New reference charts for testicular volume in Dutch children and adolescents allow the calculation of standard deviation scores

Molecular insights into Sertoli cell function: how do metabolic disorders in childhood and adolescence affect spermatogonial fate?

Male infertility is a major public health concern globally with unknown etiology in approximately half of cases. The decline in total sperm count over the past four decades and the parallel increase in childhood obesity may suggest an association between these two conditions. Here, we review the molecular mechanisms through which obesity during childhood and adolescence may impair future testicular function. Several mechanisms occurring in obesity can interfere with the delicate metabolic processes taking place at the testicular level during childhood and adolescence, providing the molecular substrate to hypothesize a causal relationship between childhood obesity and the risk of low sperm counts in adulthood.

Inter-individual exposure variability interpretation through reflection of biological age algorithm in physiologically based toxicokinetic model: Application to human risk assessment of di-isobutyl-phthalate

Age-related changes and interindividual variability in the degree of exposure to hazardous substances in the environment are pertinent factors to be considered in human risk assessment. Existing risk assessments remain in a one-size-fits-all approach, often without due consideration of inter-individual toxicokinetic variability factors, such as age. The purpose of this study was to advance from the existing risk assessment of hazardous substances based on toxicokinetics to a precise human risk assessment by additionally considering the effects of physiologic and metabolic fluctuations and interindividual variability in age. Qualitative age-associated physiologic and metabolic changes in humans, obtained through a meta-analysis, were quantitatively modeled to produce the final biological age algorithm (BAA). The developed BAAs (for males) were extended and applied to the reported testicular reproductive toxicity-focused di-isobutyl-phthalate (DiBP)-mono-isobutyl-phthalate (MiBP) physiologically based toxicokinetic (PBTK) model in males. The advanced PBTK model combined with the BAA was applied to the human risk assessment based on MiBP biomonitoring data. As a result, the specialized DiBP external exposure values for each age could be estimated. Additionally, by applying the Monte Carlo simulation, the distribution of internal exposure diversity among individuals according to the same external exposure dose could be estimated. The contributions of physiologic and metabolic factors to the age-dependent toxicokinetic changes were approximately 93.41-99.99 and 0.01-6.59%, respectively. In addition, the relative contribution of metabolic factors was major in infants and continued to decrease as age increased (up to about age 30 years). This study provides a step-by-step platform that can be widely applied to overcome the limitations of existing toxicokinetic models that still require interindividual pharmacokinetic variability explanations. This will be important for the rationalization and explanation of inter-individual variability in the pharmacokinetics of many substances.

Mini review shows that a testicular volume of 3 mL was the most reliable clinical sign of pubertal onset in males

AIM

We aimed to evaluate aspects of pubertal development to identify the most reliable clinical sign of pubertal onset in males.

METHODS

We performed a mini review of the literature.

RESULTS

In 1951 Reynolds and Wines categorised pubic hair growth and genital development in five stages by visual inspection. Today the Tanner scale is used to assess the five stages of pubertal development, The second genital stage, characterised by enlargement of the scrotum defines pubertal onset in males. Testicular volume may be evaluated by using a calliper or by ultrasound scan. The Prader orchidometer, described in 1966, offers a method for evaluating testicular growth by palpation. Pubertal onset is commonly defined as testicular volume >3 or ≥4 mL. The development of sensitive laboratory methods has enabled studies analysing hormonal activity in the hypothalamus-pituitary-gonadal axis. We review the relationships between physical and hormonal signs of puberty. We also discuss the results of studies assessing different aspects of pubertal development with a focus on identifying the most reliable clinical sign of pubertal onset in males.

CONCLUSION

A substantial amount of evidence supports testicular volume of 3 mL as the most reliable clinical sign of male pubertal onset.

Longitudinal association of prepubertal urinary phthalate metabolite concentrations with pubertal progression among a cohort of boys

BACKGROUND

Epidemiological studies have reported associations of anti-androgenic phthalate metabolite concentrations with later onset of male puberty, but few have assessed associations with progression.

OBJECTIVES

We examined the association of prepubertal urinary phthalate metabolite concentrations with trajectories of pubertal progression among Russian boys.

METHODS

At enrollment (ages 8-9 years), medical history, dietary, and demographic information were collected. At entry and annually to age 19 years, physical examinations including testicular volume (TV) were performed and spot urines collected. Each boy's prepubertal urine samples were pooled, and 15 phthalate metabolites were quantified by isotope dilution LC-MS/MS at Moscow State University. Metabolites of anti-androgenic parent phthalates were included: butylbenzyl (BBzP), di-n-butyl (DnBP), diisobutyl (DiBP), di(2-ethylhexyl) (DEHP) and diisononyl (DiNP) phthalates. We calculated the molar sums of DEHP, DiNP, and all AAP metabolites. We used group-based trajectory models (GBTMs) to identify subgroups of boys who followed similar pubertal trajectories from ages 8-19 years based on annual TV. We used multinomial and ordinal regression models to evaluate whether prepubertal log-transformed phthalate metabolite concentrations were associated with slower or faster pubertal progression trajectories, adjusting for covariates.

RESULTS

304 boys contributed a total of 752 prepubertal urine samples (median 2, range: 1-6) for creation of individual pools. The median length of follow-up was 10.0 years; 79% of boys were followed beyond age 15. We identified three pubertal progression groups: slower (34%), moderate (43%), and faster (23%) progression. A standard deviation increase in urinary log-monobenzyl phthalate (MBzP) concentrations was associated with higher adjusted odds of being in the slow versus faster pubertal progression trajectory (aOR 1.47, 95% CI 1.06-2.04). None of the other phthalate metabolites were associated with pubertal progression.

CONCLUSIONS

On average, boys with higher concentrations of prepubertal urinary MBzP had a slower tempo of pubertal progression, perhaps attributable to the disruption of androgen-dependent biological pathways.

Childhood cancer and hematological disorders negatively affect spermatogonial quantity at diagnosis: a retrospective study of a male fertility preservation cohort

STUDY QUESTION

What is the impact of cancer or hematological disorders on germ cells in pediatric male patients?

SUMMARY ANSWER

Spermatogonial quantity is reduced in testes of prepubertal boys diagnosed with cancer or severe hematological disorder compared to healthy controls and this reduction is disease and age dependent: patients with central nervous system cancer (CNS tumors) and hematological disorders, as well as boys <7 years are the most affected.

WHAT IS KNOWN ALREADY

Fertility preservation in pediatric male patients is considered based on the gonadotoxicity of selected treatments. Although treatment effects on germ cells have been extensively investigated, limited data are available on the effect of the disease on the prepubertal male gonad. Of the few studies investigating the effects of cancer or hematologic disorders on testicular function and germ cell quantity in prepuberty, the results are inconsistent. However, recent studies suggested impairments before the initiation of known gonadotoxic therapy. Understanding which diseases and at what age affect the germ cell pool in pediatric patients before treatment is critical to optimize strategies and counseling for fertility preservation.

STUDY DESIGN, SIZE, DURATION

This multicenter retrospective cohort study included 101 boys aged <14 years with extra-cerebral cancer (solid tumors), CNS tumors, leukemia/lymphoma (blood cancer), or non-malignant hematological disorders, who were admitted for a fertility preservation programme between 2002 and 2018.

PARTICIPANTS/MATERIALS, SETTING, METHODS

In addition to clinical data, we analyzed measurements of testicular volume and performed histological staining on testicular biopsies obtained before treatment, at cryopreservation, to evaluate number of spermatogonia per tubular cross-section, tubular fertility index, and the most advanced germ cell type prior to chemo-/radiotherapy. The controls were data simulations with summary statistics from original studies reporting healthy prepubertal boys' testes characteristics.

MAIN RESULTS AND THE ROLE OF CHANCE

Prepubertal patients with childhood cancer or hematological disorders were more likely to have significantly reduced spermatogonial quantity compared to healthy controls (48.5% versus 31.0% prevalence, respectively). The prevalence of patients with reduced spermatogonial quantity was highest in the CNS tumor (56.7%) and the hematological disorder (55.6%) groups, including patients with hydroxyurea pre-treated sickle cell disease (58.3%) and patients not exposed to hydroxyurea (50%). Disease also adversely impacted spermatogonial distribution and differentiation. Irrespective of disease, we observed the highest spermatogonial quantity reduction in patients <7 years of age.

LIMITATIONS, REASONS FOR CAUTION

For ethical reasons, we could not collect spermatogonial quantity data in healthy prepubertal boys as controls and thus deployed statistical simulation on data from literature. Also, our results should be interpreted considering low patient numbers per (sub)group.

WIDER IMPLICATIONS OF THE FINDINGS

Cancers, especially CNS tumors, and severe hematological disorders can affect spermatogonial quantity in prepubertal boys before treatment. Consequently, these patients may have a higher risk of depleted spermatogonia following therapies, resulting in persistent infertility. Therefore, patient counseling prior to disease treatment and timing of fertility preservation should not only be based on treatment regimes, but also on diagnoses and age.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by Marie Curie Initial Training Network (ITN) (EU-FP7-PEOPLE-2013-ITN) funded by European Commision grant no. 603568; ZonMW Translational Adult stem cell research (TAS) grant no. 116003002. No competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Pharmacological treatment for pubertal progression in boys with delayed or slow progression of puberty: A small-scale randomized study with testosterone enanthate and testosterone undecanoate treatment

Context

The use of testosterone enanthate (TE), 50-75 mg intramuscularly (i.m.)/month, for the treatment of boys with delayed puberty or slow progression to induce puberty is the standard of care (SoC) in Sweden. This treatment is empirical and has not been scientifically evaluated. Replacement therapy in hypogonadal boys/young men in Sweden after induction is mainly performed with testosterone undecanoate (TU), 1,000 mg/3 months. TE is only available on license. TE was deregistered in Sweden in 2006. Therefore, this study was initiated to compare the two products.

Objective

To clinically evaluate pubertal progression with six injections of TE, 75 mg i.m./month (1/3-1/5 of adult dose), compared with two injections of TU, 250 mg i.m./3 months (1/4 of adult dose).

Trial design

In the Pubertal Replacement in Boys Study (PRIBS), boys aged 14-16 years in West Sweden with pubertal delay were randomized in a parallel study to TE or TU for pubertal progression. Inclusion criteria were morning testosterone levels of 0.5-3 nmol/L and testicular volume ≤6 ml. Between June 2014 and Nov 2019, 27 boys were included.

Methods

The primary outcome was testicular enlargement ≥8 ml after 12 months. TU treatment was considered clinically similar if the number of boys with testicular enlargement ≥8 ml was 80%-125% of the number of boys with TE. Fisher's exact chi-square test was used for this analysis.

Results

Both treatments were well tolerated. Twelve of 14 (86%) TU-treated boys reached the primary outcome and 12/12 in the TE group. Fisher's exact chi-square testing indicated a one-sided p-value of 0.28 (the two-sided p-value was 0.483). The TU treatment was considered not clinically different from SoC. A post-hoc study showed 25% power. Therefore, no evidence-based conclusion can be drawn from the results even if the clinical data support a similar effect of the treatments.

Conclusion

The present small-scale study supports that both TE and TU had similar effects in terms of pubertal progression.

Clinical Trial Registration

https://www.clinicaltrials.gov/ct2/home, identifier NCT05417035; https://www.clinicaltrialsregister.eu/ctrsearch/search, identifier EUDRACTEudraCT nr 2012-002337-11.

Diurnal salivary androstenedione and 17-hydroxyprogesterone levels in healthy volunteers for monitoring treatment efficacy of patients with congenital adrenal hyperplasia

OBJECTIVE

Treatment of congenital adrenal hyperplasia (CAH) patients with glucocorticoids is often challenging since there is a delicate balance between over- and undertreatment. Treatment can be monitored noninvasively by measuring salivary androstenedione (A4) and 17-hydroxyprogesterone (17-OHP). Optimal treatment monitoring requires the establishment of reference values in saliva.

DESIGN

A descriptive study.

PATIENTS

For this study saliva of 255 healthy paediatric and adult volunteers with an age range of 4-75 years old was used.

MEASUREMENTS

We developed a sensitive liquid chromatography-tandem mass spectrometry method, assessed salivary A4 and 17-OHP stability, and measured A4 and 17-OHP concentrations in saliva collected in the morning, afternoon, and evening.

RESULTS

We quantified A4 and 17-OHP concentrations in the morning, afternoon, and evening and demonstrated that there is a significant rhythm with the highest levels in the morning and decreasing levels over the day. A4 and 17-OHP concentrations display an age-dependent pattern. These steroids remain stable in saliva at ambient temperature for up to 5 days.

CONCLUSIONS

Good stability of the steroids in saliva enables saliva collection by the patient at home. Since salivary A4 and 17-OHP display a diurnal rhythm and age-dependent pattern, we established reference values for both children and adults at three time points during the day. These reference values support treatment monitoring of children and adults with CAH.

Corifollitropin Alfa Combined With Human Chorionic Gonadotropin in Adolescent Boys With Hypogonadotropic Hypogonadism

CONTEXT

Adolescent males with hypogonadotropic hypogonadism (HH) have traditionally been treated with exogenous testosterone (T) or human chorionic gonadotropin (hCG) to produce virilization; however, those modalities do not result in growth of the testes and may promote premature maturation and terminal differentiation of Sertoli cells prior to their proliferation, which may impact future fertility. Another option is to use gonadotropins in those individuals to induce testicular growth, proliferation and maturation of Sertoli cells, and production of endogenous T with consequent virilization.

OBJECTIVE

We examined the efficacy and safety of corifollitropin alfa (CFA) combined with hCG for the induction of testicular growth and pubertal development in adolescent boys with HH.

METHODS

This was a 64-week, multicenter, open-label, single-group study of CFA in adolescent boys, aged 14 to younger than 18 years, with HH. Seventeen participants initiated a 12-week priming period with CFA (100 μg if weight ≤ 60 kg, or 150 μg if weight > 60 kg) given subcutaneously once every 2 weeks, after which they entered a 52-week combined treatment period with CFA, once every 2 weeks, and subcutaneous hCG, twice-weekly (hCG dose adjusted between 500 IU and 5000 IU to keep total T and estradiol levels within protocol-specified ranges). The primary efficacy end point was change from baseline in testicular volume (TV), measured as the sum of volumes of left and right testes by ultrasound.

RESULTS

After 64 weeks of therapy with CFA/CFA combined with hCG, geometric mean fold increase from baseline in TV was 9.43 (95% CI, 7.44-11.97) (arithmetic mean of change from baseline at week 64, 13.0 mL). Hormonal, Tanner stage, and growth velocity changes were consistent with initiation and progression of puberty. Treatment was generally well tolerated. No participant developed anti-CFA antibodies.

CONCLUSION

Treatment of adolescent boys with HH with CFA alone for 12 weeks followed by CFA combined with hCG for 52 weeks induced testicular growth accompanied by pubertal progression, increased T, and a pubertal growth spurt (EudraCT: 2015-001878-18).

Testicular volume and Tanner stage: determinant factors for testicular torsion

Objective

To assess testicular volumes and sexual maturation in patients with testicular torsion.

Methods

A retrospective analysis of consecutively treated patients with testicular torsion between 2016 and 2018. Age, pubic hair staging (Tanner), and by ultrasonography, volume of the unaffected testis (in cubic centimeters) were evaluated either immediately before surgery or at the first postoperative visit. Patients with previous testicular disease, such as cryptorchidism, or with no records of testicular volume were excluded. The analysis included descriptive statistics and Bayesian regression.

Results

We treated 149 patients during the study period, and 141 (94.6%, median age 17.3 years) met the inclusion criteria. Median testicular volume was 13.0cm³ (interquartile range of 10.5-15.2), with similar right and left volumes (12.9cm³versus 13.3cm³; p=0.94). Sixty-five (46.1%) patients were Tanner stage IV, 17 (12.1%) stage III, and 59 (41.8%) stage V.

Conclusion

In this study, we were able to estimate volumes of testicular torsion, which aggregated around late puberty values (13.0cm³ for the whole dataset, 12.2cm³ for patients <25 years), suggesting that testicular hypermobility, due to congenital anatomical abnormalities, remains quiescent until the organ reaches a critical volume, after which torsion becomes possible. These findings provide a tentative explanation for the disease’s age distribution.

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.

Case Report: A Detailed Phenotypic Description of Patients and Relatives with Combined Central Hypothyroidism and Growth Hormone Deficiency Carrying IGSF1 Mutations

In recent years, variants in immunoglobulin superfamily member 1 (IGSF1) have been associated with congenital hypopituitarism. Initially, IGSF1 variants were only reported in patients with central hypothyroidism (CeH) and macroorchidism. Later on, IGSF1 variants were also reported in patients with additional endocrinopathies, sometimes without macroorchidism. We studied IGSF1 as a new candidate gene for patients with combined CeH and growth hormone deficiency (GHD). We screened 80 male and 14 female Dutch patients with combined CeH and GHD for variants in the extracellular region of IGSF1, and we report detailed biomedical and clinical data of index cases and relatives. We identified three variants in our patient cohort, of which two were novel variants of unknown significance (p.L570I and c.1765+37C>A). In conclusion, we screened 94 patients with CeH and GHD and found variants in IGSF1 of which p.L570I could be of functional relevance. We provide detailed phenotypic data of two boys with the p.C947R variant and their large family. The remarkable phenotype of some of the relatives sheds new light on the phenotypic spectrum of IGSF1 variants.

Pubertal development in 46,XY patients with NR5A1 mutations

PURPOSE

Mutations in the NR5A1 gene, encoding the transcription factor Steroidogenic Factor-1, are associated with a highly variable genital phenotype in patients with 46,XY differences of sex development (DSD). Our objective was to analyse the pubertal development in 46,XY patients with NR5A1 mutations by the evaluation of longitudinal clinical and hormonal data at pubertal age.

METHODS

We retrospectively studied a cohort of 10 46,XY patients with a verified NR5A1 mutation and describe clinical features including the external and internal genitalia, testicular volumes, Tanner stages and serum concentrations of LH, FSH, testosterone, AMH, and inhibin B during pubertal transition.

RESULTS

Patients who first presented in early infancy due to ambiguous genitalia showed spontaneous virilization at pubertal age accompanied by a significant testosterone production despite the decreased gonadal volume. Patients with apparently female external genitalia at birth presented later in life at pubertal age either with signs of virilization and/or absence of female puberty. Testosterone levels were highly variable in this group. In all patients, gonadotropins were constantly in the upper reference range or elevated. Neither the extent of virilization at birth nor the presence of Müllerian structures reliably correlated with the degree of virilization during puberty.

CONCLUSION

Patients with NR5A1 mutations regardless of phenotype at birth may demonstrate considerable virilization at puberty. Therefore, it is important to consider sex assignment carefully and avoid irreversible procedures during infancy.

FSH-stimulated Inhibin B (FSH-iB): A Novel Marker for the Accurate Prediction of Pubertal Outcome in Delayed Puberty

BACKGROUND

Clinicians have long been struggling to find an effective tool to predict onset of puberty.

OBJECTIVE

To explore stimulability of inhibin B after exogenous FSH and its potential role for prediction of onset of puberty.

DESIGN AND PARTICIPANTS

Study subjects were enrolled into "exploratory cohort" (n = 42) and "validation cohort" (n = 19). The exploratory cohort was further divided into group 1 (healthy children with spontaneous puberty [SP], n = 26) and group 2 (patients with hypogonadotropic hypogonadism [HH], n = 16). The validation cohort included children who presented with complaints of delayed puberty.

INTERVENTION AND OUTCOME

Participants were subjected to FSH stimulation test and GnRH analogue stimulation test. Cutoffs derived from the exploratory cohort for basal and FSH stimulated inhibin B (FSH-iB) were applied on the validation cohort. Basal LH, GnRH analogue-stimulated LH, basal inhibin B, and FSH-iB were compared with clinical outcomes on a prospective follow-up for prediction of onset of puberty.

RESULTS

There was statistically significant increment in inhibin B after exogenous FSH in group 1 (SP) in both male (188.8 pg/mL; P = 0.002) and female (1065 pg/mL; P = 0.023) subjects. The increment was not statistically significant in group 2 (HH) in both sexes. FSH-iB at a cutoff of 116.14 pg/mL in males and 116.50 pg/mL in females had 100% sensitivity and specificity for labelling entry into puberty. On application of these cutoffs on the validation cohort, FSH-iB had 100% positive predictive value, negative predictive value, and diagnostic accuracy for prediction of pubertal onset.

CONCLUSION

Inhibin B was stimulable in both male and female subjects. FSH-iB can be considered a novel and promising investigation for prediction of onset of puberty. Future studies are required for further validation.

The outcome of laparoscopic assisted orchidopexy in very young children: A single hospital experience

INTRODUCTION

Early orchidopexy has been linked to improved long term outcomes of fertility and reduced malignancy rates. However, the optimal age of intervention has been subject to change over the years.

OBJECTIVE

This study aims to study males aged 6 months or less who undergo laparoscopic assisted orchidopexy for intraabdominal testes to establish the safety, efficacy, and benefit in the defined age group.

STUDY DESIGN

We prospectively assessed 19 boys at or below 6 months of age, who had laparoscopic assisted orchidopexy for intraabdominal undescended testes at Salmaniya Medical Complex in Bahrain between January 2014 and December 2018. We examined: demographics, laterality, testicular locations, testicular volumes, operative time, complications, and durations of hospitalization and follow-up. Ultrasound-derived testicular volumes were assessed before and after orchidopexy. They were calculated using the Hansen formula (Testicular volume = 0.52 × length [L] × width [W]² [1]. They were then compared with reference ranges from a Dutch cohort study of 769 healthy boys. Successful outcomes were correct intrascrotal position with minimal complications and normal testicular volumes.

RESULTS

A total of 19 males were operated at a mean age of 5.6 months and followed for a mean of 2.35 years. Of these, 7 had left-sided and 12 had right-sided cryptorchidism. Testicular locations were noted intra-operatively; 10 were above the internal ring, 5 near the iliac vessels, and 4 close to the kidney. The mean operative time was 59.58 minutes. Only 2 minor complications occurred and no cases of testicular atrophy. None of the patients required hospital-stay beyond 24 hours. The success rate was 89.46% in achieving correct scrotal position. Testicular volumes were normal before and after orchidopexy. They significantly increased after orchidopexy (P ≤ 0.05). The testicular growth rate after 24 months was slightly higher than normal.

DISCUSSION

In line with previous studies we were 89.46% successful in re-positioning testes [2]. In contrast to studies intervening at older ages which associated intra-abdominal testes with greater risks of complications, we found few minor complications and no testicular atrophy [3,4]. Testicular volumes in the affected testes were normal, contrary to decreased volumes found by other researchers [5]. Limitations of this study are the small number of patients and short follow-up which limits assessment of long-term outcomes.

CONCLUSION

Early orchiopexy is safe and effective. Laparoscopic assisted orchidopexy at an early age was beneficial and resulted in normal testicular volumes before and after surgery.

Historical trends for the standards in scrotal ultrasonography: What was, what is and what will be normal

BACKGROUND

Ultrasonography is the gold standard imaging method for scrotal investigation. Colour Doppler ultrasonography, contrast-enhanced ultrasonography and sonoelastography allow sonographers to assess size, echotexture, vascular features and stiffness of the scrotal organs and abnormalities. Scrotal ultrasonography has been used to investigate male reproductive health, scrotal pain, masses and trauma. However, ultrasonography thresholds/classifications used to distinguish normal and pathologic features of the scrotal organs have changed over time, and have not yet been fully standardized.

OBJECTIVES

To evaluate historical trends for the standards in scrotal ultrasonography: what was, what is and what will be normal.

METHODS

An extensive Medline search was performed identifying the most relevant studies in the English language from inception to date.

RESULTS

We provide here (i) a brief overview of the history of ultrasonography, (ii) current indications for scrotal ultrasonography and (iii) previous and current normal values, cut-offs and classifications of the main colour-Doppler ultrasonography parameters/characteristics of the scrotal organs, as derived from recent guidelines and evidence-based studies. In addition, we report recommendations and the clinical utility of contrast-enhanced ultrasonography and sonoelastography. Finally, we discuss critical issues needing further evidence and future directions to fill in the current gaps.

DISCUSSION

Several studies on scrotal ultrasonography are available. However, guidelines/recommendations dealing with specific ultrasonography applications have been published only in recent years. More recently, the European Academy of Andrology published evidence-based scrotal colour-Doppler ultrasonography reference ranges/normative parameters derived from a cohort of healthy, fertile men. In addition, a standardization of the methodology to evaluate qualitative and quantitative colour-Doppler ultrasonography parameters was reported. Other international societies reported indications, methodological standards, clinical utility and limitations of contrast-enhanced ultrasonography and sonoelastography.

CONCLUSIONS

To date, colour-Doppler ultrasonography normative values for the scrotal organs are available. However, a wide international consensus on assessment and classification of several ultrasonography parameters is still lacking. An alignment of the world societies on these issues is advocated.

IGSF1 Does Not Regulate Spermatogenesis or Modify FSH Synthesis in Response to Inhibins or Activins

Loss-of-function mutations in the X-linked immunoglobulin superfamily, member 1 (IGSF1) gene result in central hypothyroidism, often associated with macroorchidism. Testicular enlargement in these patients might be caused by increases in follicle-stimulating hormone (FSH) levels, as IGSF1 has been proposed to function as an inhibin B receptor or as an inhibitor of activin type I receptor (ALK4) activity in pituitary gonadotrope cells. If true, loss of IGSF1 should lead to reduced inhibin B action or disinhibition of activin signaling, thereby increasing FSH synthesis. Here, we show that FSH levels and sperm counts are normal in male Igsf1 knockout mice, although testis size is mildly increased. Sperm parameters are also normal in men with IGSF1 deficiency, although their FSH levels may trend higher and their testes are enlarged. Inhibin B retains the ability to suppress FSH synthesis in pituitaries of Igsf1-knockout mice and IGSF1 does not interact with ALK4 or alter activin A/ALK4 stimulation of FSHβ (Fshb/FSHB) subunit transcription or expression. In light of these results, it is unlikely that macroorchidism in IGSF1 deficiency derives from alterations in spermatogenesis or inhibin/activin regulation of FSH.

Low BMI, but not high BMI, influences the timing of puberty in boys

BACKGROUND

Previous studies investigating the association between weight status and onset of puberty in boys have been equivocal. It is currently unclear to what extent weight class influences puberty onset and progression.

OBJECTIVES

To explore the relationship between degree of sexual maturation and anthropometric measures in Norwegian boys.

METHODS

The following endpoints were collected in a Norwegian cross-sectional study of 324 healthy boys aged 9-16: ultrasound-determined testicular volume (USTV), total serum testosterone, Tanner pubic hair stage, height, weight, waist circumference (WC), subscapular skinfolds (SSF), and body fat percentage (%BF). Testicular volume-for-age z-scores were used to classify "early," "average," or "late" maturing boys. Ordinal logistic regression analyses with a proportional odds model were applied to analyze the association between anthropometric variables and age-adjusted degree of pubertal development, with results expressed as age-adjusted odds ratios (AOR). Cumulative incidence curves for reaching pubertal milestones were stratified by BMI.

RESULTS

Boys with a low BMI for age (BMI_z  < -1) were less likely to have reached a pubertal testicular volume (USTV ≥ 2.7 mL) or a pubertal serum level of testosterone (≥0.5 nmol/L) compared to normal weight boys (AOR 0.3, p = 0.038, AOR 0.3, p = 0.026, respectively), and entered puberty on average with a delay of approximately eight months. Boys with high BMI for age (BMI_z  > 1) exhibited a comparable timing as normal weight boys. The same was found for WC. Pubertal markers were not associated with SSF or %BF.

CONCLUSION

By examining the association between puberty and weight status classified as low, average, or high, we found that a low BMI or WC for age were associated with a less advanced pubertal development and delayed timing of puberty in boys. No significant association was observed for a high BMI or WC. Moreover, no significant effects of SSF or %BF were observed. A low weight status should also be considered when assessing pubertal development in boys.

Referential Values of Testicular Volume Measured by Ultrasonography in Normal Children and Adolescents: Z-Score Establishment

Objective: To establish Z-score regression equation derived from age for testicular volume measured by ultrasonography in normal boys aged 0 to 18 years old. Method: The length (L), width (W), and height (H) of 3,328 testicles from 1,664 Chinese boys were measured by ultrasonography. Lambert's formula: L × W × H × 0.71 was used to calculate testicular volume. Z-score regression equation derived from age was established by regression analysis of predicted values of testicular volume and standard deviations. Result: There was no significant difference between left and right testicular volumes. Testicular volume was positively correlated with age, and logarithmic transformation of testicular volume can show a fine curve fit with age. To establish Z-score regression equation derived from age, the predicted values of testicular volume used cubic regression equations, and the standard deviation used square regression equations. The Z-score regression equation derived from age was calculated by the formula: z = [lg (L × W × H × 0.71) - (-0.3524-0.01759 × x+0.009417 × x2-0.0001840 × x3)]/(0.1059+0.01434 × x-0.0005324 × x2). Conclusion: The current study provided a reference value for testicular volume of boys aged 0 to 18 years old. Z-score regression equation derived from age for testicular volume can be established. Z-score will be of great value for the testicular development assessment and disease diagnosis and follow-up.

Reference data for testicular volume measured with ultrasound and pubic hair in Norwegian boys are comparable with Northern European populations

AIM

To estimate references for testicular volume measured with ultrasound and Tanner stages of pubic hair in Norwegian boys, and to compare the timing of puberty with data from similar populations.

METHODS

Testicular volume was derived from ultrasound measurements of testicular volume in a cross-sectional study of 514 healthy boys. A continuous testicular volume for age reference curve was estimated with the LMS method. Tanner stages for pubic hair were clinically assessed in 452 boys. Age references for pubertal milestones were estimated with probit regression.

RESULTS

Puberty onset, defined by an ultrasound testicular volume of 2.7 mL, equivalent to an orchidometer volume of 4 mL, occurred at a mean (SD) age of 11.7 (1.1) years. The reference range was 9.7 (3rd) to 13.7 years (97th percentile). Pubic hair (Tanner stage 2) appeared on average at 11.8 (1.2) years with a corresponding reference range of 9.5-14.1 years.

CONCLUSION

The references for testicular volume measured with ultrasound are continuous in age and allow for the quantification of pubertal development. The age distribution of reaching pubertal milestones was comparable with data from other Northern European countries.

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.

Testicular function in boys with 47,XYY and relationship to phenotype

An additional Y chromosome occurs in ~1 in 1,000 males, resulting in the karyotype 47,XYY. The phenotype includes tall stature, hypotonia, neuropsychiatric comorbidities, and an increased risk of infertility in adulthood. Little is known about testicular function in childhood and adolescence in 47,XYY. This cross-sectional study aimed to assess testicular function serum biomarkers, including total testosterone, inhibin B, and anti-mullerian hormone (AMH), in 82 boys with XYY (11.3 ± 3.8 years) compared with 66 male controls (11.6 ± 3.8 years). The association of testicular hormones with physical features, neuropsychological phenotype, and magnetoencephalography (MEG) was assessed with multiple linear regression models. Results indicate males with XYY have significantly lower inhibin B (median 84 pg/ml vs. 109 pg/ml, p = .004) and higher AMH (median 41 ng/ml vs. 29 ng/ml, p = .011); however, testosterone, testicular volume, and stretched penile length were not different from controls. In the exploratory analysis of relationships between hormone concentrations and phenotypic assessments, higher inhibin B concentrations were positively correlated with lower BMI and better cognitive, academic, and behavioral outcomes in the XYY group. Testosterone concentrations were positively associated with better behavioral outcomes in boys with XYY. Higher testosterone and inhibin B concentrations were also associated with shorter auditory latencies measured using magnetoencephalography (MEG) in XYY. With a few exceptions, testicular hormones were not associated with phenotypic outcomes in controls. In conclusion, there is evidence of subtle impaired testicular function in boys with XYY and a newly described relationship between measures of testicular function and some aspects of the XYY phenotype.

Testicular Ultrasound to Stratify Hormone References in a Cross-Sectional Norwegian Study of Male Puberty

CONTEXT

Testicular growth represents the best clinical variable to evaluate male puberty, but current pediatric hormone references are based on chronological age and subjective assessments of discrete puberty development stages. Determination of testicular volume (TV) by ultrasound provides a novel approach to assess puberty progression and stratify hormone reference intervals.

OBJECTIVE

The objective of this article is to establish references for serum testosterone and key hormones of the male pituitary-gonadal signaling pathway in relation to TV determined by ultrasound.

DESIGN, SETTING, AND PARTICIPANTS

Blood samples from 414 healthy Norwegian boys between ages 6 and 16 years were included from the cross-sectional "Bergen Growth Study 2." Participants underwent testicular ultrasound and clinical assessments, and serum samples were analyzed by liquid chromatography tandem-mass spectrometry and immunoassays.

MAIN OUTCOME MEASURES

We present references for circulating levels of total testosterone, luteinizing hormone, follicle-stimulating hormone, and sex hormone-binding globulin in relation to TV, chronological age, and Tanner pubic hair stages.

RESULTS

In pubertal boys, TV accounted for more variance in serum testosterone levels than chronological age (Spearman r = 0.753, P < .001 vs r = 0.692, P < .001, respectively). Continuous centile references demonstrate the association between TV and hormone levels during puberty. Hormone reference intervals were stratified by TV during the pubertal transition.

CONCLUSIONS

Objective ultrasound assessments of TV and stratification of hormone references increase the diagnostic value of traditional references based on chronological age or subjective staging of male puberty.

IGSF1 Deficiency Results in Human and Murine Somatotrope Neurosecretory Hyperfunction

CONTEXT

The X-linked immunoglobulin superfamily, member 1 (IGSF1), gene is highly expressed in the hypothalamus and in pituitary cells of the POU1F1 lineage. Human loss-of-function mutations in IGSF1 cause central hypothyroidism, hypoprolactinemia, and macroorchidism. Additionally, most affected adults exhibit higher than average IGF-1 levels and anecdotal reports describe acromegaloid features in older subjects. However, somatotrope function has not yet been formally evaluated in this condition.

OBJECTIVE

We aimed to evaluate the role of IGSF1 in human and murine somatotrope function.

PATIENTS, DESIGN, AND SETTING

We evaluated 21 adult males harboring hemizygous IGSF1 loss-of-function mutations for features of GH excess, in an academic clinical setting.

MAIN OUTCOME MEASURES

We compared biochemical and tissue markers of GH excess in patients and controls, including 24-hour GH profile studies in 7 patients. Parallel studies were undertaken in male Igsf1-deficient mice and wild-type littermates.

RESULTS

IGSF1-deficient adult male patients demonstrated acromegaloid facial features with increased head circumference as well as increased finger soft-tissue thickness. Median serum IGF-1 concentrations were elevated, and 24-hour GH profile studies confirmed 2- to 3-fold increased median basal, pulsatile, and total GH secretion. Male Igsf1-deficient mice also demonstrated features of GH excess with increased lean mass, organ size, and skeletal dimensions and elevated mean circulating IGF-1 and pituitary GH levels.

CONCLUSIONS

We demonstrate somatotrope neurosecretory hyperfunction in IGSF1-deficient humans and mice. These observations define a hitherto uncharacterized role for IGSF1 in somatotropes and indicate that patients with IGSF1 mutations should be evaluated for long-term consequences of increased GH exposure.

Towards a Rational and Efficient Diagnostic Approach in Children Referred for Growth Failure to the General Paediatrician

Based on a recent Dutch national guideline, we propose a structured stepwise diagnostic approach for children with growth failure (short stature and/or growth faltering), aiming at high sensitivity for pathologic causes at acceptable specificity. The first step is a detailed clinical assessment, aiming at obtaining relevant clinical clues from the medical history (including family history), physical examination (emphasising head circumference, body proportions and dysmorphic features) and assessment of the growth curve. The second step consists of screening: a radiograph of the hand and wrist (for bone age and assessment of anatomical abnormalities suggestive for a skeletal dysplasia) and laboratory tests aiming at detecting disorders that can present as isolated short stature (anaemia, growth hormone deficiency, hypothyroidism, coeliac disease, renal failure, metabolic bone diseases, renal tubular acidosis, inflammatory bowel disease, Turner syndrome [TS]). We advise molecular array analysis rather than conventional karyotyping for short girls because this detects not only TS but also copy number variants and uniparental isodisomy, increasing diagnostic yield at a lower cost. Third, in case of diagnostic clues for primary growth disorders, further specific testing for candidate genes or a hypothesis-free approach is indicated; suspicion of a secondary growth disorder warrants adequate further targeted testing.

Losing Track of Lipids in Children and Adolescents with Type 1 Diabetes: Towards Individualized Patient Care

AIM

To assess 1) the prevalence of children and adolescents with type 1 diabetes (T1D) changing from low-risk into borderline-high-risk lipid levels or from borderline-high-risk into high-risk lipid levels ('lose track of lipids') and 2) the power of a risk score including the determinants HbA1c, body mass index (BMI), gender, age, diabetes duration and ethnicity in predicting which patients lose track of lipids.

METHODS

651 children and adolescents with T1D were included in this longitudinal retrospective cohort study. Lipid dynamics and the impact of the risk score on losing track of lipids were evaluated. Kaplan-Meier analysis was used to estimate screening intervals.

RESULTS

31-43% percent of the patients had lost track of one or more lipids at the next lipid measurement. This happened more frequently in patients with a low-risk lipid level at start. Depending on the lipid parameter, 5% of patients with low-risk lipid levels lost track of lipids after 13-23 months. The risk score based on concomitant information on the determinants was moderately able to predict which patients would lose track of lipids on the short term.

CONCLUSIONS

A considerable number of children and adolescents with T1D loses track of lipids and does so within a 2-year screening interval. The predictive power of a risk score including age, BMI, gender, HbA1c, diabetes duration and ethnicity is only moderate. Future research should focus on another approach to the determinants used in this study or other determinants predictive of losing track of lipids on the short term.

Pubertal abnormalities in adolescents with chronic disease

Pubertal disorders in the context of chronic disease especially in those with chronic inflammatory disorders or those requiring prolonged periods of treatment with glucocorticoid are common reasons for referral to the paediatric endocrine clinic. Disorders of puberty are also common in adolescents with disability requiring management by paediatric endocrinologists. In these adolescents, impaired skeletal development is also observed and this can be associated with fragility fractures. Chronic inflammation, glucocorticoid and sub-optimal nutrition all impact on the hypothalamic-pituitary gonadal axis, and can also impact on skeletal development locally by their effects on the growth plate and bone. Addressing pubertal disorders is important to ensure adolescents with chronic disease are matched with their peers, promote adequate bone mass accrual and linear growth. Careful discussion with primary clinicians, the young person and the family is needed when instituting endocrine therapies to address puberty and manage bone health.

Evaluating the four most important salivary sex steroids during male puberty: testosterone best characterizes pubertal development

Background During pubertal development in healthy boys, increased levels of different sex steroids occur which are responsible for sexual maturation and physical changes. However, relationships between various sex hormones and pubertal development stages have not been sufficiently studied. Methods The investigation included 165 normal boys (mean age 12.7±2.8 years, mean body mass index [BMI] 19.6±4.2 kg/m2). Pubic hair (PH) stages were stratified by Tanner and testicular volume (TV) by means of the Prader orchidometer and assigned to the prepubertal, pubertal and postpubertal development phase. Four different sex steroids (testosterone [TE], dehydroepiandrosterone [DHEA]/dehydroepiandrosterone-sulfate [DHEAS], androstenedione (AE), 17-hydroxyprogesterone [17-OHP]) were measured in saliva by enzyme-linked immunosorbent assay (ELISA) and as serum total steroids by different assays (radioimmunoassay [RIA], chemiluminescence immunoassay [CLIA], electrochemiluminescence immunoassay [ECLIA]). Validation of saliva-based ELISA tests included data related to inter- and intra-assay coefficients of variation (CVs), recovery and linearity. Results Using Spearman rank correlation, salivary steroids significantly correlated (p<0.001) with pubertal development: TE (TV r=0.74 and PH stages r=0.72), DHEA (r=0.58 and 0.62), AE (r=0.38 and 0.45) and 17-OHP (r=0.42 and 0.43). Correlations between salivary and serum concentrations of steroids were also statistically significant (p<0.001). Binomial logistic regression analysis revealed significant correlations between salivary TE and pubertal maturation during the development phases of prepuberty-puberty and puberty-postpuberty. Inclusion of further salivary steroids did not improve analysis results. Conclusions Salivary TE permits a good non-invasive characterization of pubertal maturation stages. The consideration of further salivary sex steroids did not improve diagnostic accuracy.

Stretched Penile Length and Testicular Size from Birth to 18 Years in Boys from Western Maharashtra

BACKGROUND

Genital stage and testicular volume examination and assessment are essential for assessment of growth puberty in boys. There is paucity of Indian data for penile and testicular parameters particularly in pubertal years.

AIM

The aim of this study is to present normative data for penile length, testicular volume, and testicular length from birth to 18 years in boys from western Maharashtra and to correlate these parameters with sexual maturity staging (SMR) (Tanner staging).

MATERIALS AND METHODS

A cross-sectional observational study was undertaken in apparently healthy boys from 0 to 18 years of age from western Maharashtra from October 2016 to October 2017. Age, anthropometric parameters, stretched penile length (SPL), testicular volume, and testicular length were measured. Pubertal stage was categorized using Tanner staging. Data were entered in Microsoft excel 2013 and using SPSS version 16. LMS method was used to construct age-specific Z-scores for SPL, testicular volume, and testicular length.

RESULTS

A total of 843 boys were enrolled in the study. Mean SPL was 4.1 ± 0.4, 5.4 ± 0.8, and 10.2 ± 1.7 cm at 1, 10, and 18 years of age, respectively, and showed a gradual rise from birth to 18 years. Mean testicular volume was 1.8 ± 0.5, 3.3 ± 1.2, and 24.1 ± 3.5 ml, whereas testicular length was 1.3 ± 0.4, 2.1 ± 0.5, and 4.4 ± 0.7 cm respectively, at 1, 10, and 18 years, respectively. The magnitude of increase for SPL and testicular volume was greater around 9-10 years. The increase in SPL and testicular size was hand in hand with SMR for genital development as well as for axillary and pubic hair stages.

CONCLUSION

Normative data on SPL, testicular volume, and testicular length from western Maharashtra are presented. These data may be useful in disorders of puberty and genitalia in boys.

Hypogonadotropic hypogonadism and pituitary hypoplasia as recurrent features in Ulnar-Mammary syndrome

Ulnar-mammary syndrome (UMS) is characterized by ulnar defects, and nipple or apocrine gland hypoplasia, caused by TBX3 haploinsufficiency. Signs of hypogonadism were repeatedly reported, but the mechanisms remain elusive. We aim to assess the origin of hypogonadism in two families with UMS. UMS was suspected in two unrelated probands referred to an academic center with delayed puberty because of the evident ulnar ray and breast defects in their parents. Clinical, biochemical and genetic investigations proved the existence of congenital normosmic IHH (nIHH) associated with pituitary hypoplasia in the two probands who were heterozygous for novel TBX3 pathogenic variants. The mutations co-segregated with delayed puberty, midline defects (nose, teeth and tongue anomalies) and other variable features of UMS in the two families (absent axillary hairs and nipple hypoplasia, asymmetrical features including unilateral ulnar or renal abnormalities). The combined analysis of these findings and of the previous UMS reports showed delayed puberty and other signs of hypogonadism in 79 and 37% of UMS males, respectively. Proband 1 was followed up to adulthood with persistence of nIHH. In conclusion, UMS should be suspected in patients with delayed puberty and midline defects, including pituitary hypoplasia, in the presence of mild cues for TBX3 mutation, even in the absence of limb malformations. In addition, TBX3 should be included among candidate genes for congenital nIHH.

A novel IGSF1 mutation in a large Irish kindred highlights the need for familial screening in the IGSF1 deficiency syndrome

OBJECTIVE

Loss-of-function mutations in IGSF1 result in X-linked central congenital hypothyroidism (CeCH), occurring in isolation or associated with additional pituitary hormone deficits. Intrafamilial penetrance is highly variable and a minority of heterozygous females are also affected. We identified and characterized a novel IGSF1 mutation and investigated its associated phenotypes in a large Irish kindred.

DESIGN, PATIENTS AND MEASUREMENTS

A novel hemizygous IGSF1 mutation was identified by direct sequencing in two brothers with CeCH, and its functional consequences were characterized in vitro. Genotype-phenotype correlations were investigated in the wider kindred.

RESULTS

The mutant IGSF1 protein (c.2318T > C, p.L773P) exhibited decreased plasma membrane expression in vitro due to impaired trafficking from the endoplasmic reticulum. Ten hemizygous males and 11 heterozygous females exhibited characteristic endocrine deficits. Ireland operates a TSH-based CH screening programme, which does not detect CeCH; therefore, genetic ascertainment preceded biochemical diagnosis of moderate CH in five of seven boys as well as their 75-year-old grandfather. Clinical features potentially attributable to hypothyroidism were variable; normal free T3 (FT3) and low/low normal reverse T3 (rT3) concentrations suggested that preferential deiodination of FT4 to FT3 may help maintain tissue euthyroidism in some individuals. However, neonatal jaundice, delayed speech or growth, and obesity were observed in seven subjects in whom diagnosis was delayed.

CONCLUSIONS

As observed with other IGSF1 mutations, p.L773P results in variably penetrant IGSF1 deficiency syndrome. Our observations emphasize the need for multi-generation genetic ascertainment in affected families, especially where TSH-based CH screening programmes may fail to detect CeCH at birth.

Central Hypothyroidism and Novel Clinical Phenotypes in Hemizygous Truncation of TBL1X

Transducin β-like 1 X-linked (TBL1X) gene encodes a subunit of the nuclear corepressor-silencing mediator for retinoid and thyroid hormone receptor complex (NCoR-SMRT) involved in repression of thyroid hormone action in the pituitary and hypothalamus. TBL1X defects were recently associated with central hypothyroidism and hearing loss. The current study aims to describe the clinical and genetic characterization of a male diagnosed with central hypothyroidism through thyroid hormone profiling, TRH test, brain MRI, audiometry, and psychological evaluation. Next-generation sequencing of known genes involved in thyroid disorders was implemented. The 6-year-old boy was diagnosed with central hypothyroidism [free T4: 10.42 pmol/L (normal: 12 to 22 pmol/L); TSH: 1.57 mIU/L (normal: 0.7 to 5.7 mIU/L)], with a mildly reduced TSH response to TRH. He was further diagnosed with attention-deficit/hyperactivity disorder (ADHD) at 7 years, alternating episodes of encopresis and constipation, and frequent headaches. MRI showed a normal pituitary but detected a Chiari malformation type I (CMI). At 10 years, audiometry identified poor hearing threshold at high frequencies. Sequencing revealed a nonsense hemizygous mutation in TBL1X [c.1015C>T; p.(Arg339Ter)] largely truncating its WD-40 repeat domain involved in nuclear protein-protein interactions. In conclusion, to our knowledge, we identified the first severely truncating TBL1X mutation in a patient with central hypothyroidism, hypoacusia, and novel clinical features like ADHD, gastrointestinal dysmotility, and CMI. Given the relevance of TBL1X and NCoR-SMRT for the regulation of transcriptional programs at different tissues (pituitary, cochlea, brain, fossa posterior, and cerebellum), severe mutations in TBL1X may lead to a distinct syndrome with a phenotypic spectrum wider than previously reported.

Ultrasound-based measurements of testicular volume in 6- to 16-year-old boys - intra- and interobserver agreement and comparison with Prader orchidometry

BACKGROUND

Prader orchidometry has been the standard method for evaluating testicular size. As this technique is subjective and tends to overestimate the testicular volume, ultrasound (US) has been proposed as more reliable.

OBJECTIVE

To evaluate the intra- and interobserver agreement of US measurements of testicular volume and to compare US with the Prader orchidometer.

MATERIALS AND METHODS

Dimensions of the right testicle were measured using US in 57 boys ages 6.5 to 16.4 years (mean: 12.0 years). The measurements were performed twice by one main observer and once by a second observer. A third observer estimated testicular volume using a Prader orchidometer. Agreement was investigated with Bland-Altman plots, summarized as the mean and standard deviation (SD) of differences, 95% limits of agreement and technical error of measurement.

RESULTS

Mean intra-observer difference of testicular volume was 2.2%, SD=9.2% (limits of agreement: -20.3 to 15.9%) and technical error of measurement 6.5%. The mean interobserver difference was 4.8%, SD=20.7% (limits of agreement: -35.7 to 45.3%) and technical error of measurement 14.6%. Comparing US and orchidometer volumes required conversion that was nonlinear and volume dependent, estimated as Vol_OM = 1.96×Vol_US^0.71. The mean difference after transformation was 0.7% with an SD of 18.0% (limits of agreement: -34.5 to 35.9%).

CONCLUSION

Our results showed a small mean intra- and interobserver difference that indicates the potential of US for measurement of testicular volume at group level. The intra-observer error was limited, which justifies its use in longitudinal follow-up of testicular development in an individual child, but the larger interobserver variability indicates the need for good standardization of methods. Agreement between the two methods requires a power transformation.

2018 European Thyroid Association (ETA) Guidelines on the Diagnosis and Management of Central Hypothyroidism

OBJECTIVES

Central hypothyroidism (CeH) is a rare form of hypothyroidism characterized by insufficient thyroid stimulation due to disturbed pituitary and/or hypothalamic functioning. Due to its origin and the whole clinical context, CeH represents a challenging condition in clinical practice as it is characterized by suboptimal accuracy of clinical and biochemical parameters for diagnosis and management. Since no expert consensus or guidance for this condition is currently available, a task force of experts received the commitment from the European Thyroid Association (ETA) to prepare this document based on the principles of clinical evidence.

STUDY DESIGN

The task force started to work in February 2017 and after a careful selection of appropriate references (cohort studies, case reports, expert opinions), a preliminary presentation and live discussion during the 2017 ETA meeting, and several revision rounds, has prepared a list of recommendations to support the diagnosis and management of patients with CeH.

RESULTS

Due to the particular challenges of this rare condition in the different ages, the target users of this guidance are pediatric and adult endocrinologists. Experts agreed on the need to recognize and treat overt CeH at all ages, whereas treatment of milder forms may be dispensable in the elderly (> 75 years).

CONCLUSIONS

Despite the lack of randomized controlled clinical trials, the experts provide 34 recommendations supported by variable levels of strength that should improve the quality of life of the affected patients and reduce the metabolic and hormonal consequences of inadequate management.

Ultrasound Evaluation of Testicular Volume in Patients with Testicular Microlithiasis

Purpose

Ultrasonography is a useful tool to measure testicular volume. According to the European Society of Urogenital Radiology, the combination of testicular atrophy and testicular microlithiasis (TML) is a risk factor for testicular cancer. Testicular atrophy is defined as a volume of less than 12 ml. The aim of this study was to compare testicular volume in patients with TML to patients with normal testicular tissue.

Materials and Methods

From 2013 to 2015 we included a total of 91 adult patients with TML, and 91 adult patients with normal testicular tissue as a control group. All patients underwent scrotal B-mode ultrasound investigation including measurement of width, length and height in both testicles. Testicular volume was calculated using the formula π/6×length×height×width.

Results

The median age for patients with TML was 48 years (range: 19-94 years), and 48 years (range: 20–75 years) in patients with normal tissue. No statistically significant difference was found between total testicular volume (both testes) >30 ml in patients with TML compared to patients without (OR 0.77 (95% CI 0.43-1.38, p=0.37). However, patients with TML tended to have lower testicular volume compared to patients without TML, when investigating testicular volume below 12 ml.

Conclusion

Overall, no association was found between testicular volume and TML, but there was a trend indicating that severe atrophy is often seen in patients with TML compared to patients without TML. However, a significant difference was only found in testicular volume ≤8 ml.

Mutations in IRS4 are associated with central hypothyroidism

BACKGROUND

Four genetic causes of isolated congenital central hypothyroidism (CeH) have been identified, but many cases remain unexplained. We hypothesised the existence of other genetic causes of CeH with a Mendelian inheritance pattern.

METHODS

We performed exome sequencing in two families with unexplained isolated CeH and subsequently Sanger sequenced unrelated idiopathic CeH cases. We performed clinical and biochemical characterisation of the probands and carriers identified by family screening. We investigated IRS4 mRNA expression in human hypothalamus and pituitary tissue, and measured serum thyroid hormones and Trh and Tshb mRNA expression in hypothalamus and pituitary tissue of Irs4 knockout mice.

RESULTS

We found mutations in the insulin receptor substrate 4 (IRS4) gene in two pairs of brothers with CeH (one nonsense, one frameshift). Sequencing of IRS4 in 12 unrelated CeH cases negative for variants in known genes yielded three frameshift mutations (two novel) in three patients and one male sibling. All male carriers (n=8) had CeH with plasma free thyroxine concentrations below the reference interval. MRI of the hypothalamus and pituitary showed no structural abnormalities (n=12). 24-hour thyroid-stimulating hormone (TSH) secretion profiles in two adult male patients showed decreased basal, pulsatile and total TSH secretion. IRS4 mRNA was expressed in human hypothalamic nuclei, including the paraventricular nucleus, and in the pituitary gland. Female knockout mice showed decreased pituitary Tshb mRNA levels but had unchanged serum thyroid hormone concentrations.

CONCLUSIONS

Mutations in IRS4 are associated with isolated CeH in male carriers. As IRS4 is involved in leptin signalling, the phenotype may be related to disrupted leptin signalling.

Appraisal of testicular volumes: volumes matching ultrasound values referenced to stages of genital development

Background

Testicular volumes obtained with orchidometers or external linear measurements in the scrotum (centimeter ruler or calipers) grossly over-estimate ultrasound volumes, have much variability and may not be accurate or reproducible. The reference of the values obtained by orchidometers or US, to age or Tanner stages is not useful to determine the normal values for stages of puberty, because overlapping of ages and values. Pubertal development is determined by two events, genital and pubic hair development, that should be analyzed independently because one could be out of step with the other. The ultrasound (US) measurement of testicular volumes is the gold standard but is somewhat inconvenient, because it requires another procedure and, mainly, is costly.

The solution of the problems would be to determine testicular volumes matching US values, from the width of the testis obtained in the scrotum with a centimeter ruler, by formulas recently described, and to reference them to the stages of genital development.

Methods

The width and length of the testes in the scrotum with a centimeter ruler were obtained in 159 study subjects, in different stages of genital development and adults, for a total of 318 testicular determinations, from the age of 3 to 34 years. The width obtained in the scrotum was corrected by subtracting the values of the double scrotal skin (ss). The formulas were then applied and the testicular volumes matching US values were calculated. The volumes and the range of ages for different stages of genital development were determined. Penile measurements were obtained in 145 subjects and pubic and other hair recorded.

Paired and unpaired 2 tail student t-test was used to compare the means of the different groups expressed as means and SD and, in addition the Wilcoxon rank sum test and Bootstrap methods for the testicular volume groups. A p value of 0.05 or less was considered significant.

The Institutional Review Board (IRB) of Nationwide Children’s Hospital determined that this study did not require IRB approval.

Results

With a simple measurement of the width of the testis in the scrotum, with a centimeter ruler, testicular volumes matching US values were calculated and normative values for each stage of genital development were determined.

Conclusion

This information should solve present problems.

Electronic supplementary material

The online version of this article (doi:10.1186/s13633-017-0046-x) contains supplementary material, which is available to authorized users.

Testicular growth and development in puberty

PURPOSE OF REVIEW

To describe pubertal testicular growth in humans, changes in testicular cell populations that result in testicular growth, and the role of testosterone and gonadotrophins follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in testicular growth. When human data were not available, studies in nonhuman primates and/or rodents were used as surrogates.

RECENT FINDINGS

Testicular growth in puberty follows a sigmoidal growth curve, with a large variation in timing of testicular growth and adult testicular volume. Testicular growth early in puberty is due to increase in Sertoli cell number and length of seminiferous tubules, whereas the largest and fastest growth results from the increase in the diameter of the seminiferous tubules first due to spermatogonial proliferation and then due to the expansion of meiotic and haploid germ cells. FSH stimulates Sertoli cell and spermatogonial proliferation, whereas LH/testosterone is mandatory to complete spermatogenesis. However, FSH and LH/testosterone work in synergy and are both needed for normal spermatogenesis.

SUMMARY

Testicular growth during puberty is rapid, and mostly due to germ cell expansion and growth in seminiferous tubule diameter triggered by androgens. Pre-treatment with FSH before the induction of puberty may improve the treatment of hypogonadotropic hypogonadism, but remains to be proven.

A Novel IGSF1 Mutation in a Boy With Short Stature and Hypercholesterolemia: A Case Report

Context

IGSF1 deficiency is a recently discovered syndrome consisting of congenital central hypothyroidism (CeH) and macroorchidism. Here, we report on a patient presenting with short stature, who was found to carry a pathogenic mutation in the IGSF1 gene.

Case Description

A 14-year-old Israeli boy was referred to the Academic Medical Center in Amsterdam, The Netherlands, for follow-up on short stature ascribed to constitutional delay of growth and puberty, and familial hypercholesterolemia. Primary hypothyroidism had previously been excluded by a normal thyroid-stimulating hormone (TSH) concentration. However, in follow-up, plasma free thyroxine (FT4) concentrations were repeatedly low, and the patient was diagnosed with CeH. Because of coexistent relative macroorchidism, IGSF1 gene analysis was performed, revealing a mutation (c.2588C>G; p.Ser863Cys). The mutant IGSF1 protein was retained mainly in the endoplasmic reticulum and reached the plasma membrane with poor efficiency compared with wild-type protein. After starting thyroxine treatment, plasma cholesterol almost normalized.

Conclusions

This case illustrates the necessity of measuring both FT4 and TSH when hypothyroidism is suspected, or needs to be ruled out. In addition, this case suggests that the presence of childhood hypercholesterolemia may be an indication of undiagnosed hypothyroidism.

The syndrome of central hypothyroidism and macroorchidism: IGSF1 controls TRHR and FSHB expression by differential modulation of pituitary TGFβ and Activin pathways

IGSF1 (Immunoglobulin Superfamily 1) gene defects cause central hypothyroidism and macroorchidism. However, the pathogenic mechanisms of the disease remain unclear. Based on a patient with a full deletion of IGSF1 clinically followed from neonate to adulthood, we investigated a common pituitary origin for hypothyroidism and macroorchidism, and the role of IGSF1 as regulator of pituitary hormone secretion. The patient showed congenital central hypothyroidism with reduced TSH biopotency, over-secretion of FSH at neonatal minipuberty and macroorchidism from 3 years of age. His markedly elevated inhibin B was unable to inhibit FSH secretion, indicating a status of pituitary inhibin B resistance. We show here that IGSF1 is expressed both in thyrotropes and gonadotropes of the pituitary and in Leydig and germ cells in the testes, but at very low levels in Sertoli cells. Furthermore, IGSF1 stimulates transcription of the thyrotropin-releasing hormone receptor (TRHR) by negative modulation of the TGFβ1-Smad signaling pathway, and enhances the synthesis and biopotency of TSH, the hormone secreted by thyrotropes. By contrast, IGSF1 strongly down-regulates the activin-Smad pathway, leading to reduced expression of FSHB, the hormone secreted by gonadotropes. In conclusion, two relevant molecular mechanisms linked to central hypothyroidism and macroorchidism in IGSF1 deficiency are identified, revealing IGSF1 as an important regulator of TGFβ/Activin pathways in the pituitary.

Associations of Peripubertal Serum Dioxin and Polychlorinated Biphenyl Concentrations with Pubertal Timing among Russian Boys

BACKGROUND

Dioxins, furans, and polychlorinated biphenyls (PCBs), dioxin-like and non-dioxin-like, have been linked to alterations in puberty.

OBJECTIVES

We examined the association of peripubertal serum levels of these compounds [and their toxic equivalents (TEQs)] with pubertal onset and maturity among Russian boys enrolled at ages 8-9 years and followed prospectively through ages 17-18 years.

METHODS

At enrollment, 473 boys had serum dioxin-like compounds and PCBs measured. At the baseline visit and annually until age 17-18 years, a physician performed pubertal staging [genitalia (G), pubarche (P), and testicular volume (TV)]. Three hundred fifteen subjects completed the follow-up visit at 17-18 years of age. Pubertal onset was defined as TV > 3 mL, G2, or P2. Sexual maturity was defined as TV ≥ 20 mL, G5, or P5. Multivariable interval-censored models were used to evaluate associations of lipid-standardized concentrations with pubertal timing.

RESULTS

Medians (interquartile ranges) of the sum of dioxin-like compounds, TEQs, and non-dioxin-like PCBs were 362 pg/g lipid (279-495), 21.1 pg TEQ/g lipid (14.4-33.2), and 250 ng/g lipid (164-395), respectively. In adjusted models, the highest compared to lowest TEQ quartile was associated with later pubertal onset [TV = 11.6 months (95% CI: 3.8, 19.4); G2 = 10.1 months (95% CI: 1.4, 18.8)] and sexual maturity [TV = 11.6 months (95% CI: 5.7, 17.6); G5 = 9.7 months (95% CI: 3.1, 16.2)]. However, the highest compared to the lowest quartile of non-dioxin-like PCBs, when co-adjusted by TEQs, was associated with earlier pubertal onset [TV = -8.3 months (95% CI:-16.2, -0.3)] and sexual maturity [TV = -6.3 months (95% CI:-12.2, -0.3); G5 = -7.2 months (95% CI:-13.8, -0.6)]; the non-dioxin-like PCB associations were only significant when adjusted for TEQs. TEQs and PCBs were not significantly associated with pubic hair development.

CONCLUSIONS

Our results suggest that TEQs may delay, while non-dioxin-like PCBs advance, the timing of male puberty. Citation: Burns JS, Lee MM, Williams PL, Korrick SA, Sergeyev O, Lam T, Revich B, Hauser R. 2016. Associations of peripubertal serum dioxin and polychlorinated biphenyl concentrations with pubertal timing among Russian boys. Environ Health Perspect 124:1801-1807; http://dx.doi.org/10.1289/EHP154.

Anti-Müllerian hormone as a marker of steroid and gonadotropin action in the testis of children and adolescents with disorders of the gonadal axis

In pediatric patients, basal testosterone and gonadotropin levels may be uninformative in the assessment of testicular function. Measurement of serum anti-Müllerian hormone (AMH) has become increasingly widespread since it provides information about the activity of the male gonad without the need for dynamic tests, and also reflects the action of FSH and androgens within the testis. AMH is secreted in high amounts by Sertoli cells from fetal life until the onset of puberty. Basal AMH expression is not dependent on gonadotropins or sex steroids; however, FSH further increases and testosterone inhibits AMH production. During puberty, testosterone induces Sertoli cell maturation, and prevails over FSH on AMH regulation. Therefore, AMH production decreases. Serum AMH is undetectable in patients with congenital or acquired anorchidism, or with complete gonadal dysgenesis. Low circulating levels of AMH may reflect primary testicular dysfunction, e.g. in certain patients with cryptorchidism, monorchidism, partial gonadal dysgenesis, or central hypogonadism. AMH is low in boys with precocious puberty, but it increases to prepubertal levels after successful treatment. Conversely, serum AMH remains at high, prepubertal levels in boys with constitutional delay of puberty. Serum AMH measurements are useful, together with testosterone determination, in the diagnosis of patients with ambiguous genitalia: both are low in patients with gonadal dysgenesis, including ovotesticular disorders of sex development, testosterone is low but AMH is in the normal male range or higher in patients with disorders of androgen synthesis, and both hormones are normal or high in patients with androgen insensitivity. Finally, elevation of serum AMH above normal male prepubertal levels may be indicative of rare cases of sex-cord stromal tumors or Sertoli cell-limited disturbance in the McCune Albright syndrome.

Mild deficits in attentional control in patients with the IGSF1 deficiency syndrome

OBJECTIVE

Male patients with the X-linked IGSF1 deficiency syndrome are characterized by central hypothyroidism, delayed pubertal testosterone rise, adult macroorchidism, variable prolactin deficiency and occasionally transient partial growth hormone deficiency. Thyroid hormone plays a vital role in brain development and functioning, and while most patients receive adequate replacement therapy starting shortly after birth, it is unknown whether this syndrome is accompanied by long-term impaired cognitive functioning. We therefore assessed cognitive functioning in male patients with IGSF1 deficiency.

METHODS

Fifteen adult male patients with IGSF1 deficiency participated in neuropsychological assessment of executive functioning and memory, and completed validated questionnaires on health-related quality of life (HRQoL), mood and fatigue. Results were compared to data from previous studies by our department: 54 healthy controls (76 for the attention task) for the test battery and 191 healthy controls for the questionnaires.

RESULTS

All patients had central hypothyroidism, and twelve were treated with levothyroxine. Patients performed worse than controls in tasks that required attentional control (Trail Making Test, Letter-Digit Substitution Test, and Sustained Attention to Response Task) (all P < 0·001). Memory was unaffected. In addition, patients reported more mental fatigue and reduction of activity (Multidimensional Fatigue Inventory) (both P < 0·01), while HRQoL and mood reports were not different from controls. Age at the start of replacement therapy and current thyroxine levels were not related to outcome.

CONCLUSIONS

Adult male patients with IGSF1 deficiency exhibit mild deficits in attentional control on formal testing. This finding was not related to the age at start of replacement therapy, or current levothyroxine treatment.

Testicular hypertrophy as a predictor for contralateral monorchism: Retrospective review of prospectively recorded data

OBJECTIVES

Testicular hypertrophy has previously been evaluated as a predictor of monorchism. However, its implication in clinical practice is not well evaluated. The aim of the present study was to examine its value in planning the operative time.

PATIENTS AND METHODS

Medical charts of prospectively recorded data of 76 consecutive patients with unilateral impalpable testis from 2011 to 2014 were reviewed at the present institute. Inclusion criteria included prepubertal patients with non-palpable testes by examination under anesthesia. Contralateral testes were prospectively measured using a Takihara orchidometer. Orchiectomy or orchiopexy was performed according to the viability of the undescended testis (UDT). Collected data included age of surgery, contralateral testicular size, surgical time and laparoscopic findings. A ROC curve was used to define the best cut-off volume of the contralateral testis that can predict ipsilateral testicular viability. The Student's t-test was used to examine if this cut-off volume would be useful in allocating the operative time.

RESULTS

Of 76 patients, four palpable testes by examination under anesthesia were excluded. The remaining 72 patients were included in the study. Ipsilateral normal viable testes were found in 26 (36.1%) patients, while 46 (63.9%) had non-viable testes (testicular nubbins or vanishing testes) (Figure). A contralateral testicular volume > 2 ml was significantly predictive for monorchism with 71.7% sensitivity and 100% specificity (P < 0.001). The mean operative time for management of UDT with a contralateral size >2 ml was 50 min, which was significantly shorter than that for UDT with a contralateral size ≤ 2 ml, which was 88 min (P < 0.001).

DISCUSSION

In previously published reports, the cut-off value for testicular hypertrophy that predicts monorchism greatly varied. This is likely due to the different methods used for testicular measurements that make it impractical to make a direct comparison. The usefulness of predicting monorchism before surgery has not previously been used as a guide for allocating operative time in the management of a unilateral non-palpable testicle. This study had some limitations, including a relatively small sample size and involvement of different surgeons, which may have affected the operative time.

CONCLUSION

Using the cut-off volume of a contralateral testis >2 ml as a predictor for monorchism can reduce the allocated operative time by approximately one third.

Pituitary Hormone Secretion Profiles in IGSF1 Deficiency Syndrome

BACKGROUND

Loss-of-function mutations in immunoglobulin superfamily member 1 (IGSF1) cause an X-linked syndrome of central hypothyroidism, macroorchidism, delayed pubertal testosterone rise, variable prolactin deficiency and variable partial GH deficiency in childhood. The clinical features and gene expression pattern suggest a pivotal role for IGSF1 in the pituitary, but detailed knowledge on pituitary hormone secretion in this syndrome is lacking. We therefore aimed to study the 24-hour pituitary hormone secretion in male patients with IGSF1 deficiency.

METHODS

We collected blood samples every 10 min for 24 h in eight adult male IGSF1-deficient patients and measured circulating TSH, prolactin and gonadotropins. Deconvolution, modified cosinor and approximate entropy analyses were applied to quantify secretion rates, diurnal rhythmicity and regularity of hormone release. Results were compared to healthy controls matched for age and body mass index.

RESULTS

Compared to healthy controls, IGSF1-deficient patients showed decreased pulsatile secretion of TSH with decreased disorderliness and reduced diurnal variation. Basal and pulsatile secretion of FSH was increased by over 200%, while LH secretion did not differ from healthy controls. We observed a bimodal distribution of prolactin secretion, i.e. severe deficiency in three and increased basal and total secretion in the other five patients.

CONCLUSION

The altered TSH secretion pattern is consistent with the previously hypothesized defect in thyrotropin-releasing hormone signaling in IGSF1 deficiency. However, the phenotype is more extensive and includes increased FSH secretion without altered LH secretion as well as either undetectable or increased prolactin secretion.