Basal luteinizing hormone and follicular stimulating hormone: is it sufficient for the diagnosis of precocious puberty in girls?

Screening for central precocious puberty by single basal Luteinizing Hormone levels

PURPOSE

To identify cut-off for basal LH levels and for pelvic ultrasound uterine and ovarian parameters indicating an Hypotalamic-Pituitary-Gonadal (HPG) axis activation as diagnostic of Central Precocious Puberty (CPP).

METHODS

248 girls referred for suspected precocious/early puberty who had undergone a GnRH stimulation test were enrolled and divided into three groups: Premature Idiopathic Thelarche (PIT), CPP, and Early Puberty (EA). For every patient basal serum Luteinising Hormone (LH) and Follicle Stimulating Hormone (FSH), basal LH/FSH ratio and pelvic ultrasonographic parameters were also collected. Through the use of Receiver Operating Curves (ROCs) the sensitivity (Se) and specificity (Sp) of basal LH, FSH, LH/FSH ratio and ultrasonographic parameters were evaluated at each level and Area Under the Curve (AUC) was measured.

RESULTS

Basal LH model ≥0.14 mIU/mL reached the highest predictability (90.6% and 78.2%, Se and Sp, respectively). Basal LH/FSH ratio ≥0.1 showed a sensitivity of 85.90% and a specificity of 78.14%, while basal FSH cut-off (≥2.36 mIU/mL) had the lowest predictability, with a less favourable sensitivity (71%) and specificity (70.5%). Cut-off point for uterine length as 35 mm, (83.5% and 42.9% of Se and Sp, respectively) was calculated. For ovarian volumes, ROC curves showed very low sensitivity and specificity.

CONCLUSION

A single basal LH measurement under the cut-off limit may be adequate to exclude an HPG axis activation as CPP.

Diagnostic model based on multiple factors for girls with central precocious puberty

OBJECTIVES

The GnRH stimulation test has been used as the gold standard for the diagnosis of central precocious puberty (CPP), but it has some practical barriers. This study intends to build a diagnostic model of CPP in girls based on the population in northern China.

METHODS

A total of 163 girls with precocious puberty (PP) were included from December 2018 to December 2019. Multifactor logistic regression analysis was conducted. Based on the results of multivariate logistic regression analysis, a nomogram was established for clinical application.

RESULTS

A multi logistic regression model showed that LH (OR=1.238, 95 % CI: 1.067-1.436, p=0.005), inhibin B (OR=1.066, 95 % CI: 1.032-1.100, p<0.001), bone age (OR=1.563, 95 % CI: 1.037-2.358, p=0.033), and uterine length (OR=1.180, 95 % CI: 1.034-1.348, p=0.014) were diagnostic factors for CPP. The prediction model AUC was 0.906 (95 % CI: 0.852-0.959, p<0.001).

CONCLUSIONS

We successfully developed a nomogram model for CPP patients based on clinical data. The diagnostic prediction model included four indicators: basal LH, inhibin B, bone age, and uterine body length.

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

CONTEXT

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.

OBJECTIVE

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.

METHODS

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.

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.

CONCLUSION

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.

Urine Sampling Protocol Recommendations for Reliable Determination of Total Urinary Luteinizing Hormone Immunoreactivity in the Pediatric Population

This study investigates day-to-day variations in urinary luteinizing hormone (U-LH) concentrations in children, focusing on potential minimization or correction methods. 95 children and adolescents (51 boys, 44 girls, ages 5-17) provided daytime and evening urine samples for U-LH determinations over three consecutive days. No consistent day-to-day differences in U-LH levels were observed, although random variations, particularly in adolescents aged 13 or older, were noted. The net inter-assay CV% for U-LH changes over three days showed high variability, averaging 24.6% to 28.0% for boys and 21.6% to 27.3% for girls, independent of sex, collection time, or U-LH level. To reliably determine total urinary luteinizing hormone immunoreactivity in the pediatric population, it is advisable to collect multiple first-morning voided samples for at least three consecutive days as an interim solution, pending the development of a standardized protocol or correction method for varying urine composition. Strict adherence, especially for adolescents aged 13 or older, is vital.

Precocious Puberty: Types, Pathogenesis and Updated Management

Precocious puberty (PP) means the appearance of secondary sexual characters before the age of eight years in girls and nine years in boys. Puberty is indicated in girls by the enlargement of the breasts (thelarche) in girls and in boys by the enlargement of the testes in either volume or length (testicular volume = 4 mL, testicular length = 25 mm, or both). Two types of PP are recognized - namely central PP (CPP) and peripheral PP (PPP). This paper aims to describe the clinical findings and laboratory workup of PP and to illustrate the new trends in the management of precocious sexual maturation. Gonadotropin-releasing hormone (GnRH)-independent type (PPP) refers to the development of early pubertal maturation not related to the central activation of the hypothalamic-pituitary-gonadal (HPG) axis. It is classified into genetic or acquired disorders. The most common forms of congenital or genetic causes involve McCune-Albright syndrome (MAS), familial male-limited PP, and congenital adrenal hyperplasia. The acquired causes include exogenous exposure to androgens, functioning tumors or cysts, and the pseudo-PP of profound primary hypothyroidism. On the other hand, CPP is the most common and it is a gonadotropin-dependent form. It is due to premature maturation of the HPG axis. CPP may occur as genetic alterations, such as MKRN3, DLK1, or KISS1;as a part of mutations in the epigenetic factors that regulate the HPG axis, such as Lin28b and let-7; or as a part of syndromes, central lesions such as hypothalamic hamartoma, and others. A full, detailed history and physical examination should be taken. Furthermore, several investigations should be conducted for both types of PP, including the estimation of serum gonadotropins such as luteinizing and follicle-stimulating hormones and sex steroids, in addition to a radiographic workup and thyroid function tests. Treatment depends on the type of PP: Long-acting GnRHa, either intramuscularly or implanted, is the norm of care for CPP management, while in PPP, especially in congenital adrenal hyperplasia, the goal of management is to suppress adrenal androgen secretion by glucocorticoids. In addition, anastrozole and letrozole - third-generation aromatase inhibitors - are more potent for MAS.

Slower progression of central puberty in overweight girls presenting with precocious breast development

PURPOSE

Overweight (OW)/obese girls tend to have an earlier pubertal onset than girls with normal weight. However, only a few studies have reported the progression of puberty in these girls. This study aimed to identify risk factors for rapid pubertal progression in OW/obese girls presenting with precocious breast development.

METHODS

This retrospective cohort study reviewed the medical records of 110 OW (body mass index [BMI] ≥85th percentile for age and sex) and 213 nonoverweight (NW, BMI <85th percentile for age and sex) girls who presented with breast budding before 8 years of age. OW girls were divided into 2 subgroups: girls with central puberty progression before 9 years of age (OW-RP) and those without (OW-SP).

RESULTS

Progression to central puberty before the age of 9 was more common in NW girls than in OW girls (83.8 % vs. 65.2 % in NW vs. OW group, p<0.001), and progression-free survival for 1, 2, and 3 years was higher in the OW group (p<0.001). In a subgroup analysis of OW girls, the OW-RP subgroup had more advanced bone age (BA) at the first visit (p=0.047) and higher initial luteinizing hormone (LH, p=0.010) levels than the OW-SP subgroup. Being NW (p=0.001) and having more advanced BA (p=0.023) at the initial workup were the risk factors for pubertal progression before age 9.

CONCLUSION

Pubertal progression seems to be slower in OW girls than in NW girls presenting with precocious breast development. However, it can progress rapidly in OW girls with particularly pronounced BA advancement and high LH levels at the initial workup.

Metabolic characteristics and pathogenesis of precocious puberty in girls: the role of perfluorinated compounds

BACKGROUND

Precocious puberty (PP) in girls is traditionally defined as the onset of breast development before the age of 8 years. The specific biomarkers of premature thelarche (PT) and central precocious puberty (CPP) girls are uncertain, and little is known about their metabolic characteristics driven by perfluorinated compounds (PFCs) and clinical phenotype. This study aimed to screen specific biomarkers of PT and CPP and elucidate their underlying pathogenesis. The relationships of clinical phenotype-serum PFCs-metabolic characteristics were also explored to reveal the relationship between PFCs and the occurrence and development of PT and CPP.

METHODS

Nuclear magnetic resonance (NMR)-based cross-metabolomics strategy was performed on serum from 146 PP (including 30 CPP, 40 PT, and 76 unspecified PP) girls and 64 healthy girls (including 36 prepubertal and 28 adolescent). Specific biomarkers were screened by the uni- and multivariate statistical analyses. The relationships between serum PFCs and clinical phenotype were performed by correlation analysis and weighted gene co-expression network analysis to explore the link of clinical phenotype-PFCs-metabolic characteristics in PT and CPP.

RESULTS

The disordered trend of pyruvate and butyrate metabolisms (metabolites mapped as formate, ethanol, and 3-hydroxybutyrate) were shared and kept almost consistent in PT and CPP. Eight and eleven specific biomarkers were screened for PT and CPP, respectively. The area under curve of specific biomarker combination was 0.721 in CPP vs. prepubertal, 0.972 in PT vs. prepubertal, 0.646 in CPP vs. prepubertal integrated adolescent, and 0.822 in PT vs. prepubertal integrated adolescent, respectively. Perfluoro-n-heptanoic acid and perfluoro-n-hexanoic acid were statistically different between PT and CPP. Estradiol and prolactin were significantly correlated with PFCs in CPP and PT. Clinical phenotypes and PFCs drive the metabolic characteristics and cause metabolic disturbances in CPP and PT.

CONCLUSIONS

The elevation of formate, ethanol, and 3-hydroxybutyrate may serve as the early diagnostic indicator for PP in girls. But the stratification of PP still needs to be further determined based on the specific biomarkers. Specific biomarkers of CPP and PT exhibited good sensitivity and can facilitate the classification diagnosis of CPP and PT. PFC exposure is associated with endocrine homeostasis imbalance. PFC exposure and/or endocrine disturbance directly or indirectly drive metabolic changes and form overall metabolic network perturbations in CPP and PT.

Evaluation of Clinical and Laboratory Findings in the Differential Diagnosis of Central Precocious Puberty and Premature Thelarche

Aim

In this study, it was aimed to examine the clinical and laboratory findings that can be used to predict central precocious puberty (CPP) in cases whose breast development started before the age of 8.

Materials and Methods

The chronological age, anthropometric measurements, bone age (BA), hormone test results and pelvic ultrasonography findings of the cases were recorded. Those with a peak luteinizing hormone (LH) level of ≥5 IU/L in the gonadotropin-releasing hormone (GnRH) stimulation test were classified as CPP and those with a peak LH level of <5 IU/L were classified as prepubertal cases. A receiver operating characteristic (ROC) analysis was performed to determine the diagnostic accuracy of laboratory variables.

Findings

A total of 297 female cases were included in the study. The age at the time of admission, height-standard deviation score (SDS), BA, the long axis of the uterus and the volumes of the right and left ovaries of the cases diagnosed with CPP were found to be significantly higher than those of the prepubertal group. The cut-off value providing the best sensitivity (99%) and specificity (99%) for the peak LH was found to be 4.55; the cut-off value providing the best sensitivity (94%) and specificity (85%) for the peak LH/follicle-stimulating hormone (FSH) ratio was found to be 0.32 and the cut-off value providing the best sensitivity (47%) and specificity (93%) for the basal LH was found to be 0.13.

Conclusion

We believe that in female cases with early breast development, a peak LH level of ≥4.55 may possibly indicate CPP and a basal LH level of <0.13 can significantly rule out CPP.

Machine Learning Approach for Prediction of the Test Results of Gonadotropin-Releasing Hormone Stimulation: Model Building and Implementation

Precocious puberty in girls is defined as the onset of pubertal changes before 8 years of age, and gonadotropin-releasing hormone (GnRH) agonist treatment is available for central precocious puberty (CPP). The gold standard for diagnosing CPP is the GnRH stimulation test. However, the GnRH stimulation test is time-consuming, costly, and requires repeated blood sampling. We aimed to develop an artificial intelligence (AI) prediction model to assist pediatric endocrinologists in decision making regarding the optimal timing to perform the GnRH stimulation test. We reviewed the medical charts of 161 girls who received the GnRH stimulation test from 1 August 2010 to 31 August 2021, and we selected 15 clinically relevant features for machine learning modeling. We chose the models with the highest area under the receiver operating characteristic curve (AUC) to integrate into our computerized physician order entry (CPOE) system. The AUC values for the CPP diagnosis prediction model (LH ≥ 5 IU/L) were 0.884 with logistic regression, 0.912 with random forest, 0.942 with LightGBM, and 0.942 with XGBoost. For the Taiwan National Health Insurance treatment coverage prediction model (LH ≥ 10 IU/L), the AUC values were 0.909, 0.941, 0.934, and 0.881, respectively. In conclusion, our AI predictive system can assist pediatric endocrinologists when they are deciding whether a girl with suspected CPP should receive a GnRH stimulation test. With proper use, this prediction model may possibly avoid unnecessary invasive blood sampling for GnRH stimulation tests.

Triptorelin stimulated luteinizing hormone concentrations for diagnosing central precocious puberty: study of diagnostic accuracy

PURPOSE

Gonadotropin-releasing hormone (GnRH) stimulation test is the gold standard for diagnosing central precocious puberty (CPP). However, intravenous GnRH is not always readily available. The aim of the present study was to evaluate the diagnostic accuracy of triptorelin-stimulated luteinizing hormone (LH) concentrations in the diagnosis of CPP among girls presenting with premature thelarche compared to the gold standard GnRH test.

METHODS

A prospective, case-control (CPP vs isolated premature thelarche), clinical study evaluating the diagnostic accuracy of triptorelin-stimulated LH concentrations in 60 girls with premature thelarche was performed. All girls underwent stimulation with subcutaneous triptorelin injection and intravenous GnRH in a randomized order. During the stimulation test with triptorelin, LH and FSH were measured at time 0, 30, 60, 90, 120, and 180 min after the injection. Estradiol was sampled 24 h after the injection. During the GnRH test, LH and FSH were measured at time 0, 30, 45, and 60 min. Girls with peak GnRH-stimulated LH concentrations ≥5.0 IU/L were classified as having CPP. Area under the curve (AUC) for triptorelin-stimulated LH concentrations was assessed using the receiver operating characteristic (ROC) analysis.

RESULTS

Triptorelin-stimulated LH concentrations were significantly higher in girls who had CPP according to the GnRH test (53.3%). LH peaked at 180 min after the triptorelin injection. The highest diagnostic accuracy for CPP (AUC = 0.973, sensitivity 96.9%, specificity 89.3%) at 180 min was at a LH concentration ≥3.4 IU/L. The 24 h estradiol concentration did not improve the predictive model.

CONCLUSIONS

Measuring LH concentrations 180 min after triptorelin injection with a cut-off value of ≥3.4 IU/L demonstrated a high diagnostic accuracy compared to the GnRH test. Thus, stimulation with triptorelin can be used as a reliable alternative for diagnosing CPP in girls with premature thelarche.

Development and Validation of Clinical Diagnostic Model for Girls with Central Precocious Puberty: Machine-learning Approaches

BACKGROUND

A brief gonadotropin-releasing hormone analogues (GnRHa) stimulation test which solely focused on LH 30-minute post-stimulation was considered to identify girls with central precocious puberty (CPP). However, it was tested using traditional statistical methods. With advanced computer science, we aimed to develop a machine learning-based diagnostic model that processed baseline CPP-related variables and a brief GnRHa stimulation test for CPP diagnosis.

METHODS

We recruited girls suspected of precocious puberty and underwent a GnRHa stimulation test at Children Hospital 2, Vietnam, and Cathay General Hospital, Taiwan. Clinical data, bone age measurement, and 30-min post-stimulation blood test were used to build up the predictive model. The candidate model was developed by different machine learning algorithms that were mainly evaluated by sensitivity, specificity, the area under the receiver operator characteristic curve (AUC), and F1-score in internal and external validation data to classify girls as CPP and non-CPP at different time-points (0-min, 30-min, 60-min, and 120-min post-stimulation).

RESULTS

Among the 614 girls diagnosed with PP, 524 (85.3%) had CPP. The random forest algorithm yielded the highest value of F1-score (0.976), specificity (0.893), positive predicted value (0.987), and relatively high value of AUC (0.972) that contributed to high probability to identify CPP. The performance metrics of the 30-min post-stimulation diagnostic model including sensitivity and specificity surpassed those of the 0-minute model (0-min) and were equivalent to those of the model obtained 60-min and 120-min post-stimulation. Hence, our machine learning-based model helps shorten the stimulation test to 30 minutes after GnRHa injection, in general, it requires 120 minutes for a completed GnRHa stimulation test.

CONCLUSIONS

We developed a diagnostic model based on clinical features and a single sample 30-minute post-stimulation to identify CPP in girls that can reduce distress for children caused by multiple blood samplings.

The utility of serum inhibin B, anti-Müllerian hormone and insulin growth factor-1 in predicting a positive response to GnRH analogs for diagnosing central precocious puberty in girls

OBJECTIVES

The use of inhibin B (INHB), anti-Müllerian hormone (AMH) and insulin-like growth factor-1 (IGF-1) in differentiating central precocious puberty (CPP) from non-CPP was evaluated.

METHODS

In total, 115 Chinese girls were recruited (CPP: 44, non-CPP: 71). The diagnostic performance of INHB, AMH and IGF-1 in differentiating CPP from non-CPP was analyzed using receiver operating characteristic (ROC) curves.

RESULTS

INHB levels were higher in the CPP group than in the non-CPP group (55.56 ± 22.42 vs. 32.97 ± 15.59 pg/mL; p<0.001). AMH levels were similar in the CPP and non-CPP groups (6.63 ± 3.74 vs. 5.70 ± 3.15 pg/mL; p=0.158), and IGF-1 levels were much higher in the CPP group than in the non-CPP group (290.75 ± 79.78 vs. 200.10 ± 54.01 pg/mL; p<0.001). The area under the ROC curve (AUC) was greatest for INHB (0.819, standard error (SE) 0.041), followed by IGF-1 (0.809, SE 0.047) and AMH (0.567, SE 0.057). Among the ROC curves including combinations of these parameters, the AUC for INHB + IGF-1 was 0.849 and that for INHB + AMH was 0.768.

CONCLUSIONS

Serum INHB and IGF-1 measurements could predict positive responses to gonadotropin-releasing hormone (GnRH) analog stimulation in girls with precocious puberty.

Diagnosis and management of precocious sexual maturation: an updated review

The classic definition of precocious sexual maturation is the development of secondary sexual characteristics before 8 years of age in girls and before 9 years of age in boys. It is classified as central precocious puberty when premature maturation of the hypothalamic-pituitary-gonadal axis occurs, and as peripheral precocious puberty when there is excessive secretion of sex hormones, independent of gonadotropin secretion. Precocious sexual maturation is more common in girls, generally central precocious puberty of idiopathic origin. In boys, it tends to be linked to central nervous system abnormalities. Clinical evaluation should include a detailed history and physical examination, including anthropometric measurements, calculation of growth velocity, and evaluation of secondary sexual characteristics. The main sign to suspect the onset of puberty is breast tissue development (thelarche) in girls and testicular enlargement (≥4 mL) in boys. Hormonal assessment and imaging are required for diagnosis and identification of the etiology. Genetic testing should be considered if there is a family history of precocious puberty or other clinical features suggestive of a genetic syndrome. Long-acting gonadotropin-releasing hormone analogs are the standard of care for central precocious puberty management, while peripheral precocious puberty management depends on the etiology.Conclusion: The aim of this review is to address the epidemiology, etiology, clinical assessment, and management of precocious sexual maturation. What is Known: • The main sign to suspect the onset of puberty is breast tissue development (thelarche) in girls and testicular enlargement (≥4 mL) in boys. The classic definition of precocious sexual maturation is the development of secondary sexual characteristics before 8 years of age in girls and before 9 years of age in boys. • Long-acting gonadotropin-releasing hormone agonist (GnRHa) is the standard of care for CPP management, and adequate hormone suppression results in the stabilization of pubertal progression, a decline in growth velocity, and a decrease in bone age advancement. What is New: • Most cases of precocious sexual maturation are gonadotropin-dependent and currently assumed to be idiopathic, but mutations in genes involved in pubertal development have been identified, such as MKRN3 and DLK1. • A different preparation of long-acting GnRHa is now available: 6-month subcutaneous injection.

[Clinical guidelines «Precocious puberty»]

The precocious puberty is an urgent problem of pediatric endocrinology characterized by clinical and pathogenetic heterogeneity. The appearance of secondary sex characteristics before the age of 8 years in girls and 9 years in boys requires timely diagnosis and the appointment of pathogenetically justified treatment in order to achieve the target indicators of final growth and prevent social deprivation. The developed clinical guidelines are the main working tool of the practitioner. They briefly and structurally present the main information about the epidemiology and modern classification of рrecocious puberty, methods of its diagnosis and treatment based on the principles of evidence-based medicine.

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

BACKGROUND

The 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.

METHODS

A 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.

RESULTS

CPP 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.

CONCLUSIONS

A 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).

Effectiveness of basal LH in monitoring central precocious puberty treatment in girls

OBJECTIVES

Treatment of central precocious puberty (CPP) is based on administration of GnRH agonists in order to suppress hypothalamic-pituitary-gonadal axis and thus induce the stabilization or regression of pubertal development. Our aim was to determine whether the single basal serum LH and/or FSH concentration could be an effective tool to assess the efficacy of treatment to suppress activation of hypothalamic-pituitary axis.

PATIENTS AND METHODS

Serum LH and FSH were measured before and after the GnRH injection, as well as E2 basal levels in 60 girls with documented idiopathic CPP at diagnosis and 18 and 30 months after the beginning of therapy.

RESULTS

At diagnosis, peaks of >5 IU/L of LH and of FSH were observed in 100 and 91.6% of girls, respectively, with basal LH values of <1 IU/L in 70% and basal FSH levels of <1 IU/L in 10%. E2 were <20 pg/mL in 36.6%. After 18 months, a suppressed peak (i.e. <3 IU/L) was recorded in 85% of girls (p<0.01) for LH and in 98.3% for FSH (p<0.01). Basal LH <1 IU/L was detected in 85% (p<0.01) and basal FSH ≤1 IU/L in 40% (p<0.01). Serum E2 ≤20 pg/mL was recorded in 61.6% (p<0.01). After 30 months, all patients showed LH suppressed peak (p<0.01) and 98.3% suppressed FSH peak (p<0.01). 100% showed basal LH concentrations <1 IU/L (p<0.01) and 38.3% FSH basal values <1 UI/mL (p<0.01). E2 ≤20 pg/mL was observed in 32.72% (p=NS).

CONCLUSIONS

Basal LH values are a reliable indicator of the efficacy of GnRHa therapy after 30 months of GnRHa therapy.

Adequacy of basal luteinizing hormone levels in the diagnosis of central precocious puberty

AIM

To determine the clinical, anthropometric, and laboratory parameters that could be used for differentiating central precocious puberty from premature thelarche in girls who had breast development between the ages of 3 and 8 years.

MATERIAL AND METHODS

The study included 344 girls (196 girls with idiopathic central precocious puberty, 148 girls with premature thelarche) who underwent gonadotropin- releasing hormone stimulation tests for breast development. Age at diagnosis, bone age, anthropometric measurements, basal/stimulated hormone levels were recorded. Univariate regression analysis was performed to determine the parameters that could be used for differentiating precocious puberty from premature thelarche. Significant parameters in univariate analyses were grouped according to the thresholds determined using receiver operating characteristic curves and reevaluated through multivariate analysis.

RESULTS

The bone age, height-standard deviation score, body mass index-standard deviation score, and growth velocity-standard deviation score at diagnosis were found to be higher; pubertal stages were found to be more advanced; uterus and ovary volumes were found to be larger; and the basal/peak luteinizing hormone, follicle-stimulating hormone, luteinizing hormone/follicle-stimulating hormone levels were found to be higher in the subjects with precocious puberty. There was no difference between estradiol levels between the two groups. The best thresholds to differentiate the two groups were found as 0.65 IU/L (78% sensitivity, 100% specificity), 1.9 IU/L (100% sensitivity, 72% specificity), 0.25 (67% sensitivity, 100% specificity) and 1.1 (69% sensitivity, 71% specificity), respectively, for basal luteinizing hormone, follicle-stimulating hormone, luteinizing hormone/follicle-stimulating hormone ratio, and the growth velocity-standard deviation score.

CONCLUSION

In girls presenting with early breast development, a basal luteinizing hormone level of ≥0.65 IU/L and a luteinizing hormone/follicle-stimulating hormone ratio of ≥0.25 are sensitive ways to demonstrate activation of the hypothalamo-pituitary-gonadal axis. Among these, the variable that gives the best sensitivity and specificity is the measurement of basal luteinizing hormone levels (≥0.65 IU/L), which can be used as a screening test in the diagnosis of central precocious puberty.

Basal serum luteinising hormone cut-off, and its utility and cost-effectiveness for aiding the diagnosis of the onset of puberty in girls with early stages of breast development

OBJECTIVE

To determine basal and gonadotrophin-releasing hormone analogue (GnRHa)-stimulated peak luteinising hormone (LH) cut-offs to diagnose onset of early or normal puberty in girls with each Tanner stage of breast (II and III).

DESIGN, PATIENTS AND MEASUREMENTS

A retrospective study of 601 girls with breast onset before 8 years of age who underwent GnRHa test was conducted. Patients were categorized as CPP and premature thelarche. Each group was divided into two subgroups; Tanner II and III. Cost-effectiveness analysis was performed.

RESULTS

In comparison with basal LH cut-off of 0.3 IU/L, basal LH cut-off of 0.2 IU/L had comparable specificity (Tanner II: 98.0% vs 94.8%, Tanner III: 98.8% vs 93.8%), but greater sensitivity (Tanner II: 28.3% vs 41.7%, Tanner III: 45.2% vs 59.3%). Specificity of basal LH cut-off of 0.2 IU/L was not inferior to that of the traditionally used peak LH of 5 IU/L. Using basal LH cut-off of 0.2 IU/L followed by GnRHa test in girls with negative basal LH was more cost-saving when compared with using the cut-off of 0.3 IU/L. Moreover, using basal LH cut-off of 0.2 IU/L followed by GnRHa test provided a cost reduction when compared with performing GnRHa test in all patients.

CONCLUSIONS

Basal serum LH cut-off of 0.2 IU/L could be a simple and cost-saving tool for initial diagnosis of onset of early or normal puberty in girls with Tanner II and III before proceeding to GnRH testing.

Near final adult height, and body mass index in overweight/obese and normal-weight children with idiopathic central precocious puberty and treated with gonadotropin-releasing hormone analogs

Background The standard treatment of central precocious puberty (CPP) is gonadotropin-releasing hormone analogues (GnRHa). It is a concern that children treated with GnRHa are at risk of developing obesity which could impair the treatment outcomes. This study aimed to investigate the effect of GnRHa on body mass index (BMI) standard deviation score (SDS), and the influence of BMI status on treatment outcomes in children with idiopathic CPP (iCPP). Methods A retrospective cohort study in children with iCPP who completed GnRHa treatment and had attained near final adult height (NFAH) was conducted. Children with a history of disease or drug ingestion which could affect their BMI were excluded. BMI, BMI SDS, height (Ht), Ht SDS, predicted adult height (PAH), and NFAH were compared at baseline, 1 and 2 years during treatment, and at NFAH according to the baseline BMI status; normal weight and overweight/obesity. Results Fifty-eight children with iCPP treated with GnRHa were enrolled. The BMI SDS was significantly increased at 1 and 2 years during treatment in the overweight/obese group and at 1 year during treatment in the normal-weight group. However, at NFAH (2 years after treatment discontinuation), the BMI SDS was not statistically different from baseline in both groups. Ht gain, change in Ht SDS and BMI SDS were not statistically different from the baseline in both groups. Conclusions GnRHa results in a transient increase in BMI SDS during treatment and returned to baseline after treatment cessation. The benefit of GnRHa treatment on final Ht improvement is similar between overweight/obese and normal-weight patients.

Dynamic Testing for Evaluation of Adrenal and Gonadal Function in Pediatric and Adult Endocrinology: An Overview

Dynamic tests are often considered as the backbone of endocrinology. These tests involve the use of an exogenous agent to manipulate the body's hormonal milieu for the diagnosis and characterization of an endocrine disorder. They are especially helpful in the evaluation of certain endocrine conditions, such as disorders of growth and pubertal maturation and disorders of sex development. A great deal of heterogeneity exists across clinicians with regard to the usage, methodology, and interpretation of these tests. This review outlines various dynamic tests used to evaluate adrenal and gonadal function in pediatric and adult endocrinology, along with their clinical application and interpretation.

Random urinary gonadotropins as a useful initial test for girls with central precocious puberty

Recent evidence indicates that urinary gonadotropins may be an alternative method for detecting pubertal disorders. The aim of this study was to evaluate the associations of first morning voided (FMV) and random urinary gonadotropins with the pubertal response to a gonadotropin-releasing hormone (GnRH) stimulation test to determine whether random urinary gonadotropins can be used as an alternative method for evaluating central precocious puberty (CPP). In total, 100 girls aged 6.0-8.9 years were enrolled. The subjects were divided into two groups according to their pubertal response to the GnRH stimulation test: a positive group (n = 68) and a negative group (n = 32). Random urinary luteinizing hormone (LH), follicle-stimulating hormone (FSH), and the LH:FSH ratio were significantly positively correlated with FMV urinary LH (r = 0.411, p < 0.001), FMV urinary FSH (r = 0.494, p < 0.001), and the FMV urinary LH:FSH ratio (r = 0.519, p < 0.001). The optimal cutoff values from receiver operating characteristic (ROC) curve analyses were determined to be 0.20 IU/L for random urinary LH (area under the curve (AUC) of 0.812, p < 0.001), 3.03 IU/L for random urinary FSH (AUC of 0.670, p = 0.004) and 0.08 for the random urinary LH:FSH ratio (AUC of 0.784, p < 0.001). No differences were observed between FMV and random urinary LH (p = 0.827), between FMV and random urinary FSH (p = 0.650), or between the FMV and random urinary LH:FSH ratio (p = 0.688) in ROC curve analyses with DeLong's test. Based on our findings, random urinary gonadotropins may be applicable in clinical practice as a useful initial test for girls with CPP.

Basal serum luteinizing hormone value as the screening biomarker in female central precocious puberty

PURPOSE

Precocious puberty refers to the development of secondary sex characteristics before ages 8 and 9 years in girls and boys, respectively. Central precocious puberty (CPP) is caused by premature activation of the hypothalamus-pituitary-gonadal (HPG) axis and causes thelarche in girls before the age of 8. A gonadotropin-releasing hormone (GnRH) stimulation test is the standard diagnostic modality for diagnosing CPP. However, the test cannot always be used for screening because it is expensive and time-consuming. This study aimed to find alternative reliable screening parameters to identify HPG axis activation in girls &lt;8 years old (CPP) and for girls 8-9 years old (early puberty, EP).

METHODS

From January 2013 to June 2015, medical records from 196 girls younger than 9 years old with onset of breast development were reviewed, including 126 girls who had a bone age (BA) 1 year above their chronological age. All patients underwent a GnRH stimulation test, and 117 underwent pelvic sonography. The girls were divided into 4 groups based on age and whether the GnRH stimulation test showed evidence of central puberty. Subanalyses were also conducted within each group based on peak luteinizing hormone (LH) level quartiles.

RESULTS

Basal serum LH level was the most sensitive marker for screening CPP and EP. The cutoff values were 0.245 IU/L for CPP under 8 years old (P=0.049, area under the curve [AUC]=0.764, 88% sensitivity, 48% specificity) and 0.275 IU/L for EP between 8-9 years old (P=0.005, AUC=0.813, 79% sensitivity, 77% specificity). Peak LH level decreased as BMI z-score among subgroups increased when there was no difference in BA; however, higher BA eliminated this effect.

CONCLUSION

Basal serum LH level is a useful screening parameter for diagnosing CPP and EP in girls. Peak LH levels were lower with increasing BMI z-score, although older BA eliminated this effect.

Central precocious puberty, functional and tumor-related

Precocious puberty is defined as the appearance of secondary sex characteristics before 8 years of age in girls and before 9 years of age in boys. Central precocious puberty (CPP) is diagnosed when activation of the hypothalamic-pituitary axis is identified. It is a rare disease with a clear female predominance. A background of international adoption increases its risk, with other environmental factors such as endocrine disruptors also being associated with CPP. The causes of CPP are heterogeneous, with alterations of the CNS being of special interest. Physical injuries of the CNS are more frequent in boys, while idiopathic etiology is more prevalent among girls. However, in the last decade the number of idiopathic cases has diminished thanks to the discovery of mutations in different genes, including KISS1, KISS1R, MKRN3, and DLK1 that cause CPP. For the diagnosis of CPP, hormone studies are needed in addition to the clinical data regarding signs of pubertal onset. For this purpose, the GnRH test continues to be the gold standard. Imaging analyses, such as bone age and brain MRI, are also very useful. Furthermore, genetic testing must be incorporated in the diagnosis of CPP, especially in familial cases. Early puberty has been related to various consequences in the medium and long term such as behavioral problems, breast cancer, obesity, and metabolic comorbidities. However, there are few studies that have exclusively analyzed patients with CPP. GnRH analogs are the most frequent treatment election with the main objective being to improve adult height. Currently, there are new formulations that are being investigated.

Paraneoplastic syndromes and other systemic disorders associated with neuroendocrine neoplasms

Neuroendocrine paraneoplastic syndromes (PNS) consist of metabolic disorders that accompany benign and malignant neoplasms but remain unrelated to mass effects or invasion by the primary tumor or its metastases. The underlying pathogenesis responsible for PNS usual clinical presentation relies on aberrant production of protein hormones, proteins and other substances by the tumor. Prompt recognition of characteristic signs and symptoms combined with serological identification of key substances may result in early diagnosis of PNS and its underlying malignancy. For these reasons, healthcare professionals should familiarize themselves with tumor-induced hypercalcemia, syndrome of inappropriate antidiuretic hormone, carcinoid syndrome, virilisation syndrome, gynecomastia, acromegaly, Cushing syndrome, osteogenic osteomalacia, tumor-induced hypoglycemia, necrolytic migratory erythema, and watery diarrhea, hypokalemia and achlorydria syndrome. Medical awareness for PNS can improve patient outcomes through earlier administration of cancer therapy and treatment, better symptomatic relief and prolong overall survival.

Morning basal luteinizing hormone, a good screening tool for diagnosing central precocious puberty

PURPOSE

The standard method used to diagnose central precocious puberty (CPP) is the gonadotropin releasing hormone stimulation test (GnRHST). However, this test is inconvenient for children because it is time-consuming and requires multiple samples. This study aimed to determine the reliability of morning unstimulated luteinizing hormone (mLH) level when screening for CPP, with an emphasis on the influence of diurnal variation.

METHODS

This study included 160 girls with signs of early puberty (SMR 2) under 8 years of age. They were classified as CPP or non-CPP based on their standard GnRHST. The auxological, biochemical, and hormonal characteristics of subjects were retrospectively evaluated. The prognostic value of single morning unstimulated gonadotropin level was examined for use in CPP screening.

RESULTS

Of 160 patients, 121 (75.6%) presented with CPP, and 39 (24.4%) were determined to be prepubertal. The mLH/mFSH (morning unstimulated follicular stimulating hormone) ratio showed significant differences between the 2 groups (P&lt;0.001). The mLH was correlated with GnRHST variables (r=0.532, P&lt;0.001). The mLH cutoff point when screening for CPP was 0.22 IU/L, which had sensitivity and specificity of 69.4% and 82.1%, respectively. In regression analysis, bone age (BA) (odds ratio [OR], 1.018; 95% confidence interval [CI], 0.967-1.071; P=0.506) and body mass index (BMI) (OR, 0.874; 95% CI, 0.583-1.310; P=0.515) were not significant predictors. The mLH≥0.22 IU/L group (OR, 9.596; 95% CI, 3.853-23.900; P&lt;0.001) was highly suggestive of CPP.

CONCLUSION

In this study, single morning unstimulated luteinizing hormone had clinical efficacy for CPP screening, but BA advanced over chronological age and BMI was not useful for CPP screening.

Central precocious puberty in girls: Diagnostic study and auxological response to triptorelin treatment

INTRODUCTION

There are several controversies regarding the diagnostic tests and management of central precocious puberty (CPP). The aim of this study is to present the experience acquired in a group of girls with CPP treated with triptorelin, and to analyze the auxological characteristics and diagnostic tests.

MATERIAL AND METHODS

An observational, retrospective study in a group of 60 girls with CPP was conducted between January 2010 and December 2017. Sociodemographic, auxological and hormonal data were recorded at diagnosis, and pelvic ultrasound and magnetic resonance imaging of the head were performed. Girls were treated with triptorelin and monitored after treatment discontinuation until menarche.

RESULTS

At treatment start, chronological age and bone age were 7.7±0.7 and 9.7±0.8 years respectively, and growth velocity was 8.3±1.6cm/year. Target height was 161.1±5.8cm. Peak LH level after stimulation was 16.6±12.1 IU/l. Ovarian volumes were greater than 3mL in 35% of cases. MRI of the head was pathological in seven girls (11.7%). At treatment completion, chronological age and bone age were 10.3±1.1 and 11.2±0.8 years respectively, and growth velocity was 4.7±1.4cm/year. At the age of menarche (11.9±0.9 years), height was 157.5±5.7cm.

CONCLUSIONS

Treatment of CPP with triptorelin appears to be beneficial. The possibility to block pubertal development and slow skeletal maturation allows patients to reach their target height. However, individualized auxological monitoring would be mandatory.

Advanced bone age as an indicator facilitates the diagnosis of precocious puberty

OBJECTIVE

Diagnosis of central precocious puberty has always been challenging in clinical practice. As an important method in the diagnosis of central precocious puberty, luteinizing hormone-releasing hormone stimulation test is complex and time-consuming. In many cases, clinical traits are inconsistent with luteinizing hormone-releasing hormone stimulation test results, therefore not reliable for diagnosis. In this study, the authors intended to find an indicator that predicts the results of the luteinizing hormone-releasing hormone stimulation test among subjects with early pubertal signs.

METHODS

Cases of 382 girls with early breast development before 8 years old and luteinizing hormone-releasing hormone stimulation test before 9 years old were included and underwent follow-up tests. Patients with peak luteinizing hormone level ≥5IU/L were considered positive in the luteinizing hormone-releasing hormone stimulation test. Anthropometric data, body mass index, bone age evaluation, blood hormones levels of luteinizing hormone, estradiol, follicle-stimulating hormone, and uterine and ovarian volumes were analyzed.

RESULTS

Subjects with positive results in the initial test demonstrated early bone maturation, accelerated growth, and elevated basal blood luteinizing hormone, estradiol, and follicle-stimulating hormone levels, when compared with subjects with negative results in the initial test. Subjects with positive results in the follow-up test presented a more advanced bone age and more accelerated linear growth, when compared with subjects with negative results in the follow-up test.

CONCLUSIONS

According to the statistical analysis, advanced bone age is the most effective predictor of the result of luteinizing hormone-releasing hormone stimulation test.

Diurnal variation of gonadotropin levels in girls with early stages of puberty

PURPOSE

Pubertal gonadotropin secretion shows circadian pattern and the luteinizing hormone (LH) levels tend to rise in later stages of puberty in girls. We studied the usefulness of basal LH in the evaluation of central precocious puberty with emphasis on the influence of sampling time.

METHODS

Medical records of 334 girls that underwent gonadotropin-releasing hormone stimulation test (GnRHST) were reviewed. Auxological and laboratory data were compared between those with early morning (EM, before 10 AM) and late morning/afternoon (LM/A, after 10 AM) basal samples.

RESULTS

Among those in sexual maturity rating (SMR) 2, EM samples showed higher basal LH (P=0.004) compare to LM/A samples, whereas those in SMR 3 showed no difference in LH levels between EM and LM/A samples. Among girls with pubertal response, EM group showed higher basal LH (P=0.031) and follicular stimulating hormone (P=0.008) than LM/A group. The EM basal LH was more closely related with the peak stimulated LH than the LM/A basal LH did (rs=0.871 vs. rs=0.524). The optimal basal LH cutoffs to predict a pubertal response to GnRHST were 0.11 IU/L with a sensitivity of 66.7% and a specificity of 78.7% in EM group, and 0.07 IU/L with a sensitivity of 60.0% and a specificity of 78.9% in LM/A group, respectively.

CONCLUSIONS

In girls with early stages of puberty, EM basal LH is a more sensitive screening tool than the LM/A basal LH. Diurnal variation should be considered in evaluating children with precocious puberty.

Central precocious puberty: revisiting the diagnosis and therapeutic management

Clinical and laboratory diagnosis and treatment of central precocious puberty (CPP) remain challenging due to lack of standardization. The aim of this revision was to address the diagnostic and therapeutic features of CPP in Brazil based on relevant international literature and availability of the existing therapies in the country. The diagnosis of CPP is based mainly on clinical and biochemical parameters, and a period of follow-up is desirable to define the "progressive" form of sexual precocity. This occurs due to the broad spectrum of pubertal development, including isolated premature thelarche, constitutional growth and puberty acceleration, progressive and nonprogressive CPP, and early puberty. Measurement of basal and stimulated LH levels remains challenging, considering that the levels are not always in the pubertal range at baseline, short-acting GnRH is not readily available in Brazil, and the cutoff values differ according to the laboratory assay. When CPP is suspected but basal LH values are at prepubertal range, a stimulation test with short-acting or long-acting monthly GnRH is a diagnostic option. In Brazil, the treatment of choice for progressive CPP and early puberty is a long-acting GnRH analog (GnRHa) administered once a month or every 3 months. In Brazil, formulations of GnRHa (leuprorelin and triptorelin) are available and commonly administered, including 1-month depot leuprorelin 3.75 mg and 7.5 mg, 1-month depot triptorelin 3.75 mg, and 3-month depot leuprorelin 11.25 mg. Monthly or 3-month depot GnRHa are effective and safe to treat CPP. Arch Endocrinol Metab. 2016;60(2):163-72.

Predictive Value of Dental Maturity for a Positive Gonadotropin-Releasing Hormone Stimulation Test Result in Girls with Precocious Puberty

Dental maturity is associated with skeletal maturity, which is advanced in girls with central precocious puberty (CPP). We investigated the performance of dental maturity as a screening method for CPP using mandibular second premolar and molar calcification stages, assessed the associated anthropometric and laboratory factors, and evaluated pubertal response predictors using the gonadotropin-releasing hormone stimulation test (GnRHST) in prepubertal and pubertal girls. A prospective case-control study was conducted in girls, aged 7.0-8.9 years, classified into pubertal (peak luteinizing hormone [LH] after GnRHST ≥ 5 IU/L), prepubertal (peak LH < 5 IU/L), and control groups. Auxological and biochemical tests, panoramic radiographs, and GnRHSTs in participants with breast development were conducted. Dental maturity was assessed using the Demirjian index (DI). We included 103 girls (pubertal, 40; prepubertal, 19; control, 44). Chronological age (CA) was not significantly different between groups. Bone age (BA) and BA advancement was higher in the pubertal and prepubertal groups. Increased DI values at the mandibular second premolar and molar were significantly associated with CA, BA, BA advancement, height standard deviation score (SDS), peak LH after GnRHST, and insulin-like growth factor-I (IGF-I) (all P < 0.05). Moreover, odds ratio (OR) of the mandibular second premolar and molar (a DI value of ≥ E) for predicting a positive response to GnRHST was 8.7 (95% confidence intervals [CI], 2.9-26.1) and 5.2 (95% CI, 2.2-12.7), respectively. Dental maturity was a strong predictor for diagnosing CPP. Determining dental maturity in girls with suspected precocious puberty might help determine the performance of GnRHSTs.

The investigation of children and adolescents with abnormalities of pubertal timing

Concerns with pubertal development are common and can cause considerable distress to patients and their carers. Many presentations reflect normal variations of pubertal timing and primarily require reassurance, although patients may opt for interventions. Other presentations need active management to avoid significant adverse effects on growth and psychosocial development. All should undergo careful assessment, particularly as some children or adolescents presenting with abnormalities in pubertal timing may have serious pathology which requires urgent investigations and treatment. This review describes the appropriate investigations and their interpretation for young people presenting with disorders in pubertal timing.

Causes, diagnosis, and treatment of central precocious puberty

Central precocious puberty results from the premature activation of the hypothalamic-pituitary-gonadal axis. It mimics physiological pubertal development, although at an inappropriate chronological age (before 8 years in girls and 9 years in boys). It can be attributable to cerebral congenital malformations or acquired insults, but the cause in most cases in girls remains unknown. MKRN3 gene defects have been identified in familial disease, with important basic and clinical results. Indeed, genetic analysis of this gene should be included in the routine clinical investigation of familial and idiopathic cases of central precocious puberty. Gonadotropin-releasing hormone agonists are the gold-standard treatment. The assessment and management of this disease remain challenging for paediatric endocrinologists. In this Series paper, we describe current challenges involving the precise diagnosis and adequate treatment of this disorder.

Clinical and laboratory findings in the differential diagnosis of central precocious puberty and premature thelarche

AIM

In this study, it was aimed to evaluate the clinical, antropometric and laboratory findings of female patients diagnosed with central precocious puberty and to determine the laboratory value with the best diagnostic accuracy in the diagnosis of central precocious puberty.

MATERIALS AND METHOD

Female patients whose breast development began before the age of 8 years were included in the study. The data of the patients were obtained by retrospectively examining file records. The chronogical age, age at the time of onset of the complaint, antropometric variables, bone age and hormonal tests were recorded. The patients whose bone age/chronological age ratio was >1 and in whom pubertal response was obtained to gonodotropin releasing hormone stimulation test were considered central precocious puberty and the patients who did not meet these criteria were considered premature thelarche. Receiver operating charecteristic curve (ROC) analysis was performed to determine the diagnostic accuracy of the laboratory variables.

RESULTS

Fifty one patients with idiopathic central precocious puberty and 36 patients with premature thelarche were included in the study. In the patients with central precocious puberty, the height standard deviation score, bone age and bone age/chronological age ratio were found to be significantly higher compared to the patients with premature thelarche. The basal luteinizing hormone, basal follicle stimulating hormone, basal luteinizing hormone/follicle stimulating hormone, peak luteinizing hormone, peak follicle stimulating hormone and peak luteinizing hormone/follicle stimulating hormone values were found to be significantly higher in the patients with central precocious puberty. When the cut-off value for the peak luteinizing hormone/follicle stimulating hormone ratio was taken as >0.24, the sensitivity was found to be 100% and specificity was found to be 84%. When the cut-off value for the basal follicle stimulating hormone was taken as >1.9 IU/L, the sensitivity was found to be 71% and specificity was found to be 68%. When the cut-off value for the basal luteinizing hormone was taken as >0.1 IU/L, the sensitivity was found to be 71% and specificity was found to be 64%.

CONCLUSIONS

In female children, a peak luteinizing hormone/follicle stimulating hormone ratio of >0.24 can be used in the diagnosis of central precocious puberty. However, the findings should be assessed in association with the clinical and antropometric variables.