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.

Clinical Characteristics and Management of Patients With McCune-Albright Syndrome With GH Excess and Precocious Puberty: A Case Series and Literature Review.

Background: McCune-Albright syndrome is a rare disorder characterized by fibrous dysplasia, café au lait skin spots, and hyperfunctioning endocrinopathies. The coexistence of precocious puberty and growth hormone excess in McCune-Albright syndrome is rare. Both conditions can manifest as accelerated growth, and treatments can be more challenging for such patients. This study aimed to describe the clinical manifestations of combined GH excess and PP in the context of McCune-Albright syndrome and analyze the clinical features and treatments of these patients. Method: Clinical data from 60 McCune-Albright syndrome patients from Peking Union Medical College Hospital were obtained. The demographic characteristics, growth hormone, insulin-like growth factor-1, prolactin, alkaline phosphatase, and sex hormone levels; growth velocity; and bone age data were obtained. The growth velocity Z-score, bone age over chronological age ratio, and predicted adult height Z-score were calculated before and after treatment. Published studies and case reports were systemically searched, and data on demographic, clinical, and biochemical characteristics and treatment outcomes were obtained. Results: We reviewed seven patients among 60 McCune-Albright syndrome patients at Peking Union Medical College Hospital (5 female) and 39 patients (25 female) from the published literature. Six of the seven patients from Peking Union Medical College Hospital and half of the patients from the published studies were pediatric patients. These patients had increased growth velocity Z-scores and bone age over chronological age ratios. After good control of both conditions, the growth velocity Z-score and bone age over chronological age ratio decreased significantly, and the predicted adult height Z-score increased. The final heights and predicted adult height Z-scores were not impaired in patients with gigantism. All the patients had craniofacial fibrous dysplasia associated with optic and otologic complications. Conclusion: McCune-Albright syndrome with growth hormone excess and precocious puberty is more common in girls. Patients have accelerated linear growth and advanced skeletal age, and early and good control of both conditions leads to a reduced growth velocity and stabilized bone age. The predicted adult and final heights are not negatively affected when growth hormone excess is diagnosed in pediatric patients.

Efficacy of Triptorelin 3-Month Depot Compared to 1-Month Depot for the Treatment of Korean Girls with Central Precocious Puberty in Single Tertiary Center.

BACKGROUND: Triptorelin depot is largely used to treat central precocious puberty (CPP) in children, and a 3-month depot has been introduced. However, data about the 3-month gonadotropin-releasing hormone use for treatment of CPP in Korean girls are not available. This study was conducted to compare the efficacy of a triptorelin 11.25 mg 3-month depot with that of a 3.75 mg 1-month depot in suppressing pubertal development for the treatment of CPP. METHODS: A retrospective study, including 106 girls with CPP treated with triptorelin, was conducted. Fifty patients were treated with a triptorelin 3-month depot, and 56 were treated with a triptorelin 1-month depot. Serum luteinizing hormone (LH), follicle-stimulating hormone, and estradiol levels were analysed every 6 months after the visit. The height and bone age of each patient was evaluated at the beginning of treatment, after 6 months, and one year after therapy. RESULTS: The baseline characteristics of the girls treated with a 3-month depot were similar to those of the girls treated with a 1-month depot. A suppressed levels of LH to the triptorelin injection (serum LH < 2.5 IU/L) at 6 months was seen in 90.0% and 98.2% of the girls treated with the 3-month and 1-month depots, respectively (P = 0.160). After 1 year of treatment, a suppressed levels of LH was seen in 93.5% and 100% of the girls treated with the 3-month and 1-month depots, respectively (P = 0.226). Height velocity showed no significant difference between the two groups. Degree of bone age advancement decreased from 1.22 ± 0.07 and 1.22 ± 0.08 years at baseline (P = 0.914) to 1.16 ± 0.07 and 1.17 ± 0.08 in the girls treated with the 3-month and 1-month depots after 1 year, respectively (P = 0.481). CONCLUSION: This study showed that the efficacy of long-acting triptorelin 3-month was comparable to 1-month depot regarding hormonal suppression and inhibition of bone maturation. The triptorelin 11.25 mg 3-month depot is an effective treatment for girls with CPP.

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

OBJECTIVES: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

Altered cardiometabolic profile in girls with central precocious puberty and adipokines: A propensity score matching analysis.

OBJECTIVE: To compare cardiometabolic factors and adipokines between patients with recently diagnosed CPP and controls without CPP, paired by BMI Z scores (BMIz) and classified into girls with adequate nutritional status and girls who are overweight or obese. METHODS: This cross-sectional study was performed from January 2012 to May 2015 at two tertiary care pediatric centers in Mexico City. We included female patients with idiopathic CPP without other chronic pathology and healthy controls. Patients were divided into groups, BMI < 85th and BMI ≥ 85th percentile, according to 2000 CDC Growth Charts. Anthropometric data and fasting plasma concentrations of lipids, glucose, insulin, and leptin were assessed. RESULTS: There were 73 patients with CPP and 82 without CPP. Sixty-six patients were matched between the groups; no significant difference was noted between the groups according to zBMI. However, differences in the bone/chronological age relationship, birth weight and proportions in different Tanner stages were observed. Among girls with normal BMI, the percentage of body fat (24.6% vs 18.9%, p < 0.001), serum triglycerides (102.9 vs 54.3 mg/dl, p < 0.001), leptin (7.46 vs 5.4 ng/ml, p = 0.010) and free leptin (0.44 vs 0.29 ng/ml, p = 0.044) were higher in those with CPP; additionally, girls with CPP presented a higher proportion of hypertriglyceridemia. In the overweight/obese group, adiponectin levels were lower in girls with CPP (6.23 vs 7.28 pg/ml, p = 0.011). CONCLUSIONS: Girls with CPP and normal BMI at diagnosis had a worse cardiometabolic profile, as reflected by higher levels of free leptin, and higher proportion of hypertriglyceridemia than girls without CPP.

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.

Insulin-like Growth Factor 1, but Not Insulin-Like Growth Factor-Binding Protein 3, Predicts Central Precocious Puberty in Girls 6-8 Years Old: A Retrospective Study.

BACKGROUND: Central precocious puberty (CPP) in females is characterized by thelarche before 8 years of age. Evidence of reproductive axis activation confirms the diagnosis (basal serum luteinizing hormone (LH) ≥0.3 IU/L or LH-releasing hormone (LHRH)-stimulated LH ≥5 IU/L). Stimulation testing is the diagnostic gold standard but is time-consuming and costly. Serum levels of insulin-like growth factor-1 (IGF-1) and insulin-like growth factor-binding protein 3 (IGFBP-3) are increased in girls with CPP. OBJECTIVE: The aim of the study was to assess the utility of serum IGF-1 and IGFBP-3 in identifying CPP in girls aged 6-8 years. METHODS: The study was a single-center retrospective study. Girls with confirmed CPP (n = 44) and isolated premature precocious adrenarche/ precocious thelarche (PA/PT, n = 16) had baseline biochemical profiling and LHRH stimulation testing. Serum IGF-1 and IGFBP-3 results were converted to standard deviation scores (SDS). Correlations were calculated and receiver operating characteristic curves were plotted. RESULTS: Girls with CPP had higher basal and peak LH, IGF-1 SDS, and growth velocity (p < 0.05). IGF-1 SDS correlated positively with basal and peak LH (p < 0.05). IGF-1 SDS (1.75-2.15) differentiated CPP and PA/PT with 89% sensitivity and 56% specificity (basal LH) and 94% specificity and 55% sensitivity (peak LH). IGFBP-3 SDS did not differ between groups or by CPP parameters. CONCLUSIONS: In clinical practice, IGF-1 SDS may be an additional tool for identifying CPP in girls aged 6 to 8 years when baseline clinical and laboratory diagnostic criteria are inconclusive, possibly avoiding more time-consuming and costly procedures.

Diagnostic evaluation of central precocious puberty in girls.

BACKGROUND: The gonadotropin-releasing hormone (GnRH) stimulation test is the gold standard for confirming the activation of the hypothalamic-pituitary-gonadal axis in central precocious puberty (CPP). However, it is time-consuming and costly. Our aim was to search for a simpler diagnostic modality for CPP by 1) evaluating the performance of basal serum luteinizing hormone (LH), 2) constructing a practical scoring system, and 3) determining the optimal single sampling time for serum LH in the GnRH stimulation test. METHODS: Data of girls aged between 3 and 9 years at the time of the GnRH stimulation test, who attended our endocrine clinic at the MacKay Children's Hospital for signs of puberty between July 2014 and June 2019, were analyzed retrospectively. We recorded patients' age, height, weight, breast Tanner stage (BS), bone age, serum LH, and follicle-stimulating hormone (FSH). Receiver operating characteristic (ROC) curves and the Youden index were used to obtain the optimal basal serum LH level. Binary logistic regression was employed to construct a practical scoring system. Cross-sectional, cumulative frequency, and ROC curves were used to simplify the GnRH stimulation test. RESULTS: Overall, 381 sets of GnRH stimulation tests were performed in 313 patients. Basal serum LH ≥ 0.2 IU/L demonstrated 70% sensitivity and 70% specificity for predicting positive GnRH stimulation test results. The practical scoring system (3 × BS + 3 × LH + 4 × FSH) showed 76% sensitivity and 72% specificity. The serum LH level at 30 min after intravenous gonadorelin exhibited 99% sensitivity and 100% specificity. CONCLUSION: Single sampling of serum LH at 30th minute post-injection of GnRH demonstrated a diagnostic performance equivalent to the traditional GnRH stimulation test in diagnosing CPP. Therefore, this approach could become the simplest diagnostic modality.

Serum Irisin Levels in Central Precocious Puberty and Its Variants.

AIM: The exact mechanisms that trigger the onset of puberty are not well known. Adipomyokines are postulated to stimulate the central neural network. In the present study, we investigated irisin levels in girls with central precocious puberty (CPP), slowly progressing precocious puberty (SPPP), or premature thelarche (PT); we also studied prepubertal girls and to determine if this adipomyokine could be used as a marker in this context. METHODS: A total of 94 girls including 33 with CPP, 31 with precocious puberty (PP) variants (SPPP or PT), and 30 healthy controls were enrolled to the study. The mean irisin levels were compared between groups. The bivariate correlations of irisin levels with clinical and laboratory parameters were assessed. Multivariate linear regression analysis was performed to determine independent predictive factors of irisin levels. RESULTS: Irisin levels were higher in the CPP group compared with the other groups (CPP group: 723.25 ±â€…62.35 ng/mL; PP variants group: 529.60 ±â€…39.66 ng/mL; and control group: 325.03 ±â€…27.53 ng/mL) (P < 0.001). Irisin levels were positively correlated with body mass index standard deviation scores (BMI-SDS), height-SDS, weight-SDS, bone age, uterus long axis, ovary size, baseline FSH and LH, and peak LH levels. Multivariate linear regression analysis revealed that irisin levels had the strongest correlation with peak LH. The other independent predictive factor of irisin levels was BMI-SDS. CONCLUSIONS: The mean irisin levels were higher in patients with CPP compared with other groups. The results of this study imply that increased irisin levels may be used as a marker of CPP provided that these findings are confirmed in larger prospective studies.

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.

Serum level of NPTX1 is independent of serum MKRN3 in central precocious puberty.

OBJECTIVES: Makorin ring finger protein 3 (MKRN3) is associated with the initiation of puberty, and loss of function mutation of MKRN3 is the most common genetic cause of central precocious puberty (CPP). A recent study reported that MKRN3 interacts with and suppresses neural pentraxin-1 precursor (NPTX1) activity via polyubiquitination during early puberty in the mouse hypothalamus. This study investigated the correlation between serum NPTX1 and MKRN3 in CPP girls and predicted the potential role of NPTX1 in pubertal progression. METHODS: In this case-control study, we examined 34 girls diagnosed with CPP and 34 healthy prepubertal girls. Anthropometric and hormonal parameters were measured and serum levels of NPTX1 and MKRN3 were evaluated with commercial enzyme-linked immunosorbent assay kits. RESULTS: Serum MKRN3 level decreased significantly in CPP patients compared to controls (344.48 ± 333.77 and 1295.21 ± 780.80 pg/mL, respectively, p<0.001). Serum MKRN3 tended to decrease as Tanner breast stage increased. However, no significant difference was observed in serum NPTX1 levels between patients and controls (20.14 ± 31.75 ng/mL and 12.93 ± 8.28 ng/mL, respectively, p=0.248). The serum level of NPTX1 did not change significantly with the Tanner breast stage. Serum NPTX1 was correlated with the height standard deviation score (r=0.255; p<0.05), but was not correlated with serum MKRN3 level or the others. Conclusion: Although serum NPTX1 level was independent of serum MKRN3 level, the possibility they might be involved in the progression of puberty or CPP remains. Further research is needed to determine their role in the hypothalamus.

Elevated Pre-injection Basal Luteinizing Hormone Concentrations are Common in Girls Treated for Central Precocious Puberty

Objective: A consensus on how to monitor girls with central precocious puberty (CPP) during gonadotropin-releasing hormone agonist (GnRHa) treatment is lacking. Increased, unstimulated basal luteinizing hormone (LH) concentrations have been suggested to indicate lack of suppression. The aim was to evaluate pre-injection basal LH concentrations during GnRHa (leuprorelin 3.75 mg) treatment every four weeks in girls with CPP. Methods: Medical records were reviewed for girls with CPP treated at a single center from 2014-2019. Clinical characteristics and laboratory findings during treatment were systematically recorded. Results: A total of 587 GnRHa pre-injection basal LH concentrations were analyzed in 74 girls. Basal LH was pubertal (≥0.3 IU/L) in 53.5% of blood samples and 87.8% of all girls had a pubertal basal LH concentration at least once. A GnRH test (n=29) was repeated in 23 girls due to suspicion of clinical progression, elevated basal LH or recordable estradiol concentrations. None had a stimulated LH >3.1 IU/L. The predictability of treatment suppression (specificity) of basal LH concentrations was 12.0% when compared to repeated GnRH stimulation tests. Despite shortening the GnRHa injection interval to three weeks, basal LH concentrations remained pubertal in 85.7% girls. A significant reduction in height standard deviation score (p<0.001) and bone age advance (p<0.001) was observed during treatment. Conclusion: Pre-injection basal LH remains at pubertal concentrations during treatment with leuprorelin 3.75 mg in girls with CPP. Clinical monitoring of pubertal progression is preferable to routine basal LH concentrations. Repeat GnRH stimulation testing should be regarded as the gold standard.

Serum Levels of Thyroid Stimulating Hormone and Luteinizing Hormone Are Decreased in Girls with Central Precocious Puberty after 12-Month GnRH Agonist Treatment.

Puberty is the transitional period from childhood to adult that leads to growth spurt, sexual maturation and attainment of reproductive capacity. Precocious puberty is defined when secondary sexual characteristics develop before the age of eight for girls and nine for boys. Central precocious puberty (CPP) is diagnosed when the process is driven by premature activation of hypothalamic gonadotropin-releasing hormone (GnRH) secretion. Many factors promote CPP, and the thyroid function is thought to be one of them. In our previous study, thyroid stimulating hormone (TSH) was higher in the CPP group than that of the participants without CPP. This elevation of TSH in CPP is said to be associated with pubertal luteinizing hormone (LH) elevation. The aim of this study was to evaluate the causal relationship between TSH and LH in CPP patients. A total of 221 girls diagnosed with CPP and treated with GnRH agonists were included. All participants except one showed LH suppression (peak LH < 3 IU/L), and serum levels of follicle stimulating hormone (FSH) were also lower after the treatment. These results indicate that puberty has slowed down and that the patients were successfully treated for CPP. As for thyroid hormones, TSH was significantly lower and free thyroxine (fT4) levels were higher after 12 months of GnRH agonist treatment compared with baseline. With GnRH agonist treatment, the serum levels of LH and TSH were decreased, suggesting that the increase in serum TSH levels is associated with premature LH elevation in girls with CPP.

Premature Adrenarche in Girls Characterized By Enhanced 17,20-Lyase and 17ß-Hydroxysteroid Dehydrogenase Activities.

CONTEXT: Girls with premature adrenarche (PA) may have a higher risk of developing polycystic ovary syndrome (PCOS) and metabolic syndrome. The biological purpose of adrenarche is unknown and the role of novel biosynthetic pathways remains unclear. OBJECTIVE: To compare the urinary steroid metabolome and enzyme activities of girls with PA to age-matched control girls and to published steroid values of girls with normal adrenarche and of women with PCOS and their newborn daughters. DESIGN: Prospective observational study from 2009 to 2014. SETTING: Academic pediatric endocrinology referral center. PARTICIPANTS: Twenty-three girls with PA and 22 healthy, age-matched girls. MAIN OUTCOME MEASURES: Steroid metabolites in 24-hour urine samples, including 4 progesterones, 5 corticosterones, aldosterone, 13 androgens, 2 estrogens, 14 glucocorticoids, and enzyme activities represented by metabolite ratios. RESULTS: Girls with PA had a higher body mass index (mean standard deviation scores 0.9 vs -0.3, P = 0.013). Androgen excretion was higher in PA girls than in control girls (median 3257 nmol/24 hours vs 1627 nmol/24 hours, P < 0.001), in particular metabolites from alternate androgen pathways. The amount of progesterone, corticosterone, aldosterone, estrogen, and cortisol metabolites were similar between groups. Activities of 17ß-hydroxysteroid-dehydrogenase and of 17,20-lyase were higher in girls with PA. Activities of 3ß-hydroxysteroid-dehydrogenase, 21-hydroxylase, and 5α-reductase activity were not different between groups, in contrast to published results on girls with normal adrenarche or PCOS females. CONCLUSIONS: Metabolites and enzymes involved in alternate androgen pathways appear to be markers of PA. Prospective studies should assess whether steroid production in PA also differs from adrenarche at normal timing and persists into adulthood.

Novel Genetic and Biochemical Findings of DLK1 in Children with Central Precocious Puberty: A Brazilian-Spanish Study.

BACKGROUND: Central precocious puberty (CPP) has been associated with loss-of-function mutations in 2 paternally expressed genes (MKRN3 and DLK1). Rare defects in the DLk1 were also associated with poor metabolic phenotype at adulthood. OBJECTIVE: Our aim was to investigate genetic and biochemical aspects of DLK1 in a Spanish cohort of children with CPP without MKRN3 mutations. PATIENTS: A large cohort of children with idiopathic CPP (Spanish PUBERE Registry) was studied. Genomic deoxyribonucleic acid was obtained from 444 individuals (168 index cases) with CPP and their close relatives. Automatic sequencing of MKRN3 and DLK1 genes were performed. RESULTS: Five rare heterozygous mutations of MKRN3 were initially excluded in girls with familial CPP. A rare allelic deletion (c.401_404 + 8del) in the splice site junction of DLK1 was identified in a Spanish girl with sporadic CPP. Pubertal signs started at 5.7 years. Her metabolic profile was normal. Familial segregation analysis showed that the DLK1 deletion was de novo in the affected child. Serum DLK1 levels were undetectable (<0.4 ng/mL), indicating that the deletion led to complete lack of DLK1 production. Three others rare allelic variants of DLK1 were also identified (p.Asn134=; g.-222 C>A and g.-223 G>A) in 2 girls with CPP. However, both had normal DLK1 serum levels. CONCLUSION: Loss-of-function mutations of DLK1 represent a rare cause of CPP, reinforcing a significant role of this factor in human pubertal timing.

Long-term effects of treatment of central precocious puberty with gonadotropin-releasing hormone analogs every three months.

BACKGROUND: Gonadotropin-releasing hormone (GnRH) analogs represent the treatment of choice in patients with central precocious puberty (CPP). Recently, GnRH analogs that can be administered every 3 months have been developed and appear to be as safe and effective as one-monthly formulations. However, there are limited data regarding its long term safety and efficacy profile. We aimed to evaluate the long-term safety and efficacy treatment of CPP with GnRH analogs every 3 months. METHODS: We prospectively studied all patients who were diagnosed with CPP in our center between January 2015 and December 2019. All patients were treated with intramuscular leuprolide acetate 11.25 mg every 3 months. RESULTS: Twenty-four patients with CPP were included in the study. Mean follow-up was 3.1 years. Height gain ranged between 4 and 6 cm. Bone mineral density (BMD) was not affected. Body mass index (BMI) increased in all subjects but none was obese at the end of follow-up. CONCLUSIONS: Treatment of patients with CPP with GnRH analogs every 3 months induces substantial increases in height and does not affect BMI or BMD. Therefore, it represents an attractive option for these young patients.

Rapid progressive central precocious puberty: diagnostic and predictive value of basal sex hormone levels and pelvic ultrasound.

Objectives Data on the predictive values of parameters included in the diagnostic work-up for precocious puberty (PP) remain limited. We detected the diagnostic value of basal sex hormone levels, pelvic ultrasound parameters and bone age assessment for activation of the hypothalamic-pituitary-gonadal axis in girls with PP, in order to help in the decision to perform GnRH testing. Patients and methods We retrospectively considered 177 girls with PP. According to puberty evolution, the girls were divided into two groups: rapid progressive central precocious puberty (RP-CPP) and non/slowly progressive/transient forms (SP-PP). In all patients we considered Tanner stage, basal luteinizing hormone (LH) and estradiol (E2) values, bone age, and pelvis examination. We assessed the diagnostic value of each variable and identified the number of pathological parameters that best identify patients with RP-CPP. Results Basal LH ≥ 0.2IU/L, E2 level ≥ 50 pmol/L, uterine longitudinal diameter ≥ 3.5 cm, transverse uterine diameter ≥ 1.5 cm, endometrial echo and ovarian volume ≥ 2 cm3 were significantly associated with RP-CPP (p ≤ 0.01). The ability to diagnose RP-CPP was enhanced with increasing number of pathological hormonal and instrumental parameters (p < 0.001). With more than three parameters detected, sensitivity and specificity reached 58% (95%CI 48-67) and 85% (95%CI 74-92), respectively, with a PPV = 86% (95%CI 76-93) and PPN = 54% (95%CI 43-54); the area under the ROC curve was 0.71 (95%CI 0.65-0.78). Conclusion Despite the availability of different tests, diagnosing RP-CPP remains difficult. A diagnosis model including at least three hormonal and/or ultrasound parameters may serve as a useful preliminary step in selecting patients who require GnRH testing for early detection of RC-PP.

Girls with Premature Thelarche Younger than 3 Years of Age May Have Stimulated Luteinizing Hormone Greater than 10 IU/L

Objective: Premature thelarche (PT) is defined as isolated breast development in girls before eight years of age. Gonadotropin-releasing hormone (GnRH) stimulation test is sometimes used to distinguish between PT and central precocious puberty (CPP), although the interpretation of the test at early ages is challenging. The objective of this study was to determine the follicle stimulating hormone (FSH) and luteinizing hormone (LH) responses to GnRH stimulation in girls with PT below 3 years of age. Methods: A standardized GnRH stimulation test, bone age and pelvic ultrasound were evaluated and those without pubertal progression after a minimum of one-year follow up were included in the study. Results: On GnRH stimulation test, the median (range) baseline LH was 0.29 (0.10-0.74) IU/L, baseline FSH was 4.96 (3.18-7.05) mIU/mL, and the peak median LH was 5.75 (3.31-8.58) IU/L with the peak mean±standard deviation FSH was 40.38±20.37 mIU/mL. Among the patients, 33.3% (n=10) had baseline LH >0.3 IU/L, 67% (n=20) had peak LH >5 IU/l and 16.6% (n=5) >10 IU/L. The mean peak LH/FSH ratio was 0.17±0.09 and was ≤0.43 in all participants. Conclusion: Although consensus statements usually define baseline LH >0.3-0.5 IU/L, peak LH >5 IU/L, and LH/FSH ratios >0.66-1.0 as diagnostic cut-offs for CPP, in children below 3 years of age, the baseline and peak LH values may be similar to pubertal values, possibly due to mini-puberty. A dominant FSH response on GnRH stimulation test is more valuable than the peak LH response in the diagnosis of PT.

Inhibin B as a screening tool for early detection and treatment monitoring of central precocious puberty.

Anti-Müllerian hormone (AMH) and inhibin B are considered possible biomarkers of central precocious puberty (CPP). The aim of this study was to evaluate serum levels of AMH and inhibin B, to investigate their regulatory patterns, and to study their clinical significance in girls with CPP. In total, 48 girls with CPP and 35 age-matched prepubertal control girls were enrolled in the study. AMH and inhibin B levels were determined in the CPP and control groups. In the patient group, AMH and inhibin B levels were evaluated during 1 year of gonadotropin releasing hormone analog (GnRHa) treatment. The mean inhibin B level in the CPP group was significantly higher than that in the control. AMH levels were not different between the two groups. After GnRHa treatment. AMH and inhibin B levels decreased significantly. Based on the ROC analysis, the cutoff value for inhibin B to determine CPP was 19.59 pg/mL, with 83.3% sensitivity and 82.9% specificity, and the area under the curve was 0. 852. Inhibin B was useful for determining CPP and the therapeutic effects of GnRHa treatment in girls with CPP. AMH interacted, in part, with the hypothalamo-pituitary gonadal axis, but its clinical implications in CPP should be further investigated.

The association between vitamin D levels and precocious puberty: a meta-analysis.

The objective of this short communication was the relationship between vitamin D and precocious puberty (PP). In this study, a comprehensive search of multiple databases was performed to identify studies focused on the association between vitamin D deficiency and PP. Studies that compared serum vitamin D levels between patients with PP and controls were selected for the systematic meta-analysis. The main outcome was the mean difference in serum vitamin D levels between PP and controls. Vitamin D-deficient subjects were more likely to develop PP. Our findings suggest that PP may be linked to vitamin D deficiency. Thus, providing supplements of vitamin D to PP patients may improve their nutritional status and prevent diseases. But, the amount of vitamin D required is uncertain, so it is important to be careful when taking vitamin D supplements.