Sensitive RIA measures testosterone concentrations in prepubertal and pubertal children comparable to tandem mass spectrometry.

BACKGROUND: Immunoassays have been criticized for poor accuracy at low testosterone concentrations. Mass spectrometry (MS) has been proposed as the only reliable method for testosterone determination. The aim of this study was to compare a sensitive testosterone radioimmunoassay (RIA) with results from different MS. METHODS: We compared testosterone concentrations determined by a sensitive testosterone RIA, lower limit of detection 0.03 nmol/L and limit of quantitation 0.1 nmol/L, with four tandem MS that were included in an international external quality assessment program for laboratory medicine. We also compared the morning concentrations of testosterone in girls and boys at different pubertal stages, using results from the RIA, with reported values determined by LC-MS/MS, developed for androgen determination in children. RESULTS: The mean (SD), concentrations were similar between RIA and MS: 1.5 (0.3) and 1.4 (0.4) in the child/women range (0.8-2.6 nmol/L) and 16.0 (3.7) and 17.8 (4.5) nmol/L for the adult male range (10.1-30.0 nmol/L), respectively. The ratio between RIA and MS versus results from mean values of the four MS methods was 1.0 (0.18); 1.1 (0.18) for child/women concentrations and 0.9 (0.13) for male testosterone concentrations. Furthermore, compared to the pediatric reference values determined by LC-MS/MS, the sensitive testosterone RIA delivered similar testosterone values across the different pubertal stages. CONCLUSIONS: The comparison between different tandem MS methods and a sensitive testosterone RIA illustrates that there are immunoassays that deliver clinically useful information in prepubertal and pubertal children.

Comparison of methods for evaluation of the suppressive effects of prednisolone on the HPA axis and bone turnover: changes in s-DHEAS are as sensitive as the ACTH test.

OBJECTIVE: Different hypothalamic-pituitary-adrenal (HPA) axis function tests are used for diagnosing disease and evaluating suppressive effects of corticosteroid treatment. Our objectives were to evaluate sensitivity and precision of different HPA axis tests to be able to select one that combines good performance with good practicability, suitable for investigation of new corticosteroids in clinical trials. METHODS: In this descriptive, double-blind, parallel-group study, 60 healthy male volunteers were treated with once-daily morning doses of prednisolone for 2 weeks. The volunteers were randomized to 1 of 5 treatment groups (prednisolone 2.5, 5, 7.5, 10, or 15 mg). We compared the plasma-cortisol (p-cortisol) 24-hour average concentration (Cav) with morning (08:00 hours) p-cortisol, daytime p-cortisol Cav, and 24-hour urinary cortisol excretion. Adrenocorticotrophic hormone (ACTH) stimulation tests and the metyrapone test were also performed. Furthermore, we analyzed levels of serum dehydroepiandrosterone sulfate (s-DHEAS), insulin, and markers of bone turnover. RESULTS: Dose-related effects were shown, but the magnitude of effects and sensitivities varied greatly between the tests. P-cortisol measurements over the course of 24 hours were used as the reference method. Low- and standard-dose ACTH tests and morning s-DHEAS levels had similar sensitivity. Urinary cortisol excretion and the metyrapone stimulation test had low sensitivity. The effects of prednisolone on markers of bone turnover were, in general, less than those on the HPA axis. Only osteocalcin, procollagen Type 1 C-peptide and procollagen Type 3 N-peptide were significantly affected. Treatment with prednisolone was well tolerated. CONCLUSION: Changes in s-DHEAS and the low-dose ACTH test combine good sensitivity and precision for evaluation of the suppressive effect of exogenous corticosteroids on the HPA axis, and they are easy to perform.

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.

Longitudinal assessment of bone mineral density in children and adolescents with inflammatory bowel disease.

OBJECTIVES: Low bone mineral density (BMD) is recognized as a potential problem in children with inflammatory bowel disease (IBD). We aimed to describe the longitudinal development of BMD in a population of Swedish pediatric patients with IBD. METHODS: A total of 144 patients with IBD (93 males; 83 with ulcerative colitis [UC], 45 with Crohn disease [CD]) were examined with dual-energy x-ray absorptiometry at baseline. At follow-up 2 years later, 126 of the initial 144 patients were reexamined. BMD values are expressed as z scores. RESULTS: Children with UC and CD had significantly lower mean BMD z scores for the lumbar spine (LS) at baseline and after 2 years. The reduction in BMD was equally pronounced in patients with UC and CD, and neither group improved their z score during the follow-up period. Furthermore, significantly lower mean BMD z scores for the LS were found at baseline in boys (-1.1 SD, ±2.7 SD, P < 0.001), but not in girls (-0.0 SD, ±3.0 SD). This finding remained unchanged at follow-up. Subanalyses of the different age groups at baseline showed the lowest BMD values in the group of patients ages 17 to 19 years in boys (mean z score for the LS 1.59 SD, ±3.1 SD) and in girls (mean z score for the LS -3.40 SD, ±3.1 SD); however, at follow-up, these patients had improved their BMD significantly (mean change z score for the LS 1.00 SD, 95% CI 0.40-1.60; 1.90 SD, 95% CI 0.60-3.20). CONCLUSIONS: In this longitudinal study, the entire group of pediatric patients with IBD showed permanent decreases in their BMD z scores for the LS; however, our data indicate that afflicted children have the potential to improve their BMD by the time they reach early adulthood.

Tolerability, pharmacokinetics, and pharmacodynamics of the glucokinase activator AZD1656, after single ascending doses in healthy subjects during euglycemic clamp.

OBJECTIVES: AZD1656 is a novel glucokinase activator with a postulated dual mechanism of action by activating glucokinase in both the pancreas and the liver, and with the potential to deliver effective glucose-lowering in Type 2 diabetes mellitus. Here, we present the tolerability, pharmacokinetics and pharmacodynamics of AZD1656 in two single-blind, randomized, placebo-controlled studies, one with Western and the other with Japanese healthy adult male subjects. METHODS: Both studies evaluated oral single ascending doses of AZD1656 of up to 180 mg, administered during euglycemic clamp conditions to explore a wide dose range without risking hypoglycemia. Safety, pharmacokinetics and effects on serum insulin and glucose infusion rate were assessed. A population pharmacokinetics analysis was also conducted. RESULTS: AZD1656 was well tolerated in single doses up to 180 mg in both populations. AZD1656 was rapidly absorbed, and a dose-proportional increase in total exposure was observed for AZD1656 and the equipotent metabolite, AZD5658. Taking differences in body weight into account, there were no differences in pharmacokinetic parameters between Western and Japanese subjects. A dose-dependent blood glucose lowering effect was indirectly demonstrated by the increased glucose infusion rate required to maintain euglycemia, which was of similar magnitude in both populations. Dose-dependent increases in insulin secretion were also observed. CONCLUSIONS: No safety concerns were raised. AZD1656 displayed uncomplicated pharmacokinetics and dose-dependent pharmacodynamics effects were observed. The results suggest no ethnic differences in AZD1656 tolerability, pharmacokinetics or pharmacodynamics.

Efficacy and safety of dapagliflozin in children and young adults with type 2 diabetes: a prospective, multicentre, randomised, parallel group, phase 3 study.

BACKGROUND: Since there are few treatment options for young people with type 2 diabetes, we aimed to assess the efficacy and safety of dapagliflozin as add-on therapy in children, adolescents, and young adults with type 2 diabetes receiving metformin, insulin, or both. METHODS: This multicentre, placebo-controlled, double-blind, randomised phase 3 study was undertaken at 30 centres in five countries (Hungary, Israel, Mexico, Russia, and the USA). Participants aged 10-24 years with type 2 diabetes and HbA1c concentration of 6·5-11% (48-97 mmol/mol) were randomly assigned 1:1 to oral dapagliflozin 10 mg or placebo during a 24 week double-blind period, which was then followed by a 28 week open-label safety extension in which all participants received dapagliflozin. Participants and study personnel were masked and participants were randomly assigned treatment (placebo or study drug) using an interactive web and voice response system. The primary outcome was between-group differences in change in HbA1c concentration from baseline to 24 weeks (intention-to-treat analysis). A prespecified sensitivity analysis of the primary outcome was also assessed in the per-protocol population, which included only protocol-compliant participants. This trial is registered with ClinicalTrials.gov, NCT02725593. FINDINGS: Between June 22, 2016, and March 15, 2019, 72 participants (19 [26%] of whom were aged 18-24 years) were randomly assigned (39 to dapagliflozin and 33 to placebo). Mean age was 16·1 (SD 3·3) years. In the intention-to-treat analysis, after 24 weeks, mean change in HbA1c concentration was -0·25% (95% CI -0·85 to 0·34; -2·7 [-9·3 to 3·7] mmol/mol) for dapagliflozin and 0·50% (-0·18 to 1·17; 5·5 [-2·0 to 12·8] mmol/mol) for placebo. The between-group difference was -0·75% (95% CI -1·65 to 0·15; -8·2 [-18·0 to 1·6] mmol/mol; p=0·10). In a sensitivity analysis in the per-protocol population (34 in the dapagliflozin group and 26 in the placebo group) after 24 weeks, mean change was -0·51% (-1·07 to 0·05; -5·6 [-11·7 to 0·5] mmol/mol) for dapagliflozin and 0·62% (-0·04 to 1·27; 6·8 [-0·4 to 13·9] mmol/mol) for placebo. The between-group difference was -1·13% (-1·99 to -0·26; -12·4 [-21·8 to -2·8] mmol/mol; p=0·012). Adverse events occurred in 27 (69%) dapagliflozin-assigned participants and 19 (58%) placebo-assigned participants over 24 weeks, and in 29 (74%) participants who received dapagliflozin over 52 weeks. Hypoglycaemia occurred in 11 (28%) dapagliflozin-assigned and six (18%) placebo-assigned participants who received dapagliflozin over 24 weeks and in 13 participants (33%) who received dapagliflozin over 52 weeks; none were considered as serious adverse events. No adverse events of diabetic ketoacidosis occurred. INTERPRETATION: The primary outcome of change in HbA1c concentration was not significant in the intention-to-treat analysis of children, adolescents, and young adults with type 2 diabetes receiving dapagliflozin in addition to standard-of-care treatment. A prespecified sensitivity analysis of protocol-compliant participants showed a significant difference in HbA1c concentration between groups. No new safety signals were identified and there was a low risk of severe hypoglycaemia. FUNDING: AstraZeneca.

Pubertal timing predicts leg length and childhood body mass index predicts sitting height in young adult men.

OBJECTIVE: To investigate the impact of pubertal timing and childhood body mass index (BMI), both within normal range, on adult anthropometrics. STUDY DESIGN: Detailed growth charts were retrieved for the men participating in the population-based Gothenburg Osteoporosis and Obesity Determinants study. Age at peak height velocity and childhood BMI were calculated (n = 527), and anthropometric measurements were performed. RESULTS: Analysis of variance analysis of tertiles according to age at peak height velocity demonstrated that the early peak height velocity tertile had a lower adult height (180.9 ± 6.8 cm) compared with the middle tertile group (182.7 ± 6.9 cm, P < .05), and this difference was attributable to shorter leg length. No difference was seen for sitting height. In contrast, analysis of tertiles according to childhood BMI demonstrated low sitting height in the low BMI tertile (93.7 ± 3.3 cm for low, 94.6 ± 3.3, for middle, and 94.8 ± 3.3 cm for high childhood BMI tertiles, P < .05 and P < .01, respectively), but childhood BMI did not affect adult height and leg length. CONCLUSION: We demonstrate that subjects with early pubertal timing have reduced adult height and leg length, and subjects with low childhood BMI have reduced adult sitting height. Thus childhood body composition and pubertal timing have different impact on trunk growth and growth of long bones.

Familial resemblance of bone mineral density in children with inflammatory bowel disease.

BACKGROUND AND AIM: Low bone mineral density (BMD) has recently been recognized as a potential health problem in children with inflammatory bowel disease (IBD). Our aim was to investigate the familial resemblance of BMD in pediatric patients with IBD. PATIENTS AND METHODS: In this population-based study from western Sweden, we assessed 144 children with IBD, 83 with ulcerative colitis, 45 with Crohn disease, 16 with indeterminate colitis, and their parents (136 mothers and 130 fathers) with dual-energy X-ray absorptiometry (DEXA). After adjustment for sex, age, weight, height, and parental IBD, we correlated the BMD of the patients to the BMD of their mothers, fathers, and the midparent value ([mother's BMD + father's BMD]/2) at different skeletal sites and calculated the Pearson correlation coefficient (r) to evaluate the extent of familial resemblance. RESULTS: The BMD of the children with IBD was clearly related to the BMD of their parents. The strongest correlation was found in the femoral neck with r = 0.55 (P < 0.001, 95% CI 0.41-0.66) between BMD of the children and the midparent value. The group of children with IBD had an odds ratio of 5.96 for decreased BMD (lumbar spine z score < -1 standard deviation) given that decreased BMD was diagnosed in both parents. CONCLUSIONS: We conclude that BMD in children and adolescents with IBD is significantly related to that of their parents. In a clinical setting, it may be helpful to assess the parents of children with IBD with DEXA to interpret the children's DEXA measurements.

Correction to: How is the Pharmaceutical Industry Structured to Optimize Pediatric Drug Development? Existing Pediatric Structure Models and Proposed Recommendations for Structural Enhancement.

The article How is the Pharmaceutical Industry Structured to Optimize Pediatric Drug Development? Existing Pediatric Structure Models and Proposed Recommendations for Structural Enhancement, written by Thomas Severin et al. was originally published electronically on the publisher's internet portal on February 6, 2020 without open access. With the author(s)' decision to opt for Open Choice the copyright of the article changed on April 22, 2020 to © The Author(s) 2020 and the article is forthwith distributed under a Creative Commons Attribution 4.0 International License https://creativecommons.org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

How is the Pharmaceutical Industry Structured to Optimize Pediatric Drug Development? Existing Pediatric Structure Models and Proposed Recommendations for Structural Enhancement.

BACKGROUND: Pediatric regulations enacted in both Europe and the USA have disrupted the pharmaceutical industry, challenging business and drug development processes, and organizational structures. Over the last decade, with science and innovation evolving, industry has moved from a reactive to a proactive mode, investing in building appropriate structures and capabilities as part of their business strategy to better tackle the challenges and opportunities of pediatric drug development. METHODS: The EFGCP Children's Medicines Working Party and the IQ Pediatric working group have joined their efforts to survey their member company representatives to understand how pharmaceutical companies are organized to fulfill their regulatory obligations and optimize their pediatric drug development programs. RESULTS: Key success factors and recommendations for a fit-for-purpose Pediatric Expert Group (PEG) were identified. CONCLUSION: Pediatric structures and expert groups were shown to be important to support optimization of the development of pediatric medicines.

Prevalence of Premature Thelarche at 18 Months of Age: A Population- and Hospital-Based Study of Prevalence and Incidence in Girls Born at Northern Älvsborg County Hospital in Sweden.

OBJECTIVE: The aim of this work was to investigate the prevalence of premature thelarche (PT) in 18-month-old girls, and the incidence of clinically evaluated PT for girls aged 18-36 months. METHODS: In the prevalence substudy, a prospective population-based cohort of 3,140 girls born at Northern Älvsborg county hospital (NÄL) in Trollhättan, Sweden, was followed for 2 years. Girls with breast development at the 18-month health check were referred to one pediatric center in NÄL for evaluation. All girls with PT were included and followed for clinical outcome and 17ß-estradiol. The prospective incidence substudy covered 8 years in a 10-year period and included all girls aged 18-36 months born at NÄL who were clinically evaluated for PT. RESULTS: The prevalence of PT at 18 months in our cohort was 1.6/1,000. The 5 girls with PT no longer showed symptoms at the follow-up 3-6 months later. The incidence was 1.1/1,000 for girls aged 18-36 months and 1.0/1,000 for girls aged 18-30 months who were clinically evaluated for their PT. CONCLUSION: This is the first prospective population-based study of PT and it shows a prevalence of PT at age 18 months of 1.6/1,000. The incidence of clinically evaluated PT was 1.1/1,000. Our result is in line with other studies reporting the incidence of PT from medical records (0.4-40/1,000). The outcome of PT in our study, as in the other studies, is that the great majority of girls show only benign symptoms.

Twenty-four hours secretion pattern of serum estradiol in healthy prepubertal and pubertal boys as determined by a validated ultra-sensitive extraction RIA.

BACKGROUND: The role of estrogens in male physiology has become evident. However, clinically useful normative data for estradiol secretion in boys has not previously been established due to the insensitivity of current methods used in clinical routine. By use of a validated ultra-sensitive extraction RIA, our aim was to establish normative data from a group consisting of healthy boys in prepuberty and during pubertal development. METHODS: Sixty-two 24-hours serum profiles (6 samples/24 hours) were obtained from 44 healthy boys (ages; 7.2-18.6 years) during their pubertal development, classified into five stages: prepuberty (testis, 1-2 mL), early (testis, 3-6 mL), mid (testis, 8-12 mL), late-1 (testis,15-25 mL, not reached final height) and late-2 (testis,15-25 mL, reached final height). Serum estradiol was determined by an ultra- sensitive extraction radioimmunoassay with detection limit 4 pmol/L and functional sensitivity 6 pmol/L. RESULTS: Mean estradiol concentrations during 24-hours secretion increased from prepuberty (median: <4 (5-95 percentiles: <4 - 7) pmol/L) to early puberty (6 (<4 - 12 pmol/L) but then remained relatively constant until a marked increase between mid-puberty (8 (4 - 17) pmol/L) and late-1 (21 (12 - 37) pmol/L) puberty, followed by a slower increase until late-2 puberty (32 (20 - 47) pmol/L). The diurnal rhythm of serum estradiol was non-measurable in pre- and early puberty, but discerned in mid-puberty, and become evident in late pubertal stages with peak values at 0600 to 1000 h. CONCLUSION: With the use of an ultra-sensitive extraction RIA, we have provided clinically useful normative data for estradiol secretion in boys.

Pubertal timing is an independent predictor of central adiposity in young adult males: the Gothenburg osteoporosis and obesity determinants study.

The role of puberty and normal variations in pubertal timing for the development of obesity in men is unclear. The aim of the current study was to investigate the impact of pubertal timing and prepubertal BMI (kg/m(2)) for young adult BMI and fat mass distribution. Detailed growth charts from birth to age 18-20 years were retrieved for the men participating in the population-based Gothenburg Osteoporosis and Obesity Determinants study. Age at peak height velocity (PHV) and BMI at age 10 years were estimated for 579 subjects, and PHV was used as an assessment of pubertal timing. The fat mass characterization and distribution were analyzed using dual X-ray absorptiometry and peripheral as well as abdominal computed tomography at age 18.9 +/- 0.5 years. We demonstrate that age at PHV is an independent negative predictor of young adult BMI and whole-body fat mass. Interestingly, age at PHV is an independent negative predictor of central, but not peripheral, fat mass. In contrast, BMI at 10 years of age predicts both central and peripheral subcutaneous fat mass. In conclusion, we demonstrate that early pubertal onset specifically predicts a central fat mass distribution, while a predominantly subcutaneous obese phenotype is strongly predicted by a high prepubertal BMI.

17ß-Estradiol and Gonadotropin Levels for the Diagnosis of the Benign Form of Breast Development in Girls Aged up to 4 Years in Real-Life Clinical Practice.

BACKGROUND: Early onset of breast development in a young girl is usually a benign and isolated prepubertal condition, i.e., premature thelarche (PT), but can sometimes be progressive and the first sign of pubertal precocity (PP). Serum 17ß-estradiol (17ß-E2) level is a possible marker to differentiate between benign and pathological forms of breast development. We defined an upper serum 17ß-E2 level for benign, "classic" PT for girls aged 9-48 months. METHODS: Serum 17ß-E2 was analysed with a highly sensitive extraction radioimmunoassay (RIA). Gonadotropins, Tanner breast stage, growth, other investigations, and clinical outcome were assessed in 125 girls with breast development, in a population-based study in West Sweden. RESULTS: A total of 125 of 128 girls had a benign form of breast development with a mean serum 17ß-E2 level of 15.2 pmol/L and a mean + 2 SD of 31 pmol/L, which was regarded as the upper limit for benign PT; 3 girls with PP had 17ß-E2 levels above 70 pmol/L. CONCLUSION: This is the first study to define an upper serum 17ß-E2 level associated with benign PT. Girls aged 9-48 months with PT and Tanner breast stage 2 have 17ß-E2 levels below 32 pmol/L using extraction RIA. LH below the detection limit (0.1 IU/L) and measurable FSH support benign PT.

Pubertal timing predicts previous fractures and BMD in young adult men: the GOOD study.

UNLABELLED: The importance of pubertal timing for adult BMD in males was studied through association of pubertal timing with young adult bone phenotype. Pubertal timing was found to predict both cortical and trabecular volumetric BMD and previous fractures in young adult men. Thus, late puberty is a risk factor for low BMD and previous fractures in young adult men. INTRODUCTION: Peak bone mass (PBM), achieved during puberty, is a determinant of the risk for osteoporosis and future fractures. The role of variations within the normal range in pubertal timing for fractures during pubertal development and for adult bone mass in men is unknown. MATERIALS AND METHODS: The aim of this study was to investigate the importance of pubertal timing for adult BMD and for fractures before achievement of PBM in men. The population-based Gothenburg Osteoporosis and Obesity Determinants (GOOD) study is a well-characterized cohort of young adult Swedish males 18-20 years of age. Detailed growth charts from birth to 18-20 years of age were retrieved for 642 men participating in the GOOD study. Age at peak height velocity (PHV) was estimated and used as an assessment of pubertal timing. The skeletal phenotype was analyzed at young adult age using DXA and pQCT and previous fractures were assessed by questionnaires. RESULTS: Age at PHV was a negative independent predictor of both adult cortical and trabecular volumetric BMD and of total body and radius areal BMD. Moreover, age at PHV was associated with previous fractures in a logistic regression analysis. The OR for cortical osteopenia was 2.49 (95% CI, 1.91-3.24; p < 0.001) and for previous upper limb fractures was 1.35 (95% CI, 1.04-1.75; p < 0.05) per year increment in age at PHV. CONCLUSIONS: Age at PHV is a negative independent predictor of BMD and a positive predictor of previous fractures in young adult men. Longitudinal studies to determine if pubertal timing also predicts BMD and fractures in elderly men are required.

Sex Steroid Replacement Therapy in Female Hypogonadism from Childhood to Young Adulthood.

The overall goal of pubertal sex hormone replacement therapy (HRT) in girls is not only about development of secondary sexual characteristics, but also to establish an adult endocrine and metabolic milieu, as well as adult cognitive function. Estradiol (E2) is the first choice for HRT compared to ethinyl estradiol (EE2). E2 is the most potent endogenous estrogen in the circulation, with established levels during spontaneous puberty. Transdermal E2, compared to oral administration, is the first choice to start pubertal HRT. Transdermal application avoids liver exposure to supraphysiologic estrogen concentrations and provides a more physiologic mechanism for hormone delivery. By cutting E2 matrix patches in doses of 0.05-0.07 µg/kg or administrate E2 gel in doses of 0.1 mg/day, serum concentrations of E2 seen in early spontaneous puberty can be obtained. Patches can be removed in the morning and thereby mimic the normal circadian rhythm. For those clinics with access to sensitive E2 determinations methods (extraction followed by radioimmunoassay or mass spectrometry) monitoring the attained E2 serum levels is recommended in order to optimally mimic the levels seen in early puberty as well as growth velocity, breast and uterus development. Mid- and late pubertal HRT is obtained by increased doses of E2, adding cyclic oral or transdermal progestin, as well as testosterone gel over the pubic area if indicated.

First Morning Voided Urinary Gonadotropin Measurements as an Alternative to the GnRH Test.

AIMS: We studied whether first morning voided (FMV) urinary gonadotropin measurements could be used as a noninvasive alternative to the GnRH test in the assessment of the hypothalamic-pituitary-gonadal function in children. METHODS: In a single-center study, we compared FMV urinary gonadotropin concentrations with basal and GnRH-stimulated serum gonadotropin levels in 274 children and adolescents (78 girls, 196 boys) aged 5-17 years referred for growth and pubertal disorders. The concordance between FMV urinary gonadotropin concentrations and GnRH test results was assessed. RESULTS: FMV urinary LH (U-LH), urinary FSH (U-FSH) and their ratios correlated well with the corresponding basal and GnRH-stimulated serum parameters (r ≥ 0.66, p < 0.001). Receiver operating characteristic curve analyses using urinary and serum LH and FSH concentrations showed that FMV U-LH and U-LH/U-FSH performed equally well as the GnRH test in the differentiation of early puberty (Tanner stage 2) from prepuberty (Tanner stage 1) (area under the curve 0.768-0.890 vs. 0.712-0.858). FMV U-LH and U-LH/U-FSH performed equally well as basal serum LH in predicting a pubertal GnRH test result (area under the curve 0.90-0.93). CONCLUSION: FMV U-LH determination can be used for the evaluation of pubertal development and its disorders, reducing the need for invasive GnRH stimulation tests.

Inhibition of estrogen biosynthesis with a potent aromatase inhibitor increases predicted adult height in boys with idiopathic short stature: a randomized controlled trial.

CONTEXT: In males as well as in females, estrogen is an essential regulator of bone maturation, growth plate fusion, and cessation of longitudinal growth. Therefore, an increase in predicted adult height (PAH) may be achieved in short boys by blocking estrogen biosynthesis. OBJECTIVE: We tested the hypothesis that a decrease in the rate of bone maturation and an increase in PAH can be achieved in boys with idiopathic short stature (ISS) by the method of blocking estrogen biosynthesis with an aromatase inhibitor. Secondarily, we investigated the effects of aromatase inhibition on bone mineralization. DESIGN: This was a prospective, double-blind, randomized, placebo (Pl)-controlled clinical study. SETTING: The study was performed at a university hospital out-patient clinic. PATIENTS: Thirty-one boys, aged 9.0-14.5 yr, with ISS were studied. INTERVENTION: The boys were treated with the aromatase inhibitor letrozole (Lz; 2.5 mg/d) or Pl for 2 yr. MAIN OUTCOME MEASURE: The main outcome measure was the change in PAH after 24 months of treatment. RESULTS: PAH increased by 5.9 cm (P < 0.0001), and height SD score for bone age increased by 0.7 SD score (P < 0.0001) in the Lz-treated boys, whereas no changes occurred in the respective measures in Pl-treated boys. Areal bone mineral density of the lumbar spine and femoral neck, assessed by dual-energy x-ray absorptiometry, increased in a similar fashion in both groups during the treatment, whereas bone mineral apparent density increased only in those taking Lz (median increase, 4.3%; P = 0.009). CONCLUSIONS: Treatment with the aromatase inhibitor Lz delays bone maturation and improves PAH in boys with ISS. No adverse effects on bone mineralization were evident after 2 yr of treatment.

Testotoxicosis: current viewpoint.

Testotoxicosis is a form of gonadotropin-independent (peripheral) precocious puberty in which boys experience early onset and progression of puberty. Patients have accelerated growth, early development of secondary sexual characteristics and usually reduced adult height. Testotoxicosis is caused by an activating mutation of the luteinizing hormone (LH) receptor, leading to increased levels of sex steroids in the context of low LH. Therapy has, therefore, traditionally targeted steroidogenesis. However, the drugs used have been associated with side effects. More recently, a combination of an oral anti-androgen (spironolactone) and an aromatase inhibitor (testolactone) decreased height velocity and improved predicted height. A phase II study in testotoxicosis is currently underway,exploring the combination of a highly selective anti-androgen, bicalutamide, and the potent aromatase inhibitor, anastrozole. These agents are well tolerated in the populations in which they have been studied and effectively inhibit testosterone activity and estrogen production, in adult patients.

Changes of diurnal rhythm and levels of total and free testosterone secretion from pre to late puberty in boys: testis size of 3 ml is a transition stage to puberty.

OBJECTIVE: To establish levels for comparison for 24-h total and free serum testosterone in prepubertal boys and throughout pubertal development. DESIGN: The study subjects were 55 healthy boys, aged 5.0-18.6 years, who underwent serial sampling one or more times during their pubertal development. METHODS: Testicular volumes were determined by orchidometer. Serum testosterone was measured by a modified RIA (detection limit, 0.03 nmol/l). Free testosterone was calculated (calc-FT) using a formula derived from the law of mass action. RESULTS: Significant increases in testosterone and calc-FT concentrations in boys were found between testis volumes of 1 ml to 2 ml, 2 ml to 3 ml, 6 ml to 8 ml, and 10 ml to 15 ml. No differences were found between testis volumes of 3, 4, 5 and 6 ml neither were there differences between 8 and 10 ml, or between 15, 20 and 25 ml. Boys who had reached their final height had higher calc-FT values than boys who had the same pubertal development but had not reached their final height. Based on the results, puberty was classified into six stages: pre1 (testis, 1 ml), pre2 (testis, 2 ml), early (testis, 3-6 ml), mid (testis, 8-12 ml), late1 (testis,15-25 ml, not reached final height) and late2 (testis, 15-25 ml, reached final height). Serum testosterone was secreted with a diurnal variation in prepuberty and during puberty. The increase of testosterone in the morning hours started earlier in pubertal than in pre-pubertal boys. The most pronounced diurnal rhythm was found in early and in mid puberty. CONCLUSION: Using a sensitive method, and a pubertal reclassification, we have established levels for comparison of testosterone and calc-FT in prepubertal and pubertal boys. The existence of data for comparison forms the basis for future studies on pubertal disorders.