Quantification of overnight urinary gonadotropin excretion predicts imminent puberty in girls: a semi-longitudinal study.

PURPOSE: We explored the alternative of using overnight fold change in gonadotropin levels by comparing the last-night-voided (LNV) and first-morning-voided (FMV) urine concentrations of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) as a conceptual analogy to the invasive gonadotropin-releasing hormone (GnRH) stimulation test setting. METHODS: We investigated the nocturnal changes in the immunoreactivity levels of urinary gonadotropins between early and late prepubertal stages as well as between early and late pubertal stages in FMV and LNV urine samples from 30 girls, of whom those who were prepubertal were further investigated through follow-up visits within the 1-year period from the start of the study. RESULTS: ROC analysis revealed that the FMV total U-LH and FMV U-FSH concentrations at or above 0.3 IU/L and 2.5 IU/L, respectively, were excellent predictors of forthcoming onset of puberty within 1 year (100% sensitivity, 100% specificity, AUC: 1.00, and n = 10, for both). FMV total U-LH concentration at or above 0.8 IU/L represented the cut-off for clinical signs of puberty. FMV/LNV total U-LH and FMV/LNV U-FSH ratios at or below 4.11 and 1.38, respectively, were also good predictors of the onset of clinical puberty within 1 year. An overnight increase (FMV/LNV ratio) in total U-LH concentrations and in the U-LH/U-FSH ratio at or below 1.2-fold in pubertal girls was associated with the postmenarcheal pubertal stage. CONCLUSION: FMV total U-LH and U-FSH above 0.3 IU/L and 2.5 IU/L, respectively, can be used as cut-off values to predict the manifestation of the clinical signs of puberty within 1 year. FMV total U-LH concentrations 0.3-0.8 IU/L and 0.6 IU/L may represent the range and the threshold, respectively, that reflect the loosening of the central brake on the GnRH pulse generator. An overnight increase of 20% or less in total U-LH concentrations and in the U-LH/U-FSH ratio in an early pubertal girl may serve as an indicator of imminent menarche, a presumed timing of which can be unraveled by future longitudinal studies.

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.

The negative impact of levothyroxine treatment on urinary luteinizing hormone measurements in pediatric patients with thyroid disease.

Objectives: Previous studies suggest urinary luteinizing hormone (LH) and follicle-stimulating hormone (FSH) measurements by immunofluorometric assays (IFMA) as noninvasive alternatives to serum assays for puberty assessment. However, these studies excluded patients with other endocrine disorders and those taking medications. Besides, the recent discontinuation of IFMA manufacturing is a concern. We explored the utility of luminometric assays (LIA) for urinary gonadotropins and thyroid-stimulating hormone (TSH) determinations in euthyroid patients with thyroid pathologies. Methods: We used LIA and IFMA assays to measure serum and first-morning-voided (FMV) urine LH, FSH, and TSH concentrations in euthyroid patients with various thyroid disorders. Of the 47 euthyroid patients with normal serum TSH (S-TSH) levels, 14 were receiving levothyroxine therapy. Results: FMV total urinary LH (U-LH) concentrations correlated significantly with those measured in serum using either LIA (r=0.67, P<.001) or IFMA (r=0.83, P=.003) in patients not receiving levothyroxine treatment; however, no significant correlation could be detected in patients receiving levothyroxine regardless of the assay method (for LIA: r=0.50, P=.08 and IFMA r=0.44, P=.15). Urinary TSH (U-TSH) concentrations correlated poorly with those in serum in both the untreated and the treated groups (r=-0.13, P=.49, and r=-0.45, P=.11, respectively). Conclusion: FMV total U-LH determinations by LIA can be used to assess pubertal development in patients with thyroid pathology, provided the euthyroid patient is not on levothyroxine treatment. U-TSH measurements by LIA cannot replace invasive S-TSH measurements at least in patients with normal S-TSH levels. Further research may reveal the utility of U-TSH determinations in patients with elevated S-TSH levels.

Urinary gonadotropin measurements by enhanced luminometric assays (LIA) for the evaluation of pubertal development.

OBJECTIVES: Determination of LH in urine has proved to be a reliable method for evaluation of pubertal development. The human LH assay based on time-resolved immunofluorometric (IFMA) technology (AutoDELFIA, PerkinElmer, Wallac) has been found to be suitable for this purpose thanks to its high sensitivity but other assays have not been evaluated. We have analyzed our data obtained by another potentially sensitive detection technique, enhanced luminometric assay (LIA) with the objective of finding a viable alternative to IFMA since these may not be available in the future. METHODS: LIA was used to measure LH and FSH in serum and urine samples from 100 healthy subjects of each Tanner stage and both genders, whose pubertal development has been determined. RESULTS: Urinary gonodotropin concentrations measured by LIA correlated well with Tanner stage [(r=0.93 for girls, r=0.81 for boys; p<0.01 for LH) and (r=0.81 for girls, r=0.73 for boys; p<0.01 for FSH)]. LIA determinations revealed the increase in U-LH concentrations during the transition from Tanner stage 1-2 in both girls and boys (p<0.001), whereas U-FSH and S-LH were able to detect the increase from Tanner stage 1-2 only in boys or girls, respectively (both p<0.001). CONCLUSIONS: Measurement of urinary gonadotropin concentrations by LIA may be useful for the evaluation of overall pubertal development and also in the detection of transition from prepuberty to puberty.

Sleep Disorders and Obesity in Childhood: A New Component in Solving Obesity.

Sleep disorders have been widely reported in obese individuals. Previous studies have shown that together with an increase in obesity prevalence, so does sleep duration in children and adolescents decrease. By contributing to energy imbalances, hormonal changes occurring with reduced sleep quality may cause weight gain and obesity. Current evidence shows that short sleep duration has effects on body weight and weight gain. Compared to individuals sleeping for a normal duration, insulin sensitivity is lower in those who sleep less. Lack of sleep increases the desire for food and has a direct effect on physical activity. Further studies are required to determine the contribution of sufficient sleep to obesity treatment.

A Synopsis of Current Practice in the Diagnosis and Management of Patients with Turner Syndrome in Turkey: A Survey of 18 Pediatric Endocrinology Centers

Objective: A comprehensive survey was conducted to evaluate the shortcomings of clinical care in patients with Turner syndrome (TS) in Turkey. Methods: A structured questionnaire prepared by the Turner study group in Turkey, which covered relevant aspects of patient care in TS was sent to 44 pediatric endocrinology centers. Results: Eighteen centers (41%) responded to the questionnaire. In the majority of the centers, diagnostic genetic testing, screening for Y chromosomal material, protocols regarding the timing and posology of growth hormone (GH) and estrogen, thrombophilia screening, fertility information and screening for glucose intolerance, thyroid, and coeliac diseases in patients with TS were in line with the current consensus. Thirteen centers (72.2%) performed GH stimulation tests. Only four centers (22.2%) used oxandrolone in patients with TS with very short stature. The majority of the centers relied on bone age and breast development to assess estrogen adequacy, though together with variable combinations of oestrogen surrogates. Two centers (11.1%) reported performing serum estradiol measurements. Eight centers (44.4%) routinely conducted cardiac/thoracic aorta magnetic resonance imaging. Screening for hearing, dental and ophthalmologic problems were performed by thirteen (72.2%), six (33.3%) and ten (55.6%) centers, respectively. Psychiatric assessments were made by four centers (22.2%) at diagnosis, with only one center (5.6%) requiring annual reassessments. Conclusion: Although we found some conformity between the current consensus and practice of the participating centers in Turkey regarding TS, further improvements are mandatory in the multi-disciplinary approach to address co-morbidities, which if unrecognized, may be associated with reduced quality of life and even mortality.

Homozygous loss-of-function mutations in SOHLH1 in patients with nonsyndromic hypergonadotropic hypogonadism.

CONTEXT: Hypergonadotropic hypogonadism presents in females with delayed or arrested puberty, primary or secondary amenorrhea due to gonadal dysfunction, and is further characterized by elevated gonadotropins and low sex steroids. Chromosomal aberrations and various specific gene defects can lead to hypergonadotropic hypogonadism. Responsible genes include those with roles in gonadal development or maintenance, sex steroid synthesis, or end-organ resistance to gonadotropins. Identification of novel causative genes in this disorder will contribute to our understanding of the regulation of human reproductive function. OBJECTIVES: The aim of this study was to identify and report the gene responsible for autosomal-recessive hypergonadotropic hypogonadism in two unrelated families. DESIGN AND PARTICIPANTS: Clinical evaluation and whole-exome sequencing were performed in two pairs of sisters with nonsyndromic hypergonadotropic hypogonadism from two unrelated families. RESULTS: Exome sequencing analysis revealed two different truncating mutations in the same gene: SOHLH1 c.705delT (p.Pro235fs*4) and SOHLH1 c.27C>G (p.Tyr9stop). Both mutations were unique to the families and segregation was consistent with Mendelian expectations for an autosomal-recessive mode of inheritance. CONCLUSIONS: Sohlh1 was known from previous mouse studies to be a transcriptional regulator that functions in the maintenance and survival of primordial ovarian follicles, but loss-of-function mutations in human females have not been reported. Our results provide evidence that homozygous-truncating mutations in SOHLH1 cause female nonsyndromic hypergonadotropic hypogonadism.

Novel growth hormone-releasing hormone receptor gene mutations in Turkish children with isolated growth hormone deficiency.

OBJECTIVE: Isolated growth hormone deficiency (IGHD) is defined as a medical condition associated with growth failure due to insufficient production of GH or lack of GH action. Mutations in the gene encoding for GH-releasing hormone receptor (GHRHR) have been detected in patients with IGHD type IB. However, genetic defects on GHRHR causing IGHD in the Turkish population have not yet been reported. To identify mutations on GHRHR gene in a population of Turkish children with IGHD. METHODS: Ninety-six Turkish children with IGHD were included in this study. Exon1-13 and exon/intron boundaries of GHRHR were amplified by suitable primers. The polymerase chain reaction products for GHRHR gene were sequenced with primers. RESULTS: We analyzed the GHRHR gene for mutations in ninety-six patients with IGHD based on sequence results. We identified novel p.K264E, p.S317T, p.S330L, p.G369V, p.T257A and C base insertion on position 380 (c.380inserC) mutations. In 5 of the patients, the mutation was homozygote and in 1-heterozygote (p.S317T). CONCLUSION: Six new missense mutations and one first case of insertion mutations for the GHRHR gene are reported.

Subclinical hypothyroidism in childhood and adolescense.

Subclinical hypothyroidism (SH) is defined as a serum thyroid-stimulating hormone (TSH) level above the reference range with normal serum free thyroxin (sT4) and free triiodothyronine (sT3) levels. The prevalence of SH in children and adolescents is reported between 1.7% and 9.5%. Hashimoto's thyroiditis is the most prevalent cause of SH in children. Although it has been suggested that SH is entirely an asymptomatic laboratory diagnosis, typical hypothyroid symptoms as well have been reported in some patients. Results of the adult studies on SH revealed that SH had unfavorable effects on cardiovascular system (atherosclerosis); metabolic parameters (dyslipidemia, insulin resistance, etc.); neuromuscular system; and cognitive functions in the long term. The number of studies investigating the effect of childhood SH on growth, bone maturation, lipid parameters, carbohydrate metabolism, neuromuscular system, and cognitive and cardiac function is limited. Knowledge about the natural history of SH is unclear even though there are numerous studies upon this subject. In children and adults, treatment of SH with L-T4 is still a matter of debate, and there is no consensus on this issue yet.

Isolated hyperthyrotropinemia in childhood obesity and its relation with metabolic parameters.

PURPOSE: The aim of the presented study was to evaluate the prevalence of isolated hyperthyrotropinemia (IH) in obese children and the relation between anthropometric and metabolic parameters. METHODS: Hospital records of the children, who presented to the Pediatric Endocrinology outpatient clinic of our institution with obesity, and age and gender-matched healthy children, who had undergone thyroid function test for any reason were retrospectively reviewed. RESULTS: The prevalence of IH was significantly higher in the obese group than in the controls (9.2 and 3.8 %, respectively). Body mass index-standard deviation score (BMI-SDS), thyroid-stimulating hormone (TSH), lipid parameters were significantly different in the obese group than in the control group. A positive correlation between TSH and BMI-SDS and negative correlation between TSH and free T4 (fT4) levels were found in obese subjects. Stepwise multiple linear regression analysis confirmed that BMI-SDS, fT4 and triglyceride levels were the strongest independent variables correlated with TSH level in obese subjects (r (2) = 0.046, p = 0.001). CONCLUSIONS: IH prevalence is higher in obese children as compared to healthy children and the increase in TSH level correlates negatively with serum fT4 and positively with BMI-SDS and triglyceride levels in obese children.

Monitoring and prognostic evaluation of patients with congenital hypothyroidism treated in a pediatric endocrinology unit.

In this study, the etiological factors, diagnostic approaches, dose, and duration of treatment were compared between cases with transient and permanent congenital hypothyroidism (CH) with respect to prognosis. One hundred and twenty-two patients who received treatments with the diagnosis of CH in the last 10 years were included in the study. The records of the patients were reviewed retrospectively. Serum thyroid- stimulating hormone (TSH) levels at the time of diagnosis were found to be significantly higher, and total thyroxine (TT4) levels were found to be significantly lower in the permanent CH group in comparison to the transient CH group. A statistically significant difference was present between the groups regarding treatment doses, the time needed for TSH decrease to <5 mIU/ml and the TSH and free thyroxine (FT4) levels obtained one month after discontinuation of the treatment. The association between age at the time of initiation of treatment and results of Denver Developmental Test was noted to be statistically significant. The high frequency of transient CH in our region leads to the result that some of the patients had to be unnecessarily treated with L-thyroxine for a long time.

The role of initial clinical and laboratory findings in infants with hyperthyrotropinemia to predict transient or permanent hypothyroidism.

OBJECTIVE: Studies on the clinical course of children with hyperthyrotropinemia are scarce. We aimed to evaluate the role of presentation findings in such infants to predict eventual outcome. METHODS: Files of infants diagnosed as suspicious congenital hypothyroidism (CH) in the neonatal or early infancy period in the past ten years were analyzed retrospectively, and 37 patients (M/F: 20/17) with hyperthyrotropinemia diagnosed at a median age of 3.2 months were included in the study. Criteria for inclusion were: normal free thyroxine (fT4) levels and thyrotropin (TSH) levels between 10-20 µIU/mL during the initial neonatal screening (or TSH<10µIU/mL afterwards). Cases with permanent CH (Group 1) were compared to those with transient hyperthyrotropinemia (Group 2) regarding age at the time of diagnosis, sex, gestational age, birth weight, symptoms, ultrasonographic and scintigraphic findings, initial thyroid function tests, and state of mental and motor development. RESULTS: Of the total group, 20 patients (54%) were eventually diagnosed as permanent CH. T4 doses that maintained normal thyroid function tests were significantly higher at the end of the first and second years of life in this group. Age, TSH and fT4 levels at the time of diagnosis, sex, gestational age, birth weight, symptoms, ultrasonographic and scintigraphic findings, and the state of mental and motor development were similar in the two groups. CONCLUSIONS: T4 dose required to maintain a euthyroid state was the only parameter which distinguished between transient and permanent CH.

Vitamin D in childhood cancer: a promising anticancer agent?

Children diagnosed and treated for cancer are vulnerable to Vitamin D deficiency depending on many factors. The Vitamin D status in children with cancer has been mostly regarded as a contributory factor for skeletal pathologies so far. However, the calcitriol was found to promote cell differentiation, inhibit malignant proliferation, and exhibit antiinflammatory, proapoptotic and antiangiogenic properties. In addition to this, numerous epidemiological studies link Vitamin D and cancer and indicate to possible role of Vitamin D in cancer pathogenesis and progression. This article aims to provide an overview of the possible role of Vitamin D deficiency in childhood cancer in terms of prevention and treatment.

Clinical and diagnostic characteristics of hyperprolactinemia in childhood and adolescence.

Pituitary adenoma is the most common cause of hyperprolactinemia, which is a rare endocrine disorder encountered in pediatric patient care. Epidemiological and clinical information about hyperprolactinemia in childhood and adolescence is limited. Clinical signs of hyperprolactinemia are very heterogeneous. In girls, disturbances in menstrual function and galactorrhea may be seen, whereas in boys, headache, visual disturbances, delayed pubertal development and hypogonadism are often present. Owing to the ease of ordering a serum prolactin measurement, an evidence-based, cost-effective approach to the management of this endocrine disorder is required. Before a diagnosis of hyperprolactinemia is made, drug use, renal insufficiency, hypothyroidism, and parasellar tumors should be excluded. The main objectives of treatment are normalization of prolactin level, adenoma shrinkage, and recovery from clinical signs related to hyperprolactinemia. In patients with microadenoma, invasive or non-invasive macroadenoma, and even in patients with visual field defects, dopamine agonists are the first-line treatment. Surgical treatment is indicated in patients who are unresponsive or intolerant to medical treatment or who have persistent neurological signs. Radiotherapy should be considered as a supportive treatment for patients in whom surgery fails or medical response is not achieved.

Newborn screening for congenital hypothyroidism.

Newborn screening (NS) for congenital hypothyroidism (CH) is one of the major achievements in preventive medicine. Most neonates born with CH have normal appearance and no detectable physical signs. Hypothyroidism in the newborn period is almost always overlooked, and delayed diagnosis leads to the most severe outcome of CH, mental retardation, emphasizing the importance of NS. Blood spot thyroid stimulating hormone (TSH) or thyroxine (T4) or both can be used for CH screening. The latter is more sensitive but not cost-effective, so screening by TSH or T4 is used in different programs around the world. TSH screening was shown to be more specific in the diagnosis of CH. T4 screening is more sensitive in detecting especially those newborns with rare hypothalamic-pituitary-hypothyroidism, but it is less specific with a high frequency of false positives mainly in low birth weight and premature infants. The time at which the sample is taken may vary. In the majority of the centers, blood is obtained from a heel prick after 24 hours of age to minimize the false positive high TSH due to the physiological neonatal TSH surge that elevates TSH levels and causes dynamic T4 and T3 changes in the first 1 or 2 days after birth. Early discharge of mothers postpartum has increased the ratio of false positive TSH elevations. Although transient hypothyroidism may occur frequently, all these infants should be treated as having CH for the first 3 years of life, taking into account the risk of mental retardation. A reevaluation after 3 years is needed in such patients. The goal of initial therapy in CH is to minimize neonatal central nervous system exposure to hypothyroidism by normalizing thyroid function, as rapidly as possible.

McCune-Albright syndrome mimicking malignancy: an endocrine disease from oncologist's perspective.

Fibrous dysplasia (FD) is categorized as either monostotic or polyostotic and may occur as a component of McCune-Albright syndrome (MAS). Imaging findings can mimic neoplastic diseases. We present a case of MAS initially suspected to have neoplastic disease. A 9-year-old girl was admitted to pediatric emergency with ataxia. Upon hospitalization, an extradural mass was seen on cranial magnetic resonance imaging (MRI) and the bone survey showed lytic lesions in the long bones. The patient was referred to the pediatric oncology department with a presumptive diagnosis of Langerhans cell histiocytosis or metastatic tumor. Further investigations demonstrated that the patient had MAS and coexisting postinfectious cerebellitis. The findings in this patient demonstrate that the radiographic findings and the clinical presentation of FD and MAS may be similar to those of malignant diseases.

Clinical profile and etiologies of children with central diabetes insipidus: a single-center experience from Turkey.

AIM: The aim of this study is to evaluate the clinical, anthropometric, hormonal, and radiological characteristics of children with central diabetes insipidus (DI). METHODS: Case records of 34 children (22 boys and 12 girls) with documented central DI referred to the Pediatric Endocrinology and Adolescent Clinic of Dokuz Eylul University Faculty of Medicine were reviewed. The mean age at diagnosis was 6.4 +/- 5.6 years (range, 0.08-16 years). All patients underwent anterior pituitary function assessment and magnetic resonance imaging of pituitary at diagnosis. The median duration of follow-up was 7.9 +/- 4.5 years. RESULTS: The etiology of central DI was organic in 22 (64.7%) patients, trauma in 2 (5.9%) patients, and idiopathic in 10 (29.4%) patients. Organic causes consisted of craniopharyngioma in 7 patients, Langerhans cell histiocytosis in 4 patients, germinoma in 4 patients, holoprosencephaly in 3 patients, astrocytoma in 1 patient, cavernous hemangioma in 1 patient, Rathke's cleft cyst in 1 patient, and autoimmune polyendocrinopathy in 1 patient. Anterior pituitary hormone deficiencies were documented in 18 (53%) patients. Organic central DI group had a greater prevalence of anterior pituitary hormone deficiency when compared with the idiopathic group (66% and 10%, respectively; p = 0.007). The final height of patients with organic etiology were significantly lower than the idiopathic group (155 and 178, cm respectively; p = 0.021). CONCLUSIONS: Etiological diagnosis is possible in a significant proportion (70.6%) of children with central DI. Findings of this study suggest that accompanying anterior pituitary hormone deficiencies and short stature may be considered as indicators of organic etiology.

Fetal and neonatal endocrine disruptors.

Endocrine disruptors are substances commonly encountered in every setting and condition in the modern world. It is virtually impossible to avoid the contact with these chemical compounds in our daily life. Molecules defined as endocrine disruptors constitute an extremely heterogeneous group and include synthetic chemicals used as industrial solvents/lubricants and their by-products. Natural chemicals found in human and animal food (phytoestrogens) also act as endocrine disruptors. Different from adults, children are not exposed only to chemical toxins in the environment but may also be exposed during their intrauterine life. Hundreds of toxic substances, which include neuro-immune and endocrine toxic chemical components that may influence the critical steps of hormonal, neurological and immunological development, may affect the fetus via the placental cord and these substances may be excreted in the meconium. Children and especially newborns are more sensitive to environmental toxins compared to adults. Metabolic pathways are immature, especially in the first months of life. The ability of the newborn to metabolize, detoxify and eliminate many toxins is different from that of the adults. Although exposures occur during fetal or neonatal period, their effects may sometimes be observed in later years. Further studies are needed to clarify the effects of these substances on the endocrine system and to provide evidence for preventive measures.

Hyperprolactinemia in children: clinical features and long-term results.

Hyperprolactinemia is a rare endocrine disorder in childhood, which may result from hypophyseal adenoma. We aimed to review the etiologic reasons and clinical features in hyperprolactinemia patients retrospectively. The mean age of 11 female patients at diagnosis was 14.2 ± 1.3 years. Five patients had microadenoma, four patients had macroadenoma, and two patients were diagnosed with idiopathic hyperprolactinemia. The most frequent symptoms were menstrual disorders, headache, and galactorrhea, and one-third of the patients had obesity at diagnosis. There was no anterior pituitary hormone deficiency. All patients received bromocriptine as initial therapy; only two patients with macroadenoma and one patient with microadenoma were switched to cabergoline. Transsphenoidal surgery was performed for a patient with macroadenoma, who had cavernous sinus invasion and visual field defect. Medical treatment should be the first-line treatment option in both microadenoma and macroadenoma cases without any neurological signs. Surgery should be employed with limited indications.