Estrogen-specific action on bone geometry and volumetric bone density: longitudinal observations in an adult with complete androgen insensitivity

Dilemmas in management of osteoporosis in patients with complete androgen insensitivity syndrome

Complete androgen insensitivity syndrome (CAIS)-resulting in 46,XY karyotype, but female phenotype-is a disorder of sex development and primary amenorrhea, but its effect on bone mineral density (BMD) is singular and difficult to manage. Androgens are an important modulator of bone remodeling and health, and the androgen receptor (AR) is pivotal for signaling within the bone cells. CAIS results in a severely disrupted AR throughout the body, causing an elevated risk of early osteoporosis. Timing of gonadectomy and hormone replacement therapy protocols are not established, creating a wide variety of treatment plans and BMD profiles. Our objective is to report a patient with CAIS status post prepubertal orchiectomy that developed early osteoporosis and to describe the lack of optimal strategies and consensus available to improve bone health in this population. Additionally, our case illustrates the fact there are no guidelines advocating the use of newer drugs for osteoporosis in this population.

Complete Androgen Insensitivity Syndrome: From Bench to Bed

Complete androgen insensitivity syndrome (CAIS) is due to complete resistance to the action of androgens, determining a female phenotype in persons with a 46,XY karyotype and functioning testes. CAIS is caused by inactivating mutations in the androgen receptor gene (AR). It is organized in eight exons located on the X chromosome. Hundreds of genetic variants in the AR gene have been reported in CAIS. They are distributed throughout the gene with a preponderance located in the ligand-binding domain. CAIS mainly presents as primary amenorrhea in an adolescent female or as a bilateral inguinal/labial hernia containing testes in prepubertal children. Some issues regarding the management of females with CAIS remain poorly standardized (such as the follow-up of intact testes, the timing of gonadal removal and optimal hormone replacement therapy). Basic research will lead to the consideration of new issues to improve long-term well-being (such as bone health, immune and metabolic aspects and cardiovascular risk). An expert multidisciplinary approach is mandatory to increase the long-term quality of life of women with CAIS.

Case Report: Low Bone and Normal Lean Mass in Adolescents With Complete Androgen Insensitivity Syndrome

INTRODUCTION

Osteopenia and osteoporosis have been reported in adults with Complete Androgen Insensitivity Syndrome (CAIS). Little is known about changes in bone mineral density (BMD) in adolescents with CAIS and whether it is affected by early gonadectomy. Body composition data have not been reported.

METHODS

Single-center, retrospective study of CAIS adolescents who underwent dual-energy x-ray absorptiometry (DXA) (Hologic, Horizon A). Body composition is presented as lean and fat mass indices (LMI, FMI). Z-scores for lumbar spine areal BMD (LBMD), total body less head (TBLH), bone mineral content (BMC), LMI, and FMI were calculated using female normative data. Results are expressed as median and min, max.

RESULTS

Six females with genetically confirmed CAIS were identified-one with intact gonads and five with history of gonadectomy at 2-11 months. In the subject with intact gonads, LBMD-Z and TBLH BMC-Z were -1.56 and -1.26, respectively, at age 16 years. Among those with gonadectomy, LBMD-Z was -1.8 (-3.59 to 0.49) at age 15.6 years (12-16.8) and decreased in all three subjects who had longitudinal follow-up despite hormone replacement therapy (HRT). Adherence to HRT was intermittent. LMI-Z and FMI-Z were 0.1 (-1.39 to 0.7) and 1.0 (0.22 to 1.49), respectively.

CONCLUSIONS

These limited data indicate that adolescents with CAIS have bone mass deficit. Further studies are needed to understand the extent of BMD abnormalities and the effect of gonadectomy, especially early in childhood, and to establish the optimal HRT regimen for bone accrual. Data on lean mass are reassuring.

Factors of mineral homeostasis impairment and bone mineral density loss in women with central hypogonadism

OBJECTIVE

The aims of the study were to estimate markers of mineral turnover and bone mineral density (BMD) in young women with central hypogonadism (CH) in comparison with healthy young and postmenopausal women, and to reveal the possible impact of different factors on BMD.

METHOD

We examined 73 patients with CH (mean age 25 [21.2; 30.5] years, mean duration of amenorrhea 5 [2.3; 10.1] years), 47 young healthy women (mean age 24 [23.1; 28.0] years) and 50 healthy women in natural postmenopause (mean age 56 [53; 58] years, mean duration of 6 [2; 10] years since last menstrual period). Women with CH were examined before and after 12 months of treatment with 17β-estradiol 2 mg and dydrogesterone 10 mg in continuous sequential fashion.

RESULTS

Levels of calcium, alkaline phosphatase, and C-terminal telopeptide of type I collagen were statistically higher in women with CH without treatment than in young healthy women but did not differ from those in postmenopausal women. Prevalence of T-score ≤-2.5 standard deviations was higher in CH than in postmenopause both in lumbar vertebrae and total femur. Factors that were responsible for lower BMD in young women with CH included the duration of hypoestrogenism, primary amenorrhea, and hypoandrogenism.

CONCLUSION

Central hypogonadism at a young age poses a higher risk of bone metabolism impairment than physiological menopause.

Androgens and Androgen Receptor Actions on Bone Health and Disease: From Androgen Deficiency to Androgen Therapy

Androgens are not only essential for bone development but for the maintenance of bone mass. Therefore, conditions with androgen deficiency, such as male hypogonadism, androgen-insensitive syndromes, and prostate cancer with androgen deprivation therapy are strongly associated with bone loss and increased fracture risk. Here we summarize the skeletal effects of androgens—androgen receptors (AR) actions based on in vitro and in vivo studies from animals and humans, and discuss bone loss due to androgens/AR deficiency to clarify the molecular basis for the anabolic action of androgens and AR in bone homeostasis and unravel the functions of androgen/AR signaling in healthy and disease states. Moreover, we provide evidence for the skeletal benefits of androgen therapy and elucidate why androgens are more beneficial than male sexual hormones, highlighting their therapeutic potential as osteoanabolic steroids in improving bone fracture repair. Finally, the application of selective androgen receptor modulators may provide new approaches for the treatment of osteoporosis and fractures as well as building stronger bones in diseases dependent on androgens/AR status.

Long-term consequences of androgen insensitivity syndrome

Androgen insensitivity syndrome (AIS) is one of the most common sexual developmental disorders. According to the grade of the remaining androgen receptor (AR) function, AIS is classified as complete (CAIS), partial (PAIS) or mild (MAIS). In CAIS, the prevalence of germ cell tumours is increased compared with the general population. Although patients with CAIS used to undergo gonadectomy before puberty, nowadays a gonadectomy is recommended after spontaneous puberty, and up to 15% of patients retain their gonads. Nevertheless, the risk of germ cell tumour increases gradually after puberty. Annual follow-up with ultrasound or magnetic resonance imaging (MRI) is recommended. Unfortunately, these imaging methods are not sensitive enough for the diagnosis of an in situ germ cell tumour. In PAIS, the risk of germ cell tumour is higher than in CAIS; therefore, an early gonadectomy or an orchidopexy is indicated. Optimal hormone replacement therapy (HRT) is necessary for long-term health. The risks of osteopenia and of regimen osteoporosis are higher, ESPECIALLY in patients with early gonadectomy. Infertility is the rule in CAIS and PAIS. A few mutations do not affect fertility detrimentally, and these are responsible for MAIS. In PAIS leading to a predominantly male phenotype or ambiguous genitalia, multiple surgical procedures for gynaecomastia and/or hypospadias are required. Some small studies have found a higher risk of obesity, hyperlipidaemia and impaired insulin sensitivity. Psychological support is essential, as the prevalence of psychiatric disorders is increased. In conclusion, the diagnosis of AIS has long-term consequences for which shared decision-making (physicians, patients, parents) is appropriate.

Different Clinical Presentations and Management in Complete Androgen Insensitivity Syndrome (CAIS)

Complete androgen insensitivity syndrome (CAIS) is an X-linked recessive genetic disorder resulting from maternally inherited or de novo mutations involving the androgen receptor gene, situated in the Xq11-q12 region. The diagnosis is based on the presence of female external genitalia in a 46, XY human individual, with normally developed but undescended testes and complete unresponsiveness of target tissues to androgens. Subsequently, pelvic ultrasound or magnetic resonance imaging (MRI) could be helpful in confirming the absence of Mullerian structures, revealing the presence of a blind-ending vagina and identifying testes. CAIS management still represents a unique challenge throughout childhood and adolescence, particularly regarding timing of gonadectomy, type of hormonal therapy, and psychological concerns. Indeed this condition is associated with an increased risk of testicular germ cell tumour (TGCT), although TGCT results less frequently than in other disorders of sex development (DSD). Furthermore, the majority of detected tumoral lesions are non-invasive and with a low probability of progression into aggressive forms. Therefore, histological, epidemiological, and prognostic features of testicular cancer in CAIS allow postponing of the gonadectomy until after pubertal age in order to guarantee the initial spontaneous pubertal development and avoid the necessity of hormonal replacement therapy (HRT) induction. However, HRT is necessary after gonadectomy in order to prevent symptoms of hypoestrogenism and to maintain secondary sexual features. This article presents differential clinical presentations and management in patients with CAIS to emphasize the continued importance of standardizing the clinical and surgical approach to this disorder.

Oestrogen versus androgen in hormone-replacement therapy for complete androgen insensitivity syndrome: a multicentre, randomised, double-dummy, double-blind crossover trial

BACKGROUND

Women with complete androgen insensitivity syndrome (CAIS) after gonadectomy have complained about reduced psychological wellbeing and sexual satisfaction. The aim of this study was to compare the effectiveness of hormone-replacement therapy with either androgen or oestrogen in women with 46,XY karyotype and CAIS after gonadectomy.

METHODS

This national, multicentre, double-blind, randomised crossover trial was performed at three university medical centres and three specialised treatment institutions in Germany. Eligible participants were women aged 18-54 years with 46,XY karyotype, genetically diagnosed CAIS, and removed gonads. Participants were randomly assigned (14:12) by a central computer-based minimisation method to either oestradiol 1·5 mg/day for 6 months followed by crossover to testosterone 50 mg/day for 6 months (sequence A) or to testosterone 50 mg/day for 6 months followed by crossover to oestradiol 1·5 mg/day for 6 months (sequence B). Participants also received oestradiol or testosterone dummy to avoid identification of the active substance. All participants received oestradiol 1·5 mg/day during a 2 months' run-in phase. The primary outcome was mental health-related quality of life, as measured with the standardised German version of the SF-36 questionnaire. Secondary outcomes were psychological wellbeing, as measured with the Brief Symptom Inventory (BSI), sexual function, as measured with the Female Sexual Function Index (FSFI), and somatic effects, such as signs of virilisation and effects on metabolic blood values. The primary analysis included all patients who were available at least until visit 5, even if protocol violations occurred. The safety analysis included all patients who received at least oestradiol during the run-in phase. This trial is registered with the German Clinical Trials Register, number DRKS00003136, and with the European Clinical Trials Database, number 2010-021790-37.

FINDINGS

We enrolled 26 patients into the study, with the first patient enrolled on Nov 7, 2011, and the last patient leaving the study on Jan 23, 2016. 14 patients were assigned to sequence A and 12 were assigned to sequence B. Ten participants were withdrawn from the study, two of whom attended at least five visits and so could be included in the primary analysis. Mental health-related quality of life did not differ between treatment groups (linear mixed model, p=0·794), nor did BSI scores for psychological wellbeing (global severity index, p=0·638; positive symptom distress index, p=0·378; positive symptom total, p=0·570). For the FSFI, testosterone was superior to oestradiol only in improving sexual desire (linear mixed model, p=0·018). No virilisation was observed, and gonadotrophin concentrations remained stable in both treatment groups. Oestradiol and testosterone concentrations changed substantially during the study in both treatment groups. 28 adverse events were reported for patients receiving oestradiol (23 grade 1 and five grade 2), and 38 adverse events were reported for patients receiving testosterone (34 grade 1, three grade 2, and one grade 3). One serious adverse event (fibrous mastopathy) and 20 adverse events (16 grade 1 and four grade 2) were reported during the run-in phase, and 12 adverse events during follow-up (nine grade 1 and three grade 2).

INTERPRETATION

Testosterone was well tolerated and as safe as oestrogen for hormone-replacement therapy. Testosterone can be an alternative hormone substitution in CAIS, especially for woment with reduced sexual functioning.

FUNDING

German Federal Ministry of Education and Research.

Caring for individuals with a difference of sex development (DSD): a Consensus Statement

The term differences of sex development (DSDs; also known as disorders of sex development) refers to a heterogeneous group of congenital conditions affecting human sex determination and differentiation. Several reports highlighting suboptimal physical and psychosexual outcomes in individuals who have a DSD led to a radical revision of nomenclature and management a decade ago. Whereas the resulting recommendations for holistic, multidisciplinary care seem to have been implemented rapidly in specialized paediatric services around the world, adolescents often experience difficulties in finding access to expert adult care and gradually or abruptly cease medical follow-up. Many adults with a DSD have health-related questions that remain unanswered owing to a lack of evidence pertaining to the natural evolution of the various conditions in later life stages. This Consensus Statement, developed by a European multidisciplinary group of experts, including patient representatives, summarizes evidence-based and experience-based recommendations for lifelong care and data collection in individuals with a DSD across ages and highlights clinical research priorities. By doing so, we hope to contribute to improving understanding and management of these conditions by involved medical professionals. In addition, we hope to give impetus to multicentre studies that will shed light on outcomes and comorbidities of DSD conditions across the lifespan.

Proandrogenic and Antiandrogenic Progestins in Transgender Youth: Differential Effects on Body Composition and Bone Metabolism

CONTEXT

Progestins can be used to attenuate endogenous hormonal effects in late-pubertal transgender (trans) adolescents (Tanner stage B4/5 and G4/5). Currently, no data are available on the effects of progestins on the development of bone mass or body composition in trans youth.

OBJECTIVE

To study prospectively the evolution of body composition and bone mass in late-pubertal trans adolescents using the proandrogenic or antiandrogenic progestins lynestrenol (L) and cyproterone acetate (CA), respectively.

DESIGN AND OUTCOME MEASUREMENTS

Forty-four trans boys (Tanner B4/5) and 21 trans girls (Tanner G4/5) were treated with L or CA for 11.6 (4 to 40) and 10.6 (5 to 31) months, respectively. Anthropometry, grip strength, body composition, and bone mass, size, and density were determined by dual-energy X-ray absorptiometry and peripheral quantitative computed tomography before the start of progestin and before addition of cross-sex hormones.

RESULTS

Using L, lean mass [+3.2 kg (8.6%)] and grip strength [+3 kg (10.6%)] significantly increased, which coincided with a more masculine body shape in trans boys. Trans girls showed loss of lean mass [-2.2 kg (4.7%)], gain of fat mass [+1.5 kg (9.4%)], and decreased grip strength Z scores. CA limited normal bone expansion and impeded pubertal bone mass accrual, mostly at the lumbar spine [Z score: -0.765 to -1.145 (P = 0.002)]. L did not affect physiological bone development.

CONCLUSION

Proandrogenic and antiandrogenic progestins induce body composition changes in line with the desired appearance within 1 year of treatment. Bone health, especially at the lumbar spine, is of concern in trans girls, as bone mass accrual is severely affected by androgen suppressive therapy.

Estrogens and Androgens in Skeletal Physiology and Pathophysiology

Estrogens and androgens influence the growth and maintenance of the mammalian skeleton and are responsible for its sexual dimorphism. Estrogen deficiency at menopause or loss of both estrogens and androgens in elderly men contribute to the development of osteoporosis, one of the most common and impactful metabolic diseases of old age. In the last 20 years, basic and clinical research advances, genetic insights from humans and rodents, and newer imaging technologies have changed considerably the landscape of our understanding of bone biology as well as the relationship between sex steroids and the physiology and pathophysiology of bone metabolism. Together with the appreciation of the side effects of estrogen-related therapies on breast cancer and cardiovascular diseases, these advances have also drastically altered the treatment of osteoporosis. In this article, we provide a comprehensive review of the molecular and cellular mechanisms of action of estrogens and androgens on bone, their influences on skeletal homeostasis during growth and adulthood, the pathogenetic mechanisms of the adverse effects of their deficiency on the female and male skeleton, as well as the role of natural and synthetic estrogenic or androgenic compounds in the pharmacotherapy of osteoporosis. We highlight latest advances on the crosstalk between hormonal and mechanical signals, the relevance of the antioxidant properties of estrogens and androgens, the difference of their cellular targets in different bone envelopes, the role of estrogen deficiency in male osteoporosis, and the contribution of estrogen or androgen deficiency to the monomorphic effects of aging on skeletal involution.

Size-controllable ultrathin carboxylated polypyrrole nanotube transducer for extremely sensitive 17β-estradiol FET-type biosensors

Size-controllable aptamer conjugated ultrathin carboxylated polypyrrole nanotubes (A-UCPPyNTs) were successfully fabricated as transducers in 17β-estradiol field-effect transistor (FET)-type biosensors which has extremely high sensitivity (∼1 fM) and unique selectivity.

Effect of a single injection of testosterone enanthate on 17β estradiol and bone turnover markers in hypogonadal male patients

PURPOSE

Several clinical studies testify the critical role played by estrogens in male bone metabolism. The aim of our study is to assess the effect of a single injection of testosterone enanthate in a group of hypogonadal men on 17β estradiol serum levels and some bone metabolic parameters.

METHOD

Twenty-one hypogonadal males were given one testosterone enanthate injection (250 mg). Blood samples were drawn before the injection and after 1, 2 and 3 weeks. The following variables were measured: Total testosterone (TT), 17β estradiol (17β E2), Sex hormone binding globulin, total alkaline phosphatase, osteocalcin, and C-telopeptide of type I collagen (CTx).

RESULTS

After testosterone injection, both TT and 17β E2 increased, peaking 1 week after the injection. Individual observation of the response of 17β E2 to testosterone showed that a subgroup (n = 9) failed to respond with any increase in 17β E2 at any of the weekly tests (group E2-), while the remainder (n = 12) showed a significant increase in 17β E2, which reached a mean value three times higher than at baseline (group E2+). The E2- patients reached a TT peak lower than that observed in the E+ group. CTx serum levels declined progressively in the E2+ group, reaching the significance (p = 0.03) at the end of the study, while it did not change in E- group.

CONCLUSION

This study suggests that a single injection of testosterone might have different effects on the production of endogenous estrogens, and a significant reduction of bone resorption parameters takes place only in the patients who show a significant increase of 17ß estradiol in response to testosterone administration.

The endocrine role of estrogens on human male skeleton

Before the characterization of human and animal models of estrogen deficiency, estrogen action was confined in the context of the female bone. These interesting models uncovered a wide spectrum of unexpected estrogen actions on bone in males, allowing the formulation of an estrogen-centric theory useful to explain how sex steroids act on bone in men. Most of the principal physiological events that take place in the developing and mature male bone are now considered to be under the control of estrogen. Estrogen determines the acceleration of bone elongation at puberty, epiphyseal closure, harmonic skeletal proportions, the achievement of peak bone mass, and the maintenance of bone mass. Furthermore, it seems to crosstalk with androgen even in the determination of bone size, a more androgen-dependent phenomenon. At puberty, epiphyseal closure and growth arrest occur when a critical number of estrogens is reached. The same mechanism based on a critical threshold of serum estradiol seems to operate in men during adulthood for bone mass maintenance via the modulation of bone formation and resorption in men. This threshold should be better identified in-between the ranges of 15 and 25 pg/mL. Future basic and clinical research will optimize strategies for the management of bone diseases related to estrogen deficiency in men.

An ultrasensitive detection of 17β-estradiol using a gold nanoparticle-based fluorescence immunoassay

A fluorescence immunoassay based on functionalized gold nanoparticle amplification and immunomagnetic separation was constructed for E₂detection.

Neonatal estrogen exposure results in biphasic age-dependent effects on the skeletal development of male mice

Peak bone mass, one of the most important predictors for fracture risk later in life, is attained during puberty and adolescence and influenced by neonatal and pubertal sex-specific gonadal hormones and GH-IGF-I secretion patterns. This study examined the effects of brief neonatal estrogen (NE) exposure on growth and skeletal development in C57BL/6J mice. A single injection of 100-μg estradiol or vehicle was administered on the first day of life. Growth parameters were monitored and skeletal phenotyping performed at 16 weeks in female mice and at 4 and 16 weeks in male mice. NE exposure negatively impacted adult femoral length in both sexes, but adult body weight, areal bone density, and bone strength in female mice were unaffected. In contrast, somatic growth was attenuated in estrogen-exposed male mice throughout the study period. At the prepubertal time point, the estrogen-exposed males exhibited higher bone mineral density, cortical volume, and cortical thickness compared with controls. However, by the time of peak bone mass acquisition, the early skeletal findings had reversed; estrogen-exposed mice had lower bone density with reduced cross-sectional area, cortical volume, and cortical thickness, resulting in cortical bones that were less resistant to fracture. NE exposure also resulted in reduced testicular volume and lower circulating IGF-I. Male mice exposed to estrogen on the first day of life experience age-dependent changes in skeletal development. Prepubertal animals experience greater endocortical bone acquisition as a result of estrogen exposure. However, by adulthood, continued developmental changes result in overall reduced skeletal integrity.

Sex steroid actions in male bone

Sex steroids are chief regulators of gender differences in the skeleton, and male gender is one of the strongest protective factors against osteoporotic fractures. This advantage in bone strength relies mainly on greater cortical bone expansion during pubertal peak bone mass acquisition and superior skeletal maintenance during aging. During both these phases, estrogens acting via estrogen receptor-α in osteoblast lineage cells are crucial for male cortical and trabecular bone, as evident from conditional genetic mouse models, epidemiological studies, rare genetic conditions, genome-wide meta-analyses, and recent interventional trials. Genetic mouse models have also demonstrated a direct role for androgens independent of aromatization on trabecular bone via the androgen receptor in osteoblasts and osteocytes, although the target cell for their key effects on periosteal bone formation remains elusive. Low serum estradiol predicts incident fractures, but the highest risk occurs in men with additionally low T and high SHBG. Still, the possible clinical utility of serum sex steroids for fracture prediction is unknown. It is likely that sex steroid actions on male bone metabolism rely also on extraskeletal mechanisms and cross talk with other signaling pathways. We propose that estrogens influence fracture risk in aging men via direct effects on bone, whereas androgens exert an additional antifracture effect mainly via extraskeletal parameters such as muscle mass and propensity to fall. Given the demographic trends of increased longevity and consequent rise of osteoporosis, an increased understanding of how sex steroids influence male bone health remains a high research priority.

Androgens and estrogens in skeletal sexual dimorphism

Bone is an endocrine tissue expressing androgen and estrogen receptors as well as steroid metabolizing enzymes. The bioactivity of circulating sex steroids is modulated by sex hormone-binding globulin and local conversion in bone tissue, for example, from testosterone (T) to estradiol (E2) by aromatase, or to dihydrotestosterone by 5α-reductase enzymes. Our understanding of the structural basis for gender differences in bone strength has advanced considerably over recent years due to increasing use of (high resolution) peripheral computed tomography. These microarchitectural insights form the basis to understand sex steroid influences on male peak bone mass and turnover in cortical vs trabecular bone. Recent studies using Cre/LoxP technology have further refined our mechanistic insights from global knockout mice into the direct contributions of sex steroids and their respective nuclear receptors in osteoblasts, osteoclasts, osteocytes, and other cells to male osteoporosis. At the same time, these studies have reinforced the notion that androgen and estrogen deficiency have both direct and pleiotropic effects via interaction with, for example, insulin-like growth factor 1, inflammation, oxidative stress, central nervous system control of bone metabolism, adaptation to mechanical loading, etc., This review will summarize recent advances on these issues in the field of sex steroid actions in male bone homeostasis.

Functional hypothalamic amenorrhea and its influence on women's health

INTRODUCTION

Functional hypothalamic amenorrhea (FHA) is one of the most common causes of secondary amenorrhea. There are three types of FHA: weight loss-related, stress-related, and exercise-related amenorrhea. FHA results from the aberrations in pulsatile gonadotropin-releasing hormone (GnRH) secretion, which in turn causes impairment of the gonadotropins (follicle-stimulating hormone and luteinizing hormone). The final consequences are complex hormonal changes manifested by profound hypoestrogenism. Additionally, these patients present mild hypercortisolemia, low serum insulin levels, low insulin-like growth factor 1 (IGF-1) and low total triiodothyronine.

AIM

The aim of this work is to review the available data concerning the effects of FHA on different aspects of women's health.

RESULTS

Functional hypothalamic amenorrhea is related to profound impairment of reproductive functions including anovulation and infertility. Women's health in this disorder is disturbed in several aspects including the skeletal system, cardiovascular system, and mental problems. Patients manifest a decrease in bone mass density, which is related to an increase in fracture risk. Therefore, osteopenia and osteoporosis are the main long-term complications of FHA. Cardiovascular complications include endothelial dysfunction and abnormal changes in the lipid profile. FHA patients present significantly higher depression and anxiety and also sexual problems compared to healthy subjects.

CONCLUSIONS

FHA patients should be carefully diagnosed and properly managed to prevent both short- and long-term medical consequences.

[Bone and androgens]

Sexual steroids are major determinants of skeletal maturation and steady state. Estrogens are mandatory in both sexes. They induce endochondral bone formation and growth plate knitting. Androgens are mainly active in male. They increase length and radial bone growth. These differences explain the duality of biomechanics in both sexes. Deep androgen deficiency induces rapid bone loss and increases bone fracture risk. The androgen treatment of andropause has weak rationale. Androgens interact with bone metabolism within the medulla-bone unit. They activate the whole osteoblastic lineage and interact with preosteoclastic regulation. Androgens found their place in bone metabolism regulation through RANK/osteoprotegerin and Wnt/sclerostin pathways.

Skeletal status and body composition in young women with functional hypothalamic amenorrhea

CONTEXT

Functional hypothalamic amenorrhea (FHA) related to hypoestrogenism and hormonal status may influence skeletal homeostasis and body composition. The study aimed to evaluate hormones concentrations, body composition and bone strength in FHA cases.

PATIENTS AND METHODS

Total body scans using DXA method (DPX-L, GE Lunar) were performed in a group of 27 women aged 21.8 years ± 3.9 with FHA related to weight loss. References of healthy control subjects were used to calculate Z-scores (age and gender matched), SD-scores (height and gender matched), and SDs-scores (weight and gender matched). Whole skeleton bone mineral content (TBBMC, g) and density (TBBMD, g/cm(2)), lumbar spine (L2-L4) bone mineral density (SBMD; g/cm(2)), lean body mass (LBM, g) and fat mass (FM, g) were investigated. Relative bone strength index was calculated as the TBBMC/LBM ratio. Serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol, testosterone, and prolactin (PRL) concentrations were assayed to characterize hormonal profile of FHA cases.

RESULTS

Hormonal evaluation in patients with FHA revealed significantly decreased serum concentrations of gonadotropins and estradiol. Serum LH concentrations were 1.47 ± 0.89 mIU/ml, FSH 4.44 ± 1.94 mIU/ml. Estradiol concentrations in serum were 27.08 ± 13.10 pg/ml. As evidenced by Z-scores, FHA cases had decreased SBMD, TBBMD and TBBMC Z-scores of -1.23 ± 0.90 (p < 0.0001), -0.72 ± 0.86 (p < 0.001), and -0.90 ± 1.40 (p < 0.01), respectively. Reduced FM, LBM and FM/LBM ratio Z-scores of -1.80 ± 2.28 (p < 0.001), -0.59 ± 1.49 (p < 0.05) and -0.74 ± 1.55 (p < 0.05), but not TBBMC/LBM Z-score of -0.54 ± 2.14 (ns) were noted in FHA cases compared with healthy control cases. TBBMC, TBBMD, TBBMC/LBM when BH- or BW-matched were normal as evidenced by SD-scores and SDs-scores. SBMD remained reduced when BH-matched (SD-score = -0.40 ± 0.86; p < 0.05) whereas FM and FM/LBM were lower than expected in healthy, both compared to BH- and BW-dependent references. The length of amenorrhea in months negatively correlated with SBMD Z-score (R = -0.39, p < 0.05), and SD-scores for SBMD (R = -0.48), TBBMD (R = -0.43), TBBMC (R = -0.46) (all p < 0.05) and positively with SDs-scores for FM (R = 0.44, p < 0.05).

CONCLUSION

Patients with FHA were characterized by lower concentrations of serum FSH, LH and estradiol concentrations. Moreover, FHA cases had decreased FM and an imbalanced relationship between BW, FM, and LBM. Despite reduced BMD and BMC, bone strength was not significantly affected by FHA.

Testosterone and the male skeleton: a dual mode of action

Testosterone is an important hormone for both bone gain and maintenance in men. Hypogonadal men have accelerated bone turnover and increased fracture risk. In these men, administration of testosterone inhibits bone resorption and maintains bone mass. Testosterone, however, is converted into estradiol via aromatization in many tissues including male bone. The importance of estrogen receptor alpha activation as well of aromatization of androgens into estrogens was highlighted by a number of cases of men suffering from an inactivating mutation in the estrogen receptor alpha or in the aromatase enzyme. All these men typically had low bone mass, high bone turnover and open epiphyses. In line with these findings, cohort studies have confirmed that estradiol contributes to the maintenance of bone mass after reaching peak bone mass, with an association between estradiol and fractures in elderly men. Recent studies in knock-out mice have increased our understanding of the role of androgens and estrogens in different bone compartments. Estrogen receptor activation, but not androgen receptor activation, is involved in the regulation of male longitudinal appendicular skeletal growth in mice. Both the androgen and the estrogen receptor can independently mediate the cancellous bone-sparing effects of sex steroids in male mice. Selective KO studies of the androgen receptor in osteoblasts in male mice suggest that the osteoblast in the target cell for androgen receptor mediated maintenance of trabecular bone volume and coordination of bone matrix synthesis and mineralization. Taken together, both human and animal studies suggest that testosterone has a dual mode of action on different bone surfaces with involvement of both the androgen and estrogen receptor.

Hypoestrogenism in young women and its influence on bone mass density

One of the most important hormonal factors responsible for bone health is estradiol. Genetic factors, adequacy of hormonal functioning, nutrition and physical activity may be the markers of bone status and development in young women. During adolescence, women reach peak bone acquisition and develop a skeletal mass. This process is largely regulated by endocrine factors mainly such as adequate levels of gonadal, adrenal and pituitary hormones. The crucial role played by estradiol and its impact on bones are very multiple. Estradiol induces growth factors' activation, receptor activator of nuclear factor kappa B ligand (RANKL) production inhibition and is mainly referred to antiresorptive activity. Clinical situations leading to hypoestrogenism has been linked to decreased bone mineral density leading to osteopenia and osteoporosis. This status both in fertile and perimenopausal women can increase the risk of pathological fractures. Such conditions as hypothalamic-pituitary insufficiency (functional hypothalamic amenorrhea, anorexia nervosa, Kallmann syndrome, hyperprolactinemia), ovarian failure (gonadal dysgenesis, premature ovarian failure) and iatrogenic treatment (surgery, chemotherapy, radiotherapy) can cause hypoestrogenism. The treatment of osteopenia and osteoporosis caused by hypoestrogenism is very essential and multidirectional. The crucial role of the therapy is the achievement of proper serum estradiol concentration and eliminate the causes of hypoestrogenism.

Sex hormones and bone health in males

Sex steroids play a key role in maintaining skeletal integrity lifelong, through a complex variety of endocrine, but also paracrine and possibly autocrine actions. The current knowledge that androgens may act as pro-hormones for estrogens has seriously challenged many traditional views, so that, at least for their skeletal actions, these can no longer be considered exclusively "male" or "female" hormones.

Augmentation of cortical bone mineral density in women with polycystic ovary syndrome: a peripheral quantitative computed tomography (pQCT) study

BACKGROUND

Women with polycystic ovary syndrome (PCOS) may have increased cortical bone mineral density (BMD) and probably higher bone material quality as well as better resistance in the compression strength of the tibia, measured by peripheral quantitative computed tomography (pQCT), in comparison with that of age-matched healthy subjects.

METHODS

Thirty women with PCOS, (15 lean and 15 obese) and 15 age-matched healthy controls were enrolled in this study. The clinical, biochemical and ultrasound characteristics of the two groups were evaluated. Using pQCT, the following parameters were measured: volumetric cortical density (CBD) and volumetric trabecular density (TBD) BMD, total bone cross-sectional area (ToA), cortical area (CoA), cortical thickness (CRT-THK-C) and finally the strength-strain index (SSI).

RESULTS

The geometrical parameters (CoA, ToA, CRT-THK-C), the SSI as well as the TBD were increased in the PCOS women; however, these differences did not achieve statistical significance between lean PCOS women, obese PCOS women, and controls. Conversely, CBD was significantly higher in PCOS women compared with controls (P < 0.000) and furthermore in lean PCOS women compared with obese ones (P < 0.01040).

CONCLUSIONS

The PCOS women of our study seem to have a higher quality of bone material in the distal tibia and probably a better resistance of bone in the compression strength without alterations in bone mass and geometry (especially the lean PCOS women), indicating that our oligomenorrheic and hyperandrogonemic PCOS women may be protected from the development of osteoporosis and fracture risk later in life.

Sex steroids and the male skeleton: a tale of two hormones

Traditionally, the stronger male skeleton was considered to result from higher androgen levels in men compared to women. However, the regulation of male bone growth by sex steroids appears more complex than originally anticipated. Based on clinical observations and studies in animal models, not only androgens and androgen receptor (AR), but also estrogens and estrogen receptor-alpha (not ERbeta) are required for optimal bone mineral acquisition during male growth. In addition, both sex steroids are involved in the maintenance of male skeletal health. In fact, bone loss and fracture risk have been associated with estrogen exposure in elderly men. Overall, a compelling body of evidence suggests that both androgens and estrogens are crucial for male skeletal growth and maintenance.

Complete androgen insensitivity syndrome: diagnosis and management

Complete androgen insensitivity syndrome (CAIS) is an X-linked genetic disorder affecting 46,XY individuals, characterized by the loss of function of the androgen receptor gene resulting in complete peripheral androgen resistance. Patients have a nonambiguous female phenotype with normal female external genitalia. Gonads are undescended testes (either intra-abdominal or inguinal), there is no uterus and the length of the vagina is usually very short. Gender identity is always female. This review focuses on the importance of accurate diagnosis of CAIS versus partial androgen insensitivity syndrome and other disorders of sex development by genotyping the androgen receptor, and raises issues of the optimal management of these patients. In the era of the Consensus Statement on Management of Intersex Disorders, we provide new insights into CAIS screening, surgical management of the gonads (balancing between hormonal production and malignancy risk) and of vaginal adequacy, and the ethics concerned with the disclosure to patients and their families.