Gonadotropin-Releasing Hormone Analogs for Treatment of Central Precocious Puberty in Children Younger than 2 Years of Age.

Although gonadotropin-releasing hormone analogs are the standard of care for the treatment of central precocious puberty, they are not approved for children/< age 2 years. We reviewed experience with the use of gonadotropin-releasing hormone analogs in 47 children younger than age 2 years, which revealed efficacy and safety comparable with that in older children.

Variability in Oral Desmopressin Dose Requirements in Children with Central Diabetes Insipidus.

There is inconsistency in the amount of oral desmopressin that children with central diabetes insipidus require. We investigated whether clinical characteristics influenced desmopressin dose requirements in 100 children with central diabetes insipidus. Extremely large doses were associated with acquired etiology (P = .04), greater body mass index z score, intact thirst, and additional pituitary hormone deficiencies (P < .001).

DIFFERENCES IN BONE AGE READINGS BETWEEN PEDIATRIC ENDOCRINOLOGISTS AND RADIOLOGISTS.

Objective: Pediatric endocrinologists (PEs) have historically read their own bone age (BA) X-rays based on the belief that radiologists do not accurately interpret these tests. Whether there are significant differences in BA interpretations between these two groups has not been systematically explored. The objectives of the study were to compare BA readings performed by PEs and radiologists and determine whether clinical variables were associated with discrepancies in readings. Methods: A retrospective chart review of children presenting for initial evaluation of short stature (SS) or precocious puberty (PP) who had a BA X-ray completed was performed. Clinical variables analyzed included age, gender, ethnicity, Tanner stage, body mass index, reason for referral, radiologist location (Children's vs. outside hospital), and PE and radiologist BA readings using the Greulich and Pyle method. Results: Of 103 patients aged 9 ± 3.66 years, there was a discrepancy between the PE and radiologist readings on 70 images (68%). Discrepancy ranged from -1.5 to 3.5 years, with a mean of 4 ± 12 months. Patients referred for PP were more likely to have discrepant interpretations than those referred for SS (8.4 months vs. 0.8 months; P = .007). No differences were seen in interpretations between in-house radiologists and those at outside hospitals. Conclusion: Radiologists interpreted BAs differently than PEs in the majority of images. In patients referred for PP, BAs were interpreted as being older by radiologists than by PEs, perhaps due to bias from the reason for referral. Our results provide support for continued independent BA interpretations by PEs. Abbreviations: BA = bone age; GP = Greulich and Pyle; PE = pediatric endocrinologist; PP = precocious puberty; SS = short stature.

PRACTICE VARIATION IN THE MANAGEMENT OF GIRLS AND BOYS WITH DELAYED PUBERTY.

Objective: Delayed puberty is a common condition, and typical management includes "watchful waiting" and/or sex-steroid therapy. We sought to characterize treatment practices and to assess provider comfort with the management of delayed puberty in girls and boys. Methods: A national survey of pediatric endocrine providers assessed definitions of delayed puberty, practices around sex-steroid therapy, reasons for treatment, and comfort in managing delayed puberty in girls and boys. Results: Of 184 respondents (12% participation rate), 64% and 71% used the traditional age cutoffs for defining delayed puberty of 13 years for girls and 14 years for boys, respectively. Nearly half (45%) of providers would treat boys relatively earlier than girls, compared to 18% who would treat girls relatively earlier (P<.0001). Providers were more likely to cite bone density as a reason to treat girls and alleviating patient and parental distress, accelerating growth, and "jump starting" puberty as reasons to treat boys. Greater experience in endocrine practice was associated with greater comfort managing delayed puberty in both boys and girls. Approximately 80% of providers agreed that clinical guidelines are needed for the management of delayed puberty. Conclusion: There is a high degree of variability in the clinical management of delayed puberty, and our results suggest that providers are more hesitant to treat girls compared to boys and have different reasons for treating each. It remains to be determined if these discrepancies in treatment are justified by biologic differences between girls and boys or represent nonevidence-based disparities in care. Abbreviation: U.S. = United States.

Prevalence of Nephrocalcinosis in Pseudohypoparathyroidism: Is Screening Necessary?

The prevalence of nephrocalcinosis in persons with pseudohypoparathyroidism has not been systematically examined. We conducted a retrospective study of renal imaging and biochemical results in 19 patients with pseudohypoparathyroidism with 49 imaging assessments. No cases of nephrocalcinosis were identified. Routine screening for nephrocalcinosis in pseudohypoparathyroidism may not be necessary.

TARGETED LEVOTHYROXINE THERAPY FOR TREATMENT OF CONGENITAL HYPOTHYROIDISM.

OBJECTIVE: The purpose of this study was to determine if infants with congenital hypothyroidism (CH) whose initial dose of levothyroxine (LT4) is based on thyroid gland anatomy require fewer dose adjustments in the first 6 months of life than those who were started empirically on LT4. METHODS: Newborns with CH who had a thyroid ultrasound performed at diagnosis were eligible for this prospective, historical case-controlled study. The daily LT4 dose prescribed was based on results on the thyroid ultrasound as follows: 15 mcg/kg for athyreosis, 12 mcg/kg for a dysgenetic thyroid, and 10 mcg/kg for an anatomically normal gland. Routine labs according to standard guidelines were obtained, and the number of dose adjustments over the first 6 months of therapy was recorded. Each study participant was matched with 2 historical controls with CH based on sex and thyroid anatomy. RESULTS: Twenty-two subjects (10 with athyreosis, 4 with dysgenetic glands, and 8 with anatomically normal glands) were matched to 44 controls. There was no significant difference in the overall number of adjustments in the study group compared to controls (P = .74). However, there were significantly fewer adjustments made for undertreatment (P = .03) and significantly more adjustments made for overtreatment (P = .006) in subjects with athyreosis compared to controls. CONCLUSION: Targeted LT4 therapy does not appear to decrease the overall frequency of dose adjustments for infants with CH. However, 15 mcg/kg/day appears to exceed thyroid hormone requirements in infants with CH due to athyreosis. ABBREVIATIONS: CH = congenital hypothyroidism LT4 = levothyroxine OT = overtreatment T4 = thyroxine TSH = thyroid-stimulating hormone UT = undertreatment.

CHARACTERIZATION OF SPONTANEOUS AND INDUCED PUBERTY IN GIRLS WITH TURNER SYNDROME.

OBJECTIVE: To characterize puberty in girls with Turner syndrome (TS) and determine whether specific patient characteristics are associated with the timing of menarche. We also sought to compare spontaneous versus induced puberty in these patients. METHODS: Medical records of girls followed in our Pediatric Endocrine clinic for TS from 2007 to 2015 were reviewed. RESULTS: Fifty-three girls were included, of whom 10 (19%) achieved menarche spontaneously and 43 (81%) received hormone replacement therapy (HRT). Of girls receiving HRT, a younger age at estrogen initiation correlated with a longer time to menarche (P = .02), and a mosaic karyotype was associated with a shorter time to menarche (P = .02), whereas no relationship was seen for body mass index, estrogen regimen, or maternal age at menarche. Nineteen girls (44%) receiving HRT had bleeding on estrogen alone at a wide dose range and were more likely to be on transdermal than oral preparations (P = .01). Girls with spontaneous puberty achieved menarche at a younger age (P<.01) and were more likely to have mosaic TS (P = .02). CONCLUSION: Significant variability in the timing of menarche exists among girls with TS. However, age at pubertal induction and karyotype were significantly correlated with age at menarche in our patients. A wide range of estrogen doses is seen in girls who bleed prior to progesterone, suggesting extreme variability in estrogen sensitivity among patients with TS. Girls achieving spontaneous menarche are younger and more likely to have a mosaic karyotype than those with induced menarche. Large-scale prospective studies are needed to confirm these results. ABBREVIATIONS: BMI = body mass index; HRT = hormone replacement therapy; TS = Turner syndrome.

Treatment of Girls and Boys with McCune-Albright Syndrome with Precocious Puberty - Update 2017.

The most common endocrinopathy associated with McCune-Albright Syndrome (MAS) is peripheral precocious puberty (PP) which occurs far more often in girls than in boys. We will discuss the latest advancements in the treatment of precocious puberty in MAS that have been achieved during the past 10 years. However, due to the rarity of the condition and the heterogeneity of the disease, research in this field is limited particularly in regards to treatment in boys. In girls, a period of watchful waiting is recommended prior to initiating therapy due to extreme variability in the clinical course. This article will review in detail current pharmacologic treatment in girls, which typically consists of either inhibiting estrogen production or blocking estrogen action at the level of the end-organ. The two treatments with the most evidence at this time are Tamoxifen (which is an estrogen receptor modulator) and Letrozole (which is a 3rd generation aromatase inhibitor). This article will also review the current treatment strategies in boys which typically include using an androgen receptor blocker and an aromatase inhibitor. Due to the rarity of the condition, large multicenter collaborative studies are needed to further investigate efficacy and safety with the goal of establishing the gold standard for treatment of PP in children with MAS.

INCIDENCE OF CENTRAL DIABETES INSIPIDUS IN CHILDREN PRESENTING WITH POLYDIPSIA AND POLYURIA.

OBJECTIVE: Polydipsia and polyuria are common reasons for referral to the Pediatric Endocrine clinic. In the absence of hyperglycemia, diabetes insipidus (DI) should be considered. The objectives of the study were to determine the prevalence of central DI (CDI) in a group of children presenting for evaluation of polydipsia and polyuria, and to determine if predictive features were present in patients in whom the diagnosis of DI was made. METHODS: The study was a retrospective chart review of children presenting to the endocrine clinic with complaints of polydipsia and polyuria over a 5-year period. RESULTS: The charts of 41 patients (mean age 4.9 ± 3.7 years, 28 males) were reviewed. CDI was diagnosed in 8 (20%) children based on abnormal water deprivation test (WDT) results. All but one patient had abnormal magnetic resonance imaging (MRI) findings, the most common being pituitary stalk thickening. Children with DI were older (7.86 ± 4.40 vs. 4.18 ± 3.20 years, P = .01) and had a higher propensity for cold beverages intake and unusual water-seeking behaviors compared to those without DI. Baseline WDT also revealed higher serum sodium (Na) and osmolality. CONCLUSION: The incidence of CDI in children presenting with polydipsia and polyuria is low. Factors associated with higher likelihood of pathology include older age, propensity for cold beverage intake, and higher baseline serum Na and osmolality on a WDT. ABBREVIATIONS: BMI = body mass index CDI = central diabetes insipidus DI = diabetes insipidus Na = sodium WDT = water deprivation test.

BIRD'S-EYE VIEW OF GnRH ANALOG USE IN A PEDIATRIC ENDOCRINOLOGY REFERRAL CENTER.

OBJECTIVE: Gonadotropin-releasing hormone analogs (GnRHa) are standard of care for the treatment of central precocious puberty (CPP). GnRHa have also been prescribed in other clinical settings with the hope of increasing adult stature, although evidence to support this practice is lacking. The degree to which GnRHa are being prescribed for indications other than CPP in routine clinical care has not been described. We sought to systematically examine GnRHa prescribing practices among the pediatric endocrinologists at our academic medical center. METHODS: We reviewed medical records of children treated with GnRHa during a 6-year interval. Variables analyzed included gender, age at start of treatment, indication for therapy, and use of growth hormone as adjunctive treatment. Nonparametric analyses were utilized to compare treatment characteristics of those with CPP versus those without. RESULTS: A total of 260 patients (82% female) aged 8.06 ± 2.68 years were identified. Of these, 191 (73.5%) were treated for CPP, whereas 69 (26.5%) were treated for normally timed puberty in the context of idiopathic short stature/poor predicted height (n = 37), growth hormone deficiency (n = 17), congenital adrenal hyperplasia (n = 10), primary hypothyroidism (n = 4), and developmental delay (n = 1). Of the 161 girls with CPP, GnRHa therapy was initiated at ≥8 years of age in 62 (39%). CONCLUSION: Whereas most patients were treated for CPP, ~27% were treated for other indications. Of girls with CPP, 39% were treated at an age when benefit in terms of height is unlikely. This highlights the need for rigorous studies of GnRHa use for indications beyond CPP.

Resumption of puberty in girls and boys following removal of the histrelin implant.

OBJECTIVES: To determine time to menarche in girls and testicular volume increase in boys after removal of a histrelin implant, which causes profound hypothalamic-pituitary-gonadal axis suppression. STUDY DESIGN: Medical records of patients treated with a histrelin implant were reviewed. Seventy-one patients (56 girls) treated with the histrelin implant were identified, of these patients, 37 explanted girls (68% naïve) and 6 explanted boys (83% naïve) were included in the analysis. Time to menarche after explantation in girls and time to testicular volume increase after explantation in boys were determined. Additional variables investigated included indication for and duration of treatment, history of menarche (girls), previous therapy, and age at beginning and end of histrelin treatment. RESULTS: Of the girls, 30 were treated for central precocious puberty (CPP), 26 had menarche at an average of 12.75 months after explantation. Of the 30, 7 were treated for other indications, of whom 6 had reached menarche. In girls with CPP, older age at explantation correlated with sooner menarche (P = .04). All boys achieved spontaneous testicular enlargement within 1 year of explantation. CONCLUSIONS: This study documented resumption of puberty after histrelin explantation in treatment naïve and non-naïve boys and girls with and without CPP. Menarche in girls with CPP occurs within a similar timeframe to that observed after other treatment approaches.

Presentation and Care for Children with Peripheral Precocious Puberty.

Peripheral precocious puberty (PPP) refers to the early onset of sexual maturation that is independent of central nervous system control. The extensive differential diagnosis includes congenital and acquired causes. Presenting features depend on which class of sex steroids is involved, and diagnosis rests on hormonal and, if indicated, imaging and/or genetic studies. Effective treatment exists for nearly all causes of PPP. Ongoing research will advance our therapeutic armamentarium and understanding of the pathophysiologic basis of these conditions.

Treatment of Central Precocious Puberty with a Focus on Girls.

The age of thelarche has declined in the past few decades but not the age of menarche. This is important when assessing girls who present with breast development between 6 and 8 years because not all of them will need treatment. The decision for treatment depends on age, bone age (BA), rate of pubertal progression, height velocity, psychosocial factors, and predicted adult height (PAH), with the caveat that height predictions are not precise and BA interpretation is variable.

Diagnostic Conundrum of a Sertoli Cell Tumor in a 2-Year-Old Girl with Peripheral Precocious Puberty and a Café-au-Lait Macule: A Case Report.

INTRODUCTION: Ovarian Sertoli cell tumors represent a subset of sex cord stromal tumors and are exceedingly rare in prepubertal children. Here, we report a girl with vaginal bleeding due to a Sertoli cell tumor who was originally thought to have McCune-Albright syndrome (MAS). CASE PRESENTATION: A previously healthy girl presented at age 2 years 6 months with breast development and vaginal bleeding. On exam, she had Tanner 4 breasts, Tanner 1 pubic hair, estrogenized vaginal mucosa, and a café-au-lait macule. Laboratory studies revealed an elevated estradiol with suppressed gonadotropins and negative tumor markers. Her bone age was advanced by more than 3 years. Pelvic ultrasound (US) revealed an enlarged uterus and a slightly larger left compared to right ovary. She was started on tamoxifen for presumed MAS. A repeat pelvic US 1 month later showed a heterogenous mass in the left ovary which was subsequently resected. Pathology revealed a Sertoli cell tumor, lipid-rich variant. Germline sequencing revealed a pathogenic STK11 variant, diagnostic for Peutz-Jeghers syndrome (PJS). CONCLUSION: The findings in our patient were strikingly similar to those encountered in MAS. To our knowledge, our patient is the youngest ever reported to present with precocious puberty due to a Sertoli cell tumor in the setting of PJS.

Random luteinizing hormone often remains pubertal in children treated with the histrelin implant for central precocious puberty.

OBJECTIVE: To investigate the use of random ultrasensitive (US) luteinizing hormone (LH) levels to monitor children being treated with a histrelin implant for central precocious puberty (CPP). STUDY DESIGN: This was a prospective, uncontrolled, observational study at a pediatric endocrinology tertiary center. Thirty-three children (26 girls; mean age 7.2 ± 2.5 years) treated with a histrelin implant for CPP were enrolled. A random US LH measurement was obtained at 6 months, and a gonadotropin-releasing hormone analog stimulation test was performed at 12 months. Clinic visits occurred at baseline and at 6-month intervals. RESULTS: In 59% of the patients (17 of 29), the 6-month random US LH exceeded the prepubertal range of ≤0.3 IU/L. In contrast, gonadotropin-releasing hormone analog stimulation tests revealed complete hypothalamic-pituitary-gonadal axis suppression (peak LH <4 IU/L) in all 31 patients who underwent testing. US LH levels were highly correlated with peak stimulated LH levels. The mean peak stimulated LH level was higher in patients with a pubertal random LH than in those with a prepubertal random LH (1.2 ± 0.5 IU/L vs 0.5 ± 0.1 IU/L; P < .01). No patient had clinical evidence of pubertal progression. CONCLUSION: The random US LH level does not revert to a prepubertal range in more than one-half of patients with a histrelin implant and documented hypothalamic-pituitary-gonadal axis suppression. Long-term studies are needed to elucidate the optimal strategy for monitoring treatment in children with CPP.

Incidence and characteristics of pseudoprecocious puberty because of severe primary hypothyroidism.

Severe primary hypothyroidism is a presumed rare cause of pseudoprecocious puberty (PsPP). Here, we report a 24% incidence of PsPP among 33 children with profound hypothyroidism. Those with PsPP were older and trended toward a higher thyroid stimulating hormone. Increased awareness of PsPP can hasten diagnosis and appropriate treatment.

A single histrelin implant is effective for 2 years for treatment of central precocious puberty.

We investigated whether a "yearly" histrelin implant would provide pubertal suppression when left in place for 2 years. Equivalent suppression was observed when comparing 12 and 24 months in 33 children with central precocious puberty. A single implant for 2 years reduces cost and number of implant procedures.

Central precocious puberty: a review of diagnosis, treatment, and outcomes.

Central precocious puberty (CPP) refers to early activation of the hypothalamic-pituitary-gonadal (HPG) axis and is manifested by breast development in girls or testicular enlargement in boys before the normal physiological age ranges. CPP can be precipitated by intracranial pathology, exposure to high levels of sex steroids, or environmental risk factors, but most cases are idiopathic. Monogenic causes have also been identified. In this Review, we summarise pathophysiology, risk factors, diagnosis, and management of CPP. Concern for CPP should prompt referral to paediatric endocrinology where diagnosis is confirmed by clinical, biochemical, radiological, and genetic testing. CPP is treated with a gonadotropin-releasing hormone analogue, the primary aims of which are to increase adult height and postpone development of secondary sexual characteristics to an age that is more commensurate with peers. Although long-term outcomes of treatment with gonadotropin-releasing hormone analogues are reassuring, additional research on the psychological effect of CPP is needed.

Rhabdomyolysis: A Rare Presentation of Hashimoto Thyroiditis in an Adolescent Boy and Review of the Literature.

INTRODUCTION: Hypothyroidism-induced rhabdomyolysis without precipitating factors is extremely rare, particularly in pediatric patients. We describe a previously healthy adolescent boy who came to our institution with vague symptoms and was found to have rhabdomyolysis secondary to hypothyroidism due to Hashimoto thyroiditis. We also summarize previously published cases in children and adolescents. CASE PRESENTATION: A 16-year-old boy presented to the emergency department at Riley Hospital for Children with a 2-week history of bilateral eye and lip swelling, fatigue, and slowing of speech initially attributed to angioedema. His laboratory studies were significant for acute kidney injury secondary to rhabdomyolysis. Additional evaluation revealed profound primary hypothyroidism and positive TPO antibodies. Although his free T4 was undetectable, his TSH was only 32.2 mcU/mL. He received IV hydration and thyroid replacement, and his symptoms improved after several months of treatment. DISCUSSION: Rhabdomyolysis without any risk factors is very rare, especially in children. Our patient was not on any medications, had no family history of neuromuscular disorders, and no history of trauma, infection, or strenuous exercise. The reason behind the disproportionately mild elevation of TSH in the setting of an undetectable free T4 is unclear. CONCLUSION: It is important for clinicians to be aware that rhabdomyolysis may be a presenting sign of severe hypothyroidism, as delay in diagnosis and treatment can be detrimental.