Transdermal testosterone application: pharmacokinetics and effects on pubertal status, short-term growth, and bone turnover

The Roles of Androgens in Humans: Biology, Metabolic Regulation and Health

Androgens are an important and diverse group of steroid hormone molecular species. They play varied functional roles, such as the control of metabolic energy fate and partition, the maintenance of skeletal and body protein and integrity and the development of brain capabilities and behavioral setup (including those factors defining maleness). In addition, androgens are the precursors of estrogens, with which they share an extensive control of the reproductive mechanisms (in both sexes). In this review, the types of androgens, their functions and signaling are tabulated and described, including some less-known functions. The close interrelationship between corticosteroids and androgens is also analyzed, centered in the adrenal cortex, together with the main feedback control systems of the hypothalamic-hypophysis-gonads axis, and its modulation by the metabolic environment, sex, age and health. Testosterone (T) is singled out because of its high synthesis rate and turnover, but also because age-related hypogonadism is a key signal for the biologically planned early obsolescence of men, and the delayed onset of a faster rate of functional losses in women after menopause. The close collaboration of T with estradiol (E2) active in the maintenance of body metabolic systems is also presented Their parallel insufficiency has been directly related to the ravages of senescence and the metabolic syndrome constellation of disorders. The clinical use of T to correct hypoandrogenism helps maintain the functionality of core metabolism, limiting excess fat deposition, sarcopenia and cognoscitive frailty (part of these effects are due to the E2 generated from T). The effectiveness of using lipophilic T esters for T replacement treatments is analyzed in depth, and the main problems derived from their application are discussed.

Defining the role of pre-operative hormonal therapy in hypospadias

In hypospadias surgery, pre-operative hormonal therapy (PHT) is primarily used to increase penile dimensions and the vascularity of tissues available for reconstruction, but its use is non-uniform in clinical practice, with no consensus on application or utility. This review aims to summarise: (i) the penile tissue response to hormone therapy, (ii) its impact on hypospadias surgery outcomes, and (iii) the endocrinological considerations and sequelae. PHT is more often indicated for complex cases such as proximal hypospadias, hypospadias with microphallus and hypospadias reoperations. While PHT has clear effects on penile morphometry, and more recent controlled trials suggest improved surgical outcomes, the lack of consistent outcome definitions and generally inadequate follow-up periods continue to consign many of the potential long-term effects of PHT to the unknown. There is currently insufficient robust evidence to allow a clinical guideline to be constructed. The need for a well-powered multi-centre prospective randomised trial to address this question is evident but awaits a unified consensus on issues surrounding the understanding of aetiology, classification of hypospadias morphology, definition of important prognostic variables and uniform application of outcome measures. The effects of PHT may be utilised to improve outcomes in cases of proximal and severe hypospadias, which under the current paradigm represent a significant surgical challenge.

Puberty Induction in Adolescent Males: Current Practice

Puberty is a developmental stage characterized by the appearance of secondary sexual characteristics which leads to complete physical, psychosocial, and sexual maturation. The current practice of hormonal therapy to induce puberty in adolescent males is based on published consensus and expert opinion. Evidence-based guidelines on optimal timing and regimen in puberty induction in males are lacking, and this reflects some discrepancies in practice among endocrinologists. It is worth mentioning that the availability of various hormonal products in markets, their different routes of administration, and patients/parents’ preference also have an impact on clinical decisions. This review outlines the current clinical approach to delayed puberty in boys with an emphasis on puberty induction.

Testosterone therapy in children and adolescents: to whom, how, when?

Male production of testosterone is crucial for the development of a wide range of functions. External and internal genitalia formation, secondary sexual characteristics, spermatogenesis, growth velocity, bone mass density, psychosocial maturation, and metabolic and cardiovascular profiles are closely dependent on testosterone exposure. Disorders in androgen production can present during all life-stages, including childhood and adolescence, and testosterone therapy (TT) is in many cases the only treatment that can correct the underlying deficit. TT is controversial in the pediatric population as hypoandrogenism is difficult to classify and diagnose in these age groups, and standardized protocols of treatment and monitorization are still lacking. In pediatric patients, hypogonadism can be central, primary, or a combination of both. Testosterone preparations are typically designed for adults' TT, and providers need to be aware of the advantages and disadvantages of these formulations, especially cognizant of supratherapeutic dosing. Monitoring of testosterone levels in boys on TT should be tailored to the individual patient and based on the anticipated duration of therapy. Although clinical consensus is lacking, an approximation of the current challenges and common practices in pediatric hypoandrogenism could help elucidate the broad spectrum of pathologies that lie behind this single hormone deficiency with wide-ranging implications.

Hypogonadism in Male Infants and Adolescents: New Androgen Formulations

BACKGROUND

Male hypogonadism may be associated with micropenis and cryptorchidism in newborn, absent or incomplete pubertal development when it occurs during childhood. During puberty, androgen replacement therapy plays a pivotal role in subjects with hypogonadism to induce sexual maturation, growth acceleration, anabolic effects on fat-free mass growth increasing muscle strength, directly and indirectly on the attainment of peak bone mass in young men. Moreover, in newborns with congenital hypogonadism, androgen therapy could be effective to increase genital size.

SUMMARY

Testosterone replacement therapy (TRT) represents the cornerstone of the management of hypogonadism in boys. During puberty, replacement therapy needs to be modulated with gradual dosing increase to better mimic the physiologic pubertal development. Currently, intramuscular testosterone (T) esters (in particular testosterone enanthate) and subcutaneous T pellets are the only formulations approved by the US Food and Drug Administration for delayed puberty, while no preparation is approved for long-term use in the adolescent age. Several new T formulations (as transdermal, nasal, subcutaneous, and oral formulation) are recently developed to improve the pharmacokinetic profile and to ease the administration route increasing patient compliance in adult males with hypogonadism. All these formulations are not approved for pediatric age, although some of them are used as "off-label" regimens. This special issue is aimed to illustrate new T formulations and their potential role as replacement therapy in the pediatric population, as well as to highlight investigational areas to contribute to health care improvement in these patients.

KEY MESSAGES

Despite the lack of evidence-based guidelines regarding the choice of T formulation in the pediatric population, new formulations appear to have a potential role for TRT in adolescent age. They have been designed for adult age with a little flexibility of dosage, although a few formulations may be attractive for pubertal induction and penile enlargement thanks to their greater flexibility and easing of administration. On the other hand, long-acting and stable formulations could meet post-pubertal needs, increasing TRT compliance in a critical phase as the adolescent age. Further controlled, long-term safety, and efficacy studies for all these new T formulations within the pediatric population are needed.

Male hypogonadism: therapeutic choices and pharmacological management

Male hypogonadism, defined as an inadequate testosterone production, recognizes a testicular (primary hypogonadism) or a hypothalamic-pituitary dysfunction (central hypogonadism), although combined forms can also occur. Moreover, it has been known that intensive exercise training might be a cause of functional hypogonadism. Many therapeutic choices are currently available, depending on the timing of hypogonadism onset and fertility issue. The aim of this review was to comprehensively supply therapeutic options and schemes currently available for male hypogonadism, including pharmacological management of primary and central forms. Evidence on testosterone formulations, human chorionic gonadotropin, selective estrogen receptor modulators and aromatase inhibitors will be provided.

Testosterone Use in Adolescent Males: Current Practice and Unmet Needs

Testosterone replacement therapy (TRT) is routinely prescribed in adolescent males with constitutional delay of growth and puberty (CDGP) or hypogonadism. With many new testosterone (T) formulations entering the market targeted for adults, we review current evidence and TRT options for adolescents and identify areas of unmet needs. We searched PubMed for articles (in English) on testosterone therapy, androgens, adolescence, and puberty in humans. The results indicate that short-term use of  T enanthate (TE) or oral  T undecanoate is safe and effective in inducing puberty and increasing growth in males with CDGP. Reassuring evidence is emerging on the use of transdermal  T to induce and maintain puberty. The long-term safety and efficacy of TRT for puberty completion and maintenance have not been established. Current  TRT regimens are based on consensus and expert opinion, but evidence-based guidelines are lacking. Limited guidance exists on when and how  T should be administered and optimal strategies for monitoring therapy once it is initiated. Only  TE and  T pellets are US Food and Drug Administration approved for use in adolescent males in the United States. Despite the introduction of a wide variety of new  T formulations, they are designed for adults, and their metered doses are difficult to titrate in adolescents. In conclusion, TRT in adolescent males is hindered by lack of long-term safety and efficacy data and limited options approved for use in this population. Additional research is needed to identify the route, dose, duration, and optimal timing for TRT in adolescents requiring androgen therapy.

Androgens During Infancy, Childhood, and Adolescence: Physiology and Use in Clinical Practice

We provide an in-depth review of the role of androgens in male maturation and development, from the fetal stage through adolescence into emerging adulthood, and discuss the treatment of disorders of androgen production throughout these time periods. Testosterone, the primary androgen produced by males, has both anabolic and androgenic effects. Androgen exposure induces virilization and anabolic body composition changes during fetal development, influences growth and virilization during infancy, and stimulates development of secondary sexual characteristics, growth acceleration, bone mass accrual, and alterations of body composition during puberty. Disorders of androgen production may be subdivided into hypo- or hypergonadotropic hypogonadism. Hypogonadotropic hypogonadism may be either congenital or acquired (resulting from cranial radiation, trauma, or less common causes). Hypergonadotropic hypogonadism occurs in males with Klinefelter syndrome and may occur in response to pelvic radiation, certain chemotherapeutic agents, and less common causes. These disorders all require testosterone replacement therapy during pubertal maturation and many require lifelong replacement. Androgen (or gonadotropin) therapy is clearly beneficial in those with persistent hypogonadism and self-limited delayed puberty and is now widely used in transgender male adolescents. With more widespread use and newer formulations approved for adults, data from long-term randomized placebo-controlled trials are needed to enable pediatricians to identify the optimal age of initiation, route of administration, and dosing frequency to address the unique needs of their patients.

Testosterone Therapy in Adolescent Boys: The Need for a Structured Approach

BACKGROUND

In adolescents, testosterone may have several effects including promotion of secondary sexual characteristics and pubertal growth, attainment of optimal muscle mass and peak bone mass, optimization of the metabolic profile, and psychosocial maturation and well-being.

SUMMARY

Testosterone therapy is a cornerstone of the management of hypogonadism in boys. Since the initial report of the chemical synthesis of testosterone, several formulations have continued to develop, and although many of these have been used in boys, none of them have been studied in detail in this age group. Given the wide ranging effects of testosterone, the level of evidence for their effects in boys and the heterogeneity of conditions that lead to early-onset hypogonadism, a standardized protocol for monitoring testosterone replacement in this age group is needed. Key Messages: In this review, we focus on the perceived benefits of androgen replacement in boys affected by pubertal delay and highlight the need to improve the health monitoring of boys who receive androgen replacement therapy, proposing different approaches based on the underlying pathophysiology.

Single-Centre Experience of Testosterone Therapy for Boys with Hypogonadism

BACKGROUND

Hypogonadism in boys is one of the commonest conditions encountered in paediatric endocrinology.

AIMS

To study variations in management in a contemporary group of boys at a single specialist centre.

METHODS

Retrospective review of case records of all boys treated with testosterone at a tertiary endocrine service from 2012 to 2017.

RESULTS

Of the 358 boys reviewed for hypogonadism, 46 (13%) were initiated on testosterone therapy at a median age (range) of 14.2 years (12.1, 17.7). Indications for therapy included a functional delay of puberty that was constitutional in 17 (37%) or related to chronic disease in 10 (22%) or organic hypogonadism due to primary gonadal failure in 7 (15%), multiple pituitary hormone deficiency in 6 (13%), and isolated hypogonadotropic hypogonadism in 6 (13%). Of the 46 boys, 40 (89%) were started on intramuscular testosterone, 4 (9%) on oral testosterone, and 1 (2%) on transdermal gel. Of the 19 boys (40%) with organic hypogonadism re-quiring long-term therapy, 12 (63%) had assessment of liver function, 6 (32%) had a haematocrit, and 2 (11%) had a DXA scan in the year of commencing treatment.

CONCLUSIONS

Testosterone therapy is administered in about 13% of boys reviewed for hypogonadism and its monitoring requires standardisation.

Testing the influence of testosterone administration on men's honesty in a large laboratory experiment

The impact of testosterone on decision-making is a growing literature, with several reports of economically relevant outcomes. Similar to Wibral et al. (2012), we investigate the effects of exogenous testosterone administration on deception in a double-blind placebo controlled study. Participants (N = 242) were asked to roll a die in private and were paid according to their reported roll, which creates the opportunity to lie about the outcome to increase earnings. We find evidence for self-serving lying in both treatment and control groups and a statistically insignificant negative effect (d = −0.17, 95% CI[−0.42, 0.08]) indicating more honest behavior (i.e., lower reports) following testosterone administration. Although insignificant, the direction was the same as in the Wibral et al. study, and the meta-analytic effect of the two studies demonstrates lower reporting (i.e., more honesty) following testosterone (vs. placebo) administration, significant at the 0.05 level (d = −0.27, 95% CI[−0.49, −0.06]). We discuss how our results and methodology compare with Wibral et al. and identify potential causes for differences in findings. Finally, we consider several plausible connections between testosterone and lying that may be further investigated using alternative methodologies.

Testosterone prior to hypospadias repair: Postoperative complication rates and long-term cosmetic results, penile length and body height

INTRODUCTION

The use of hormonal therapy was first described in 1971 before hypospadias surgery, and it has been debated ever since. The long-term outcomes after puberty of patients treated with pre-operative testosterone in childhood are lacking.

OBJECTIVES

Possible long-term effects of testosterone are often asked about in daily practice. The current study investigated the long-term outcomes regarding height, penile length and penile cosmesis in adult men after hypospadias surgery in childhood with and without pre-operative testosterone.

METHODS

Adult men (n = 121) who underwent primary hypospadias repair in childhood were included. Pre-operative penile appearance, judged by a paediatric urologist, determined the use of pre-operative testosterone. Data on hypospadias characteristics, healing complications, surgical repair, and testosterone use were collected retrospectively. At adult age, stretched penile length and body height were measured, and penile cosmesis was evaluated using the Pediatric Penile Perception Score (PPPS).

RESULTS

Postoperative complication rates in patients (n = 121) with and without testosterone were similar (50% vs. 43%; P = 0.54). Sixty adult patients (50%) with a median age of 19.8 years and follow-up time of 18.3 years were examined at the outpatient clinic at adult age. Of this group, testosterone was applied in 12/43 patients with distal, 3/6 patients with midshaft, and 9/11 patients with proximal hypospadias. Adult stretched penile length (12.0 cm vs. 12.4 cm; P = 0.47) and adult height (180.1 cm vs. 179.0 cm P = 0.65) showed no difference between patients with and without testosterone treatment. Penile cosmesis was (very) satisfactory in all PPPS domains, and showed no difference between the testosterone group and the non-testosterone group. Univariate and multivariate analysis was conducted to determine if the hypospadias type or pre-operative testosterone therapy had more influence on the long-term outcomes. None of the long-term outcomes were significantly associated with pre-operative testosterone therapy on multivariate analysis.

DISCUSSION

This was the first study reporting long-term outcomes of hypospadias patients after puberty who received pre-operative hormonal therapy. Validated instruments were used as much as possible. Shortcomings of this study were the 50% response rate, the retrospective design, and the lack of objective inclusion criteria reported to indicate pre-operative testosterone therapy.

CONCLUSION

This study suggested that the long-term results of patients receiving pre-operative testosterone treatment, who often had more challenging hypospadias, were similar to those who did not. However, a randomised controlled study is needed to confirm these results.

Laparoscopic approach for gonadectomy in pediatric patients with intersex disorders

The birth of a child with a disorder of sex development (DSD) prompts a long-term management strategy that involves a myriad of professionals working with the family. There has been progress in diagnosis, surgical techniques and in understanding psychosocial issues related to this condition. However, since these kinds of disorders are rare and have many anatomical variations, individual care is necessary, especially regarding surgical management. Gonadectomy is indicated in a number of intersex disorders with a Y chromosome to reduce the associated risk of cancer. Recently, laparoscopy has gained wide acceptance in pediatric urology. Laparoscopy is also reported to be a useful tool for diagnosing and treating DSD because of its minimal invasiveness and favorable cosmetic outcome. However, reports of evaluation and management using laparoscopy for large numbers of DSD patients are limited and debate is still open about indications and timing of gonadectomy. In this study, we reviewed the literature of the last 10 years about the role of laparoscopic gonadectomy in patients with DSD. In the analyzed papers, all the procedures were accomplished successfully using laparoscopy. No conversions to open surgery neither intra-operative complications were reported in all series. Post-operative complications were reported only in one series and included 1 umbilical port infection [2% (1/50)] and 1 pelvic abscess [2% (1/50)], both treated with antibiotic therapy (grade I Clavien-Dindo). Of the analyzed series, 7/10 reported postoperative diagnosis of gonadal tumors. The histopathologic examinations revealed 15 cases of gonadoblastoma, 7 cases of dysgerminoma and 2 cases of seminoma. Analyzing the single series, the incidence of these tumors varied between 10% and 33%. The results of our review confirmed the safety and efficacy of laparoscopic gonadectomy in DSD patients. In our mind, laparoscopic gonadectomy should be accepted as the treatment of choice in children and adolescents with these rare conditions. It thereby eliminates the risk of malignancies of gonadal origin with the advantages of a minimally invasive procedure, with lower morbidity, quicker postoperative recovery and excellent cosmetic results.

Recent advances in the understanding and management of delayed puberty

Delayed puberty, especially in boys, is a common presentation in paediatrics. Recent advances have improved our understanding of the neuroendocrine, genetic and environmental factors controlling pubertal development, and hence inform the pathophysiology of delayed puberty. The discovery of kisspeptin signalling through its receptor identified neuroendocrine mechanisms controlling the gonadotrophin-releasing hormone (GnRH) pulse generator at the onset of puberty. Genetic mechanisms from single gene mutations to single nucleotide polymorphism associated with delayed puberty are being identified. Environmental factors, including nutritional factors and endocrine disruptors, have also been implicated in changes in secular trends and abnormal timing of puberty. Despite these advances, the key clinical question is to distinguish delayed puberty associated with an underlying pathology or hypogonadism from constitutional delay in growth and puberty, which remains challenging as biochemical tests are not always discriminatory. The diagnostic accuracies of newer investigations, including 36-hour luteinising hormone releasing hormone (LHRH) tests, GnRH-agonist tests, antimullerian hormone and inhibin-B, require further evaluation. Sex hormone replacement remains the main available treatment for delayed puberty, the choice of which is largely dictated by clinical practice and availability of the various sex steroid preparations. Spontaneous reversal of hypogonadism has been reported in boys with idiopathic hypogonadotrophic hypogonadism after a period of sex steroid treatment, highlighting the importance of reassessment at the end of pubertal induction. Novel therapies with a more physiological basis such as gonadotrophins or kisspeptin-agonist are being investigated for the management of hypogonadotrophic hypogonadism. Careful clinical assessment and appreciation of the normal physiology remain the key approach to patients with delayed puberty.

The influence of pre-operative hormonal stimulation on hypospadias repair

Androgen stimulation to temporarily promote penile growth has been commonly used to facilitate hypospadias repair. Although some series suggest improvement in both functional and cosmetic outcomes, a recent systematic review and meta-analysis showed a possible relationship between pre-operative hormonal stimulation and higher complications. As a result, indications and treatment regimens remain controversial. Here, we review the available literature and present our clinical practice.

Issues in the diagnosis and management of disorders of sexual development

Disorders of sexual development (DSD) are a complex group of disorders to manage, not only because the diagnosis is difficult, but also because it involves many factors related to the psychosexual well being, the social stigma associated with the disorder, confusion and reluctance on the part of medical professionals in dealing with this issue, catastrophic experience of parents of these children and difficult interpersonal relationships between parents and children born with this disorder. This brief review attempts to throw light on the recent advances in understanding and management of these disorders to help improve immediate and long term care of these patients and their families.

Disorders of sex development

The birth of a new baby is one of the most dramatic events in a family, and the first question is usually "is it a boy or a girl?" The newborn infant with ambiguous external genitalia often comes as a surprise for the doctors as well as the parents and is sometimes described as an endocrine emergency situation presenting a problem of sex assignment. The nomenclature such as 'intersex', 'hermaphrodite', and 'pseudohermaphrodite' is out of date as well as confusing, and many urologists are concerned that these confusing terms could be perceived to be pejorative by some affected families. In response to concerns regarding outdated and controversial terms, the Chicago Consensus held in 2005 recommended new terminology based on the umbrella term disorders of sex differentiation (DSDs). The term DSD has a comprehensive definition including any problem noted at birth in which the genitalia are atypical in relation to the chromosomes or gonads. The karyotype is used as a prefix defining the classification of DSD. DSDs are rare and complex. The optimal management of patients with DSD must be individualized and multidisciplinary, considering all aspects, including psychological care and full disclosure of alternatives relating to surgery type and timing. Although further studies are necessary to confirm guidelines and recommendations fitting for the individual patients with DSD, this article is an attempt to provide a balanced perspective for new taxonomy, clinical evaluation, and medical, surgical, and psychological management of DSD.

Etiology and treatment of hypogonadism in adolescents

Adequate functioning at all levels of the hypothalamic-pituitary-gonadal axis is necessary for normal gonadal development and subsequent sex steroid production. Deficiencies at any level of the axis can lead to a hypogonadal state. The causes of hypogonadism are heterogeneous and may involve any level of the reproductive system. This review discusses various causes of hypogonadism, describes the evaluation of hypogonadal states, and outlines treatment options for the induction of puberty in affected adolescents. Whereas some conditions are clearly delineated, the exact etiology and underlying pathogenesis of many disorders is unknown.

Etiology and treatment of hypogonadism in adolescents

Adequate functioning at all levels of the hypothalamic-pituitary-gonadal axis is necessary for normal gonadal development and subsequent sex steroid production. Deficiencies at any level of the axis can lead to a hypogonadal state. The causes of hypogonadism are heterogeneous and may involve any level of the reproductive system. This review discusses various causes of hypogonadism, describes the evaluation of hypogonadal states, and outlines treatment options for the induction of puberty in affected adolescents. Whereas some conditions are clearly delineated, the exact etiology and underlying pathogenesis of many disorders is unknown.

Cross-sectional analysis of testosterone therapies in hypopituitary men on stable pituitary hormone replacement

OBJECTIVE

The last decade has seen a proliferation in options for testosterone replacement. However, little is known as to the benefits of different treatment modalities. Our objective was to determine the testosterone prescription pattern and to examine the impact on various outcome measures.

SUBJECTS AND METHODS

A total of 816 adult-onset hypopituitary males on stable pituitary replacement for at least 1 year were identified from the KIMS database. Patients were classified as either eugonadal (n = 106), or hypogonadal (n = 710) on intramuscular (IM, n = 558), oral (n = 74), transdermal (n = 61), and depot (n = 17) testosterone.

RESULTS

After 1 year of stable pituitary replacement therapy, body composition, cardiovascular parameters, GH replacement and quality of life were not significantly different in androgen-replaced hypogonadal patients compared to eugonadal patients. There were no differences in outcome variables within the hypogonadal group according to the testosterone replacement regimen used and no difference in response to GH therapy.

CONCLUSIONS

The majority of hypopituitary patients in the last decade have received IM testosterone. Body composition, cardiovascular parameters, GH replacement and quality of life were not different between eugonadal and hypogonadal patients and were not differentially affected by the mode of testosterone replacement. These findings are reassuring that there is no major difference in response to different testosterone replacement regimens.

Consensus statement on management of intersex disorders

Management of intersex disorders

Consensus statement on management of intersex disorders

The birth of an intersex child prompts a long-term management strategy that involves a myriad of professionals working with the family. There has been progress in diagnosis, surgical techniques, understanding psychosocial issues and in recognizing and accepting the place of patient advocacy. The Lawson Wilkins Paediatric Endocrine Society (LWPES) and the European Society for Paediatric Endocrinology (ESPE) considered it timely to review the management of intersex disorders from a broad perspective, to review data on longer term outcome and to formulate proposals for future studies. The methodology comprised establishing a number of working groups whose membership was drawn from 50 international experts in the field. The groups prepared prior written responses to a defined set of questions resulting from an evidence based review of the literature. At a subsequent gathering of participants, a framework for a consensus document was agreed. This paper constitutes its final form.

Undetectable salivary testosterone in young women with premature ovarian failure

BACKGROUND

The extent of androgen deficiency in young women with premature ovarian failure (POF) is unclear.

AIM

Cross-sectional study of androgen status in young women with POF.

PATIENTS

Twenty women with POF: six had Turner syndrome (group A); eight had iatrogenic POF either secondary to bilateral oophorectomy or treatment of malignancy (group B); and six had idiopathic POF (group C). The median age was 30.5 years (range 19-39); in groups B and C the median duration of ovarian failure was 10.0 years (range 1-35).

METHODS

After a 2-month wash-out period without sex steroid replacement (SSR), serum testosterone (T), androstenedione (A4), dehydroepiandrosterone (DHEAS), SHBG, salivary testosterone (SalT) and the free androgen index [FAI = (serum T/SHBG) x 100] were measured.

RESULTS

Median serum A4 was 4.6 nmol/l (10th, 90th centiles, 3.6, 5.1) and DHEAS was 3.2 micromol/l (10th, 90th centiles, 2.3, 9.3). Although median serum T was relatively low at 1.4 nmol/l (10th, 90th centiles, 1.1, 1.7), median SHBG was also low at 34 nmol/l (10th, 90th centiles 22.2, 67.5) and the median calculated FAI was within the normal range at 3.7 (10th, 90th centiles, 2.3, 7.0). However, SalT was undetectable in almost all subjects in the three groups of POF.

CONCLUSIONS

Serum T and SHBG are relatively low in young women with POF and their FAI is therefore within the normal range. However, SalT, which measures free testosterone, is consistently low to undetectable in these young women with POF. The reliability of the FAI as a marker of androgen deficiency remains questionable.

Calcium and Exercise Affect the Growing Skeleton

Adequate dietary calcium and bone-stimulating exercise during growth are known to affect skeletal development, but the combined effects of dietary calcium and osteogenic exercise have received scant attention. Animal research has showed a compensatory effect of impact loading on calcium-deprived bones, while various human studies have suggested compensatory, additive, or possibly synergistic effects in certain skeletal locations. Current evidence suggests that the best strategy for strong bones by the end of childhood may be either high-impact exercise with a moderate or greater calcium intake or a combination of moderate-impact exercise and adequate calcium during growth.