Search

Context There is a lack of knowledge on longitudinal sex steroid patterns during infancy, especially for boys born preterm or with low birth weight (LBW). Objective To find out whether LBW boys have a disturbed sex steroid profile during infancy. Design and setting Population-based longitudinal study performed at Sahlgrenska University Hospital, Gothenburg, Sweden. Participants Ninety-eight singleton boys (47 LBW) born at gestational age 32.0 to 36.9 weeks were included. Because of dropout, 83 of the boys were still in the study at 10 months’ corrected age. Main outcome measures Serum androgen and estrogen concentrations were analyzed by gas chromatography-tandem mass spectrometry and IGF-I was determined with radioimmunoassay in umbilical cord and at 0, 2, 5, and 10 months’ corrected age. Results Serum levels of androstenedione, estrone, and estradiol declined gradually from birth to 10 months corrected age. In both LBW boys and their counterparts, a surge was seen at 2 months’ corrected age (3 months’ chronological age) for testosterone, median (range) 6.5 (2.0-18.9) nmol/L, and in dihydrotestosterone 1.2 (0.4-4.3) nmol/L. At birth, LBW boys had higher median testosterone (0.7 vs 0.4 nmol/L, P = 0.019), and at 0 months’ corrected age, both had higher testosterone (5.7 vs 3.5 nmol/L, P = 0.003) and dihydrotestosterone (1.2 vs 0.9 nmol/L, P = 0.006) than their counterparts. At 10 months’ corrected age, catch-up in weight SD score from birth correlated with testosterone (rho = 0.27, P = 0.044) and androstenedione (rho = 0.29, P = 0.027). Conclusions Moderately to late preterm LBW boys showed a disturbed sex hormone profile, with elevated concentrations of androgens in early infancy.

AIM We investigated longitudinal adrenal androgen concentrations and any relationship between gestational age, birth size, anthropometric parameters and adrenal androgen concentrations during childhood in boys born moderate to late preterm. METHODS This longitudinal, prospective study included 58 boys born at 32+0 to 36+6 weeks of gestation. Dehydroepiandrosterone sulphate and androstenedione were analysed by liquid chromatography-tandem mass spectrometry, and anthropometric data were recorded from 5 to 10 years of age. RESULTS Dehydroepiandrosterone sulphate concentrations correlated with weight standard deviations scores (SDS) from 7 to 10 years of age and waist-to-height ratios at seven and 10 years of age. Androstenedione correlated with weight SDS from 7 to 10 years of age and waist-to-height ratios at 10 years of age. Longitudinal analysis showed a relationship between weight SDS and waist-to-height SDS and dehydroepiandrosterone sulphate (p

The relationship between sex hormone concentrations during childhood and birth weight (BW) is poorly understood. We aimed to investigate this relationship and the associations with anthropometric data at 5, 6, 7, 8, and 10 years of age in preterm boys.A prospective longitudinal single-centre study, including 58 boys with a BW of 1325-3320 g and gestational age (GA) of 32 + 2 to 36 + 6 weeks.Data on GA, BW and anthropometric data between 5 and 10 years of age were recorded. Testicular development was assessed at 8 and 10 years of age. Serum concentrations of sex steroids were analysed with gas chromatography-tandem mass spectrometry at 5-10 years and luteinizing hormone (LH) and follicle-stimulating hormone (FSH) with immunoassays at 10 years of age.At 8 years of age, testosterone and estrone correlated negatively with BW, (ρ = -0.35, p = .021) and (ρ = -0.34, p = .024), respectively. At 10 years of age, testosterone, dihydrotestosterone, estrone and estradiol correlated negatively with BW (ρ = -0.39, p = .010), (ρ = -0.38, p = .013), (ρ = -0.44, p = .003) and (ρ = -0.36, p = .019), respectively. Weight gain from birth correlated with testosterone at 5 years (ρ = 0.40, p = .002), 7 years (ρ = 0.30, p = .040), 8 years (ρ = 0.44, p = .003) and 10 years (ρ = 0.40, p = .008) of age. At 10 years of age, testosterone correlated with LH (ρ = 0.42, p = .006) and FSH (ρ = 0.33, p = .033) but not with testicular volume.Lower BW was associated with increased sex steroid concentrations from 8 years of age, independently of clinical signs of puberty.

Quantitation of endogenous steroids and their precursors is essential for diagnosis of a wide range of endocrine disorders. Usually, these analyses have been carried out using immunoassays. However, immunoassays often overestimate concentrations due to assay interference by other endogenous steroids, especially for low concentrations. Mass spectrometry based methods offer superior specificity, accuracy, and sensitivity. We therefore present a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method with automated sample preparation for determination of 17α-hydroxyprogesterone (17OHP), cortisol, cortisone, dehydroepiandrosterone sulfate (DHEAS), androstenedione (A

Background: Boys born small for gestational age (SGA) are at increased risk of testicular dysgenesis syndrome, and girls born SGA face the risk of polycystic ovary syndrome later in life. Our aim w...

Low androgen levels may contribute to sexual dysfunction in women after allogeneic hematopoietic cell transplantation (alloHCT). However, data on serum androgens in women after alloHCT are limited. The aim of this study was to assess androgen levels and their association with chronic GvHD (cGvHD) and glucocorticoid (GC) therapy. Included were 65 allografted women, 33 with cGvHD, and 23 of these were on GC therapy. Controls were 94 healthy, age-matched women. Supportive study groups were women after autologous HCT (autoHCT; n=20) and non-transplanted women on GC therapy (n=26). Compared with controls, free testosterone (free T) and dehydroepiandrosterone sulfate (DHEAS) levels were lower in both the alloHCT group and GC groups; P

The aim of this study was to investigate the impact of sex and puberty stage on circadian changes in sodium excretion, sodium-regulating hormones, and hemodynamics. Thirty-nine healthy volunteers (9 prepuberty boys, 10 prepuberty girls, 10 puberty boys, and 10 puberty girls) were included. They all underwent a 24-h circadian in-patient study under standardized conditions regarding activity, diet, and fluid intake. Blood samples were drawn every 4 h, and the urine was collected in fractions. Blood pressure and heart rate were noninvasively monitored. Atrial natriuretic peptide (ANP), angiotensin II, aldosterone, and renin were measured in blood. Children in puberty had lower plasma levels of renin ( P < 0.05) and angiotensin II ( P < 0.05) and a 26% reduction in filtered sodium without changes in sodium excretion compared with prepuberty children. A circadian rhythm in sodium excretion, the renin-angiotensin system, ANP, and blood pressure was found with a midnight ANP peak ( P < 0.001), a nighttime decrease in hemodynamic parameters ( P < 0.001), an increase in plasma renin ( P < 0.001) and angiotensin II ( P < 0.001), and a decrease in sodium excretion ( P < 0.001) mainly on the basis of increased sodium reabsorption ( P < 0.001). The timing of the changes did not depend on sex or puberty group. There is a circadian rhythm of sodium excretion and sodium regulation in 7- to 15-yr-old children. This rhythm is similar in boys and girls. As an important new finding, puberty changes the plasma levels of renin and angiotensin II without changing the amount of sodium excreted or the day to night sodium excretion ratio.

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.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.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.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.

Background Androgen and estrogen determinations serve as important diagnostic markers in a variety of clinical conditions. However, one challenge is to enhance assay sensitivity for determination in the lowest range, such as in prepubertal children. We here present a recently developed gas chromatography–tandem mass spectrometry (GC–MS/MS) method for determination of androstenedione (A4), dihydrotestosterone (DHT), testosterone (T), estrone (E1), and estradiol (E2) in children, which we have compared with the sensitive radioimmunoassays; E2 extraction-RIA and T-RIA. Methods Steroids were extracted in ethyl acetate n-hexane solution from serum spiked with isotopically labeled internal standard and derivatized sequentially with pentafluorobenzyl bromide, pentafluorobenzyl hydroxylamine and pentafluoropropionic acid anhydride and analyzed by GC–MS/MS using a triple quadrupole mass spectrometer operated in negative chemical ionization mode. Leftover routine samples (n = 414) were used to evaluate the concordance between GC–MS/MS and RIAs and the validity of GC–MS/MS for pediatrics; of these samples, 101 were from seemingly healthy children. Pubertal stage was recorded for reference interval evaluation. Results Lower limit of detection for A4, T, DHT, E1, and E2 were 0.1 nmol/L, 0.1 nmol/L, 27 pmol/L, 9 pmol/L, and 2 pmol/L, respectively. Good agreement was found between GC–MS/MS and T-RIA (r = 0.98) as well as between GC–MS/MS and E2 extraction-RIA (r = 0.98, for E2 concentrations above 14 pmol/L). In boys, T and DHT increased significantly from prepuberty throughout pubertal development, and in girls the same increase was observed for E1 and E2. The greatest increase in A4 for both genders, as well as E1 and E2 in boys and T and DHT in girls, occurred in mid to late puberty. Conclusions We report the development of a GC–MS/MS method sensitive enough to accurately determine serum levels of androgens and estrogens in children.

Background/Aims: Growth Hormone (GH) dosage in childhood is adjusted for body size, but there is no consensus whether body weight (BW) or body surface area (BSA) should be used. We aimed at comparing the biological effect and cost-effectiveness of GH treatment dosed per m2 BSA in comparison with dosing per kg BW in girls with Turner syndrome (TS). Methods: Serum IGF-I, GH dose, and adult height gain (AHG) from girls participating in two Dutch and five Swedish studies on the efficacy of GH were analyzed, and the cumulative GH dose and costs were calculated for both dose adjustment methods. Additional medication included estrogens (if no spontaneous puberty occurred) and oxandrolone in some studies. Results: At each GH dose, the serum IGF-I standard deviation score remained stable over time after an initial increase after the start of treatment. On a high dose (at 1 m2 equivalent to 0.056-0.067 mg/kg/day), AHG was at least equal on GH dosed per m2 BSA compared with dosing per kg BW. The cumulative dose and cost were significantly lower if the GH dose was adjusted for m2 BSA. Conclusion: Dosing GH per m2 BSA is at least as efficacious as dosing per kg BW, and is more cost-effective.

ObjectiveTo characterise changes in testicular size and reproductive hormones and to investigate the aetiology of delayed puberty and impaired fertility in males with Noonan syndrome (NS).DesignIn this study, 12 males with NS were longitudinally followed from pre/early puberty until adulthood. Of the 12 males, ten had no medical history other than NS and were divided into two groups, undescended testes (UT), and descended testes (DT) and compared with a reference population.MethodsHormone concentrations in serum were determined by immunoassays and testicular volume was measured using an orchidometer.ResultsBefore puberty, reproductive hormone levels were within the expected range in almost all cases. In some cases, LH, FSH and testosterone and oestradiol (E2) concentrations started to increase during puberty and inhibin B and anti-Müllerian hormone (AMH) declined to subnormal levels. Most of the boys studied had small testes that, in the majority of cases, progressed to normal size in adulthood. No difference in reproductive hormones was observed between the UT and DT groups either during puberty or at adulthood. However, as adults, males with NS had higher LH (5.7 vs 4.0 U/l, PPP2 (66 vs 46 pmol/l, PPPConclusionsIn NS males, both Sertoli and Leydig cell dysfunction is common with reproductive hormone levels deteriorating progressively to adulthood.

Although postmenopausal hormone-replacement therapy (HRT) is known to prevent fractures, knowledge on the influence of long-term HRT on bone strength and its determinants other than areal bone mineral density is scarce. This study used a genetically controlled design with 24 monozygotic female twin pairs aged 54 to 72 years in which one cotwin was using HRT (mean duration 8 years) and the other had never used HRT. Estimated bone strength, cross-sectional area, volumetric bone mineral density, bone mineral mass, and cross-sectional density and mass distributions were assessed in the tibial shaft, distal tibia, and distal radius with peripheral computed tomography (pQCT). In the tibial shaft, HRT users had 9% [95% confidence interval (CI) 3%–15%] higher estimated bending strength than their nonusing cotwins. Larger cortical area and higher cortical bone mineral density accounted for this difference. The cortex was larger in the HRT users in the endocortical region. In the distal tibia, estimated compressive strength was 24% (95% CI 9%–40%) higher and in the distal radius 26% (95% CI 11%–41%) higher in the HRT users than in their nonusing cotwins owing to higher volumetric bone mineral density. No difference between users and nonusers was observed in total bone cross-sectional area in any measured bone site. The added mineral mass in the HRT users was distributed evenly within and between bone sites. In postmenopausal women, long-term HRT preserves estimated bone strength systemically by preventing bone mineral loss similarly in body weight–loaded and non-weight-loaded bone. © 2011 American Society for Bone and Mineral Research.

We investigated whether long-term hormone replacement therapy (HRT) is associated with mobility and lower limb muscle performance and composition in postmenopausal women. Fifteen 54- to 62-yr-old monozygotic female twin pairs discordant for HRT were recruited from the Finnish Twin Cohort. Habitual (HWS) and maximal (MWS) walking speeds over 10 m, thigh muscle composition, lower body muscle power assessed as vertical jumping height, and maximal isometric hand grip and knee extension strengths were measured. Intrapair differences (IPD%) with 95% confidence intervals (CI) were calculated. The mean duration of HRT use was 6.9 ± 4.1 yr. MWS was on average 7% (0.9 to 13.1%, P = 0.019) and muscle power 16% (−0.8 to 32.8%, P = 0.023) greater in HRT users than in their cotwins. Thigh muscle cross-sectional area tended to be larger (IPD% = 6%, 95% CI: −0.07 to 12.1%, P = 0.065), relative muscle area greater (IPD% = 8%, CI: 0.8 to 15.0%, P = 0.047), and relative fat area smaller (IPD% = −5%, CI: −11.3 to 1.2%, P = 0.047) in HRT users than in their sisters. There were no significant differences in maximal isometric strengths or HWS between users and nonusers. Subgroup analyses revealed that estrogen-containing therapies (11 pairs) significantly decreased total body and thigh fat content, whereas tibolone (4 pairs) tended to increase muscle cross-sectional area. This study showed that long-term HRT was associated with better mobility, greater muscle power, and favorable body and muscle composition among 54- to 62-yr-old women. The results indicate that HRT is a potential agent in preventing muscle weakness and mobility limitation in older women.

Are Estradiol results determined by the tandem mass spectrometry assay clinically useful for children? : reply

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.

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.

Objective: In males, the pubertal increase in sex hormone production has been associated with proatherogenic changes in lipid and carbohydrate metabolism. Aromatase inhibitors, a novel treatment modality for some growth disorders, may significantly influence these risk factors for cardiovascular disease by suppressing oestrogen biosynthesis and stimulating gonadal androgen production. In the current study, we explored the effects of aromatase inhibition on lipid metabolism, insulin sensitivity, body composition and serum adiponectin in peripubertal boys. Design: Prospective, double-blind, randomised, placebo-controlled clinical study. Methods: Thirty-one boys, aged 9.0–14.5 years, with idiopathic short stature were treated with the aromatase inhibitor letrozole (2.5 mg/day) or placebo for 2 years. During the treatment, the concentrations of sex hormones, IGF-I, lipids, lipoproteins and adiponectin were followed-up. The percentage of fat mass (FM) was assessed by skinfold measurements and insulin resistance by homeostasis model assessment (HOMA) index. Results: In pubertal boys, who received letrozole, high-density lipoprotein cholesterol (HDL-C) decreased by 0.47 mmol/l (PP Conclusions: In males, aromatase inhibition reduces HDL-C and decreases relative FM after the start of puberty. The treatment does not adversely affect insulin sensitivity in lean subjects.

OBJECTIVE: To determine whether there is evidence for impaired testicular function at final height in short boys treated with growth hormone (GH) during their childhood and adolescence. STUDY DESIGN: The analysis was restricted to males who had isolated GH deficiency or idiopathic short stature, and who were included in the Swedish National Registry and the Swedish GH trials. The subjects had to have been treated with GH for at least 4 years; the treatment had to have been started prepubertally, given for at least one year before the onset of puberty and the subjects had to have reached final height. One hundred and eleven boys fulfilled the criteria. METHODS: Testicular volumes were determined by orchidometer in each boy when GH treatment was started and at final height. Samples for testosterone measurements were collected from 77 boys at final height, and were measured by RIA. RESULTS: Each subject had normal testicular size (15 ml or more) and for those in whom concentrations were determined, serum testosterone levels and diurnal rhythm were normal. CONCLUSIONS: The results of our survey do not show evidence of testicular impairment following GH therapy.

The objective of pubertal induction in children with hypogonadism is to mimic spontaneous puberty in terms of physical and psychological development. In a clinical observation study, we induced puberty in 15 girls with hyper- or hypogonadotropic hypogonadism using low doses of transdermal estradiol patches attached only during the night and compared the estradiol concentrations obtained with those in healthy girls. Pubertal induction was started between the ages of 12.3 and 18.1 yr. A transdermal matrix patch of 17β-estradiol (25 μg/24 h; Evorel, Janssen Pharmaceuticals-Cilag) was cut into pieces corresponding to 3.1, 4.2, or 6.2 μg/24 h initially and attached to the buttock. After 4–14 months, the dose was increased gradually. Serum 17β-estradiol concentrations were measured every 2 h by RIA (detection limit, 6.0 pmol/L; 1.6 pg/mL). The results show that it is possible to mimic the spontaneous levels as well as the diurnal pattern of serum 17β-estradiol in early puberty, by cutting a transdermal 17β-estr...

Summary Background The role of oestrogens in the closure of growth plates in both sexes is unequivocal. We postulated that inhibition of oestrogen synthesis in boys with delayed puberty would delay maturation of the growth plates and ultimately result in increased adult height. Methods We did a randomised, double-blind, placebo-controlled study in which we treated boys with constitutional delay of puberty with testosterone and placebo, or testosterone and letrozole. Boys who decided to wait for the spontaneous progression of puberty without medical intervention composed the untreated group. Findings Letrozole effectively inhibited oestrogen synthesis and delayed bone maturation. Progression of bone maturation was slower in the letrozole group than in the placebo group. In 18 months, bone age had advanced 1·1 (SD 0·8) years in the untreated group and 1·7 (0·9) years in the group treated with testosterone and placebo, but only 0·9 (0·6) years in the letrozole group (p=0·03 between the treatment groups). Predicted adult height did not change significantly in the untreated group and in the placebo group, whereas in the group treated with letrozole the increase was 5·1 (3·7) cm (p=0·004). Interpretation Our findings suggest that if oestrogen action is inhibited in growing adolescents, adult height will increase. This finding provides a rationale for studies that aim to delay bone maturation in several growth disorders.

We thank Kushnir and coworkers1 for addressing the subject of how estradiol (E2) is used clinically in pediatric endocrinology. As Kushnir et al2 mention in the introduction of their original article, high-sensitivity methods for accurate measurements of E2 concentrations are necessary for the diagnosis of sex hormone–related disorders, precocious puberty (PP), and E2 deficiency and for determining the strategy for antiestrogenic treatment. Although PP is a clinical diagnosis, the laboratory testing for sex hormones in children suspected of having PP is performed not only for confirming the diagnosis but also, most importantly, to help diagnose the origin of the condition or disease and for the treatment strategy. For girls with PP with prepubertal E2 levels Figure 1 , the origin can be exogenous estrogens or an ovarian cyst that has produced transient estrogens. PP with low E2 levels in the early puberty range (Figure 1) (in combination with increased luteinizing hormone [LH]/follicle-stimulating hormone [FSH]) can be an indication of a low tempo of the pubertal development and may not need treatment with a long-acting gonadotropin releasing hormone agonist, but patients will need close follow-up. PP with high E2 levels in the midpubertal range with increased LH/FSH needs treatment and further investigation of the origin of PP, eg, magnetic resonance imaging of the central nervous system for tumor. These are examples from routine clinical practice showing how important …

Background/Aim: The goal of estrogen replacement therapy (ERT) in girls with hypogonadism is to achieve the endocrine milieu similar to natural puberty, where transdermal administration is the most physiological route. The aim of the study was to evaluate guidelines for the induction of puberty with transdermal estradiol (E2) patches in a large outpatient setting. Methods: In a retrospective study, serum E2 levels from 18 clinics were analyzed at the Göteborg Pediatric Growth Research Center laboratory, as part of the initiation of ERT in girls with hypogonadism. Exclusion criteria were pubertas tarda and pubertal arrest. Eighty-eight observations (50 with Turner syndrome, TS) were included. Serum E2 levels were determined by extraction + radioimmunoassay (detection limit 4 pmol/l) and analyzed in relation to the dose of Evorel® (25 µg/24 h, containing 1.60 mg estradiol hemihydrate; Janssen-Cilag Pharmaceutica N.V., Beerse, Belgium). Results: There was a linear relationship between serum E2 and the weight-based dose, with r = 0.56, p < 0.0001 for all observations and r = 0.59, p < 0.0001 for the TS study group. Linear regression analysis for doses of 0.05-0.07 µg/kg resulted in serum levels of 17-23 pmol/l (TS 17-24 pmol/l) and doses of 0.08-0.12 µg/kg in 26-39 pmol/l (TS 27-39 pmol/l). Conclusions: For the initiation of ERT with nocturnally administered E2 patches, we recommend reduced starting doses of 0.05-0.07 µg/kg, with the goal of mimicking E2 levels during gonadarche. In older girls, when breast development is of high priority, the starting dose can still be 0.08-0.12 µg/kg.

Aging is associated with gradual decline of skeletal muscle strength and mass often leading to diminished muscle quality. This phenomenon is known as sarcopenia and affects about 30% of the over 60-year-old population. Androgens act as anabolic agents regulating muscle mass and improving muscle performance. The role of female sex steroids as well as the ability of skeletal muscle tissue to locally produce sex steroids has been less extensively studied. We show that despite the extensive systemic deficit of sex steroid hormones in postmenopausal compared to premenopausal women, the hormone content of skeletal muscle does not follow the same trend. In contrast to the systemic levels, muscle tissue of post- and premenopausal women had similar concentrations of dehydroepiandrosterone and androstenedione, while the concentrations of estradiol and testosterone were significantly higher in muscle of the postmenopausal women. The presence of steroidogenetic enzymes in muscle tissue indicates that the elevated postmenopausal steroid levels in skeletal muscle are because of local steroidogenesis. The circulating sex steroids were associated with better muscle quality while the muscle concentrations reflected the amount of infiltrated fat within muscle tissue. We conclude that systemically delivered and peripherally produced sex steroids have distinct roles in the regulation of neuromuscular characteristics during aging.

Aim: To study the influence of growth hormone (GH) treatment on the initiation and progression of puberty in short children. Methods: This prospective, randomized, controlled study included 124 short children (33 girls) who received GH treatment (Genotropin®; Pfizer Inc.) from a mean age of 11 years until near adult height [intent-to-treat (ITT) population]. Children were randomized into three groups: controls (n = 33), GH 33 µg/kg/day (n = 34) or GH 67 µg/kg/day (n = 57). Prepubertal children at study start constituted the per-protocol (PP) population (n = 101). Auxological measurements were made and puberty was staged every 3 months. Serum sex-steroid concentrations were assessed every 6 months. Results: No significant differences were found between the groups, of both PP and ITT populations, in time elapsed from start of treatment until either onset of puberty, age at start of puberty or age at final pubertal maturation in either sex. In the ITT population, pubertal duration was significantly longer in GH-treated girls, and maximum mean testicular volume was significantly greater in GH-treated boys than controls, but there were no differences in testosterone levels between the groups. Conclusion: GH treatment did not influence age at onset of puberty and did not accelerate pubertal development. In boys, GH treatment appeared to increase testicular volume.

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: Conclusion With the use of an ultra-sensitive extraction RIA, we have provided clinically useful normative data for estradiol secretion in boys.

ObjectiveTo test the clinical usefulness of sensitive commercial immunoassays for determination of low 17β-estradiol concentrations in children.MethodsThe lower limit of detection and clinical usefulness (functional sensitivity) of three commercial estradiol immunoassays were validated by use of 500 sera from prepubertal and pubertal children and 55 pooled sera. The three immunoassays consisted of two modified direct immunoassays; one RIA (Spectria Estradiol RIA) and one time-resolved fluoroimmunoassay (AutoDELFIA Estradiol), both with increased serum volume in relation to antibody concentration and extended incubation time. In the third method, serum was purified and concentrated using diethyl ether extraction prior to measurement by the modified Spectria Estradiol RIA.ResultsThe lower limits of detection and clinical usefulness were 9 and 30 pmol/l for the direct RIA, 11 and 50 pmol/l for the AutoDELFIA, and 4 and 6 pmol/l for serum determined by extraction RIA. When measuring the serum pool originating from girls at breast stages 1–2, the direct RIA and AutoDELFIA resulted in significantly higher 17β-estradiol concentrations when compared with the extraction RIA (+58 and +267%,PPConclusionFor determination of low serum 17β-estradiol concentrations in children, an extraction step prior to commercial immunoassay is needed to achieve clinically useful results.

Testosterone (T)-substitution therapy is widely used in adult patients with Klinefelter syndrome (KS) to prevent symp- toms and sequels of androgen deficiency, but it is currently unknown if adolescent boys with KS benefit from early T therapy. To evaluate the optimal age to start T substitution, we searched for signs of androgen deficiency in pubertal boys with KS. 14 nonmosaic 47,XXY boys, aged 10 -13.9 y, were followed up for 4 -37 mo with staging of puberty and frequent reproductive hormone measurements. Furthermore, indices reflecting androgen action (serum SHBG, lep- tin, and prostate-specific antigen (PSA) levels) were studied. Both onset and progression of puberty according to Tanner stages were normal in boys with KS. Consistently, serum T concentrations in- creased as expected and remained normal throughout follow-up. Changes in the indices of androgen action (decreases in serum SHBG and leptin, and increase in serum PSA concentrations) occurred normally, except that average leptin levels were higher in the boys with KS (KS boys 11.8 7.0 g/L; controls 7.6 4.7 g/L; p 0.033). Despite normal T concentrations, the KS boys displayed from the age of 13 y elevated serum FSH and LH levels, and exaggerated gonadotropin responses to gonadotropin-releasing hormone. These data do not demonstrate an unequivocal androgen deficiency in adolescent boys with KS that would necessitate androgen supple- mentation therapy during early puberty. (Pediatr Res 59: 854-859, 2006)

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.

OBJECTIVE: To investigate the levels and diurnal rhythm of serum leptin in healthy children, and to investigate the association between leptin levels and sex steroids. METHODS: Four girls and four boys, all healthy volunteers, were followed longitudinally throughout puberty. Their chronological ages ranged from 8.7 to 19.5 years, and body composition, expressed as weight-for-height standard deviation scores (SDS), ranged between -1.7 and +2.4. Serum leptin, oestradiol and testosterone concentrations were measured by radioimmunoassay at 1000, 1400, 1800, 2200, 0200 and 0600 h. RESULTS: In all girls and boys, both prepubertally and during pubertal development, serum leptin levels increased during the night, with no difference in relative peak amplitude. In boys, the leptin concentrations increased until the initiation of puberty and then declined, whereas in girls, the concentrations increased throughout puberty. The inter-individual variation in mean leptin levels among girls decreased to 11% at the time of menarche. A positive correlation was found for both oestradiol and testosterone versus leptin in girls throughout puberty (r=0.64 and r=0.71 respectively, P