Hormonal therapy and pubertal development in boys with selective hypogonadotropic hypogonadism

Considerations when treating male pubertal delay pharmacologically

INTRODUCTION

Delayed puberty, defined as the appearance of pubertal signs after the age of 14 years in males, usually affects psychosocial well-being. Patients and their parents show concern about genital development and stature. The condition is transient in most of the patients; nonetheless, the opportunity should not be missed to diagnose an underlying illness.

AREAS COVERED

The aetiologies of pubertal delay in males and their specific pharmacological therapies are discussed in this review.

EXPERT OPINION

High-quality evidence addressing the best pharmacological therapy approach for each aetiology of delayed puberty in males is scarce, and most of the current practice is based on small case series or unpublished experience. Male teenagers seeking attention for pubertal delay most probably benefit from medical treatment to avoid psychosocial distress. While watchful waiting is appropriate in 12- to 14-year-old boys when constitutional delay of growth and puberty (CGDP) is suspected, hormone replacement should not be delayed beyond the age of 14 years in order to avoid impairing height potential and peak bone mass. When primary or central hypogonadism is diagnosed, hormone replacement should be proposed by the age of 12 years provided that a functional central hypogonadism has been ruled out. Testosterone replacement regimens have been used for decades and are fairly standardised. Aromatase inhibitors have arisen as an interesting alternative for boy with CDGP and short stature. Gonadotrophin therapy seems more physiological in patients with central hypogonadism, but its relative efficacy and most adequate timing still need to be established.

Pubertal induction and transition to adult sex hormone replacement in patients with congenital pituitary or gonadal reproductive hormone deficiency: an Endo-ERN clinical practice guideline

An Endo-European Reference Network guideline initiative was launched including 16 clinicians experienced in endocrinology, pediatric and adult and 2 patient representatives. The guideline was endorsed by the European Society for Pediatric Endocrinology, the European Society for Endocrinology and the European Academy of Andrology. The aim was to create practice guidelines for clinical assessment and puberty induction in individuals with congenital pituitary or gonadal hormone deficiency. A systematic literature search was conducted, and the evidence was graded according to the Grading of Recommendations, Assessment, Development and Evaluation system. If the evidence was insufficient or lacking, then the conclusions were based on expert opinion. The guideline includes recommendations for puberty induction with oestrogen or testosterone. Publications on the induction of puberty with follicle-stimulation hormone and human chorionic gonadotrophin in hypogonadotropic hypogonadism are reviewed. Specific issues in individuals with Klinefelter syndrome or androgen insensitivity syndrome are considered. The expert panel recommends that pubertal induction or sex hormone replacement to sustain puberty should be cared for by a multidisciplinary team. Children with a known condition should be followed from the age of 8 years for girls and 9 years for boys. Puberty induction should be individualised but considered at 11 years in girls and 12 years in boys. Psychological aspects of puberty and fertility issues are especially important to address in individuals with sex development disorders or congenital pituitary deficiencies. The transition of these young adults highlights the importance of a multidisciplinary approach, to discuss both medical issues and social and psychological issues that arise in the context of these chronic conditions.

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.

Recent advancement in the treatment of boys and adolescents with hypogonadism

Clinical manifestations and the need for treatment varies according to age in males with hypogonadism. Early foetal-onset hypogonadism results in disorders of sex development (DSD) presenting with undervirilised genitalia whereas hypogonadism established later in foetal life presents with micropenis, cryptorchidism and/or micro-orchidism. After the period of neonatal activation of the gonadal axis has waned, the diagnosis of hypogonadism is challenging because androgen deficiency is not apparent until the age of puberty. Then, the differential diagnosis between constitutional delay of puberty and central hypogonadism may be difficult. During infancy and childhood, treatment is usually sought because of micropenis and/or cryptorchidism, whereas lack of pubertal development and relative short stature are the main complaints in teenagers. Testosterone therapy has been the standard, although off-label, in the vast majority of cases. However, more recently alternative therapies have been tested: aromatase inhibitors to induce the hypothalamic-pituitary-testicular axis in boys with constitutional delay of puberty and replacement with GnRH or gonadotrophins in those with central hypogonadism. Furthermore, follicle-stimulating hormone (FSH) priming prior to hCG or luteinizing hormone (LH) treatment seems effective to induce an enhanced testicular enlargement. Although the rationale for gonadotrophin or GnRH treatment is based on mimicking normal physiology, long-term results are still needed to assess their impact on adult fertility.

Testosterone versus hCG in Hypogonadotropic Hypogonadism – Comparing Clinical Effects and Evaluating Current Practice

Background. Gonadotropin therapy is not typically used for pubertal induction in hypogonadotropic hypogonadism (HH), however, represents a promising alternative to testosterone. It can potentially lead to the maintenance of future fertility in addition to testicular growth. We compared the pubertal effects of human chorionic gonadotropin (hCG) versus testosterone in adolescent males with HH. We evaluated the current practice, among pediatric endocrinologists, to identify barriers against gonadotropin use. Methods. In this retrospective review, we compared the effect of testosterone versus hCG therapy on mean testicular volume (MTV), penile length, growth velocity, and testosterone levels. We surveyed pediatric endocrinologists at our center, using RedCap. Results. Outcomes were assessed in 52 male patients with HH (hCG, n = 4; T, n = 48) after a mean treatment duration of 13.4 (testosterone) and 13.8 months (hCG; P = .79). Final MTV was higher with hCG (8.25 mL) than testosterone (3.4 mL; P < .001). The groups did not differ in penile length, growth velocity, or testosterone levels. Survey results showed that more than half the providers were aware of the benefits of gonadotropins, however, 91% were uncomfortable prescribing hCG. Commonly reported barriers to prescribing hCG were lack of experience (62%) and insurance coverage concerns (52%). Conclusions. Larger testicular volume predicts faster induction of spermatogenesis. Since hCG promoted better testicular growth, compared to testosterone, it may potentially improve future fertility outcomes in HH patients. Our results identify an opportunity to improve current practice among pediatric endocrinologists worldwide and reduce barriers to prescribing gonadotropins in the adolescent population.

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.

Constitutional delay of puberty versus congenital hypogonadotropic hypogonadism: Genetics, management and updates

Delayed puberty (DP) affects approximately 2% of adolescents. In the vast majority of patients in both sexes, it is due to constitutional delay of growth and puberty (CDGP), a self-limited condition in which puberty starts later than usual but progresses normally. However, some CDGP patients may benefit from medical intervention with low-dose sex steroids or peroral aromatase inhibitor letrozole (only for boys). Other causes of DP include permanent hypogonadotropic hypogonadism, functional hypogonadotropic hypogonadism (due to chronic diseases and conditions), and gonadal failure. In this review we discuss these themes along with the latest achievements in the field of puberty research, and include a brief synopsis on the differential diagnosis and management of patients with CDGP and congenital hypogonadotropic hypogonadism.

Clinical Management of Congenital Hypogonadotropic Hypogonadism

The initiation and maintenance of reproductive capacity in humans is dependent on pulsatile secretion of the hypothalamic hormone GnRH. Congenital hypogonadotropic hypogonadism (CHH) is a rare disorder that results from the failure of the normal episodic GnRH secretion, leading to delayed puberty and infertility. CHH can be associated with an absent sense of smell, also termed Kallmann syndrome, or with other anomalies. CHH is characterized by rich genetic heterogeneity, with mutations in >30 genes identified to date acting either alone or in combination. CHH can be challenging to diagnose, particularly in early adolescence where the clinical picture mirrors that of constitutional delay of growth and puberty. Timely diagnosis and treatment will induce puberty, leading to improved sexual, bone, metabolic, and psychological health. In most cases, patients require lifelong treatment, yet a notable portion of male patients (∼10% to 20%) exhibit a spontaneous recovery of their reproductive function. Finally, fertility can be induced with pulsatile GnRH treatment or gonadotropin regimens in most patients. In summary, this review is a comprehensive synthesis of the current literature available regarding the diagnosis, patient management, and genetic foundations of CHH relative to normal reproductive development.

An Investigation of the Single and Combined Phthalate Metabolite Effects on Human Chorionic Gonadotropin Expression in Placental Cells

BACKGROUND

Observational studies have reported associations between maternal phthalate levels and adverse outcomes at birth and in the health of the child. Effects on placental function have been suggested as a biologic basis for these findings.

OBJECTIVE

We evaluated the effects of phthalates on placental function in vitro by measuring relevant candidate genes and proteins.

MATERIALS AND METHODS

Human trophoblast progenitor cells were isolated at 7-14 wk of pregnancy (two female and three male concepti), and villous cytotrophoblast cells (vCTBs) were isolated at 15-20 wk (three female and four male concepti). Cells were cultured in vitro with four phthalate metabolites and their combination at concentrations based on levels found previously in the urine of pregnant women: mono-n-butyl (MnBP, 200 nM), monobenzyl (MBzP, 3μM), mono-2-ethylhexyl (MEHP, 700 nM), and monoethyl (MEP, 1.5μM) phthalates. mRNA levels of CGA, CGB, PPARG, CYP19A1, CYP11A1, PTGS2, EREG, and the intracellular β subunit of human chorionic gonadotropin (hCGβ) and peroxisome proliferator activated receptor γ (PPARγ) were measured in the cellular extracts, and protein levels for four forms of secreted hCG were measured in the conditioned media.

RESULTS

Previously reported associations between maternal phthalates and placental gene expression were reproduced experimentally: MnBP with CGA, MBzP with CYP11A1, and MEHP with PTGS2. CGB and hCGβ were up-regulated by MBzP. In some cases, there were marked, even opposite, differences in response by sex of the cells. There was evidence of agonism in female cells and antagonism in male cells of PPARγ by simultaneous exposure to multiple phthalates.

CONCLUSIONS

Concentrations of MnBP, MBzP and MEHP similar to those found in the urine of pregnant women consistently altered hCG and PPARγ expression in primary placental cells. These findings provide evidence for the molecular basis by which phthalates may alter placental function, and they provide a preliminary mechanistic hypothesis for opposite responses by sex. https://doi.org/10.1289/EHP1539.

Testicular growth and spermatogenesis: new goals for pubertal hormone replacement in boys with hypogonadotropic hypogonadism? -a multicentre prospective study of hCG/rFSH treatment outcomes during adolescence

CONTEXT/OBJECTIVE

Testosterone treatment for pubertal induction in boys with hypogonadotropic hypogonadism (HH) provides virilization, but does not induce testicular growth or fertility. Larger studies evaluating the outcomes of gonadotropin replacement during adolescence have not been reported to date; whether previous testosterone substitution affects testicular responses is unresolved. We aimed to assess the effects of human chorionic gonadotropin (hCG) and recombinant FSH (rFSH) in boys and adolescents with HH with respect to a) testicular growth, b) spermatogenesis, c) quality of life (QoL) and to identify factors influencing therapeutic success.

DESIGN/SETTING

A prospective case study was conducted in 26 paediatric endocrine centres PATIENTS/INTERVENTIONS: HCG and rFSH were administered until cessation of testicular growth and plateauing of spermatogenesis to (1) prepubertal HH boys with absent or early arrested puberty (group A) and to (2) HH adolescents who had previously received full testosterone replacement (group B).

OUTCOME MEASURES

Bi-testicular volumes (BTVs), sperm concentrations and QoL.

RESULTS

Sixty (34 A/26 B) HH patients aged 14-22 years were enrolled. BTVs rose from 5 ± 5 to 34 ± 3 ml in group A vs 5 ± 3 to 32 ± 3 ml in group B, with normal final BTVs (≥24 ml) attained in 74%/70% after 25/23 months in A/B, respectively. Sperm in the ejaculate were found in 21/23(91%)/18/19(95%), with plateauing concentrations after 31/30 months of hCG and 25/25 months of combined treatment in A/B. Sperm concentrations were normal (≥15 mill/ml) in 61%/32%, with mean concentrations of 40 ± 73 vs 19 ± 38 mill/ml in A/B (n.s.). Outcomes were better in patients without bilateral cryptorchidism, with non-congenital HH causes, higher baseline BTVs, and higher baseline inhibin B and AMH levels. QoL increased in both groups.

CONCLUSIONS

HCG/rFSH replacement during adolescence successfully induces testicular growth and spermatogenesis, irrespective of previous testosterone replacement, and enhances QoL.

Progression of puberty after initiation of androgen therapy in patients with idiopathic hypogonadotropic hypogonadism

BACKGROUND

Onset of puberty in boys usually occurs by 14 years of age. Some boys may exhibit delayed sexual maturation till about 17-18 years of age. However, pubertal onset beyond 18 years of age is exceedingly rare.

MATERIALS AND METHODS

Patients diagnosed as idiopathic hypogonadotropic hypogonadism (IHH) who had onset of puberty (increase in testicular volume >10 ml) while on androgen therapy were studied. These patients were evaluated prospectively.

RESULTS

There were nine subjects that were included in the study. The pre-therapy testicular volumes ranged from 3 to 6 ml. Luteinizing hormone (LH) levels increased from 1.2 ± 0.96 to 2.8 ± 1.0 IU/L, follicular stimulating hormone (FSH) levels increased from 1.5 ± 0.79 to 3.5 ± 1.9 IU/L, and testosterone increased from 0.36 ± 0.16 to 3.4 ± 2.1 ng/ml. Three out of nine patients had testosterone levels below 3 ng/ml.

CONCLUSION

Our present study indicates that pubertal development can occur in patients presenting with hypogonadotropic hypogonadism after 18 years of age. However, acquired pubertal status may be subnormal.

Penile growth in response to human chorionic gonadotropin (HCG) treatment in patients with idiopathic hypogonadotrophic hypogonadism

Penile growth is under androgenic control. Human chorionic gonadotropin (hCG) has a stimulatory effect on testicular steroidogenesis and penile growth. The purpose of this study was to evaluate the effect of hCG treatment on the gonadal response and penile growth in male idiopathic hypogonadotrophic hypogonadism (IHH) presenting with micropenis. A total of 20 IHH patients who met the criteria for micropenis were included in this study. hCG (1,500-2,000 IU) was administrated intramuscularly, 3 times per week, for 8 weeks. Basic laboratory and hormonal indexes (including serum testosterone and LH levels), penis length (flaccid and stretched), and testicular volume were measured before and 24 weeks after hCG treatment. The patients' mean age was 18.9 years (range, 12 to 24 years). The mean serum testosterone level was significantly increased after hCG treatment (baseline, 2, 4, 12, and 24 weeks: 0.90±1.35 ng/ml, 1.77±1.31 ng/ml, 3.74±2.24 ng/ml, 5.49±1.70 ng/ml, and 5.58±1.75 ng/ml, respectively; p<0.05). Mean penile length also increased significantly 24 weeks after treatment (flaccid length: from 3.39±1.03 cm to 5.14±1.39 cm; stretched length: from 5.41±1.43 cm to 7.45±1.70 cm; p<0.001). Mean testicular volumes increased significantly as well (left: from 5.45 cc to 6.83 cc; right: from 5.53 cc to 7.03 cc). There were no remarkable adverse effects of the hCG treatment. The hCG treatment increased the serum testosterone level, penile length, and testicular volume in IHH patients. Our results suggest that hCG treatment has a beneficial effect on gonadal function and penile growth in patients with IHH presenting with micropenis.

Induction of puberty with human chorionic gonadotropin and follicle-stimulating hormone in adolescent males with hypogonadotropic hypogonadism

OBJECTIVE

To evaluate the clinical and hormonal responses of adolescent males with hypogonadotropic hypogonadism (HH) in response to gonadotropin replacement with the use of long-term combined hCG and FSH therapy.

DESIGN

Prospective clinical study.

SETTING

Clinical pediatric department providing tertiary care.

PATIENT(S)

Seven prepubertal males with isolated HH with a mean (+/-SD) age of 15.44+/-1.97 years and seven prepubertal males with panhypopituitarism-associated HH with a mean (+/-SD) age of 18.1+/-3.24 years were studied.

INTERVENTION(S)

Human chorionic gonadotropin (1,000-1,500 IU IM) and FSH (75-100 IU SC) were administered every alternate day of the week until the total induction of puberty and spermatogenesis was achieved.

MAIN OUTCOME MEASURE(S)

Serum testosterone levels, testicular volume, penis length, and sperm count were evaluated after the administration of hCG and FSH.

RESULT(S)

All patients achieved normal sexual maturation and normal or nearly normal adult male levels of testosterone. The increase in testicular size was significant in both groups. Positive sperm production was assessed in four of five patients with isolated HH and in three of three patients with panhypopituitarism-associated HH.

CONCLUSION(S)

Long-term combined hCG and FSH therapy is effective in inducing puberty, increasing testicular volume, and stimulating spermatogenesis in adolescent males with isolated HH and panhypopituitarism-associated HH.

Gonadal function and response to human chorionic and menopausal gonadotrophin therapy in male patients with idiopathic hypogonadotrophic hypogonadism

OBJECTIVE

This study was designed to determine the response to therapy using human chorionic gonadotrophin (hCG) and human menopausal gonadotrophin (hMG) in males with idiopathic isolated hypogonadotrophic hypogonadism (IHH), and to compare the responses in patients presenting with and without cryptorchidism.

DESIGN

Analysis of male patients with IHH treated with hCG or combined hCG/hMG for a minimum of 6 months at St Bartholomew's Hospital. Clinical and endocrine assessment was performed in all patients prior to commencing therapy.

PATIENTS

A total of 26 males with IHH have been treated with exogenous gonadotrophins. Thirteen patients (Group 1) had cryptorchidism (unilateral in 7, bilateral in 6) at presentation, and 13 (Group 2) did not.

MEASUREMENTS

All patients had basal serum testosterone, LH and FSH determinations. An i.v. GnRH test was performed in 25 patients and an i.m. hCG stimulation test in 19. Testicular volume and serum testosterone were measured during both hCG and combined hCG/hMG therapy. Seminal analysis was performed at the start and monthly during hCG/hMG therapy.

RESULTS

Eighty-five per cent of the 13 patients in Group 1 had an olfactory defect (Kallmann's syndrome), compared with 23% of Group 2. Both groups of patients showed a subnormal response to initial i.v. GnRH and i.m. hCG testing. During hCG therapy only three patients in Group 1 and six in Group 2 achieved normal adult testosterone levels. The non-cryptorchid group achieved a higher mean testicular volume on hCG therapy than the cryptorchid group (mean (SD); 4.7 (1.8) ml vs 3.0 (1.6) ml (P < 0.02)), and for all patients there was a correlation between initial and maximal testicular volume (R = 0.69, P = 0.001). Four patients in Group 1 and five patients in Group 2 were treated with combined hCG/hMG for 6-15 months to induce fertility; only one patient in Group 1 achieved spermatogenesis, compared to all patients in Group 2 (leading to three pregnancies).

CONCLUSIONS

These data indicate that patients with idiopathic hypogonadotrophic hypogonadism (IHH) have a poor response to hCG therapy in terms of testicular growth and normalization of serum testosterone. Final testicular volume is dependent on initial testicular size. In addition, patients with IHH associated with cryptorchidism have a poor fertility potential to combined hCG/hMG therapy.