Gonadotropin-releasing Hormone Test Research Articles

Effectiveness of the triptorelin stimulation test compared with the classic gonadotropin-releasing hormone stimulation test in diagnosing central precocious puberty in girls.

The gonadotropin-releasing hormone (GnRH) stimulation test is the gold standard for diagnosing central precocious puberty (CPP). Gonadorelin (Relefact) is used for the test but is not always readily available; triptorelin is used as an alternative. The purpose of this study was to evaluate the diagnostic validity of the triptorelin test compared with the GnRH test in the diagnosis of CPP in girls. This retrospective study included 100 girls with premature thelarche (PT) who underwent a hypothalamic-pituitary-gonadal axis evaluation. In the overall group, 50 girls were tested with intravenous gonadorelin (Relefact) and 50 girls were tested with subcutaneous triptorelin acetate (Decapeptyl). Luteinizing hormone (LH) and follicle-stimulating hormone levels were measured at baseline and 30, 45, 60, and 90 minutes after gonadorelin injection or 30, 60, 90, and 120 minutes after triptorelin injection. Clinical characteristics of age, height, weight, body mass index, and bone age were similar between the 2 groups. The highest LH level was reached 60 minutes after stimulation in both groups. Approximately 20% of the gonadorelin group and 24% of the triptorelin group were diagnosed with CPP (P=0.52). Among those diagnosed with CPP, the mean peak LH concentrations were 8.15 mIU/mL and 9.73 mIU/mL in the gonadorelin and triptorelin groups, respectively. The triptorelin test showed similar trends of LH elevation and diagnostic rate compared with the traditional GnRH test for diagnosing CPP. This suggests that the triptorelin test may be a valid alternative to the GnRH test for differentiating CPP from self-limiting PT. Our study also demonstrated that a triptorelin stimulation test for up to 120 minutes was sufficient to diagnose CPP.

A Short-Duration Gonadotropin-Releasing Hormone Stimulation Test for the Diagnosis of Central Precocious Puberty.

Background and Objectives: The gonadotropin-releasing hormone (GnRH) stimulation test is the gold standard method for diagnosing central precocious puberty (CPP), although it requires multiple blood samplings over 120 min. This study aimed to evaluate if a shorter test may have an equivalent diagnostic accuracy. Materials and Methods: We retrospectively reviewed the GnRH tests of 188 consecutive pediatric patients (169 females) referred for signs of early pubertal development. The diagnostic accuracy of the hormonal levels was evaluated at different time points (15, 0, 60, 90, and 120 min after the GnRH stimulus). Results: A diagnosis of CPP was made in 130 cases (69%), with 111 (85%) being female. Sensitivity and specificity ratings higher than 99% for the diagnosis of CPP were achieved for LH levels ≥4.7 mU/mL at 30 and 60 min after the stimulus (area under the ROC curve (AUC) = 1), with no further increase in the diagnostic accuracy in the remaining time points. No sex differences in diagnostic accuracy were found. The LH/FSH ratio at 30 min showed a sensitivity of 94.9%, with an AUC of 0.997 and a value ≥0.76. Conclusions: A short-duration GnRH test of 60 min provided optimal results for the diagnosis of CPP. Extending the test for an extra hour is therefore unnecessary and inadvisable.

Differentiation of Idiopathic Central Precocious Puberty From Premature Thelarche Using Principal Component Analysis.

Nonprogressive premature thelarche (PT) is a self-limiting variant of early puberty, while idiopathic central precocious puberty (ICPP) is a disorder that causes progressive development of secondary sexual characteristics and often requires treatment. The diagnostic differentiation between these conditions is important but can be challenging since they often both initially present clinically with isolated breast development. To describe relevant clinical variables in a large cohort of girls referred for early puberty, and to evaluate clinical and biochemical parameters to distinguish between girls with ICPP and PT. This retrospective study included 1361 girls referred with signs of early puberty to a single, tertiary center from 2009 to 2019. We evaluated clinical presentation, medical history, growth velocity, bone age, hormonal serum concentrations, and gonadotropin-releasing hormone (GnRH) test results. Central precocious puberty was diagnosed in 11% (ICPP: n = 143, organic CPP: n = 11) girls, whereas 8% (n = 91 girls) presented with PT. Receiver operating characteristic (ROC) analysis showed several biochemical and anthropometric markers as potential parameters to differentiate between ICPP and PT; however, none were individually adequate. Principal component analysis (PCA)-derived clinical and hormone profiles could predict girls with ICPP from girls with PT with a specificity of 90% and sensitivity of 84%, outperforming any single marker. Differentiation of girls with ICPP and PT can be supported by individual clinical and biochemical parameters. However, dimension reduction of clinical and hormonal profiles by PCA improved the diagnostic value, which in the future may support the diagnostic process as a supplement to the GnRH test in evaluation of pubertal disorders.

Role of luteinizing hormone urinary levels in the diagnostic and therapeutic management of female central precocious puberty

BackgroundDiagnosing central precocious puberty (CPP) requires an integrated approach based on clinical, biochemical and instrumental data. The diagnostic gold standard is represented by GnRH (gonadotropin-releasing hormone) stimulation test. Some undoubted limitations of this procedure led the international scientific community to look for cheaper and less invasive alternative diagnostic methods, such as luteinizing hormone urinary levels (uLH) measurement. This study aims to define the reliability of urinary LH levels as a biomarker of pubertal development, both concerning the initial diagnostic management and the monitoring of patients with central precocious puberty undergoing therapy with GnRH analogues. Furthermore, the study plans to detect the potential association between LH peak serum (pLH) and urinary LH in patients undergoing diagnostic tests with GnRH and to identify a possible cut-off of uLH that may be suggestive of ensued successful hormonal stimulation.MethodsThe study includes 130 female patients with suspected precocious puberty or in follow-up during suppressive therapy. After the collection of the informed consent, the patients underwent clinical evaluation, auxological assessment, and hormone assays (basal levels of LH, FSH, and oestradiol; GnRH stimulating test in patients with suspected precocious puberty; urinary LH assay on the first-morning urine sample, collected after waking up).ResultsTwo uLH cut-off values have been identified: the first of 0.25 UI/L [C.I. 95% 0.23–0.27], able to distinguish between pubertal and pre-pubertal patients, the second of 0.45 UI/L [C.I. 95% 0,20 − 0,70] suggestive of occurred hormonal stimulation in patients with diagnosis of CPP at GnRH test. All 30 patients with CPP in follow-up during suppressive therapy presented uLH values ≤ 0.45 IU/L (pU < 0.05), and uLH collected in prepubertal group control.ConclusionsuLH assays on the first morning urine specimen could be considered a low-cost and minimally invasive tool for precocious puberty diagnosing and monitoring, making possible to be easily performed even by a general pediatrician. Thus, this could help referring only selected patients to pediatric endocrinologists. After an appropriate validation, this approach could reasonably reduce hospital attendance and costs of performing more invasive procedures, with a more significant emotional impact on the pediatric patient.

The utilization of basal luteinizing hormone in combination with the basal luteinizing hormone and follicle-stimulating hormone ratio as a diagnostic tool for central precocious puberty in girls.

Intravenous gonadotropin-releasing hormone (IV GnRH) testing is the gold standard for confirming a central precocious puberty (CPP) diagnosis. However, this test is not widely available commercially. Therefore, our study aim was to establish cutoff values for basal gonadotropin level and gonadotrophin responses to a 100-μg subcutaneous IV GnRH test that can distinguish between CPP and premature thelarche (PT) to discover a simple method to detect CPP. Girls between the ages of 6 and 8 years who attended the pediatric endocrinology outpatient clinic at our tertiary hospital between 2019 and 2022 were included in this study. They were evaluated for breast development, and a subcutaneous 100-μg GnRH test was administered by measuring the luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels in blood samples at baseline and then 30, 60, 90, and 120 minutes after injection. CPP is characterized by increased height velocity, advanced bone age, and progression of breast development. The cutoff value for diagnosis of CPP was determined using a receiver operating characteristic (ROC) analysis. In 86 Thai girls (56 with CPP and 30 with PT), the ROC analysis showed 71.4% and 100% sensitivity and specificity, respectively, for basal LH (cutoff ≥ 0.2 IU/L) plus the basal LH/FSH ratio (cutoff ≥ 0.1). The optimal cutoff values for peak LH (cutoff ≥ 7 IU/L) demonstrated a sensitivity of 94.6% and a specificity of 100%, whereas the LH value at 30 and 60 minutes after injection (cutoff ≥ 6 IU/L) demonstrated sensitivities of 92.9% and 94.6% and a specificity of 100%, respectively. Combining the basal LH (cutoff: 0.2 IU/L) and the basal LH/FSH ratio (cutoff: 0.1) can easily and cost-effectively diagnose CPP in a girl in breast Tanner stage II.

Auxological and Metabolic Parameters of Children Undergoing the Gonadotropin-Releasing Hormone Stimulation Test: Correlations with the Final Diagnosis of Central Precocious Puberty in a Single-Center Study.

Background-Central precocious puberty (CPP) is characterized by clinical, biochemical, and radiological features similar to those of normal puberty, but CPP occurs before the age of eight in girls and before the age of nine in boys, subsequently leading to a reduction in the final body height in adulthood due to premature fusion of growth plates. The diagnosis of CPP is confirmed with a gonadotropin-releasing hormone (GnRH) stimulation test, which can lead to different interpretations because the diagnostic peak levels of luteinizing hormone (LH) can vary. Patients and methods-This was a single-center, retrospective observational study investigating the possible correlation between gonadotropin peaks on the GnRH test and auxological, metabolic, and radiological parameters of patients evaluated for CPP. We collected and analyzed data from the medical records of children with suspected CPP over a period from January 2019 to July 2022 who underwent a GnRH test at the Fondazione Policlinico Universitario Agostino Gemelli in Rome, Italy. Results-Our correlation analysis revealed no statistically significant differences in any auxological and radiological parameters. Among laboratory parameters, baseline levels of LH, follicle-stimulating hormone, sex hormone-binding globulin, and 17-beta estradiol were higher in children with a definitive diagnosis of CPP than in those with a negative GnRH test. In particular, the levels of LH at baseline and after the GnRH test were statistically significant in the group of CPP patients, consistent with the interpretation of the test. In the multivariate analysis, using a cut-off value of 4.1 IU/L, LH peaks showed both very high sensitivity (94%) and very high specificity (95%); all other variables showed high specificity (90%) but unsatisfactory sensitivity. Conclusion-Basal hormone dosages and, especially, basal levels of LH should be considered before performing a GnRH test as they might anticipate the final diagnosis of CPP.

Serum kisspeptin, neurokinin Band inhibin B levels can be used as alternative parameters to distinguish idiopathic CPP from premature thelarche in the early stages of puberty.

There is controversial results about serum kisspeptin, neurokinin-B (NKB), anti-Müllerian hormone (AMH)and inhibin B (INHB) levels in girls with central precocious puberty (CPP). Aim of this study is to evaluate serum levels of these four peptides in patients presented with early pubertal signs, and to evaluate their diagnostic validity in the diagnosis of CPP. Cross-sectional study. Study included 99 girls (51 CPP, 48 premature thelarche [PT]) whose breast development started before 8 years and 42 age-matched healthy prepubertal girls. Clinical findings, antropometric measurements, laboratory and radiological findings were recorded. Gonadotropin-releasing hormone (GnRH) stimulation test was performed in all cases with early breast development. Kisspeptin, NKB, INHBand AMH levels were measured in fasting serum samples using enzyme-linked immunosorbent assay method. There was no statistically significant difference between mean ages of girls with CPP (7.1 ± 1.2 years), PT (7.2 ± 1.3 years)and prepubertal controls (7.0 ± 1.0 years). Serum kisspeptin, NKBand INHB levels were higher in CPP group compared to PT and control groups, while serum AMH level was lower in CPP group. Serum kisspeptin, NKB, and INHB were all positively correlated with bone age (BA) advancement, and peak luteinizing hormonein GnRH test. Multiple stepwise regression analysis revealed that the most important factors used to differentiate CPP from PT were advanced BA, serum kisspeptin, NKB and INHB levels (AUC: 0.819, p < .001). We, firstshowed in the same patients' group that serum kisspeptin, NKB and INHB were higher in patients with CPP and can be used as alternative parameters to distinguish CPP from PT.

Pituitary-testis axis dysfunction following adjuvant androgen deprivation therapy.

Men with high-risk, non-metastatic prostate cancer receive adjuvant androgen deprivation therapy (ADT) for at least 2 years according to Danish guidelines. It remains unclarified if patients regain the function of the pituitary-testis axis after cessation of ADT. Thus, we aimed to investigate the function of the pituitary-testis axis following adjuvant ADT. In this study, we included men who underwent external beam radiation therapy and ADT for high-risk prostate cancer. All patients underwent assessment of testosterone deficiency (TD) symptoms, full biochemical assessment of the pituitary-testis axis, and dynamic stimulatory tests of gonadotropin (gonadotropin-releasing hormone (GnRH) test) and testosterone production (human chorionic gonadotrophin (hCG) test). Patients were diagnosed with TD based on a combination of TD symptoms and testosterone below age-specific reference ranges. TD was characterized as primary, secondary, or mixed based on serum gonadotropins and stimulatory tests. We found that among the 51 patients included in the study, the median time on ADT was 3.2 years and median time since ADT cessation was 3.8 years. Twenty-eight patients were diagnosed with TD; 10 had primary TD (testicular dysfunction), 11 secondary TD (pituitary dysfunction), and 7 mixed TD (combined pituitary and testicular dysfunction). An inadequate testosterone response to hCG stimulation was shown in 42 patients, whereas only 11 patients had a subnormal gonadotropin response to GnRH. We conclude that persistent TD is a common long-term consequence of adjuvant ADT in prostate cancer survivors, equally distributed between pituitary and testicular dysfunction. The study emphasizes the necessity for systematic follow-up of full pituitary-testis axis function in patients receiving adjuvant ADT.

098 McCune-Albright syndrome in a 5 years old girl with apparently central precocious puberty: a significant diagnostic delay

Objective: In girls, precocious puberty (PP) presents with breast development, increased growth velocity and bone maturation before the age of 8yrs. The cause can be Central PP (CPP; or gonadotropin (Gn) dependent) or peripheral PP (P-PP; or Gn independent). A gonadotropin releasing hormone (GnRH) test can distinguish between CPP and P-PP.

Diagnosis of Male Central Hypogonadism During Childhood.

The diagnosis of male central (or hypogonadotropic) hypogonadism, typically based on low luteinizing hormone (LH) and testosterone levels, is challenging during childhood since both hormones are physiologically low from the sixth month until the onset of puberty. Conversely, follicle-stimulating hormone (FSH) and anti-Müllerian hormone (AMH), which show higher circulating levels during infancy and childhood, are not used as biomarkers for the condition. We report the case of a 7-year-old boy with a history of bilateral cryptorchidism who showed repeatedly low FSH and AMH serum levels during prepuberty. Unfortunately, the diagnosis could not be ascertained until he presented with delayed puberty at the age of 14 years. A gonadotropin-releasing hormone (GnRH) test showed impaired LH and FSH response. By then, his growth and bone mineralization were partially impaired. Gene panel sequencing identified a variant in exon 15 of FGFR1, affecting the tyrosine kinase domain of the receptor, involved in GnRH neuron migration and olfactory bulb morphogenesis. Testosterone replacement was started, which resulted in the development of secondary sexual characteristics and partial improvement of bone mineral density. This case illustrates the difficulty in making the diagnosis of central hypogonadism in boys during childhood based on classical criteria, and how serum FSH and AMH assessment may be helpful if it is suspected before the age of puberty, and confirm it using next-generation sequencing. The possibility of making an early diagnosis of central hypogonadism may be useful for a timely start of hormone replacement therapy, and to avoid delays that could affect growth and bone health as well as psychosocial adjustment.

The effect of GnRH stimulation on AMH regulation in central precocious puberty and isolated premature thelarche.

There is a complex interaction between the anti-müllerian hormone (AMH) and hypothalamic-pituitary-gonadal axis. However, the effect of gonadotropin-releasing hormone (GnRH) stimulation on AMH levels is not clearly known. In the study, we aimed to evaluate the effect of GnRH stimulation on AMH levels in central precocious puberty (CPP) and isolated premature thelarche (PT) groups. Sixty-three girls with breast development before the age of 8 were enrolled in the study. GnRH test was performed on all subjects. Blood samples for follicle-stimulating hormone (FSH), luteinizing hormone (LH), and AMH levels were taken at basal, 40th, and 90th minute of GnRH test. Subjects were grouped as CPP and PT group. After GnRH stimulation, AMH levels increased significantly at the 40th minute and the stimulating effect of GnRH on AMH continued till the 90th minute (p: 0.0001). There was a positive correlation between basal and 90th-minute AMH levels (r: 479, p: 0.0001). The highest FSH, LH, and AMH times were significantly different after the GnRH stimulation (p: 0.001, p: 0.001, and p: 0.007). Although the CPP group had a lower basal AMH level than the PT group's basal AMH level; AMH response to GnRH stimulation was not different (p>0.05). In our study, which examined the effect of GnRH stimulation on AMH levels in early pubertal development disorders for the first time, GnRH stimulated AMH secretion rapidly, correlated with basal AMH. Basal AMH levels were lower in patients with CPP than in those with PT; however, the effect of GnRH stimulation on AMH levels was similar in both groups.

Peripheral Precocious Puberty of Ovarian Origin in a Series of 18 Girls: Exome Study Finds Variants in Genes Responsible for Hypogonadotropic Hypogonadism

Background: Peripheral precocious puberty of ovarian origin is a very rare condition compared to central form. It may be associated with an isolated ovarian cyst (OC). The causes of OC in otherwise healthy prepubertal girls is currently unknown.Methods: Exome sequencing was performed on a cohort of 18 unrelated girls presenting with prenatal and/or prepubertal OC at pelvic ultrasonography. The presenting symptom was prenatal OC in 5, breast development in 7 (with vaginal bleeding in 3) and isolated vaginal bleeding in 6. All had OC ≥ 10 mm. The girls had no other anomalies. Four patients had a familial history of ovarian anomalies and/or infertility.Results: In 9 girls (50%), candidate or known pathogenic variants were identified in genes associated with syndromic and non-syndromic forms of hypogonadotropic hypogonadism including PNPLA6, SEMA3A, TACR3, PROK2, KDM6A, KMT2D, OFD1, GNRH1, GNRHR, GLI3, INSR, CHD7, CDON, RNF216, PROKR2, GLI3, LEPR. Basal plasma concentrations of gonadotropins were undetectable and did not increase after gonadotropin-releasing hormone test in 3 of them whilst 5 had prepubertal values. The plasma estradiol concentrations were prepubertal in 6 girls, high (576 pmol/L) in one and not evaluated in 2 of them.Conclusions: In the first study reporting exome sequencing in prepubertal OC, half of the patients with OC carry either previously reported pathogenic variants or potentially pathogenic variants in genes known to be associated with isolated or syndromic forms of congenital hypogonadotropic hypogonadism. Functional studies and studies of other cohorts are recommended to establish the causality of these variants.

Clinical risk score for central precocious puberty among girls with precocious pubertal development: a cross sectional study

BackgroundThe gold standard for the diagnosis of central precocious puberty (CPP) is gonadotropin-releasing hormone (GnRH) or GnRH analogs (GnRHa) stimulation test. But the stimulation test is time-consuming and costly. Our objective was to develop a risk score model readily adoptable by clinicians and patients.MethodsA cross-sectional study based on the electronic medical record system was conducted in the Children’s Hospital, Fudan University, Shanghai, China from January 2010 to August 2016. Patients with precocious puberty were randomly split into the training (n = 314) and validation (n = 313) sample. In the training sample, variables associated with CPP (P < 0.2) in univariate analyses were introduced in a multivariable logistic regression model. Prediction model was selected using a forward stepwise analysis. A risk score model was built with the scaled coefficients of the model and tested in the validation sample.ResultsCPP was diagnosed in 54.8% (172/314) and 55.0% (172/313) of patients in the training and validation sample, respectively. The CPP risk score model included age at the onset of puberty, basal luteinizing hormone (LH) concentration, largest ovarian volume, and uterine volume. The C-index was 0.85 (95% CI: 0.81–0.89) and 0.86 (95% CI: 0.82–0.90) in the training and the validation sample, respectively. Two cut-off points were selected to delimitate a low- (< 10 points), median- (10–19 points), and high-risk (≥ 20 points) group.ConclusionsA risk score model for the risk of CPP had a moderate predictive performance, which offers the advantage of helping evaluate the requirement for further diagnostic tests (GnRH or GnRHa stimulation test).

Gonadotropin-releasing hormone stimulation test and diagnostic cutoff in precocious puberty: a mini review.

The gonadotropin-releasing hormone (GnRH) stimulation test is a valuable tool in diagnosing and differentiating causes of early pubertal occurrences. Utility of the test can be limited in some instances, however, including the early phases of pubertal hypothalamic-pituitary-gonadal axis activation, in girls showing commonly overlapping pictures, and in obese children due to excess circulating estrogen that suppresses luteinizing hormone (LH). A lack of consistent baseline and stimulated gonadotropin cutoffs observed in different studies also contributes to limitations in testing. Nevertheless, early detection of true pathological causes for pubertal disorders is needed to allow prompt treatment and better prognosis. While basal LH can be beneficial as a good screening tool for detecting pubertal disorder, it does not preclude the need for GnRH testing. The aim of this review was to highlight the role of GnRH stimulation tests and varying testing cutoffs in diagnosis of precocious puberty and its classification.

Puberty and Inhibin B in 35 Adolescents With Pituitary Stalk Interruption Syndrome.

Background: In patients with pituitary stalk interruption syndrome (PSIS), long-term follow-up is necessary to address their gonadotrophic status. The objectives of this study were (1) to describe pubertal features of and (2) to assess the ability of serum inhibin B concentration to predict hypogonadotropic hypogonadism (HH) in patients with PSIS.Methods: This retrospective single-center study included 35 patients with PSIS and known gonadotrophic status for whom a serum sample preserved at −22°C (collected at initial evaluation or later) was available for measuring inhibin B by the same hormonal immunoassay method.Results: Among the 21 boys, 15 had normal puberty (early in two), and six had partial (n = 2) or complete (n = 4) HH. Among the 14 girls, five had normal puberty (early in one)—four with regular menses and one in the process of puberty—, four had complete HH, and five had amenorrhea (primary in three and secondary in two) after normal pubertal development, despite a normal pubertal gonadotropin response to gonadotropin-releasing hormone test. These were considered as having partial HH. Only three boys had values over the normal lower range for serum inhibin B concentrations despite partial (n = 2) or complete (n = 1) HH. Inhibin B concentrations were low in all girls with complete HH, normal in all those with partial HH except in one and in those with normal puberty except in two. Considering boys and girls together, the occurrence of under-range inhibin B was significantly higher in those with HH than in those without (47 vs. 10%, p = 0.02). All 15 patients with HH had associated thyroid-stimulating hormone and adrenocorticotropic hormone deficiency except for 3 girls with partial HH.Conclusions: Under-range inhibin B concentrations in patients with PSIS might be suggestive of HH. These concentrations provide a simple first-line predictive test, especially in boys.

Treatment with Depot Leuprolide Acetate in Girls with Idiopathic Precocious Puberty: What Parameter should be Used in Deciding on the Initial Dose?

Objective:Doses of gonadotropin releasing hormone (GnRH) analogues used to treat idiopathic central precocious puberty (iCPP) vary among clinicians. Study aims were to evaluate the efficacy of a monthly 3.75 mg dose of leuprolide acetate (LA) to suppress the hypothalamo-pituitary-gonadal (HPG) axis in girls with iCPP and to determine factors that may have an impact on the supressing dose.Methods:Study subjects were 220 girls receiving LA for iCPP. LA was started at a dose of 3.75 mg/28 days. Suppression was assessed using the GnRH test at the third month. To assess clinical suppression signs and symptoms of puberty were also evaluated. The dose of LA was increased to 7.5 mg/28 days in those who had a peak luteinising hormone (LH) ≥2 IU/L and in whom adequate clinical suppression of puberty was absent. Receiver operating characteristic curves were used to determine thresholds for clinical and hormonal factors affecting the suppressing dose of LA. Logistic regression analyses were used to investigate thresholds which might differentiate between those requiring high dose for suppression and those in whom lower dose LA was adequate.Results:Peak stimulated LH <2 IU/L was achieved in 88.6% with a dose of LA of 3.75 mg (0.11±0.03 mg/kg). Significant variables for differentiating the two doses were body weight (Wt) of 36.2 kg and/or body mass index (BMI)-standard deviation scores (SDS) of 1.64 (p<0.001). Multiple logistic regressions showed that Wt and BMI-SDS values above thresholds indicated requirement of LA at a dose of 7.5 mg/28 days (p<0.001).Conclusion:Monthly injections of 3.75 mg LA is an effective treatment in the majority of girls with iCPP. However, a higher initial dose may be preferred in patients with a Wt ≥36 kg or BMI-SDS ≥1.6 for effective suppression of the HPG axis.

Central Precocious Puberty in two Boys with Prader-Willi Syndrome on Growth Hormone Treatment

Prader-Willi syndrome (PWS) is a rare genetic neuroendocrine disorder characterized by hypotonia, obesity, short stature, and mental retardation. Incomplete or delayed pubertal development as well as premature adrenarche are usually found in PWS, whereas central precocious puberty is rarely seen. This study reports the clinical, biochemical, and histologic findings in 2 boys with PWS who developed central precocious puberty. Both boys were started on growth hormone therapy during the first years of life according to the PWS indication. They had both bilateral cryptorchidism at birth and had orchidopexy in early childhood. Retrospective histologic analysis of testicular biopsies demonstrated largely normal tissue architecture and germ cell maturation, but severely decreased number of prespermatogonia in one of the patients. Both boys had premature adrenarche around the age of 6. Precocious puberty was diagnosed in both boys with enlargement of testicular volume (>3 mL), signs of virilization and a pubertal response to a gonadotropin-releasing hormone (GnRH) test and they were both treated with GnRH analog. The cases described here displayed typical characteristics for PWS, a considerable heterogeneity of the hypothalamic-pituitary function, as well as testicular histology. Central precocious puberty is extremely rare in PWS boys, but growth hormone treatment may play a role in the pubertal timing.

Initiation of the Hypothalamic-Pituitary-Gonadal Axis in Young Girls Undergoing Central Precocious Puberty Exerts Remodeling Effects on the Prefrontal Cortex.

Central precocious puberty (CPP) has been shown to exert significant effects on psychosocial development. These early puberty-related hormones and psychosocial functional changes are considered to be associated with specific brain development. However, the biological mechanisms underlying the sculpting of human brain architecture and modulation of psychosocial transformation by puberty-related hormonal maturation remain elusive, especially during the early phase of CPP. The current investigation aims to specify the brain regions in which early hormone-related maturation effects occur during CPP and their relationships with psychological functions. 65 young girls (aged 4.3–8.0 years) underwent structural imaging on a 3T MR system, completed psychological tests and performed the gonadotropin-releasing hormone (GnRH) stimulation test to identify hormonal manifestations of hypothalamic–pituitary–gonadal axis (HPG axis) activation. Based on the GnRH test, 28 young girls were identified with CPP, whereas the other 37 girls were identified with non-central precocious puberty (NCPP). Cortical parameters were calculated and compared between the two groups after adjusting for age, weight, and height. Brain regions showing group differences were extracted and correlated with serum hormone levels and psychological parameters. The CPP girls showed thinner cortices primarily in the right rostral middle frontal cortex. This morphological difference was positively correlated with stimulated estradiol (E2) levels. Further, higher E2 levels were significantly associated with higher hyperactivity scores. Premature HPG axis activation in CPP girls at an early stage appears to exert remodeling effects on brain anatomy, primarily in the prefrontal cortex, which may affect psychological development following the emergence of robust changes in sex hormones.

Arterial Spin Labeling and Central Precocious Puberty.

To evaluate anon-invasive method to assess the progressivity of idiopathic central precocious puberty (CPP) by quantifying perfusion of the pituitary stalk with arterial spin labeling (ASL) and using the gonadotropin-releasing hormone (GnRH) test as areference test to define progressive CPP. In asingle center retrospective study, 52consecutive patients, observed between October 2015 and April 2017 and referred with early signs of puberty, were evaluated using the GnRH test and cerebral magnetic resonance imaging (MRI). Patients with peripheral or non-idiopathic puberty were excluded. The distribution of perfusion values between patients with progressive and non-progressive CPP was compared using anonparametric Mann-Whitney U‑test. In this study 35 patients were included and 29 had progressive CPP. These patients displayed significantly higher cerebral blood flow (CBF) values than the 6patients with non-progressive CPP (p = 0.006). The median CBF for patients with non-progressive and progressive CPP was 45.25 ml/min/100 g (interquartile range 36.9-54) vs. 65 ml/min/100 g (interquartile range 55.5-74.5), respectively. To determine if the CPP was progressive, the best CBF threshold was 55.5 ml/min/100 g with asensitivity of 76%, aspecificity of 83% and an accuracy of 77%. There were strong significant correlations between CBF and LH peak (r = 0.67, p < 0.001) and between CBF and LH/FSH peaks ratio [r = 0.71, p < 0.001] during the GnRH test. Arterial spin labelling (ASL) offers anovel tool to assess the progressivity of idiopathic CPP.

Meta-Analysis of Paediatric Patients with Central Precocious Puberty Treated with Intramuscular Triptorelin 11.25 mg 3-Month Prolonged-Release Formulation

Background/Aims: A meta-analysis was undertaken to assess the effect of triptorelin 11.25 mg 3-month prolonged-release formulation in central precocious puberty (CPP). Methods: All available clinical studies with triptorelin 11.25 mg were included. The primary outcome was the proportion of children with suppressed luteinising hormone (LH) response (peak LH ≤3 IU/L) to the gonadotrophin-releasing hormone (GnRH) test 3 months after triptorelin 11.25 mg injection. Secondary outcomes included: the proportion with suppressed peak LH response at 6 months and the proportion with suppressed peak follicle-stimulating hormone (FSH) response (≤3 IU/L), suppressed oestradiol (≤20 pmol/L) in girls or suppressed testosterone (≤30 ng/dL) in boys at 3 months. Results: 153 children (13 boys, 140 girls) were included. The proportion with a suppressed peak LH response to the GnRH test was 87.6% (95% CI: 81.3–92.4, p < 0.0001, for a proportion >70%) and 92.8% (95% CI: 87.5–96.4, p < 0.0001, for a proportion >70%) at 3 and 6 months, respectively. FSH peak, oestradiol, and testosterone were suppressed in 86.7% (95% CI: 79.1–92.4), 97.1% (95% CI: 91.6–99.4), and 72.7% (95% CI: 39.0–94.0) of children at 3 months, respectively. Conclusion: Triptorelin 11.25 mg 3-month formulation is efficacious in suppressing LH peak and other gonadal hormones and in slowing the progression of CPP in children.