subjects with an increased body mass index (BMI) and to determine whether both low testosterone and high inflammation have synergistic effects towards vascular dysfunction. Materials and Methods: A total of 303 men aged 40-80 years were recruited from Klang Valley, Malaysia. Their height, weight, blood pressure (BP), lipid, blood glucose level, total testosterone (TT), free testosterone (FT), and C-reactive protein (CRP) were measured. The carotid femoral pulse wave velocity (PWVCF) and augmentation index (AI) were also recorded as markers of vascular function. Results: The mean age of all the subjects was 54.46 ± 9.77 years. Subjects were divided into a low/normal body mass index (BMI) group (BMI < 25 kg/m2; NG, n = 154) and high BMI group (BMI ≥ 25 kg/m2; OG, n = 149). The mean BMI for NG was 22.20 ± 1.94 kg/m2 while for OG was 28.87 ± 3.24 kg/m2 (p < 0.01). The level of TT (OG = 21.13 ± 6.44 versus NG = 16.18 ± 6.16 nmol/L, p < 0.01) and FT (OG = 0.34 ± 0.12 versus NG = 0.39 ± 0.11 nmol/L, p < 0.01) were reduced while the level of CRP [OG = 1.05 (2.80) versus NG = 0.50 (1.50) mmol/L, p = 0.01] was increased in OG compared to NG. PWVCF (OG = 8.55 ± 1.34 versus NG = 8.52 ± 1.42 m/s, p = 0.02) and AI (OG = 16.91% ± 6.00% versus 15.88% ± 5.58%, p < 0.01) were significantly increased in OG after adjustment for other CVD risk factors. The subjects that had both a low FT and an increased CRP had higher AI when compared to those with a high CRP and high FT (p < 0.01). Conclusions: The increased BMI was associated with vascular dysfunction, mediated by a low testosterone level and increased inflammation. Furthermore, having both conditions concurrently lead to higher vascular dysfunction. Weight loss, testosterone supplementation, and the anti-inflammatory agent may be beneficial for men to prevent vascular dysfunction.

Accelerated Pubertal Tempo in a 46,XY Aromatase-Deficient Patient

BACKGROUND

Aromatase deficiency is a rare autosomal recessive disorder. 46,XY-affected patients often remain undiagnosed until late puberty. Only 2 pediatric cases have been reported. Data on pubertal development in affected males are scarce.

AIM

To report the clinical phenotype and hormonal studies of an aromatase-deficient boy during the prepubertal and early pubertal period.

RESULTS

The patient was the older brother of a 46,XX girl with aromatase deficiency. Molecular analysis revealed a previously reported homozygous mutation (Arg192Cys) in the CYP19A1 gene. Pubertal onset was at 9.8 years. At 11.3 years of age, signs of rapidly progressive puberty were seen. Laboratory tests revealed normal pubertal basal and GnRH-stimulated gonadotropin levels, normal Sertoli cell markers, and increased testosterone. The prepubertal lumbar spine bone mineral density (BMD) was normal but pubertal bone mineral accrual was incomplete, leading to osteopenia.

CONCLUSION

Estrogen restraint on gonadotropin secretion has been demonstrated in animal and human models. Interestingly, our patient presented with accelerated puberty and apparently normal pituitary gonadal function. These findings suggest that aromatase activity may be required to define pubertal progression in boys. Estrogen deficiency due to aromatase deficiency is responsible for insufficient bone mineral accrual during puberty.

Hypogonadotropic Hypogonadism in Men With Diabesity

One-third of men with obesity or type 2 diabetes have subnormal free testosterone concentrations. The lower free testosterone concentrations are observed in obese men at all ages, including adolescents at completion of puberty. The gonadotropin concentrations in these males are inappropriately normal; thus, these patients have hypogonadotropic hypogonadism (HH). The causative mechanism of diabesity-induced HH is yet to be defined but is likely multifactorial. Decreased insulin and leptin signaling in the central nervous system are probably significant contributors. Contrary to popular belief, estrogen concentrations are lower in men with HH. Men with diabesity and HH have more fat mass and are more insulin resistant than eugonadal men. In addition, they have a high prevalence of anemia and higher mortality rates than eugonadal men. Testosterone replacement therapy results in a loss of fat mass, gain in lean mass, and increase in insulin sensitivity in men with diabesity and HH. This is accompanied by an increase in insulin-signaling genes in adipose tissue and a reduction in inflammatory mediators that interfere with insulin signaling. There is also an improvement in sexual symptoms, anemia, LDL cholesterol, and lipoprotein (a). However, testosterone therapy does not consistently affect HbA_1c in men with diabetes. The effect of testosterone replacement on cardiovascular events or mortality in men with diabesity is not known and remains to be studied in prospective trials.

Intranasal Insulin Administration Does Not Affect LH Concentrations in Men with Diabetes

A quarter of men with obesity or type 2 diabetes have hypogonadotropic hypogonadism. Animal studies and in vitro data have shown that insulin action and insulin responsiveness in the brain are necessary for the maintenance of the functional integrity of the hypothalamo-hypophyseal-gonadal axis. We conducted a randomized, placebo-controlled trial to evaluate the effect of one dose of intranasal insulin (40 IU of regular insulin) or saline on LH concentrations in 14 men (8 with type 2 diabetes and 6 healthy lean men). Insulin or saline was administered intranasally on two different occasions, at least one week apart. Blood samples were collected to measure LH concentrations every 15 minutes for 5 hours. Study drug was administered intranasally after a 2-hour baseline sampling period. Patients remained fasting throughout the procedure. The primary endpoint of the study was to compare the change in LH concentrations after intranasal insulin as compared to placebo (intranasal saline). Change was defined as the difference between baseline LH concentrations (average of the 9 samples collected in two hours prior to drug administration) and average LH concentrations following drug administration (average of the 12 samples collected in 3 hours). There was no change in LH concentrations following insulin administration as compared to placebo in men with diabetes or in lean men. We conclude that one dose of 40 IU of regular insulin administered intranasally does not change LH concentrations acutely in men.

Antiandrogen withdrawal syndrome (AAWS) in the treatment of patients with prostate cancer

Antiandrogen withdrawal syndrome is an unpredictable event diagnosed in patients with hormone-sensitive prostate cancer treated with combined androgen blockade therapy. It is defined by prostate-specific antigen value reduction, occasionally associated with a radiological response, that occurs 4-6 weeks after first-generation antiandrogen therapy discontinuation. New-generation hormonal therapies, such as enzalutamide and abiraterone acetate, improved the overall survival in patients with metastatic castration-resistant prostate cancer, and recent trials have also shown the efficacy of abiraterone in hormone-sensitive disease. In the last few years, several case reports and retrospective studies suggested that the withdrawal syndrome may also occur with these new drugs. This review summarizes literature data and hypothesis about the biological rationale underlying the syndrome and its potential clinical relevance, focusing mainly on new-generation hormonal therapies. Several in vitro studies suggest that androgen receptor gain-of-function mutations are involved in this syndrome, shifting the antiandrogen activity from antagonist to agonist. Several different drug-specific point mutations have been reported. The association of the withdrawal syndrome for enzalutamide and abiraterone needs confirmation by additional investigations. However, new-generation hormonal therapies being increasingly used in all stages of disease, more patients may experience the syndrome when stopping the treatment at the time of disease progression, although the clinical relevance of this phenomenon in the management of metastatic castration-resistant prostate cancer remains to be defined.

Prevalence of hypogonadism in male Type 2 diabetes mellitus patients with and without coronary artery disease

AIM

The present study is carried out to investigate hypogonadism using serum testosterone levels in male Type 2 diabetes mellitus (T2DM) subjects with and without coronary artery disease (CAD).

SUBJECTS AND METHODS

A total of 150 age and body mass index-matched male subjects in the age group of 30-70 years were recruited in three groups; Group A - subjects with normal glucose tolerance, Group B - T2DM subjects without CAD, and Group C - T2DM subjects with CAD (n = 50 each group). Subjects with CAD were diagnosed on the basis of electrocardiogram, treadmill testing, stress echocardiography, or coronary angiography. Total testosterone (TT), free testosterone (FT), bioavailable testosterone, calculated FT and glycemic parameters were measured and compared between all the three study groups. One-way ANOVA followed by post hoc Tukey's test and Pearson's coefficient of correlation tests were used for analysis.

RESULTS

Hypogonadism (TT <3 ng/ml) was observed in 40% (20/50) of subjects in Group C and 32% (16/50) of subjects in Group B as compared to only 14% (7/50) of subjects in Group A (Groups A vs. B; P = 0.055, Groups A vs. C; P = 0.006 and Groups B vs. C; P = 0.53). Group C subjects had significantly lower levels of TT (3.55 ± 1.46 ng/ml vs. 4.73 ± 2.17 ng/ml, P = 0.005), calculated FT (0.062 ± 0.0255 pg/ml vs. 0.0951 ± 0.0508 pg/ml, P ≤ 0.001), and bioavailable testosterone (1.48 ± 0.65 ng/ml vs. 2.18 ± 1.20 ng/ml, P ≤ 0.001) compared to control Group A subjects. There was no significant difference in any of the testosterone parameters between Groups A and B. Furthermore, an overall positive correlation was found between hypogonadism and CAD (r = 0.177, P = 0.030, n = 150).

CONCLUSION

We observed hypogonadism as indicated by low testosterone levels in a significant proportion of male T2DM subjects with CAD.

Vitamin D deficiency and low ionized calcium are linked with semen quality and sex steroid levels in infertile men

STUDY QUESTION

Are low vitamin D levels linked with semen quality and sex steroids in infertile men?

SUMMARY ANSWER

Infertile men with vitamin D deficiency had lower sperm motility, total numbers of motile sperm, Inhibin B, sex-hormone-binding-globulin (SHBG) and testosterone/estradiol ratio, but higher levels of free sex steroids, than infertile men with normal vitamin D levels.

WHAT IS KNOWN ALREADY

Low vitamin D levels have been associated with decreased sperm motility in healthy men, but a relationship between vitamin D and calcium with semen quality and especially sex steroids has not been sufficiently described in infertile men.

STUDY DESIGN, SIZE, DURATION

This study comprises baseline characteristics of 1427 infertile men screened from 2011 to 2014 for inclusion in a randomized clinical trial, the Copenhagen-Bone-Gonadal Study.

PARTICIPANTS/MATERIALS, SETTING, METHODS

In total 1427 infertile men, consecutively referred to our tertiary andrological centre for fertility workup, underwent a physical examination and had semen quality assessed based on two samples and blood analysed for serum testosterone, SHBG, estradiol, inhibin B, luteinizing hormone, follicle-stimulating hormone (FSH), 25-hydroxyvitamin D (25-OHD), ionized calcium (Ca(2+)) and karyotype. There were 179 men excluded due to serious comorbidities or anabolic steroid usage, leaving 1248 patients for analyses.

MAIN RESULTS AND THE ROLE OF CHANCE

Men with 25-OHD >75 nmol/l had higher sperm motility and 66 and 111% higher total numbers of motile spermatozoa after 45 and 262 min, respectively, than men with 25-OHD <25 nmol/l (all P < 0.05). SHBG levels and testosterone/estradiol ratios were 15 and 14% lower, respectively, while free testosterone and estradiol ratios were 6 and 13% higher, respectively, in men with 25-OHD <25 nmol/l (all P < 0.05). Men with lower Ca(2+) levels had higher progressive sperm motility and inhibin B/FSH ratio but lower testosterone/estradiol ratio (all P < 0.05).

LIMITATIONS, REASONS FOR CAUTION

All outcomes presented are predefined end-points but inferral of causality is compromised by the descriptive study design. It remains to be shown whether the links between vitamin D, calcium, semen quality and sex steroids in infertile men are causal.

WIDER IMPLICATIONS OF THE FINDINGS

The associations between vitamin D deficiency and low calcium with semen quality and sex steroids support the existence of a cross-link between regulators of calcium homeostasis and gonadal function in infertile men.

STUDY FUNDING/COMPETING INTERESTS

This study was supported by the Danish Agency for Science, Technology and Innovation, Hørslev Fonden, Danish Cancer Society and Novo Nordisk Foundation. There are no conflicts of interest.

TRIAL REGISTRATION NUMBER

NCT01304927.

DATE OF TRIAL REGISTRATION

25 February 2011.

DATE OF ENROLMENT OF FIRST PATIENT

8 March 2011.

Increased antimüllerian hormone levels and other reproductive endocrine changes in adult male relatives of women with polycystic ovary syndrome

OBJECTIVE

To investigate for differences in reproductive hormone levels in male relatives of women with polycystic ovary syndrome (PCOS).

DESIGN

Cross-sectional study.

SETTING

Academic medical center.

PATIENT(S)

Sixty-three fathers and 66 brothers of women with PCOS as well as two groups of control men of comparable age to fathers (older control, n = 30) and brothers (younger control, n = 58).

INTERVENTION(S)

A single early morning fasting blood sample was obtained for the measurement of reproductive hormone levels.

MAIN OUTCOME MEASURE(S)

Testosterone, LH, FSH, antimüllerian hormone (AMH), inhibin B, estradiol (E2), and estrone (E1) levels were measured.

RESULT(S)

The AMH, LH, and FSH levels were significantly increased in male relatives compared with their respective control groups. The levels of E2, E1, T, and inhibin B did not differ between the groups.

CONCLUSION(S)

The AMH, LH, and FSH levels were increased in adult male relatives of women with PCOS, suggesting that they may have altered testicular function and changes in neuroendocrine regulation of gonadotropin secretion. These changes may reflect effects of PCOS susceptibility genes such as the recently mapped chromosome 11p14.1 locus in the region of the FSH B polypeptide gene.

Risk Factors for Hypogonadism in Male Patients with Type 2 Diabetes

BACKGROUND

Male hypogonadism is an endocrine disease characterized by low levels of serum testosterone and is closely related to the development of diabetes. The purpose of the present study was to observe the risk factors for hypogonadism in male patients with type 2 diabetes.

METHODS

A total of 213 patients with type 2 diabetes were enrolled and divided into a low total testosterone (TT) group (=75) and a normal TT group (=138). The patients' blood glucose, blood lipids, serum insulin, and sex hormones were measured. The correlations between the patients' metabolic index and sex hormone levels were analyzed.

RESULTS

Compared with the normal TT group, body mass index (BMI), fasting insulin (FINS), and HOMA insulin resistance index (HOMA-IR) levels were significantly higher, but the luteinizing hormone (LH) levels were significantly lower in the low TT group (p < 0.05). Correlation analyses found that TT was negatively correlated with BMI, waist circumference (WC), FINS, and HOMA-IR. TT was positively correlated with LH and follicle-stimulating hormone (FSH).

CONCLUSIONS

Several risk factors of diabetes associated closely with hypogonadism. BMI, metabolic syndrome (MS), HOMA-IR, and LH are independent risk factors for hypogonadism in male patients with type 2 diabetes.

The Relationships between Anabolic Hormones and Body Composition in Middle-Aged and Elderly Men with Prediabetes: A Cross-Sectional Study

The influence of anabolic hormones and body composition in men with prediabetes (PD) is unknown. In a cross-sectional study we investigated the relationships between total testosterone (TT), calculated free testosterone (cFT), dehydroepiandrosterone sulfate (DHEAS), and insulin-like growth factor 1 (IGF-1) and body composition assessed using dual-energy X-ray absorptiometry (DXA) method in 84 patients with PD (40-80 years) and 56 men in control group. Patients with PD had lower TT, cFT, and DHEAS levels but similar IGF-1 levels in both groups. Patients with PD presented the higher total and abdominal fat as well as the lower total and abdominal lean than control (p < 0.02, p < 0.01, p < 0.05, and p < 0.02, resp.). We observed negative relationship between TT and total fat (p = 0.014) and positive with abdominal lean mass (p = 0.034), while cFT was negatively associated with abdominal (p = 0.02), trunk (p = 0.024), and leg fat (p = 0.037) and positively associated with total (p = 0.022) and trunk lean (p = 0.024). DHEAS were negatively associated with total fat (p = 0.045), and IGF-1 were positively associated with abdominal (p = 0.003) and leg lean (p = 0.015). In conclusion, the lowered anabolic hormones are involved in body composition rearrangement in men with PD. Further studies are needed to establish whether the androgen replacement therapy would be beneficial in men with PD.

Psychosexual development in men with congenital hypogonadotropic hypogonadism on long-term treatment: a mixed methods study

Introduction

Congenital hypogonadotropic hypogonadism (CHH) is a rare, genetic, reproductive endocrine disorder characterized by absent puberty and infertility. Limited information is available on the psychosocial impact of CHH and psychosexual development in these patients.

Aim

The aim of this study was to determine the impact of CHH on psychosexual development in men on long-term treatment.

Methods

A sequential mixed methods explanatory design was used. First, an online survey (quantitative) was used to quantify the frequency of psychosexual problems among CHH men. Second, patient focus groups (qualitative) were conducted to explore survey findings in detail and develop a working model to guide potential nursing and interdisciplinary interventions.

Main Outcome Measures

Patient characteristics, frequency of body shame, difficulty with intimate relationships, and never having been sexually active were assessed. Additionally, we collected subjective patient-reported outcomes regarding the impact of CHH on psychological/emotional well-being, intimate relationships, and sexual activity.

Results

A total of 101 CHH men on long-term treatment (>1 year) were included for the analysis of the online survey (mean age 37 ± 11 years, range 19–66, median 36). Half (52/101, 51%) of the men had been seen at a specialized academic center and 37/101 (37%) reported having had fertility-inducing treatment. A high percentage of CHH men experience psychosexual problems including difficulty with intimate relationships (70%) and body image concerns/body shame (94/101, 93%), and the percentage of men never having been sexually active is five times the rate in a reference group (26% vs. 5.4%, P < 0.001). Focus groups revealed persisting body shame and low self-esteem despite long-term treatment that has lasting impact on psychosexual functioning.

Conclusions

CHH men frequently experience psychosexual problems that pose barriers to intimate relationships and initiating sexual activity. These lingering effects cause significant distress and are not ameliorated by long-term treatment. Psychosexual assessment in CHH men with appropriate psychological support and treatment should be warranted in these patients. Dwyer AA, Quinton R, Pitteloud N, and Morin D. Psychosexual development in men with congenital hypogonadotropic hypogonadism on long-term treatment: A mixed methods study. Sex Med 2015;3:32–41.

Late-onset hypogonadism among old and middle-aged males with prediabetes in Polish population

OBJECTIVES

Around 40% of diabetic men have lowered testosterone and symptoms of hypogonadism but the prevalence of hypogonadism among prediabetic men is unknown. The aim of this study was to investigate the prevalence of late-onset hypogonadism (LOH) in population of Polish men with prediabetes.

METHODS

This study was performed in 196 prediabetic men and in 184 normoglycemic, control group. Prediabetes was defined as impaired fasting glucose, impaired glucose tolerance and/or HbA1c 5.7-6.4%. LOH was defined as low libido, diminished frequency of morning erections and erectile dysfunctions in men with total testosterone <12 nmol/l.

RESULTS

Total testosterone (TT) level in prediabetes group was 11.78 ± 1.76 and 16.37 ± 1.6 nmol/l in control group (p < 0.001). LOH was diagnosed in 30% prediabetic men and in 13.6% control men. There were negative relationships between calculated free testosterone (cFT) and HbA1c (r = -0.3856; p < 0.005). In prediabetic group, TT and cFT levels were lower in patients with impaired glucose tolerance than impaired fasting glucose (p < 0.05 and p < 0.02, respectively). We showed inverse relationships between IIEF-5 score and cFT (r = -0.414, p < 0.005) and between IIEF-5 and HbA1c (r = -0.395, p < 0.002).

CONCLUSIONS

In population of Polish men with prediabetes we observed high prevalence of LOH. Routine testosterone screening should be performed in all prediabetic men.

Hormonal determinants of erectile dysfunction and lower urinary tract symptoms in middle-aged and elderly men with prediabetes

OBJECTIVES

Erectile dysfunction (ED) and lower urinary tract symptoms (LUTS) are common in diabetic men. The aim of this study was to investigate hormonal determinants, the prevalence and severity of ED and LUTS in middle-aged and elderly men with prediabetes (PD).

METHODS

We investigated 176 men with PD and 184 healthy peers. PD was defined according American Diabetes Association. ED according IIEF scale and LUTS according IPSS scale were assessed. Total testosterone (TT), calculated free testosterone (cFT), dehydroepiandrosterone sulfate (DHEAS) and insulin-like growth factor 1 (IGF-1) were measured.

RESULTS

The prevalence of ED in patients with PD was higher than in control group (30 versus 24%) as well as the prevalence and severity of ED and LUTS in elderly (60-80 years) and middle-aged (40-59 years) men with PD was higher than in healthy peers. In middle-aged pre-diabetic men, the more severe LUTS symptoms were associated with low TT and DHEAS, while in elderly men with low cFT and DHEAS. The higher prevalence of ED in middle-aged men with PD was associated with cFT and DHEAS, while in elderly pre-diabetic men with TT and IGF-1.

CONCLUSIONS

The prevalence and severity of LUTS and ED symptoms were higher in pre-diabetic men than in healthy peers. Hormonal determinants of these symptoms are different in middle-aged and elderly patients with PD.

The prevalence of prediabetes in population of Polish men with late-onset hypogonadism

OBJECTIVE

Prediabetes patients are likely to develop type 2 diabetes (T2DM). Low testosterone is a risk factor for impaired glucose tolerance (IGT) in men. The aim of this study was to investigate the prevalence of prediabetes in population of Polish men with late-onset hypogonadism (LOH).

METHODS

This study was performed in 246 men with LOH and in 184 eugonadal control group. Prediabetes was diagnosed in patients with impaired fasting glucose (IFG), IGT or with HbA1c from 5.7 to 6.4%. Sex hormones and metabolic parameters were measured.

RESULTS

The mean TT concentration in the LOH group was 9.55 ± 1.5 nmol/l and 16.45 ± 1.8 nmol/l in the control group (p < 0.001). We observed negative relationships between cFT and HbA1c (r = -0.336; p < 0.005) and between TT and HbA1c (r = -0.366, p < 0.002), In the LOH group, prediabetes was diagnosed in 41.5% men. In the control group, prediabetes was diagnosed in 13% of patients. In the LOH group, TT and cFT levels were lower in prediabetic patients, when compared with normoglycemic patients and patients with IGT had lower TT levels than subgroups with IFG or elevated HbA1c.

CONCLUSIONS

In a population of Polish men with LOH, we observed high prevalence of prediabetes and routine fasting glucose and glucose tolerance test should be performed in these patients.

Correlation of inhibin and several antioxidants in children with acute lymphoblastic leukemia

BACKGROUND

Acute lymphoblastic leukemia (ALL) is most common in childhood. Inhibin (a non-steroidal glycoprotein hormone of gonadal origin) can be used as marker of fertility. The current study was conducted to evaluate inhibin levels in ALL patients and to estimate its correlation with some antioxidants in these in comparison with control subjects.

MATERIALS AND METHODS

This study was conducted on sixty patients with ALL and thirty children as controls. Fasting blood samples were taken from each subject and analyzed for haemoglobin, serum protein, vitamin E and C, in addition to glutathione and inhibin.

RESULTS

The results of the study showed highly significant decreases (p<0.001) in haemoglobin, glutathione and inhibin levels with significant decreases (p<0.05) in serum protein and vitamin E levels for patients group in comparison with controls while there was no significant differences in vitamin C. Moreover, there were significant correlations between inhibin levels and serum protein, glutathione and both vitamins (E and C) in the ALL patient group (r= 0.81, 0.80, 0.77 and 0.69, respectively).

CONCLUSIONS

The present results indicated infertility in patients with ALL demonstrated by low inhibin level as a consequence of abnormality in anti-oxidative metabolism due to the cancer process. So, it can be suggested the need for routine measurement of inhibin for leukemic patients to estimate the action of hormones of gonadal origin.

The incidence of hypogonadotropic hypogonadism in type 2 diabetic men in Polish population

The aim of this study was to investigate the incidence of hypogonadotropic hypogonadism (HH) in type 2 diabetic men (T2DM) in population of Polish men and examine the possible influence of estradiol levels and glycemic control. We evaluated TT, cfT, estradiol, and glycemic control (HbA1c) in 184 diabetic men and in 149 nondiabetic control group. The mean HbA1c was 8.6 ± 0.2% and 6.1 ± 0.3% and cfT concentration was 0.315 ± 0.08 nmol/L and 0.382 ± 0.07 nmol/L, respectively. T2DM had higher E2 concentration than nonobese control men (29.4 ± 3.7 pg/mL versus 24.5 ± 2.9 pg/mL). Forty-six percent of T2DM were hypogonadal and 93% had HH. We observed inverse relationship between BMI and cfT (r = -0.341, P < 0.01) and positive between BMI and E2 (r = 0.329, P < 0.01). E2 concentration was higher in T2DM with HH versus T2DM with normal TT/cfT concentration (34.5 ± 5.2 versus 27.4 ± 3.4 pg/mL). We observed negative correlation between HbA1c and cfT (r = -0.336, P < 0.005) but positive between HbA1c and E2 levels (r = 0.337, P < 0.002). The prevalence of obesity, hypertension, and CVD was higher in men with hypogonadism. High incidence of hypogonadotropic hypogonadism in type 2 diabetic men in Polish population is associated with poor glycemic control and can be secondary to an increase in estradiol concentrations.

Testosterone Restoration by Enclomiphene Citrate in Men with Secondary Hypogonadism: Pharmacodynamics and Pharmacokinetics

OBJECTIVES

To determine the pharmacodynamic (PD) profile of serum total testosterone levels (TT) and luteinizing hormone (LH) in men with secondary hypogonadism following initial and chronic daily oral doses of enclomiphene citrate in comparison to transdermal testosterone. To determine the effects of daily oral doses of enclomiphene citrate (Androxal®) in comparison to transdermal testosterone on other hormones and markers in men with secondary hypogonadism.

PATIENTS AND METHODS

This was a randomized, single blind, two-center phase II study to evaluate three different doses of enclomiphene citrate (6.25mg, 12.5mg and 25 mg Androxal®), versus AndroGel®, a transdermal testosterone, on 24-hour LH and TT in otherwise normal healthy men with secondary hypogonadism. Forty-eight men were enrolled in the trial (ITT Population), but 4 men had T levels >350 ng/dL at baseline. Forty-four men completed the study per protocol (PP population). All subjects enrolled in this trial had serum TT in the low range (<350 ng/dL) and had low to normal LH (<12 IU/L) on at least two occasions. TT and LH levels were assessed each hour for 24 hours to examine the effects at each of three treatment doses of enclomiphene versus a standard dose (5 grams) of transdermal testosterone (AndroGel). In the initial profile TT and LH were determined in a naïve population following a single initial oral or transdermal treatment (Day 1). This was contrasted to that seen after six weeks of continuous daily oral or transdermal treatment (Day 42). The pharmacokinetics of enclomiphene was performed in a select subpopulation. Serum samples were obtained over the course of the study to determine levels of various hormones and lipids.

RESULTS

After six weeks of continuous use, the mean ± SD concentration of TT at Day 42 C0hrTT, was 604 ± 160 ng/dL for men taking the highest of dose of enclomiphene citrate (enclomiphene, 25 mg daily) and 500 ± 278 ng in those men treated with transdermal testosterone. These values were higher than Day 1 values but not different from each other (p = 0.23, T-test). All three doses of enclomiphene increased C0hrTT, CavgTT, CmaxTT, CminTT and CrangeTT. Transdermal testosterone also raised TT, albeit with more variability, and with suppressed LH levels. The patterns of TT over 24 hour period following six weeks of dosing could be fit to a non-linear function with morning elevations, mid-day troughs, and rising night-time levels. Enclomiphene and transdermal testosterone increased levels of TT within two weeks, but they had opposite effects on FSH and LH Treatment with enclomiphene did not significantly affect levels of TSH, ACTH, cortisol, lipids, or bone markers. Both transdermal testosterone and enclomiphene citrate decreased IGF-1 levels (p<0.05) but suppression was greater in the enclomiphene citrate groups.

CONCLUSIONS

Enclomiphene citrate increased serum LH and TT; however, there was not a temporal association between the peak drug levels and the Cmax levels LH or TT. Enclomiphene citrate consistently increased serum TT into the normal range and increased LH and FSH above the normal range. The effects on LH and TT persisted for at least one week after stopping treatment.

Duration of menopausal hot flushes and associated risk factors

OBJECTIVE

To estimate the duration of moderate-to-severe menopausal hot flushes and identify potential risk factors for hot flush duration.

METHODS

The Penn Ovarian Aging Study cohort was monitored for 13 years. Hot flushes were evaluated at 9-month to 12-month intervals through in-person interviews. The primary outcome was the duration of moderate-to-severe hot flushes estimated by survival analysis (n=259). Potential risk factors included menopausal stage, age, race, reproductive hormone levels, body mass index (BMI), and current smoking. A secondary analysis included women who reported any hot flushes (n=349).

RESULTS

The median duration of moderate-to-severe hot flushes was 10.2 years and was strongly associated with menopausal stage at onset. Hot flushes that started near entry into the menopause transition had a median duration greater than 11.57 years; onset in the early transition stage had a median duration of 7.35 years (95% confidence interval [CI] 4.94-8.89; P<.001); and onset in the late transition to postmenopausal stages had a median duration of 3.84 years (95% CI 1.77-5.52; P<.001). The most common ages at onset of moderate-to-severe hot flushes were 45-49 years (median duration, 8.1 years; 95% CI 5.12-9.28). African American women had a longer duration of hot flushes than white women in adjusted analysis.

CONCLUSION

The median duration of hot flushes considerably exceeded the timeframe that is generally accepted in clinical practice. The identified risk factors, particularly menopausal stage, race, and BMI, are important to consider in individualizing treatment and evaluating the risk-to-benefit ratio of hormones and other therapies.

The role of obesity and type 2 diabetes mellitus in the development of male obesity-associated secondary hypogonadism

Obesity, secondary (hypogonadotrophic) hypogonadism (SH), sleep disorders [such as obstructive sleep apnoea (OSA)] and type 2 diabetes mellitus (T2DM) in men have complex interlinks both with respect to mutual aetiopathogenesis as well as therapeutics. Correction of the attendant hypogonadism in obese men may serve to break this link and have beneficial effects beyond restoration of normal sexual function. Male obesity-associated secondary hypogonadism (MOSH) should be regarded as a distinct clinical entity and subtype of SH. A high index of suspicion for the presence of MOSH must be maintained by clinicians when assessing obese men. The pathogenesis of MOSH remains incompletely understood. Furthermore, the optimal management of MOSH and its associated sequelae will require long-term prospective studies that in turn will inform the development of future clinical guidelines for this important and prevalent condition.

Reproductive function in middle-aged males: healthy men versus male partners of infertile couples

The aim of this study was to compare the reproductive parameters and the health-related, lifestyle and educational factors in middle-aged healthy men and male partners of infertile couples. Our patient group included 164 male partners of infertile couples with a preceding period of infertility of at least 12 months and 61 men attending a prostate health screening and considering themselves healthy. Significant differences between the groups were found in testicular volume, total sperm output, density and morphology as well as oestradiol levels in serum. The analysis showed significant positive correlations between testicular volume and semen quality, while negative correlations were observed between gonadotrophin levels and sperm parameters in both groups. Physical activity and sexual capability were higher in healthy men, while coital frequency and a history of sexually transmitted diseases were higher in male partners of infertile couples. The impact of physical activity and sexual capability on semen quality for all subjects was revealed. We can conclude that impaired reproductive function, that is, semen quality, in men >45 years is related not only with general male ageing but obvious differences between subjects of infertile couples and healthy middle-aged men can be seen. Their relations with lifestyle, environmental or physiological factors need further study.

Clomiphene citrate potentiates the adverse effects of estrogen on rat testis and down-regulates the expression of steroidogenic enzyme genes

OBJECTIVE

To investigate the antiestrogenic effect of clomiphene citrate (CC) in male rats estrogenized with estradiol-3-benzoate (EB).

DESIGN

Prospective experimental study.

SETTING

Laboratory.

ANIMALS

Adult male albino rats (Holtzman strain).

INTERVENTION(S)

CC was given alone or in combination with EB.

MAIN OUTCOME MEASURE(S)

Testicular function and steroidogenic enzyme gene expression were evaluated in control versus treated groups.

RESULT(S)

EB after 30 days of treatment induced a rise in TUNEL-positive germ cells adversely affecting spermatogenesis with complete absence of elongated spermatids or sperms. CC alone had only a moderate effect. In contrast, CC+EB synergistically inflicted more adverse effects as apoptotic germ cells per tubule rose further. Significant down-regulation in expression of testicular steroidogenic enzyme genes StAR, p450scc, 3β-HSD, and p450c17 was observed. In the EB-alone group, aromatase gene expression in the testis was up-regulated but reversed in brain and liver tissues. CC alone had little modulatory effect on aromatase expression. On the other hand, CC+EB countered the EB-induced rise of aromatase expression in the testis.

CONCLUSION(S)

The above findings indicate that CC in the presence of estrogen synergistically potentiates more adverse effects in testis, inhibiting expression of upstream steroidogenic enzyme genes and leading to disruption of steroidogenesis.

Urinary concentrations of di(2-ethylhexyl) phthalate metabolites and serum reproductive hormones: pooled analysis of fertile and infertile men

Urinary concentrations of metabolites of the anti-androgenic xenobiotic di-(2-ethylhexyl) phthalate (DEHP) were previously shown to be weakly associated with serum levels of several hormones in 2 disparate US populations: partners of pregnant women participating in the Study for Future Families and partners in infertile couples from Massachusetts General Hospital infertility clinic. The observed associations between phthalate metabolites and reproductive hormones were robust and insensitive to the characteristics of the subpopulation or the laboratory in which the hormones were measured, despite the fact that these 2 populations span a range of fertility, urinary phthalate metabolites, and reproductive hormone levels. We therefore examined associations between urinary metabolites of DEHP and reproductive hormones-follicle-stimulating hormone, luteinizing hormone, testosterone (T), inhibin B, and estradiol (E(2))-and sex hormone-binding globulin (SHBG) in the pooled population. The magnitude of the associations seen were similar to those reported for each population separately, but effect estimates were more precise because of the increased sample size and the greater range of phthalate metabolite concentrations and hormone levels. Urinary concentrations of 3 metabolites of DEHP [mono(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), and mono(2-ethyl-5-oxohexyl) phthalate (MEOHP)] were inversely associated with the free androgen index (FAI = T/SHBG) and calculated free testosterone. Urinary concentrations of MEHHP and MEOHP were positively associated with SHBG, and MEHP was inversely associated with E(2). No other phthalate metabolites were associated with serum hormones, consistent with results in each population. Our results in this diverse population suggest that DEHP exposure is robustly associated with some male sex steroid hormones.

Abolition of endocrine dimorphism in hyperthyroid males? An argument for the positive feedback effect of hyperoestrogenaemia on LH secretion

Our aim was (i) to investigate the hypothalamo-hypophyseal-gonadal axis in hyperthyroid Indian males, (ii) to rule out the modulatory role of adrenal steroids on it and (iii) to determine if the simultaneous rise in oestradiol and luteinising hormone (LH) in hyperthyroid males is due to a positive feedback action of oestradiol on pituitary LH release. Age- and BMI-matched men were divided into two groups, I, euthyroid subjects (n = 17) and II, hyperthyroid patients (n = 12) on the basis of their thyroid hormone levels. Serum levels of thyroid-stimulating hormone, triiodothyronine, thyroxine, LH, follicle-stimulating hormone (FSH), prolactin, E(2), T, P(4), sex hormone binding globulin and dehydroepiandrosterone sulphate (DHEAS) were assayed. Mean levels of T and E(2) were approximately two times higher in group II in comparison with group I. DHEAS levels were similar in both groups ruling out any adrenal involvement. Mean serum LH level was 2.6 folds higher in group II in comparison with group I. Mean serum levels of FSH were higher in group II, it was marginally nonsignificant. On the basis of these and previous observations, we hypothesise that endocrinological dimorphism in human male and female is not rigid; a sustained rise in serum oestradiol probably induces a positive feedback action on pituitary leading to elevated gonadotrophin levels.

Update: Hypogonadotropic hypogonadism in type 2 diabetes and obesity

Studies over the last few years have clearly established that at least 25% of men with type 2 diabetes have subnormal free testosterone concentrations in association with inappropriately low LH and FSH concentrations. Another 4% have subnormal testosterone concentrations with elevated LH and FSH concentrations. The Endocrine Society, therefore, now recommends the measurement of testosterone in patients with type 2 diabetes on a routine basis. The subnormal testosterone concentrations are not related to glycosylated hemoglobin or duration of diabetes, but are associated with obesity, very high C-reactive protein concentrations, and mild anemia. In addition, subnormal testosterone concentrations in these men are associated with a two to three times elevated risk of cardiovascular events and death in two early studies. Short-term studies of testosterone therapy in hypogonadal men with type 2 diabetes have demonstrated an increase in insulin sensitivity and a decrease in waist circumference. However, the data on the effect of testosterone replacement on glycemic control and cardiovascular risk factors such as cholesterol and C-reactive protein concentrations are inconsistent. As far as sexual function is concerned, testosterone treatment increases libido but does not improve erectile dysfunction and thus, phosphodiesterase inhibitors may be required. Trials of a longer duration are clearly required to definitively establish the benefits and risks of testosterone replacement in patients with type 2 diabetes and low testosterone.

GnRH signaling, the gonadotrope and endocrine control of fertility

Mammalian reproductive cycles are controlled by an intricate interplay between the hypothalamus, pituitary and gonads. Central to the function of this axis is the ability of the pituitary gonadotrope to appropriately respond to stimulation by gonadotropin-releasing hormone (GnRH). This review focuses on the role of cell signaling and in particular, mitogen-activated protein kinase (MAPK) activities regulated by GnRH that are necessary for normal fertility. Recently, new mouse models making use of conditional gene deletion have shed new light on the relationships between GnRH signaling and fertility in both male and female mice. Within the reproductive axis, GnRH signaling is initiated through discrete membrane compartments in which the receptor resides leading to the activation of the extracellular signal-regulated kinases (ERKs 1/2). As defined by gonadotrope-derived cellular models, the ERKs appear to play a central role in the regulation of a cohort of immediate early genes that regulate the expression of late genes that, in part, define the differentiated character of the gonadotrope. Recent data would suggest that in vivo, conditional, pituitary-specific disruption of ERK signaling by GnRH leads to a gender-specific perturbation of fertility. Double ERK knockout in the anterior pituitary leads to female infertility due to LH biosynthesis deficiency and a failure in ovulation. In contrast, male mice are modestly LH deficient; however, this does not have an appreciable impact on fertility.

Obesity and reproductive hormone levels in the transition to menopause

OBJECTIVE

The aim of this study was to estimate associations of obesity with reproductive hormone levels as women progress from premenopausal to postmenopausal status.

METHODS

This was a longitudinal study conducted in the population-based Penn Ovarian Aging Cohort (N = 436). At cohort enrollment, the women were premenopausal, ages 35 to 47 years, with equal numbers of African Americans and whites. Anthropometric measures, menopause status, and reproductive hormone measures were evaluated for 12 years. Associations of the anthropometric measures with estradiol, follicle-stimulating hormone, and inhibin B in the menopausal transition were estimated using generalized linear regression models for repeated measures.

RESULTS

Associations between obesity and hormone levels differed by menopause status as indicated by significant interactions between each hormone and menopausal stage. Premenopausal obese and overweight women had significantly lower estradiol levels compared with nonobese women, independent of age, race, and smoking (obese: 32.8 pg/mL [95% CI, 30.6-35.2] vs nonobese: 39.8 pg/mL [95% CI, 37.0-42.8], P < 0.001). The associations reversed postmenopause, with obese women having the highest estradiol levels (obese: 20.6 pg/mL [95% CI, 17.2-24.7] vs nonobese: 12.2 pg/mL [95% CI, 10.1-14.8], P < 0.001). Inhibin B levels were significantly lower in premenopausal obese compared with nonobese women but reversed in the late transition stage. Follicle-stimulating hormone levels were lowest in postmenopausal obese compared with nonobese women (P < 0.001). Measures of waist circumference (central adiposity) and waist-to-hip ratio paralleled the body mass index results.

CONCLUSION

Obesity is an important factor in hormone dynamics independent of age, race, and smoking in midlife women, although the mechanisms remain unclear.

Potential diagnostic utility of intermittent administration of short-acting gonadotropin-releasing hormone agonist in gonadotropin deficiency

OBJECTIVE

To determine if intermittent, low-dose, short-acting gonadotropin-releasing hormone agonist (GnRH-agonist) administration sufficiently up-regulates pituitary-gonadal function in gonadotropin deficiency to be of diagnostic or therapeutic value.

DESIGN

Case-control study.

SETTING

General clinical research center.

PATIENT(S)

Normal adult volunteers and gonadotropin-deficiency patients.

INTERVENTION(S)

Low-dose leuprolide acetate administered subcutaneously at 4- to 5-day intervals up to 1 year.

MAIN OUTCOME MEASURE(S)

Levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), and sex steroid responses.

RESULT(S)

In normal men and women, low-dose GnRH-agonist repetitively transiently stimulated gonadotropins in a gender-dimorphic manner. In congenitally gonadotropin-deficient men (n = 6) and women (n = 1), none of whom had a normal LH response to an initial GnRH-agonist test dose, this regimen consistently stimulated LH to the normal baseline range within 2 weeks. Long-term GnRH-agonist administration to a partially gonadotropin-deficient man did not alleviate hypogonadism, however. Women with hypothalamic amenorrhea (n = 2) responded normally to a single GnRH-agonist injection; however, repeated dosing did not seem to induce the normal priming effect.

CONCLUSION(S)

The subnormal LH response to GnRH-agonist in patients with congenital gonadotropin deficiency normalized in response to repetitive intermittent GnRH-agonist administration but not sufficiently to improve hypogonadism. Hypothalamic amenorrhea patients lacked the priming response to repeated GnRH-agonist but otherwise had normal hormonal responses to GnRH-agonist. We conclude that intermittent administration of a short-acting GnRH-agonist is of potential diagnostic value in distinguishing hypothalamic from pituitary causes of gonadotropin deficiency.

Biochemical and physiological aspects of endogenous androgens

This review attempts to give a synopsis of the major aspects concerning the biochemistry of endogenous androgens, supplemented with several facets of physiology, particularly with respect to testosterone. Testosterone continues to be the most common adverse finding declared by World Anti-Doping Agency accredited laboratories, such samples having an augmented testosterone to epitestosterone ratio. Knowledge regarding the precursors and metabolism of endogenous testosterone is therefore fundamental to understanding many of the issues concerning doping with testosterone and its prohormones, including the detection of their administration. Further, adverse findings for nandrolone are frequent, but this steroid and 19-norandrostenedione are also produced endogenously, an appealing hypothesis being that they are minor by-products of the aromatization of androgens. At sports tribunals pertaining to adverse analytical findings of natural androgen administration, experts often raise issues that concern some aspect of steroid biochemistry and physiology. Salient topics included within this review are the origins and interconversion of endogenous androgens, the biosynthesis of testosterone and epitestosterone, the mechanism of aromatization, the molecular biology of the androgen receptor, the hypothalamic-pituitary-testicular axis, disturbances to this axis by anabolic steroid administration, the transport (binding) of androgens in blood, and briefly the metabolism and excretion of androgens.

Effects of oestradiol on gonadotrophin levels in normal and castrated men

CONTEXT

Testosterone inhibits gonadotrophin release in men either directly or after aromatization to oestradiol. We hypothesized that in males the androgen receptor-mediated effect of testosterone on LH release is negligible relative to that of oestradiol.

OBJECTIVE

To compare the effect of experimentally induced variations of plasma oestradiol levels on LH levels in normal (physiological testosterone levels) and castrated men (very low testosterone levels).

DESIGN

Prospective, open label, intervention.

SUBJECTS AND INTERVENTIONS

We suppressed endogenous oestradiol in 10 young men with letrozole 2.5 mg once daily. In these men and in 10 young healthy castrated men, we restored plasma oestradiol levels with oestradiol patches (first week 100 mug/day, second week 50 mug/day, third week 25 mug/day and fourth week no oestradiol patch).

MEASUREMENTS

The effect of the intervention on plasma levels of LH were monitored and compared between the groups.

RESULTS

With the intervention, the mean plasma oestradiol level in the two groups varied from supraphysiological to below the lower reference range. Levels of LH mirrored plasma oestradiol levels in both the groups, as did testosterone in the intact group. Despite similar oestradiol levels, mean levels of LH were significantly higher in the castrated group compared to the intact group for all doses of oestradiol, and supraphysiological levels of oestradiol were unable to suppress LH into the physiological range in the castrated group.

CONCLUSIONS

Physiological plasma oestradiol levels have a substantial suppressive effect on LH in men. However, low-normal testosterone levels are a prerequisite for suppression of LH into the normal range.

Factors that influence entry into stages of the menopausal transition

OBJECTIVE

The aim of this study was to estimate the probabilities and identify risk factors for entering the menopausal transition and moving into each subsequent transition stage.

METHODS

Estimations of probabilities of entry into each menopausal transition stage and predictors associated with each transition stage were conducted in a population-based cohort of midlife women.

RESULTS

The likelihood of entering the menopausal transition and moving into each subsequent stage was increased for each unit increase in follicle-stimulating hormone (FSH) (P < 0.001) and with each unit decrease in inhibin B (P < 0.001) in the adjusted multivariable model. The largest observed change in average FSH levels was the comparison of women in the late transition (stage 4), with an average of 24.78 mIU/mL, to those in the early transition (stage 3), with 10.38 mIU/mL. Women experiencing this amount of change in FSH had an odds of transitioning from stages 3 to 4 of 1.90 (95% CI, 1.86-1.95). Decreases in inhibin B resulted in odds ratios similar to the magnitude of changes in FSH. Current smoking increased the odds of transition into each stage by approximately 30% (odds ratio, 1.30; 95% CI, 1.28-1.32). Average estradiol levels did not change dramatically between stages. However, higher estradiol significantly increased the odds of entering the transition (P = 0.013). Age and race predicted transitions into some but not all stages. Body mass index, alcohol use, and age at menarche did not predict entrance into any stage of the menopausal transition after adjusting for other study variables.

CONCLUSIONS

These results show that increased FSH, decreased inhibin B, and smoking strongly predict entry into the earliest stages of the menopausal transition as defined by changes in bleeding patterns. African Americans entered the transition before white women, but race did not predict entry into late transition stages. Higher estradiol levels predict entry into the earliest transition stage but not subsequent stages.

The effects of long-term raloxifene and estradiol treatments on bone in a patient with congenital aromatase deficiency

INTRODUCTION

In adult aromatase-deficient men, estrogen treatment has always resulted in a rapid skeletal maturation with epiphyseal closure and improved BMD. Raloxifene is a SERM with proven estrogen agonist action on bone that leads to an improvement in BMD and a reduction in bone turnover. The present study reports the effects of raloxifene and transdermal estradiol treatment, respectively, on epiphyseal closure and BMD in an aromatase-deficient man, over a 24-month follow-up, with the aim of obtaining further insight into the role of estrogens in the male skeletal homeostasis.

MATERIALS AND METHODS

A 25-year-old Caucasian man with aromatase deficiency, a bone age of 15.3 years, unfused epiphyses and an impaired BMD was initially administered raloxifene (60 mg/day per os) for 12 months, while transdermal estradiol (25 microg twice weekly) was administered for the subsequent 12 months. During the follow-up, the effects of the two treatments on epiphyseal closure, BMD and bone turnover markers were investigated. An iliac crest bone biopsy was performed only before and after the raloxifene treatment, but it was not repeated after transdermal estradiol treatment.

RESULTS

No changes in bone age were observed after raloxifene therapy, whereas a complete epiphyseal closure was achieved with transdermal estradiol treatment. Compared with baseline values, raloxifene treatment led to improved BMD both at the ultradistal forearm and 33% radius; the transdermal estradiol treatment resulted in a further slight increase in BMD at the 33% radius, but not at the ultradistal forearm. The baseline bone biopsy showed elevated bone remodelling in trabecular bone, while the second biopsy following raloxifene treatment revealed a decrease in remodelling.

DISCUSSION

This study shows that the management of aromatase deficiency in the male cannot consider raloxifene as a first choice treatment, but should be still based on estrogen replacement treatment since in this patient the completion of bone maturation has only been obtained once estradiol substitution was performed. The present case also demonstrates that raloxifene is able to improve BMD in aromatase-deficient men.