Childhood growth in boys with congenital hypogonadotropic hypogonadism

Mini-Puberty, Physiological and Disordered: Consequences, and Potential for Therapeutic Replacement

There are 3 physiological waves of central hypothalamic-pituitary-gonadal (HPG) axis activity over the lifetime. The first occurs during fetal life, the second-termed "mini-puberty"-in the first months after birth, and the third at puberty. After adolescence, the axis remains active all through adulthood. Congenital hypogonadotropic hypogonadism (CHH) is a rare genetic disorder characterized by a deficiency in hypothalamic gonadotropin-releasing hormone (GnRH) secretion or action. In cases of severe CHH, all 3 waves of GnRH pulsatility are absent. The absence of fetal HPG axis activation manifests in around 50% of male newborns with micropenis and/or undescended testes (cryptorchidism). In these boys, the lack of the mini-puberty phase accentuates testicular immaturity. This is characterized by a low number of Sertoli cells, which are important for future reproductive capacity. Thus, absent mini-puberty will have detrimental effects on later fertility in these males. The diagnosis of CHH is often missed in infants, and even if recognized, there is no consensus on optimal therapeutic management. Here we review physiological mini-puberty and consequences of central HPG axis disorders; provide a diagnostic approach to allow for early identification of these conditions; and review current treatment options for replacement of mini-puberty in male infants with CHH. There is evidence from small case series that replacement with gonadotropins to mimic "mini-puberty" in males could have beneficial outcomes not only regarding testis descent, but also normalization of testis and penile sizes. Moreover, such therapeutic replacement regimens in disordered mini-puberty could address both reproductive and nonreproductive implications.

[Puberty induction in boys with congenital isolated hypogonadotropic hypogonadism]

BACKGROUND

Gonadotropin therapy in boys with congenital isolated hypogonadotropic hypogonadism helps to increase testes volume and induce spermatogenesis in comparison with testosterone therapy. However, difficulties with dose titration, partial therapy success, absence of generally accepted regimen protocols don't allow to use this therapy in order to induce puberty in adolescents with Kallmann syndrome or normosmic hypogonadotropic hypogonadism.

AIM

To assess the effectiveness of combination hormonal replacement therapy via human chorionic gonadotropin and recombinant follicle stimulation hormone in adolescents with congenital isolated normosmic hypogonadotropic hypogonadism and with Kallmann syndromeMATERIALS AND METHODS: This is an open single-center prospective non-controlled study. Boys with hypogonadotropic hypogonadism were receiving hormonal replacement therapy for 12 months. Initial dose of human chorionic gonadotropin was 500 IU per week. Initial dose of recombinant follicle stimulation hormone was 37.5 IU per week. Doses were doubled in 6 months. Antropometric data, Tanner stage, testes volumes, inhibin B and anti-Mullerian hormone (AMH) levels were evaluated in all the patients before the treatment, after 6 and 12 months of the therapy.

RESULTS

8 boys with hypogonadotropic hypogonadism were included into the study. Median age before therapy initiation was 15.7 years [15.33; 16.41]. In 12 months after the therapy initiation puberty development, testosterone increase from 0.44 [0.34;0.62] to 4.39 [0.88;10.51] nmol/l (p=0.012), AMH decrease from 35.70 [18.00;59.00] to 14.41 [11.60;16.65] ng/ml were noted in all the patients (p=0.017). Testes volumes increase and inhibin B level increase were not statistically significant.

CONCLUSION

Gonadotropin therapy is effective in order to puberty initiation in adolescents with congenital hypogonadotropic hypogonadism. In helps to achieve not only androgenization, but also to Sertoli cells maturation.

[Molecular genetics and phenotypic features of congenital isolated hypogonadotropic hypogonadism]

Congenital isolated hypogonadotropic hypogonadism includes a group of diseases related to the defects of secretion and action of gonadotropin-releasing hormone (GNRH) and gonadotropins. In a half of cases congenital hypogonadism is associated with an impaired sense of smell. It's named Kallmann syndrome. Now 40 genes are known to be associated with function of hypothalamus pituitary gland and gonads. Phenotypic features of hypogonadism and therapy effectiveness are related to different molecular defects. However clinical signs may vary even within the same family with the same molecular genetic defect. Genotype phenotype correlation in patients with congenital malformations prioritizes the search for mutations in candidate genes. There are data of significant contribution of oligogenicity into the phenotype of the disease are presented in the review. Moreover, an issue of current isolated hypogonadotropic hypogonadism definition and classification revision is raised in the review due to hypogonadotropic hypogonadism development while there are mutations in genes not associated with GNRH neurons secretion and function.

Serum inhibin B for differentiating between congenital hypogonadotropic hypogonadism and constitutional delay of growth and puberty: a systematic review and meta-analysis

PURPOSE

The distinction between congenital hypogonadotropic hypogonadism (CHH) and constitutional delay of growth and puberty (CDGP) in patients with delayed puberty is difficult to distinguish, but important for timely treatment. The aim of this study is to perform a systematic review and meta-analysis to determine the diagnostic performance of serum inhibin B (INHB) levels for differentiating CHH and CDGP.

METHODS

PubMed, EMBASE, and Cochrane Library databases were systematically searched from the date of database inception to November 10, 2019 for studies examining the use of serum INHB to discriminate between CHH and CDGP. Pooled odds ratios (OR), sensitivity, specificity, and 95% confidence intervals (CI) were calculated. The Quality Assessment of Diagnostic Studies-2 (QUADAS-2) was used to assess the quality of the included studies. Sub-analyses were performed including that based on testicular volume (TV) and study design.

RESULTS

Seven studies, comprising of 349 patients (96 CHH and 253 CDGP), were included in the meta-analysis. For differentiating between CHH and CDGP, INHB level exhibited good diagnostic accuracy with a pooled sensitivity of 92% (95% confidence interval [CI]: 0.86-0.96, I² = 0.4%, p = 0.4343), specificity of 92% (95% CI: 0.88-0.94, I² = 68.1%, p = 0.0009), and pooled area under the receiver operating characteristic curve (AUC) of 0.9619. The cut-off values of INHB for boys were 56, 66, 80, 96, 94.7, 111, and 113 pg/ml (assay method standardized to Gen II ELISA). Sub-analyses showed that testicular volume and study design could be a source of statistically significant heterogeneity in specificity. In boys with a testicular volume of ≤3 ml, INHB performed well with a sensitivity of 92%, specificity of 98%, and AUC of 0.9956.

CONCLUSION

INHB exhibits excellent diagnostic efficiency in distinguishing CHH from CDGP, especially in boys with severe puberty deficiency (TV ≤ 3 ml).

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.

Minipuberty in Klinefelter syndrome: Current status and future directions

Klinefelter syndrome is highly underdiagnosed and diagnosis is often delayed. With the introduction of non-invasive prenatal screening, the diagnostic pattern will require an updated description of the clinical and biochemical presentation of infants with Klinefelter syndrome. In the first months of life, the hypothalamic-pituitary-gonadal (HPG)-axis is transiently activated in healthy males during the so-called minipuberty. This period represents a "window of opportunity" for evaluation of the HPG-axis before puberty and without stimulation tests. Infants with Klinefelter syndrome present with a hormonal surge during the minipuberty. However, only a limited number of studies exist, and the results are contradictory. Further studies are needed to clarify whether infants with Klinefelter syndrome present with impaired testosterone production during the minipuberty. The aim of this review is to describe the clinical and biochemical characteristics of the neonate and infant with Klinefelter syndrome with special focus on the minipuberty and to update the clinical recommendations for Klinefelter syndrome during infancy.

Minipuberty of human infancy - A window of opportunity to evaluate hypogonadism and differences of sex development?

Activation of the hypothalamic-pituitary-gonadal (HPG) axis happens in 3 phases during life. The first phase is during fetal life and is only separated from the second phase, called minipuberty, by the high concentration of placental hormones at birth. The third period of activation of the HPG axis is puberty and is well-described. Minipuberty consists of the neonatal activation of the HPG axis, mainly in the first 1-6 months, where the resulting high levels of gonadotropins and sex steroids induce the maturation of sexual organs in both sexes. With gonadal activation, testosterone levels rise in boys with peak levels after 1-3 months, which results in penile and testicular growth. In girls, gonadal activation leads to follicular maturation and a fluctuating increase in estrogen levels, with more controversy regarding the actual influence on the target tissue. The regulation of the HPG axis is complex, involving many biological and environmental factors. Only a few of these have known effects. Many details of this complex interaction of factors remain to be elucidated in order to understand the mechanisms underlying the first postnatal activation of the HPG axis as well as mechanisms shutting down the HPG axis, resulting in the hormonal quiescence observed between minipuberty and puberty. Minipuberty allows for the maturation of sexual organs and forms a platform for future fertility, but the long-term significance is still not absolutely clear. However, it provides a window of opportunity in the early detection of differences of sexual development, offering the possibility of initiating early medical treatment in some cases.

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.

Plasma kisspeptin levels in boys with hypogonadotropic delayed puberty

BACKGROUND

In hypogonadotropic forms of delayed puberty (DP), hypophyseal follicle-stimulating (FSH) and luteinizing (LH) hormones, normally released with GnRH stimulation, are detected low. Since kisspeptin (KP) is a strong stimulant of GnRH neurons, it is considered to have a role in DP etiology. It may be hypothesized that abnormal plasma levels of KP are indicative of DP. The study aimed at evaluation and comparison of plasma KP levels in boys of pre-pubertal age, with normal puberty and diagnosed primary hypogonadotropic forms of DP.

METHODS

The study comprised 22 boys with verified hypogonadotropic DP (age 14-17 years), 25 boys with normal puberty (age 14-17 years), and 28 pre-pubertal boys (age 6-9 years). Triprorelin stimulation test was performed in DP patients. Plasma KP values were compared between three groups.

RESULTS

Statistically significant difference was found for the overall distribution of the plasma KP values across different groups (Kruskal-Wallis H=21.95, P<0.001). The highest values were found in the DP group (median: 45.0 pg/mL). Median values in the pre-pubertal boys and in the normal pubertal adolescents were equal to 13.8 pg/mL. No statistically significant difference was found for plasma KP levels in the DP boys who had either positive or negative response to Triptorelin stimulation test. Plasma KP level exceeding 16.9 pg/mL was a reliable predictor of hypoganadotropic DP (sensitivity 72.7%, specificity 92.0%).

CONCLUSIONS

Plasma KP levels are elevated in hypogonadotropic DP cases and may serve as a useful diagnostic tool in evaluating boys with DP.

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.

Postnatal Testicular Activity in Healthy Boys and Boys With Cryptorchidism

Cryptorchidism, or undescended testis, is a well-known risk factor for testicular cancer and impaired semen quality in adulthood, conditions which have their origins in early fetal and postnatal life. In human pregnancy, the interplay of testicular and placental hormones as well as local regulatory factors and control by the hypothalamic-pituitary (HP) axis, lead to testicular descent by term. The normal masculine development may be disrupted by environmental factors or genetic defects and result in undescended testes. Minipuberty refers to the postnatal re-activation of the HP-testicular (T) axis after birth. During the first weeks of life, gonadotropin levels increase, followed by activation and proliferation of testicular Leydig, Sertoli and germ cells. Consequent rise in testosterone levels results in penile growth during the first months of life. Testicular size increases and testicular descent continues until three to five months of age. Insufficient HPT axis activation (e.g., hypogonadotropic hypogonadism) is often associated with undescended testis and therefore minipuberty is considered an important phase in the normal male reproductive development. Minipuberty provides a unique window of opportunity for the early evaluation of HPT axis function during early infancy. For cryptorchid boys, hormonal evaluation during minipuberty may give a hint of the underlying etiology and aid in the evaluation of the later risk of HPT axis dysfunction and impaired fertility. The aim of this review is to summarize the current knowledge of the role of minipuberty in testicular development and descent.

Maternal peripartum urinary pyrethroid metabolites are associated with thinner children at 3.5 years in the VHEMBE birth cohort (Limpopo, South Africa)

Supplemental Digital Content is available in the text.

Background:

Pyrethroids are the most widely used insecticides globally for domestic, agricultural, and malaria vector control. In 10 countries, dichlorodiphenyl trichloroethane (DDT) is also used for the latter. Thus, high exposure to pyrethroids and DDT have been reported among women and children from rural and/or malaria-endemic areas. Experimental studies suggest that fetal exposure to pyrethroids, particularly cypermethrin, and DDT may have sex-specific growth effects. However, epidemiologic investigations are scarce and inconsistent and have not considered postnatal environment or susceptibility factors.

Methods:

In 665 mother–child dyads participating in the Venda Health Examination of Mothers, Babies, and their Environment (VHEMBE), a rural South African birth cohort with high insecticide exposure, we examined associations of maternal peripartum urinary pyrethroid metabolites and serum DDT concentrations with child anthropometrics at 3.5 years using multivariable linear regression. We investigated effect modification by child sex, maternal nutrition and HIV status, and household poverty.

Results:

Pyrethroid metabolites cis-3-(2,2-dibromovinyl)-2,2-dimethyl-cyclopropane carboxylic acid (cis-DBCA), cis-3-(2,2,-dicholorvinyl)-2,2-dimethyl-cyclopropane carboxylic acid (cis-DCCA), trans-DCCA, and 3-phenoxybenzoic acid (3-PBA) were quantified in nearly all mothers. A 10-fold increase in cis-DCCA concentration was associated with 0.21 kg/m² lower body mass index (95% confidence interval = −0.41, −0.01), with similar estimates for other cypermethrin or permethrin metabolites (trans-DCCA and 3-phenoxybenzoic acid). In stratified analyses, stronger associations were observed with lower weight, body mass index, arm circumference, and weight-for-height among boys relative to girls. Associations with cis-3-(2,2-dibromovinyl)-2,2-dimethyl-cyclopropane carboxylic acid, a metabolite specific to deltamethrin, were weaker or absent. No substantial associations were observed with DDT.

Discussion:

In a population with ubiquitous pyrethroid exposure, maternal concentrations of metabolites of cypermethrin and permethrin were associated with thinness at 3.5 years.

Congenital hypogonadotropic hypogonadism, functional hypogonadotropism or constitutional delay of growth and puberty? An analysis of a large patient series from a single tertiary center

STUDY QUESTION

What diagnoses underlie delayed puberty (DP) and predict its outcome?

SUMMARY ANSWER

A multitude of different diagnoses underlie DP, and in boys a history of cryptorchidism, small testicular size and slow growth velocity (GV) predict its clinical course.

WHAT IS KNOWN ALREADY

DP is caused by a variety of underlying etiologies. Hormonal markers can be used in the differential diagnosis of DP but none of them have shown complete diagnostic accuracy.

STUDY DESIGN, SIZE, DURATION

Medical records of 589 patients evaluated for DP in a single tertiary care center between 2004 and 2014 were retrospectively reviewed.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Clinical and biochemical data of 174 boys and 70 girls who fulfilled the criteria of DP were included in the analyses. We characterized the frequencies of underlying conditions and evaluated the predictive efficacy of selected clinical and hormonal markers.

MAIN RESULTS AND THE ROLE OF CHANCE

Thirty etiologies that underlie DP were identified. No markers of clinical value could be identified in the girls, whereas a history of cryptorchidism in the boys was associated with an increase in the risk of permanent hypogonadism (odds ratio 17.2 (95% CI; 3.4-85.4, P < 0.001)). The conditions that cause functional hypogonadotropic hypogonadism were more frequent in boys with a GV below 3 cm/yr than in those growing faster (19% vs 4%, P < 0.05). In this series, the most effective markers to discriminate the prepubertal boys with constitutional delay of growth and puberty (CDGP) from those with congenital hypogonadotropic hypogonadism (CHH) were testicular volume (cut-off 1.1 ml with a sensitivity of 100% and a specificity of 91%), GnRH-induced maximal LH (cut-off 4.3 IU/L; 100%, 75%) and basal inhibin B (INHB) level (cut-off 61 ng/L; 90%, 83%).

LIMITATIONS, REASONS FOR CAUTION

The main limitation of the study is the retrospective design.

WIDER IMPLICATIONS OF THE FINDINGS

Prior cryptorchidism and slow GV are two important clinical cues that may help clinicians to predict the clinical course of DP in boys, whereas markers of similar value could not be identified in girls. In prepubertal boys, testicular size appeared as effective as INHB and GnRH-induced LH levels in the differential diagnosis between CHH and CDGP.

STUDY FUNDING/COMPETING INTERESTS

This study was supported by the Academy of Finland (268356), Foundation for Pediatric Research (7495), Sigrid Juselius Foundation (2613) and the Finnish Medical Foundation (011115). The authors have no competing interests to report.

TRIAL REGISTRATION NUMBER

Not applicable.