Diagnosis and management of growth hormone deficiency in childhood and adolescence. Part 1: diagnosis of growth hormone deficiency

MRI-Based Evaluation of Pituitary Size and Volume in Children with Idiopathic Growth Hormone Deficiency

BACKGROUND

Growth hormone deficiency (GHD) is the most common cause of pathological short stature of endocrine origin. Among the causes of pathological short stature, pathologies in the hypothalamic-pituitary region, especially the pituitary gland, have an important place, and imaging the region with pituitary magnetic resonance imaging (MRI) is a frequently used method in the diagnosis process and guides the diagnosis and treatment process. It is known that hypoplasia or aplasia of the pituitary gland, which plays a role in the synthesis and release of many hormones in addition to GH, causes short stature.

AIM

This study aims to evaluate pituitary size and volume as potential diagnostic markers in children with idiopathic growth hormone deficiency (IGHD) compared with healthy controls.

METHODS

The study included children who presented to our hospital's pediatric endocrinology outpatient clinic with complaints of short stature/growth retardation and was diagnosed with IGHD, for whom MRI of the pituitary had been performed. Pituitary MRI examinations were retrospectively reviewed to measure the, adenohypophysis height, anterior-posterior diameter, width, and volume, and these measurements were compared with those of an age- and gender-matched control group.

RESULTS

A total of 55 patients diagnosed with IGHD were included, with a mean chronological age of 9.8 ± 3.4 years, of whom 58.2% (n = 32) were male. The control group consisted of 42 healthy children with a mean chronological age of 9.3 ± 3.4 years, with 47.6% (n = 20) being male. No significant differences in age and gender were found between the groups (P = 0.523, P = 0.306, respectively). Although the adenohypophysis height, anterior-posterior diameter, width, and volume of patients with IGHD were lower than those in the control group, no statistical differences were observed between the two groups (P > 0.05). There were no differences in pituitary size and volume based on gender in either group (P > 0.05). A positive correlation was found between pituitary height, width, and volume with age, insulin-like growth factor-1 (IGF-1) standard deviations (SD), and insulin-like growth factor binding protein-3 (IGFBP-3) SD (P < 0.05), whereas no correlation was found between stimulated peak GH levels and pituitary size and volume (P > 0.05).

CONCLUSION

We found that the size and volume of the adenohypophysis in patients with IGHD are not different from those of healthy peers; however, they showed a correlation particularly with IGF-1 and IGFBP-3 standard deviations.

New French height velocity growth charts: An innovative big-data approach based on routine measurements

AIM

Height velocity is considered a key auxological tool to monitor growth, but updated height velocity growth charts are lacking. We aimed to derive new French height velocity growth charts by using a big-data approach based on routine measurements.

METHODS

We extracted all growth data of children aged 1 month-18 years from the electronic medical records of 42 primary care physicians, between 1 January 1990 and 8 February 2018, throughout the French metropolitan territory. We derived annual and biannual height velocity growth charts until age 15 years by using the Lambda-Mu-Sigma method. These new growth charts were compared to the 1979 French and 2009 World Health Organisation (WHO) ones.

RESULTS

New height velocity growth charts were generated with 193 124 and 209 221 annual and biannual values from 80 204 and 87 260 children, respectively, and showed good internal fit. Median curves were close to the 1979 French or 2009 WHO ones, but SD curves displayed important differences. Similar results were found with the biannual height velocity growth charts.

CONCLUSION

We produced new height velocity growth charts until age 15 years by using a big-data approach applied to measurements routinely collected in clinical practice. These updated growth charts could help optimise growth-monitoring performance.

Vocal Characteristics of Children With Short Stature Before and After Growth Hormone Treatment

OBJECTIVE

To evaluate the vocal characteristics of children with short stature before and 12 months after growth hormone treatment.

MATERIAL AND METHODS

This analytical, observational cohort study included 23 children (age 5-11 years) diagnosed with short stature. Children in the short stature group (SSG) were matched (1:1) for age and sex with children with normal growth (normal stature group; NSG). Participants in the SSG underwent assessments before and 12 months after growth hormone treatment, while those in the NSG underwent the same assessments at baseline and 12 months. The assessments included evaluation of (A) vocal characteristics (history, vocal self-assessment, auditory-perceptual evaluation, and acoustic analysis), (B) anthropometry, (C) bone age, and (D) measurement of insulin-like growth factor-1 (IGF-1) levels.

RESULTS

Children in the SSG had more vocal complaints (P = 0.026) than those in the NSG. The groups were similar in terms of vocal self-assessment and auditory-perceptual evaluation (P = nonsignificant). Results of acoustic analysis were also similar for fundamental frequency (F 0) and perturbation measures (P for both = nonsignificant). F 0 and speech frequency decreased significantly at 12 months in both groups. F1 values were higher at 12 months in the NSG, while F2 values were significantly higher in the baseline evaluation in boys in the SSG. Children in the SSG compared with those in the NSG presented a greater increase in height measurements at 12 months, although the anthropometric means were lower in both evaluations (P < 0.001).

CONCLUSION

Vocal characteristics in children with short stature before and after treatment with growth hormone are comparable to those in children with normal growth.

Megalencephaly secondary to a novel germline missense variant p.Asp322Tyr in AKT3 associated with growth hormone deficiency and central hypothyroidism: A case report

Germline gain of function variations in the AKT3 gene cause brain overgrowth syndrome with megalencephaly and diffuse bilateral cortical malformations. Here we report a child with megalencephaly, who is a carrier of a novel heterozygous missense variant in the AKT3 gene NM_005465.7:c.964G>T,p.Asp322Tyr. The phenotype of this patient is associated with pituitary deficiencies diagnosed at 2 years of age: growth hormone (GH) deficiency responsible for growth delay and central hypothyroidism. After 6 months of GH treatment, intracranial hypertension was noted, confirmed by the observation of papilledema and increased intracranial pressure, requiring the initiation of acetazolamide treatment and the discontinuation of GH treatment. This is the second reported patient described with megalencephaly and AKT3 gene variant associated with GH deficiency . Other endocrine disorders have also been reported in few cases with hypothyroidism and hypoglycemia. Pituitary deficiency may be a part of the of megalencephaly phenotype secondary to germline variant in the AKT3 gene. Special attention should be paid to growth in these patients and search for endocrine deficiency is necessary in case of growth retardation or hypoglycemia.

Metabolic Bone Diseases Affecting Tooth Eruption: A Narrative Review

Tooth eruption is an essential process for the development of the oral and maxillofacial system. Several inherited and acquired diseases might affect this tightly regulated process, resulting in premature, delayed, or even failed tooth eruption. The purpose of this article is to review the literature and the clinical parameters of metabolic bone diseases that affect tooth eruption. It examines the physiological aspects of tooth eruption and the pathophysiological changes induced by metabolic bone diseases, including changes in bone metabolism, density, and structure. The search strategy for this review included an electronic search in PubMed, Google Scholar, Medline, Scopus, and the Cochrane Library using the following keywords: "metabolic bone diseases", "tooth eruption", "delayed tooth eruption", and each reported disease in combination with "tooth eruption disorders", covering publications up to March 2024 and limited to English-language sources. Understanding the influence of metabolic bone diseases on tooth eruption is crucial for managing both dental and skeletal manifestations associated with these disorders. This review suggests that a multidisciplinary approach to treatment may significantly improve oral outcomes for patients suffering from such conditions. Clinicians should be aware of the specific dental abnormalities that may arise and consider comprehensive evaluations and individualized treatment plans. These findings underscore the need for further research into targeted therapies that address these abnormalities.

Diffusion tensor imaging of the physis: the ABC's

The physis, or growth plate, is the primary structure responsible for longitudinal growth of the long bones. Diffusion tensor imaging (DTI) is a technique that depicts the anisotropic motion of water molecules, or diffusion. When diffusion is limited by cellular membranes, information on tissue microstructure can be acquired. Tractography, the visual display of the direction and magnitude of water diffusion, provides qualitative visualization of complex cellular architecture as well as quantitative diffusion metrics that appear to indirectly reflect physeal activity. In the growing bones, DTI depicts the columns of cartilage and new bone in the physeal-metaphyseal complex. In this "How I do It", we will highlight the value of DTI as a clinical tool by presenting DTI tractography of the physeal-metaphyseal complex of children and adolescents during normal growth, illustrating variation in qualitative and quantitative tractography metrics with age and skeletal location. In addition, we will present tractography from patients with physeal dysfunction caused by growth hormone deficiency and physeal injury due to trauma, chemotherapy, and radiation therapy. Furthermore, we will delineate our process, or "DTI pipeline," from image acquisition to data interpretation.

Combined growth hormone stimulation testing: Could the tests be shortened?

INTRODUCTION

Growth hormone stimulation tests (GHST) remain the cornerstone for diagnosing growth hormone deficiency (GHD), yet they can be lengthy and costly. We aimed to examine whether the combined clonidine and glucagon stimulation test (CGST) and l-dopa and glucagon stimulation test (LDGST) can be shortened without compromising the test's specificity.

MATERIAL AND METHODS

We retrospectively analyzed the baseline characteristics, auxological and laboratory data of children with short stature who had undergone a CGST and an LDGST for GHD. We compared the diagnostic accuracy for the standard test and shortened test, eliminating time points of 0 and 210 min.

RESULTS

We reviewed 830 charts (8.17 ± 2.92 years old; 56.27% males), with 431 (57.0%) children in the CGST group, and 38 (51.35%) in the LDGST group who tested negative for GHD. The peak and maximum GH levels occurred at the 60-min time point for both the CGST and LDGST. Eliminating the 0-min time point was the only time that did not affect the specificity of the CGST, with a false-positive rate of 2 (2.99%), specificity of 0.99 (0.99-0.99), and p value of 0.25. Eliminating the 0- and 210-min time points did not affect the specificity of the LDGST, with a false-positive rate of 2 (5.26%), specificity of 0.95 (0.95-0.95), and p value of 0.24.

CONCLUSIONS

We concluded that 0-min time point could be eliminated without compromising the combined GHST diagnostic value, thus resulting in cost reduction. Larger studies are needed for the combined LDGST to explore whether the 30- and 210-min time points could be eliminated, thus resulting in cost and time savings.

Prevalence of Chiari malformation type 1 is increased in pseudohypoparathyroidism type 1A and associated with aberrant bone development

BACKGROUND

Albright hereditary osteodystrophy (AHO) is caused by heterozygous inactivating mutations in GNAS. Patients with maternally-inherited mutations develop pseudohypoparathyroidism type 1A (PHP1A) with multi-hormone resistance and aberrant craniofacial and skeletal development among other abnormalities. Chiari malformation type 1 (CM1), a condition in which brain tissue extends into the spinal canal when the skull is too small, has been reported in isolated cases of PHP1A. It has been hypothesized to be associated with growth hormone (GH) deficiency. Given the adverse clinical sequelae that can occur if CM1 goes unrecognized, we investigated the previously undetermined prevalence of CM1, as well as any potential correlations with GH status, given the known increased prevalence of GH deficiency in PHP1A. We also investigated these metrics for low lying cerebellar tonsils (LLCT), defined as tonsillar descent less than 5 mm below the foramen magnum. In addition, we investigated possible correlations of CM1/LLCT with advanced hand/wrist bone ages and craniofacial abnormalities known to occur in PHP1A to determine whether premature chondrocyte differentiation and/or aberrant craniofacial development could be potential etiologies of CM1/LLCT through both human studies and investigations of our AHO mouse model.

METHODS

We examined patients with PHP1A in our clinic and noticed CM1 more frequently than expected. Therefore, we set out to determine the true prevalence of CM1 and LLCT in a cohort of 54 mutation-confirmed PHP1A participants who had clinically-indicated brain imaging. We examined potential correlations with GH status, clinical features, biological sex, genotype, and hand/wrist bone age determinations. In addition, we investigated the craniofacial development in our mouse model of AHO (Gnas E1+/-m) by histologic analyses, dynamic histomorphometry, and micro-computerized tomographic imaging (MCT) in order to determine potential etiologies of CM1/LLCT in PHP1A.

RESULTS

In our cohort of PHP1A, the prevalence of CM1 is 10.8%, which is at least 10-fold higher than in the general population. If LLCT is included, the prevalence increases to 21.7%. We found no correlation with GH status, biological sex, genotype, or hand/wrist bone age. Through investigations of our Gnas E1+/-m mice, the correlate to PHP1A, we identified a smaller cranial vault and increased cranial dome angle with evidence of hyperostosis due to increased osteogenesis. We also demonstrated that there was premature closure of the spheno-occipital synchondrosis (SOS), a cartilaginous structure essential to the development of the cranial base. These findings lead to craniofacial abnormalities and could contribute to CM1 and LLCT development in PHP1A.

CONCLUSION

The prevalence of CM1 is at least 10-fold higher in PHP1A compared to the general population and 20-fold higher when including LLCT. This is independent of the GH deficiency that is found in approximately two-thirds of patients with PHP1A. In light of potential serious consequences of CM1, clinicians should have a low threshold for brain imaging. Investigations of our AHO mouse model revealed aberrant cranial formation including a smaller cranium, increased cranial dome angle, hyperostosis, and premature SOS closure rates, providing a potential etiology for the increased prevalence of CM1 and LLCT in PHP1A.

Investigating whether serum IGF-1 and IGFBP-3 levels reflect the height outcome in prepubertal children upon rhGH therapy: LG growth study database

Serum insulin-like growth factor-1 (IGF-I) and IGF binding protein-3 (IGFBP-3) levels can be used to monitor the safety of recombinant human growth hormone (rhGH) therapy. In this study, we evaluated the changes in serum IGF-I and IGFBP-3 levels during rhGH therapy as a marker of height outcome in prepubertal children. Totally, 705 prepubertal children with short stature were enrolled from the LG Growth Study Database. Data for three groups of subjects were obtained as follows: Idiopathic GH deficiency (IGHD; n = 486); idiopathic short stature (n = 66); small for gestational age (n = 153). Serum IGF-I and IGFBP-3 levels at the baseline and after the 1st and 2nd year of rhGH therapy, as well as the Δheight standard deviation score (SDS), were obtained. Δheight SDS after the 1st and 2nd year of rhGH therapy had notably increased compared to that at the baseline for all three groups. IGF-I and IGFBP-3 levels in all three groups were significantly increased compared to those at the baseline (p <0.001). Δheight SDS was positively correlated with ΔIGF-1 SDS after the 1st year of therapy, ΔIGFBP-3 SDS after the 2nd year of therapy in the IGHD group, and ΔIGF-I SDS and ΔIGFBP-3 SDS after the 2nd year of therapy (p < 0.05), regardless of whether the height at the baseline was a covariate. The increase in IGF-I and IGFBP-3 levels during rhGH therapy was related to the growth response in children with IGHD. Therefore, it may be valuable to measure the change in serum IGF-I and IGFBP-3 levels, especially the latter, during rhGH treatment to predict the growth response upon long-term treatment.

The necessity of magnetic resonance imaging in the evaluation of pediatric growth hormone deficiency: Lessons from a large academic center

BACKGROUND

Current guidelines indiscriminately recommend magnetic resonance imaging (MRI) of the pituitary gland in pediatric growth hormone deficiency (GHD). The relationship between abnormal MRI, most importantly a tumor, and peak GH levels is not well known.

METHODS

In this retrospective chart review, pituitary MRI results of children, ages of 3-16 years with GHD were collected and divided into 3 groups according to peak stimulated GH levels; ≤5, 5-7.4 and 7.5-10 ng/mL, Groups A, B & C respectively. Clinical and MRI findings were compared between the groups.

RESULTS

A total of 399 children were included. Abnormal MRI was found in 36.9% of group A subjects, compared to group B (16.7%) and group C (17.0%), both p values =0.0002. Children with multiple pituitary hormonal deficiencies (MPHD) had a higher rate of abnormalities than those with isolated GHD. Children with isolated GHD were more likely to have abnormal MRI with peak GH level < 5 ng/mL compared to those with levels, 5-7.4 & 7.5-10 ng/mL. 4 children in group A had a craniopharyngioma. ROC analysis comparing peak GH levels with abnormal MRI findings showed an area under the curve (AUC) of 0.614 and 0.728 for IGHD and MPHD, respectively.

CONCLUSION

Although abnormal MRI was found in all 3 study groups, it was more likely at GH level < 5 ng/mL and in children with MPHD. To avoid missing a tumor, the importance of imaging in children with GHD and peak GH levels <5 ng/mL cannot be overemphasized.

A Bayesian Approach to Diagnose Growth Hormone Deficiency in Children: Insulin-Like Growth Factor Type 1 Is Valuable for Screening and IGF-Binding Protein Type 3 for Confirmation

BACKGROUND

The utility of insulin-like growth factor type 1 (IGF-1) is well established in the diagnosis of growth hormone deficiency (GHD), whereas IGF-binding protein type 3 (IGFBP-3) has a more controversial role. Most studies evaluated the value of these peptides by assessing their sensitivity and specificity but not considering the low prevalence of GHD among short children (<2%).

OBJECTIVE

To evaluate the utility of basal IGF-1 and IGFBP-3 values in the GHD diagnosis process with a Bayesian approach, based on pre- and post-test probability.

METHODS

We determined ROC curves, sensitivity, specificity, and positive and negative predictive values for IGF-1 and IGFBP-3 obtained from patients with GHD (n = 48) and GH-sufficient children (n = 175). The data were also analyzed by classifying the children into early childhood and late childhood (girls and boys younger and older than 8 and 9 years, respectively).

RESULTS

The area under the curve (AUC) of the receiver operating characteristic curve of IGF-1-SDS (standard deviation score) was greater than that of IGFBP-3-SDS (AUC 0.886 and 0.786, respectively, p = 0.001). In early childhood, the AUC of IGFBP-3-SDS was significantly improved (0.866) and similar to IGF-1-SDS (0.898). IGF-1-SDS, in comparison to IGFBP-3-SDS, had a greater sensitivity (92 vs. 45.8%, respectively), lower specificity (69 vs. 93.8%, respectively), and lower positive predictive value (5.7 vs. 13.1%, respectively), with similar negative predictive values.

CONCLUSION

IGF-1-SDS is a useful screening tool in the diagnosis of GHD. Although IGFBP-3-SDS lacks sensitivity, its high specificity supports the role to confirm GHD in short children, especially in early childhood. This strategy could simplify and reduce the necessity of a second laborious and expensive GH stimulation test to confirm the diagnosis of GHD.

Provocative growth hormone testing in children: how did we get here and where do we go now?

OBJECTIVES

Provocative growth hormone (GH) tests are widely used for diagnosing pediatric GH deficiency (GHD). A thorough understanding of the evidence behind commonly used interpretations and the limitations of these tests is important for improving clinical practice.

CONTENT

To place current practice into a historical context, the supporting evidence behind the use of provocative GH tests is presented. By reviewing GH measurement techniques and examining the early data supporting the most common tests and later studies that compared provocative agents to establish reference ranges, the low sensitivity and specificity of these tests become readily apparent. Studies that assess the effects of patient factors, such as obesity and sex steroids, on GH testing further bring the appropriateness of commonly used cutoffs for diagnosing GHD into question.

SUMMARY AND OUTLOOK

Despite the widely recognized poor performance of provocative GH tests in distinguishing GH sufficiency from deficiency, limited progress has been made in improving them. New diagnostic modalities are needed, but until they become available, clinicians can improve the clinical application of provocative GH tests by taking into account the multiple factors that influence their results.

When They're Done Growing, Don't Forget They May Still Need Growth Hormone

The effect of the growth hormone (GH) in promoting linear growth is well known; however, less recognized by practitioners especially pediatric, are its metabolic properties. This may be because the deleterious effects of improperly treated or untreated growth hormone deficiency (GHD) can present beyond the pediatric years. In addition, clinicians may lack familiarity with the potential issues that can arise due to inadequately treated GHD. Considering information from both the basic sciences research and clinical medicine, pediatric practitioners should be cognizant about the metabolic effects of GH. They should also be equipped to provide anticipatory guidance to patients regarding the importance of adherence to therapy in GHD and be prepared to transition patients with permanent GHD from pediatric GH supplementation to adult GH dosing. With a lack of proper transitioning, adverse outcomes may present beyond childhood.

Whole Exome Sequencing Uncovered the Genetic Architecture of Growth Hormone Deficiency Patients

PURPOSE

Congenital growth hormone deficiency (GHD) is a rare and etiologically heterogeneous disease. We aim to screen disease-causing mutations of GHD in a relatively sizable cohort and discover underlying mechanisms via a candidate gene-based mutational burden analysis.

METHODS

We retrospectively analyzed 109 short stature patients associated with hormone deficiency. All patients were classified into two groups: Group I (n=45) with definitive GHD and Group II (n=64) with possible GHD. We analyzed correlation consistency between clinical criteria and molecular findings by whole exome sequencing (WES) in two groups. The patients without a molecular diagnosis (n=90) were compared with 942 in-house controls for the mutational burden of rare mutations in 259 genes biologically related with the GH axis.

RESULTS

In 19 patients with molecular diagnosis, we found 5 possible GHD patients received known molecular diagnosis associated with GHD (NF1 [c.2329T>A, c.7131C>G], GHRHR [c.731G>A], STAT5B [c.1102delC], HRAS [c.187_207dup]). By mutational burden analysis of predicted deleterious variants in 90 patients without molecular diagnosis, we found that POLR3A (p = 0.005), SUFU (p = 0.006), LHX3 (p = 0.021) and CREB3L4 (p = 0.040) represented top genes enriched in GHD patients.

CONCLUSION

Our study revealed the discrepancies between the laboratory testing and molecular diagnosis of GHD. These differences should be considered when for an accurate diagnosis of GHD. We also identified four candidate genes that might be associated with GHD.

The inter - Test variability of growth hormone stimulation tests and factors affecting this variability

OBJECTIVE

To evaluate the variability of growth hormone stimulation tests results and factors affecting it in short children suspected of having growth hormone deficiency.

DESIGN

The cohort included patients with short stature suspected of having growth hormone deficiency, and who underwent a second stimulation test, after the first stimulation test was positive. Testing was done at a single center from May 2014 to October 2017. Patients' weight, height, age, sex, stimulating agents and test results were recorded.

RESULTS

The study population comprised 200 patients, 108 males and 92 females, average age 9.2 years (2.2-16.6 years). The average peak growth hormone was 5.2 μg/L and 7.8 μg/L in the first and second tests respectively and the concordance rate was 56.5%. The probability of a second positive test was increased if the peak growth hormone level in the first test was below 5 μg/L. In the second test, Clonidine and Glucagon led to higher peak growth levels than Arginine with averages of 9.02, 9.97 and 6.88 μg/L respectively. Younger children and children with higher BMI SDS only had lower peaks of growth hormone in the second test. The effect of height SDS on peak growth hormone levels was equivocal.

CONCLUSION

The reproducibility rate of GH simulation tests in our study was low. A few factors may affect the peak levels of growth hormone in the second test, the most prominent being the peak of growth hormone in the first test.

Childhood growth hormone deficiency, a diagnosis in evolution: The intersection of growth hormone history and ethics

In 1958 the first recorded case of a patient treated with human growth hormone for growth hormone deficiency was published. Since that time, the source and availability of human growth hormone have changed. With the increased availability of growth hormone, there has been an uptrend in the level below which childhood growth hormone deficiency is diagnosed based on provocative GH stimulation testing. This increase is despite better specificity of growth hormone assays in addition to a lack of supportive evidence regarding appropriate normal values. With these trends the diagnosis of childhood growth hormone deficiency is evolving, and clinicians should be aware that this may have potential ethical implications.

Incidental Findings on Brain Magnetic Resonance Imaging (MRI) in Pediatric Endocrine Patients

OBJECTIVE

To explore incidental findings on brain magnetic resonance imaging (MRI) studies of pediatric patients referred due to endocrine disorders.

METHODS

A retrospective, observational study conducted in a tertiary referral center. The neuroimaging database of 17,445 brain MRI studies of 11,011 pediatric patients were searched for cases with endocrine referrals and without medical history of malignancy, genetic syndromes, and/or neurologic comorbidities. This database was linked to the pediatric neurosurgical database. Clinical data were retrieved from medical files.

RESULTS

In total, 524 patients (50.2% males, mean age 8.5±3.5 years) were referred to brain MRI due to growth disturbances (n = 313), pubertal disorders (n = 183), prolactin hypersecretion (n = 18), central diabetes insipidus (n = 8), and obesity (n = 1). Incidental findings were found in 128 (24.4%) cases. Chiari type 1 malformation was more prevalent in patients with growth disturbances (P<.001). Small pituitary cysts were observed in 20 (3.8%) patients, and pineal cysts in 25 (4.8%) patients, mostly girls (68%, P<.001). White matter lesions were diagnosed in 30 (5.7%) patients, none with clinical evidence of neurologic disease. Brain asymmetry without clinical significance and developmental venous anomalies were observed in 14 (2.7%) and 8 (1.5%) patients, respectively. Twelve patients were diagnosed with intracranial tumors, and 5 required surgical intervention for a histopathologic diagnosis of juvenile pilocytic astrocytoma (n = 3), choroid plexus papilloma (n = 1), or inconclusive (n = 1). The rest were managed conservatively.

CONCLUSION

Incidental findings on brain MRIs of pediatric patients referred by endocrinologists are common and raise dilemmas. The spectrum ranges from structural disruptions to tumors. Decision-making is individualized and patient-centered.

A Proposal for the Interpretation of Serum IGF-I Concentration as Part of Laboratory Screening in Children with Growth Failure

The serum insulin-like growth factor-I (IGF-I) concentration is commonly used as a screening tool for growth hormone deficiency (GHD), but there is no consensus on the cut-off limit of IGF-I standard deviation score (SDS) to perform GH stimulation tests for confirmation or exclusion of GHD. We argue that the cut-off limit is dependent on the clinical pre-test likelihood of GHD and propose a diagnostic strategy in which the cut-off limit varies between zero to -2 SDS.

Towards a Rational and Efficient Diagnostic Approach in Children Referred for Growth Failure to the General Paediatrician

Based on a recent Dutch national guideline, we propose a structured stepwise diagnostic approach for children with growth failure (short stature and/or growth faltering), aiming at high sensitivity for pathologic causes at acceptable specificity. The first step is a detailed clinical assessment, aiming at obtaining relevant clinical clues from the medical history (including family history), physical examination (emphasising head circumference, body proportions and dysmorphic features) and assessment of the growth curve. The second step consists of screening: a radiograph of the hand and wrist (for bone age and assessment of anatomical abnormalities suggestive for a skeletal dysplasia) and laboratory tests aiming at detecting disorders that can present as isolated short stature (anaemia, growth hormone deficiency, hypothyroidism, coeliac disease, renal failure, metabolic bone diseases, renal tubular acidosis, inflammatory bowel disease, Turner syndrome [TS]). We advise molecular array analysis rather than conventional karyotyping for short girls because this detects not only TS but also copy number variants and uniparental isodisomy, increasing diagnostic yield at a lower cost. Third, in case of diagnostic clues for primary growth disorders, further specific testing for candidate genes or a hypothesis-free approach is indicated; suspicion of a secondary growth disorder warrants adequate further targeted testing.

Development and Validation of a Prediction Rule for Growth Hormone Deficiency Without Need for Pharmacological Stimulation Tests in Children With Risk Factors

INTRODUCTION

Practice guidelines cannot recommend establishing a diagnosis of growth hormone deficiency (GHD) without performing growth hormone stimulation tests (GHST) in children with risk factors, due to the lack of sufficient evidence.

OBJECTIVE

Our goal was to generate an evidence-based prediction rule to diagnose GHD in children with growth failure and clinically identifiable risk factors.

METHODS

We studied a cohort of children with growth failure to build the prediction model, and a second, independent cohort to validate the prediction rule. To this end, we assessed the existence of: pituitary dysgenesis, midline abnormalities, (supra)sellar tumor/surgery, CNS infection, traumatic brain injury, cranial radiotherapy, chemotherapy, genetic GHD, pituitary hormone deficiencies, and neonatal hypoglycemia, cholestasis, or hypogenitalism. Selection of variables for model building was performed using artificial intelligence protocols. Specificity of the prediction rule was the main outcome measure in the validation set.

RESULTS

In the first cohort (n=770), the resulting prediction rule stated that a patient would have GHD if (s)he had: pituitary dysgenesis, or two or more anterior pituitary deficiencies, or one anterior pituitary deficiency plus: neonatal hypoglycemia or hypogenitalism, or diabetes insipidus, or midline abnormalities, or (supra)sellar tumor/surgery, or cranial radiotherapy ≥18 Gy. In the validation cohort (n=161), the specificity of the prediction rule was 99.2% (95% CI: 95.6-100%).

CONCLUSIONS

This clinical rule predicts the existence of GHD with high specificity in children with growth disorders and clinically identifiable risk factors, thus providing compelling evidence to recommend that GHD can be safely diagnosed without recurring to GHST in neonates and children with growth failure and specific comorbidities.

Identification of Haptoglobin as a Readout of rhGH Therapy in GH Deficiency

BACKGROUND

GH deficiency (GHD) is characterized by a cluster of cardiovascular risk factors and subtle inflammation. We aimed to demonstrate, through a proteomic approach, molecules directly modulated by GHD and involved in the inflammatory state.

METHODS

Ten children with isolated GHD were studied before and after 1 year of treatment with rhGH and compared with 14 matched controls. A two-dimensional electrophoresis plasma proteomics analysis was performed at baseline and after GH treatment to identify the top molecules modulated by GH. In vitro studies on human hepatoma (HepG2) cells were performed to validate the data.

RESULTS

Twelve of 20 proteomic spots were predicted to be isoforms α and β of haptoglobin (Hp) and confirmed by liquid chromatography tandem mass spectrometry and Western immunoblot analyses. Hp levels were higher in patients with GHD than controls at baseline (P < 0.001) and were reduced following GH treatment (P < 0.01). In HepG2 cells, both GH and IGF-1 were able to downregulate IL-6-induced Hp secretion. Moreover, Hp secretion was restored in pegvisomant-treated HepG2 cells.

CONCLUSIONS

Hp is a molecule acting in the inflammatory state of GHD and a possible biomarker for GH treatment. Nevertheless, the contribution of other factors and the molecular pathways involved in the GH downregulation of Hp remain to be clearly defined.

Evaluation of IGF1/IGFBP3 Molar Ratio as an Effective Tool for Assessing the Safety of Growth Hormone Therapy in Small-for-gestational-age, Growth Hormone-Deficient and Prader-Willi Children

OBJECTIVE

IGF1 concentration is the most widely used parameter for the monitoring and therapeutic adaptation of recombinant human growth hormone (rGH) treatment. However, more than half the variation of the therapeutic response is accounted for by variability in the serum concentrations of IGF1 and IGFBP3. We therefore compared the use of IGF1/IGFBP3 molar ratio with that of IGF1 concentration alone.

METHODS

We selected 92 children on rGH for this study and assigned them to three groups on the basis of growth deficiency etiology: small for gestational age (SGA), GH deficiency (GHD) and Prader-Willi syndrome (PWS). Plasma IGF1 and IGFBP3 concentrations and their molar ratio were determined.

RESULTS

Before rGH treatment, mean IGF1/IGFBP3 molar ratio in the SGA, GHD and PWS groups was 0.14±0.04, 0.07±0.01 and 0.12±0.02, respectively. After the initiation of rGH treatment, these averages were 0.19±0.07, 0.20±0.08 and 0.19±0.09, within the normal range for most children, even at puberty and despite some significant increases in serum IGF1 levels.

CONCLUSION

We consider IGF1/IGFBP3 molar ratio to be a useful additional parameter for assessing therapeutic safety in patients on rGH, and for maintaning the values within the normal range for age and pubertal stage.

TIMING OF GH PEAK IN BOTH GLUCAGON AND CLONIDINE TESTS IS OF MAJOR CLINICAL IMPORTANCE

Objective: To detect a possible correlation between timing of the peak value of growth hormone (GH) during stimulatory tests (STs) and the effectiveness of treatment with recombinant human growth hormone (rhGH) in children with idiopathic GH deficiency (iGHD). Methods: We retrospectively studied 92 patients with iGHD (57 boys; mean age at diagnosis: 9.93 years). Diagnosis was confirmed by 2 different STs, glucagon stimulation test (GST), and clonidine stimulation test (CST). Auxologic parameters were recorded, while observed and predicted (according to KIGS Prediction Model) height velocity during the first year of treatment and the index of responsiveness (IoR) were calculated for the prepubertal children (n = 65). Results: Atypical GST was defined as that with peak GH value at time 0 minutes, 30 minutes, 60 minutes, or 180 minutes, whereas atypical CST was defined as that with peak timing at 0 minutes, 30 minutes, or 120 minutes. Atypical GST was detected in 18 patients (19.57%). IoR was lower in the prepubertal children with atypical GST (-1.81 ± 0.67 versus -1.34 ± 0.85; P = .051). In the CST, the 18 children who had atypical timing, had significantly lower IoR (-1.86 ± 0.66 versus -1.35 ± 0.84; P = .047). When the patients were categorized according to the number of atypical tests, significant differences in the IoR were detected (-2.09 ± 0.68 with 2 atypical STs [n = 6], -1.64 ± 0.61 with 1 atypical ST [n = 16], and -1.29 ± 0.87 with no atypical ST [n = 43], P = .045). Conclusion: The presence of atypical peak GH timing during ST may be a factor that predicts lower growth hormone velocity during the first year of rhGH treatment in prepubertal children with iGHD. Abbreviations: CST = clonidine stimulation test; GH = growth hormone; GHD = growth hormone deficiency; GST = glucagon stimulation test; iGHD = idiopathic growth hormone deficiency; IoR = index of responsiveness; rhGH = recombinant human growth hormone; SDS = standard deviation scores; ST = stimulatory test.

IGF-1 assessed by pubertal status has the best positive predictive power for GH deficiency diagnosis in peripubertal children

Background When evaluating peripubertal short stature patients, the interpretation of insulin-like growth factor 1 (IGF-1) levels based on chronological age (CA) can be inaccurate due to the influence of sex steroids and, presently, there is no evidence to support the assessment of IGF-1 values according to bone age (BA) and pubertal status (PS). Our objective was to assess the discriminatory performance of IGF-1 levels based on CA, BA and PS in the diagnosis of growth hormone (GH) deficiency. Methods We evaluated IGF-1 levels from 154 peripubertal short stature patients classified as GH deficient (GHD, n=23) or non-GHD (n=131). IGF-1 was assayed by a chemiluminescent immunometric assay and transformed into standard deviation scores (SDS) according to CA (IGF-1-SDS-CA), BA (IGF-1-SDS-BA) and PS (IGF-1-SDS-PS). Results The performances of IGF-1-SDS-CA, IGF-1-SDS-BA and IGF-1-SDS-PS in the receiver operator characteristics (ROC) curves were similar. There were greater accuracy and specificity of IGF-1-SDS-PS (98.4% and 93.3%, respectively) and IGF-1-SDS-BA (92.7% and 90.1%, respectively) when compared to IGF-1-SDS-CA (65.6% and 69.5%, respectively). The post-test probability of the IGF-1-SDS was also improved when compared to PS and BA - 44.8% (IGF-1-SDS-PS), 16.8% (IGF-1-SDS-BA) and 5.1% (IGF-1-SDS-CA), with similar negative predictive values. Conclusions The evaluation of IGF-1 levels based on CA has a higher sensitivity than those based on BA or PS, which justify its use as a screening tool. Additionally, IGF-1 assessed by PS has the best positive predictive power for GHD diagnosis in peripubertal age and could reduce the necessity of a second GH stimulation test.

Growth hormone therapy in children; research and practice - A review

Short stature remains the most common reason for referral to a pediatric Endocrinologist and its management remains a challenge. One of the main controversies is the diagnosis of idiopathic short stature and the role of new technologies for genetic investigation of children with inadequate growth. Complexities in management of children with short stature includes selection of who should receive interventions such as recombinant human growth hormone, and how should this agent dose be adjusted during treatment. Should anthropometrical data be the primary determinant or should biochemical and genetic data be used to improve growth response and safety? Furthermore, what is considered a suboptimal response to growth hormone therapy and how should this be managed? Treatment of children with short stature remains a "hot" topic and more data is needed in several areas. These issues are reviewed in this paper.

Relevance of Pituitary Gland Magnetic Resonance Imaging Results with Clinical and Laboratory Findings in Growth Hormone Deficiency

BACKGROUND The present study investigated the relationship between detection of organic pathologies with magnetic resonance imaging of the pituitary gland, clinical and laboratory findings, and treatment response. MATERIAL AND METHODS The study included a total of 183 patients who had isolated growth hormone deficiency, received at least 1 year of treatment, returned regularly for follow-ups, and whose pituitary magnetic resonance images were available. The patients were divided into 2 groups: those with and without pathological evidence with magnetic resonance imaging. Clinical and laboratory features and treatment responses were compared between patients with and without pathological evidence with magnetic resonance imaging. RESULTS Of the 183 patients, 105 were females and 78 were males, and 114 patients (62.2%) were prepubertal and 69 patients (37.8%) were pubertal. Their mean age was 10.01±3.25 years (1-17.6 years). Pituitary images of 153 (83.6%) patients were normal. Of the patients with detected pathologies (16.4%), 19 (10,4%) had pituitary hypoplasia, 5 (2.7%) had partial empty sella, 3 (1.7%) had ectopic neurohypophysis and 3 (1.7%) had empty sella, pineal, and arachnoid cyst. A statistically significant increase was observed in the height increase rate after treatment compared to before treatment in both groups (p<0.001). However, the group with pathology had a statistically significant (p=0. 007) post-treatment increase height rate. Although in the group with pathology there was a lower L-DOPA and clonidine peak GH response, there was not any statistically significant difference between the 2 groups (p=0.051, p=0.113). Pituitary gland length was also shorter in the group with pathology compared to the group without pathology (P<0.001). CONCLUSIONS Magnetic resonance imaging is a useful tool in assessing GH deficiency pathogenesis and in predicting treatment response.

A Critical Appraisal of Growth Hormone Therapy in Growth Hormone Deficiency and Turner Syndrome Patients in Turkey

Early detection of abnormal growth, identification of the underlying cause, and appropriate treatment of the medical condition is an important issue for children with short stature. Growth hormone (GH) therapy is widely used in GH-deficient children and also in non-GH-deficient short stature cases who have findings conforming to certain indications. Efficacy of GH therapy has been shown in a multitude of short- and long-term studies. Age at onset of GH therapy is the most important factor for a successful treatment outcome. Optimal dosing is also essential. The aim of this review was to focus on challenges in the early diagnosis and appropriate management of short stature due to GH deficiency (GHD) and Turner syndrome. These are the most frequent two indications for GH therapy in Turkey approved by the Ministry of Health for coverage by the national insurance system.

Growth, development, puberty and adult height of patients with congenital multiple pituitary hormone deficiencies

OBJECTIVE

Congenital MPHD is a rare condition caused by mutations in pituitary transcription factors genes: PROP1, POU1F1 (PIT1), HESX1, LHX3, LHX4.

DESIGN

We evaluated in a retrospective study the effects on growth and development in 29 patients with congenital MPHD (cMPHD), during hGH replacement therapy alone and combined with sex hormones. Twenty nine patients with cMPHD were included and diagnosed, treated and followed in our clinic from diagnosis to adult age. Measurements on growth and development were taken by the same medical team.

RESULTS

Mean birth weight of 21/29 neonates was 3126 ± 536 g. Mean birth length of 7/29 neonates was 48.7 ± 2 cm. Neuromotor development was normal or slightly delayed. Mean age at referral was 9.5 ± 7 years (m), 6.7 ± 3.5 years (f) (p=0.17). Height (SDS) before treatment was -2.8 ± 1.0 (m), -2.8 ± 1.0 (f) (p=0.99). Mean age at initiation of hGH treatment was 9.9 ± 6.7 years (m), 10.3 ± 4.2 years (f) (p=0.85). Mean age at initiation of sex hormone treatment was 17.0 ± 3.5 years (m), 17.1 ± 2.3 years (f) (p=0.88). Penile and testicular sizes were below normal before and after treatment. Head circumference (SD) was -1.9 ± 0.9 before and -0.6 ± 1.8 at end of treatment (p<0.001). Adult height (SDS) reached -1.1 ± 0.6 (p<0.001) for both males and females.

CONCLUSION

Despite the multiple pituitary hormone deficiencies including hGH, children with congenital MPHD present with a better auxological development than children with congenital IGHD or congenital IGF-1 deficiency. These findings may be due to irregular and incomplete hormone deficiencies increasing with progressive age and late initiation of puberty.

Natural history of growth hormone deficiency in a pediatric cohort

BACKGROUND/AIMS

Controversies still exist regarding the evaluation of growth hormone deficiency (GHD) in childhood at the end of growth. The aim of this study was to describe the natural history of GHD in a pediatric cohort.

METHODS

This is a retrospective study of a cohort of pediatric patients with GHD. Cases of acquired GHD were excluded. Univariate logistic regression was used to identify predictors of GHD persisting into adulthood.

RESULTS

Among 63 identified patients, 47 (75%) had partial GHD at diagnosis, while 16 (25%) had complete GHD, including 5 with multiple pituitary hormone deficiencies. At final height, 50 patients underwent repeat stimulation testing; 28 (56%) recovered and 22 (44%) remained growth hormone (GH) deficient. Predictors of persisting GHD were: complete GHD at diagnosis (OR 10.1, 95% CI 2.4-42.1), pituitary stalk defect or ectopic pituitary gland on magnetic resonance imaging (OR 6.5, 95% CI 1.1-37.1), greater height gain during GH treatment (OR 1.8, 95% CI 1.0-3.3), and IGF-1 level <-2 standard deviation scores (SDS) following treatment cessation (OR 19.3, 95% CI 3.6-103.1). In the multivariate analysis, only IGF-1 level <-2 SDS (OR 13.3, 95% CI 2.3-77.3) and complete GHD (OR 6.3, 95% CI 1.2-32.8) were associated with the outcome.

CONCLUSION

At final height, 56% of adolescents with GHD had recovered. Complete GHD at diagnosis, low IGF-1 levels following retesting, and pituitary malformation were strong predictors of persistence of GHD.

Adding Glucagon-Stimulated GH Testing to the Diagnostic Fast Increases the Detection of GH-Sufficient Children

BACKGROUND/AIMS

The evaluation of children with unexplained hypoglycemia may include a diagnostic fast. However, low growth hormone (GH) concentration during hypoglycemia is not specific to GH deficiency (GHD). The aim of this study was to determine if serial GH measurement following glucagon administration, in the setting of a diagnostic fast, would increase the number of children identified as not having GHD.

METHODS

We conducted a retrospective chart review of children who had serial GH measurements performed after glucagon administration at the end of a diagnostic fast. Glucagon was administered at the end of the fasting study, and GH was measured every 30 min for 210 min.

RESULTS

Of the 29 children in this series, only 3 (10%) had GH concentrations >7 ng/ml at the end of the fast, which increased by 16 (55%) after serial GH testing. The percentages of samples with GH concentrations >7 ng/ml were: 10% at baseline, and 25, 39, 41, 41, 33, 43, and 0% every 30 min thereafter.

CONCLUSION

Additional GH measurements after glucagon administration following a diagnostic fast can improve the identification of children without GHD and thereby save them unnecessary GH stimulation testing and potential GH treatment.

Burden of Growth Hormone Deficiency and Excess in Children

Longitudinal growth results from multifactorial and complex processes that take place in the context of different genetic traits and environmental influences. Thus, in view of the difficulties in comprehension of the physiological mechanisms involved in the achievement of normal height, our ability to make a definitive diagnosis of GH impairment still remains limited. There is a myriad of controversial aspects in relation to GH deficiency, mainly related to diagnostic controversies and advances in molecular biology. This might explain the diversity in therapeutic responses and may also serve as a rationale for new "nonclassical" treatment indications for GH. It is necessary to acquire more effective tools to reach an adequate evaluation, particularly while considering the long-term implications of a correct diagnosis, the cost, and safety of treatments. On the other hand, overgrowth constitutes a heterogeneous group of different pathophysiological situations including excessive somatic and visceral growth. There are overlaps in clinical and molecular features among overgrowth syndromes, which constitute the real burden for an accurate diagnosis. In conclusion, both GH deficiency and overgrowth are a great dilemma, still not completely solved. In this chapter, we review the most burdensome aspects related to short stature, GH deficiency, and excess in children, avoiding any details about well-known issues that have been extensively discussed in the literature.

Growth, development, puberty and adult height before and during treatment in children with congenital isolated growth hormone deficiency

OBJECTIVE

To describe the growth, development and puberty in children with congenital IGHD before and during hGH treatment.

SUBJECTS

Patients with cIGHD treated by hGH between the years 1958-1992.

SETTING

All patients were diagnosed, treated and followed in our clinic.

PARTICIPANTS

Data were found in 37/41 patients (21 m, 16 f). 34 had hGH-1A deletions, 7 GHRH-R mutations. Patients, referred after age 25, were excluded.

RESULTS

The birth length of 10/37 neonates was 48.29±2.26 (44-50) cm. Birth weight of 28/37 neonates was 3380±370 g (m), 3230±409 g (f). Neuromotor milestones were variable. Age at referral was 5.7±4.2 y (m) and 5.6±3.8 y (f). Initiation of hGH treatment (35μg/kg/d) was 7.5±4.8, (0.8-15.08) y (m) and 6.8±4.36 (0.8-16.5) y (f). Height SDS increased from -4.3 to -1.8 (m) and from -4.5 to -2.6 (f). Head circumference increased from -2.6 to -1.3 (m) and from -2.7 to -2.3 (f). BMI increased from 15.8 to 20.6 (m) and from 15.5 to 20.4 (f). There was a negative correlation between age of hGH initiation and change in height SDS (r=-0.66; ρ<0.01), same for bone age (r=-0.69; ρ<0.01). Upper/lower body ratio decreased from 2.5±2.1 (m±SD) to 1.08±0.1 (ρ<0.0005). Puberty was delayed in boys, less so in girls. Mean age of 1st ejaculation (14 m) was 17.6±2.2 y and of menarche (14 f. was 13.7±1.2 y. In both genders there was a positive correlation between age at start of hGH and age at onset of puberty (r=0.57; ρ<0.01). All reached full sexual development but the penile and testicular sizes were below normal. There was a positive correlation between length of hGH treatment and final testicular volume (r=0.597, ρ=0.05) and a negative correlation between the age at initiation of hGH treatment and final testicular volume(r=-0.523, ρ=0.018). All were obese and hGH treatment increased the adiposity progressively (r=0.418, ρ=0.013).

CONCLUSION

Early diagnosis and treatment of cIGHD enables normal or near normal growth, development and puberty.

Increased Secretion of Endogenous GH after Treatment with an Intranasal GH-releasing Peptide-2 Spray Does Not Promote Growth in Short Children with GH Deficiency

We investigated whether treatment with an intranasal GH-releasing peptide (GHRP)-2 spray, which acts as a potent GH secretagogue that stimulates endogenous GH secretion, promotes growth in patients with GH deficiency (GHD). This study involved 126 prepubertal short children (81 males, 45 females) with a height SD score of –2 SD or less, who had been diagnosed as having GHD based on GH stimulation tests, and in whom the serum GH concentrations increased up to 9 ng/ml after preliminary administration of an intranasal GHRP-2 spray. The subjects included in this study were divided into 3 groups by use of a double-blind method; that is 44 were placed into the placebo group (P group: 30 males, 14 females), 41 were placed into the GHRP-2 low dose group (L group: 25 males, 16 females), and 41 were placed into the GHRP-2 high dose group (H group: 26 males, 15 females). Those with a body wt of less than 20 kg were administered a placebo (P group), 50 μg of GHRP-2 (L group) or 100 μg of GHRP-2 (H group), and those with a body wt of 20 kg or more were administered a placebo (P group), 100 µg of GHRP-2 (L group) or 200 µg of GHRP-2 (H group) twice daily (morning and evening) for 48 continuous wk. Age and height SD scores at baseline were not significantly different among the three groups: 7.5 yr old and –2.26 SD in the P group, 7.3 yr old and –2.38 SD in the L group, and 7.5 yr old and –2.27 SD in the H group. Of the 126 subjects, 44, 40 and 40 subjects in the P, L and H groups, respectively, completed the 48 continuous wk of treatment. The changes in the mean height SD scores (mean growth rate) after 48 wk of treatment in the P, L and H groups were 0.07 SD, 0.03 SD, and 0.02 SD, respectively, and thus no significant differences was observed among the 3 groups. Also no significant changes in blood IGF-I levels at baseline or after 48 wk of treatment were observed among the 3 groups. This study revealed that in patients with GHD, an increase in endogenous GH secretion as a result of treatment with GHRP-2 does not promote growth. It is speculated that the area under the curve of serum GH concentration by GHRP-2 spray is too small to produce biological effects. In conclusion, it was demonstrated that growth cannot be promoted by a transient increase in endogenous GH secretion.

Prospective investigation of anterior pituitary function in the acute phase and 12 months after pediatric traumatic brain injury

PURPOSE

Although head trauma is common in childhood, there is no enough prospective study investigating both acute phase and 12 months after injury. Therefore, a prospective clinical trial was planned to evaluate the pituitary function in childhood in the acute and chronic phase after traumatic brain injury (TBI).

METHODS

Forty-one children (27 boys and 14 girls, mean age 7 ± 4.3), who were admitted to neurosurgery intensive care unit due to head trauma, were included. Twenty-one (51.2 %) patients had mild, 10 (24.4 %) had moderate, and 10 (24.4 %) had severe TBI. Twenty-two of them were reevaluated 12 months after TBI. Basal pituitary hormone levels were measured during acute (first 24 h) and chronic phase of TBI. Additionally, in the chronic phase, GHRH-arginine test was used for the diagnosis of growth hormone (GH) deficiency.

RESULTS

In the acute phase, 10 patients (24.4 %) had ACTH deficiency, and the overall 44.3 % of patients had at least one pituitary hormone dysfunction. All the pituitary hormone deficiencies during the acute phase were recovered after 12 months. Two patients (9.1 %) had new-onset GH deficiency in the chronic phase, and in one of them, ACTH deficiency was also present.

CONCLUSIONS

Present prospective data clearly demonstrated that most of the hormonal changes in the early acute phase were transient, suggesting an adaptive response, and these changes did not predict the hormone deficiencies after 1 year. In the chronic phase, although GH deficiency was present, the frequency of TBI-induced hypopituitarism was clearly lower than the adult patients.

Endocrinopathies in survivors of childhood neoplasia

Advancements in cancer treatments have increased the number of survivors of childhood cancers. Endocrinopathies are common complications following cancer therapy and may occur decades later. The objective of the current review is to address the main endocrine abnormalities detected in childhood cancer survivors including disorders of the hypothalamic-pituitary axis, thyroid, puberty, gonads, bone, body composition, and glucose metabolism.

Clonidine and glucagon stimulation for testing growth hormone secretion in children and adolescents: can we make it with fewer samples?

BACKGROUND

Our aim was to retrospectively evaluate the possibility to reduce the number of GH analyses during clonidine and glucagon tests without compromising accuracy.

SUBJECTS AND METHODS

Two hundred and forty-five tests were performed in a total of 188 children and adolescents with a mean age of 9.93 ± 2.88 yr in a single center during the last 5 yr.

RESULTS

Ninety-one out of 158 (57.59%) clonidine tests and 47/87 (54.02%) glucagon tests had at least one sample >10 μg/l (negative). For clonidine tests, not measuring GH at 30 min would have resulted in only one negative test missed (0.63% false positive result), whereas not measuring GH both at 0 and 30 min would have increased the false positive percentage to 2.53%. Ending clonidine tests at 90 min would have resulted in 7 negative tests missed (4.43% false positive results). For glucagon tests, more than half of the tests peaked at 120 min (56.32%). Skipping sampling at 0, 60 and 180 min provided a false positive rate of 5.75%.

CONCLUSIONS

For clonidine tests we can omit blood sampling at time points 0 and 30 min without significantly compromising accuracy.

The association between growth response to growth hormone and baseline body composition of children with growth hormone deficiency

OBJECTIVE

We wanted to examine the relationship between initial growth response to recombinant human Growth Hormone (rhGH) treatment and body composition in children with growth hormone deficiency (GHD).

DESIGN AND METHODS

Forty-two patients (21 boys and 21 girls) aged between 5.7-15.5 years (mean age: 10.8 ± 2.6 years) with isolated GHD. The auxological and laboratory data (GH and IGF-I levels) and results of bioelectrical impedance analyses were evaluated. Children with GHD were followed up for 12 months and categorized according to growth response to rhGH into good and poor responders (change in height of > 0.7 SDS or < 0.7 SDS over one year respectively). Mean doses of rhGH per kg of fat free mass (FFM) were calculated.

RESULTS

Forty-eight percent of patients showed a good growth response to rhGH therapy. At study entry, mean age, height SDS, weight SDS, serum IGF-1 SDS, IGFBP-3 SDS, growth velocity prior to rhGH therapy, GH after clonidine and l-dopa were similar in the two groups. At baseline, BMI SDS and waist-hip ratio were significantly higher in good responders (p = 0.02 and p = 0.006, respectively). Good responders had lower percentages of FFM (73.4 ± 8.9 vs. 83.1 ± 5.9) and total body water (TBW) (56.5 ± 5.3 vs. 63.1 ± 4.4), compared to poor responders (p < 0.05). There were significant correlations between changes in height SDS over one year and baseline body composition in children with GHD on rhGH treatment (r = -0.617 for percentage of FFM, r = -0.629 for percentage of TBW, p < 0.001). A correlation between BMI SDS, waist-hip ratio, mean rhGH dose per FFM and growth response was observed only in prepubertal subjects.

CONCLUSION

Baseline body composition data in children with GHD can be used to predict the growth response to rhGH treatment. A management strategy that involves titrating rhGH dose according to FFM as a means of optimizing the growth response to intervention requires further study.

Children with isolated growth hormone deficiency: Empty sella versus normal sella

BACKGROUND

Empty sella (ES) may be associated with variable clinical conditions ranging from the occasional discovery of a clinically asymptomatic pouch within the sella turcica to severe intracranial hypertension and rhinorrhea. The need for replacement hormone therapy in ES, as in other syndromes that may cause hypopituitarism, must be assessed for every single hormone, including growth hormone (GH).

AIM

To determine whether or not the presence of ES could allow some changes in the GH responses of the isolated growth hormone deficiency (GHD) patients.

MATERIALS AND METHODS

We included a cohort of 59 short stature children and adolescents with isolated GHD. According to computed tomography finding, they were classified into 2 groups: Group 1 included 40 children with normal sella and 19 children with ES in Group 2. All patients received recombinant human growth hormone (rhGH) with a standard dose of 20 IU/m(2)/week.

RESULTS

The baseline results were not significantly different for all variables except weight standard deviation was smaller with statistical significant difference (P = 0.02). We identified no significant differences when comparing both groups, except for height standard deviation (HTSD) after the first year of therapy which revealed significant difference in favor of group 1. When comparing pre- and the two post-treatments HTSD results of the studied cases, all showed significant changes after GH therapy. The results of related variables pre-and post-treatment in both the groups showed significant improvement in all variables of the two groups of the study.

CONCLUSION

Our study showed a similar stature outcome in the two treatment groups.

Effect of excess estrogen on breast and external genitalia development in growth hormone deficiency

BACKGROUND

The progress of sexual maturation and development in cases with growth hormone (GH) and insulin-like growth factor-I (IGF-I) deficiency is not well documented in females.

CASE

We observed breast and genitalia development in a 2-year-old girl with GH deficiency following neonatal asphyxia; this girl later developed central precocious puberty. Markedly pigmented stimulated areolas and nipples without an apparent breast mound, and non-enlarged labia minora in the external genitalia were observed as features of sexual maturation in the patient. The hormonal condition was characterized by increased circulating estradiol levels and extremely low IGF-I levels.

SUMMARY AND CONCLUSION

This case indicates that IGF-I is necessary for exerting the full effect of estrogen on the development of breasts and maturation of external genitalia.

Predicting the probability of abnormal stimulated growth hormone response in children after radiotherapy for brain tumors

PURPOSE

To develop a mathematical model utilizing more readily available measures than stimulation tests that identifies brain tumor survivors with high likelihood of abnormal growth hormone secretion after radiotherapy (RT), to avoid late recognition and a consequent delay in growth hormone replacement therapy.

METHODS AND MATERIALS

We analyzed 191 prospectively collected post-RT evaluations of peak growth hormone level (arginine tolerance/levodopa stimulation test), serum insulin-like growth factor 1 (IGF-1), IGF-binding protein 3, height, weight, growth velocity, and body mass index in 106 children and adolescents treated for ependymoma (n=72), low-grade glioma (n=28) or craniopharyngioma (n=6), who had normal growth hormone levels before RT. Normal level in this study was defined as the peak growth hormone response to the stimulation test≥7 ng/mL.

RESULTS

Independent predictor variables identified by multivariate logistic regression with high statistical significance (p<0.0001) included IGF-1 z score, weight z score, and hypothalamic dose. The developed predictive model demonstrated a strong discriminatory power with an area under the receiver operating characteristic curve of 0.883. At a potential cutoff point of probability of 0.3 the sensitivity was 80% and specificity 78%.

CONCLUSIONS

Without unpleasant and expensive frequent stimulation tests, our model provides a quantitative approach to closely follow the growth hormone secretory capacity of brain tumor survivors. It allows identification of high-risk children for subsequent confirmatory tests and in-depth workup for diagnosis of growth hormone deficiency.

Idiopathic short stature: decision making in growth hormone use

Short stature is a common concern in pediatrics. Several ambiguities and controversies persist, especially with regard to criteria, cost, medical necessity and outcomes of growth hormone (GH) therapy for idiopathic short stature (ISS). Due to these ambiguities and controversies, a series of decisions by primary care physicians (whether to refer the short child to a pediatric endocrinologist), pediatric endocrinologist (whether to recommend GH treatment), families (whether to raise concern about short stature and whether to agree to undertake treatment), and third party payers (whether to cover the costs of GH therapy) influence which individual short children will receive GH in the US. Together, these decisions determine overall GH use. Apart from child's growth characteristics, several non-physiological factors drive the critical decisions of these stakeholders. This article focuses on current ambiguities and controversies regarding GH therapy in ISS, discusses the decision-makers involved in GH therapy, and explores the factors influencing their decisions.

Does plasma IGF-BP3 measurement contribute to the diagnosis of growth hormone deficiency in children?

OBJECTIVE

To audit the contribution of plasma IGF-PB3 measurement to the diagnosis of growth hormone deficiency (GHD) in children.

POPULATION AND METHODS

Retrospective case study including boys and girls aged 0 to 18 years who attended our paediatric endocrinology clinic for short stature and/or post-irradiation follow-up, and had at least one GH provocative testing. Children with hypothyroidism, Laron or Kowarski syndromes, severe malnutrition, chronic renal failure and liver failure were excluded.

RESULTS

Fifty-eight children were enrolled and grouped as GHD [+] (19 cases) and GDH [-] (39 cases). IGF-I and IGF-BP3 assay was carried out in 88% and 62% cases respectively, both groups were comparable for age, sex, BMI, target height, pubertal stage and bone age. There was a significant difference in peak GH between GDH [-] and GHD [+] groups (41.8 mUI/L ± 21.7 versus 11.5 ± 5.9 mUI/L, P<0.00001, respectively). No difference was found between groups with regards to IGF-I Z-scores and IGF-BP3 Z-scores. There was, however, a positive correlation between IGF-I Z-scores and IGF-BP3 Z-scores (r=0.50; P<0.0016). IGF-BP3 measurement could not differentiate between GHD [+] and GHD [-] groups.

CONCLUSIONS

Measurement of plasma IGF-BP3 level contributes poorly to the diagnosis of GHD. We do not recommend it in routine use.

Pituitary stalk interruption syndrome: diagnostic delay and sensitivity of the auxological criteria of the growth hormone research society

OBJECTIVES

To study the diagnostic delay for pituitary stalk interruption syndrome (PSIS) with growth hormone deficiency (GHD) and the sensitivity of the auxological criteria of the Growth Hormone Research Society (GHRS) consensus guidelines.

METHODS

A single-center retrospective case-cohort study covering records from January 2000 through December 2007 evaluated the performance of each GHRS auxological criterion for patients with GHD and PSIS. Diagnostic delay was calculated as the difference between the age at which the earliest GHRS criterion could have been observed and the age at diagnosis of PSIS with GHD. A diagnostic delay exceeding one year was defined as late diagnosis.

RESULTS

The study included 21 patients, 16 (76%) of whom had isolated GHD and 5 (24%) multiple pituitary hormone deficiencies. The median age at diagnosis was 3.6 years (interquartile range, IQR, 2.6-5.5). The median diagnostic delay was 2.3 years (range 0-12.6; IQR 1.5-3.6), with late diagnosis for 17 patients (81%). Height more than 1.5 SDS below target height was the most effective criterion: 90% of the patients met the criterion before diagnosis at a median age of 1 year, and it was the first criterion to be fulfilled for 84%.

CONCLUSION

In our cohort, the delay for diagnosis of PSIS with GHD was long and could have been reduced by using the GHRS criteria, in particular, height more than 1.5 SDS below the target height. The specificity of such a strategy needs to be tested in healthy populations.

Evaluation of pituitary function after traumatic brain injury in childhood

OBJECTIVES

Post-traumatic hypopituitarism is well described amongst adult traumatic brain injury (TBI) survivors. We aimed to determine the prevalence and clinical significance of pituitary dysfunction after head injury in childhood.

DESIGN

Retrospective exploratory study.

PATIENTS

33 survivors of accidental head injury (27 boys). Mean (range) age at study was 13·4 years (5·4-21·7 years) and median (range) interval since injury 4·3 years (1·4-7·8 years). Functional outcome at study: 15 good recovery, 16 moderate disability, two severe disability.

MEASUREMENTS

Early morning urine osmolality and basal hormone evaluation were followed by the gonadotrophin releasing hormone (GnRH) and insulin tolerance (n = 25) or glucagon tests (if previous seizures, n = 8). Subjects were not primed. Head injury details were extracted from patient records.

RESULTS

No subject had short stature (mean height SD score +0·50, range -1·57 to +3·00). Suboptimal GH responses (<5 μg/l) occurred in six peri-pubertal boys (one with slow growth on follow-up) and one postpubertal adolescent (peak GH 3·2 μg/l). Median peak cortisol responses to insulin tolerance or glucagon tests were 538 and 562 nm. Nine of twenty-five and two of eight subjects had suboptimal responses, respectively, two with high basal cortisol levels. None required routine glucocorticoid replacement. In three, steroid cover was recommended for moderate/severe illness or injury. One boy was prolactin deficient. Other basal endocrine results and GnRH-stimulated LH and FSH were appropriate for age, sex and pubertal stage. Abnormal endocrine findings were unrelated to the severity or other characteristics of TBI or functional outcome.

CONCLUSIONS

No clinically significant endocrinopathy was identified amongst survivors of accidental childhood TBI, although minor pituitary hormone abnormalities were observed.

Somatotropin in the treatment of growth hormone deficiency and Turner syndrome in pediatric patients: a review

Growth hormone (GH), also known as somatotropin, is a peptide hormone that is synthesized and secreted by the somatotrophs of the anterior pituitary gland. The main action of GH is to stimulate linear growth in children; however, it also fosters a healthy body composition by increasing muscle and reducing fat mass, maintains normal blood glucose levels, and promotes a favorable lipid profile. This article provides an overview of the normal pathophysiology of GH production and action. We discuss the history of GH therapy and the development of the current formulation of recombinant human GH given as daily subcutaneous injections. This paper reviews two of the longest standing FDA-approved indications for GH treatment, GH deficiency and Turner syndrome. We will highlight the pathogenesis of these disorders, including presentations, presumed mechanism(s) for the associated short stature, and diagnostic criteria, with a review of stimulation test benefits and pitfalls. This review also includes current recommendations for GH therapy to help maximize final height in these children, as well as data demonstrating the efficacy and safety of GH treatment in these populations.

Rational approach to the diagnosis of severe growth hormone deficiency in the newborn

CONTEXT

Severe congenital GH deficiency (GHD) of the newborn is a rare disease, which can cause life-threatening hypoglycemias beginning in the first week of life. Reviews and consensus papers on the diagnosis of GHD repeatedly state the lack of a practical evidence-based approach to the diagnosis of GHD in the newborn.

OBJECTIVE

Here we provide for the first time sound reference values and a diagnostic cutoff for the GH levels in newborns at the age between d 3 and 5.

DESIGN, SETTING, AND PATIENTS

GH was measured in the eluate from 314 filter papers of the newborn screening test performed in our university hospital by using a highly sensitive human GH-ELISA. Reference data are compared with measurements from nine newborns with very high likelihood of having severe GHD, and cutoffs for the diagnostic work-up are defined.

RESULTS

In the presence of clinical evidence, the diagnosis of neonatal GHD can be confirmed during the first week of life by a single randomly taken GH level less than 7 microg/liter with 100% sensitivity and 98% specificity on the basis of our assay method. GH content in newborn screening cards stored for almost 3 yr were not different from the content found in recently used screening cards indicating high immunological stability of GH over time. Therefore, the diagnostic approach can use stored screening cards. In addition, we observed a clear gender dichotomy in respect to GH, with healthy female newborns having significantly higher GH levels than males. Cigarette smoking during pregnancy was associated with higher, transient tachypnea of the newborn with lower GH levels.

CONCLUSIONS

We provide the first rational approach to the diagnosis of severe GHD in the newborn and evidence for gender dichotomy of the neonatal GH axis.

Can auxology, IGF-I and IGFBP-3 measurements followed by MRI and genetic tests replace GH stimulation tests in the diagnosis of GH deficiency in children?

BACKGROUND/AIMS

GH levels < 10 ng/ml in response to two different GH stimulation tests (GHSTs) are traditionally used to identify children with GH deficiency (GHD). Since GHSTs are imprecise, other diagnostic tools have been proposed. We assessed whether auxology, IGF-I and IGFBP-3 measurements followed by brain MRI and genetic analysis can replace the current diagnostic approach.

METHODS

Fifty-three children diagnosed with GHD by two different GHSTs. GH-1 gene was sequenced.

RESULTS

At presentation, 17% of patients were with height above -1.5 SD and 28% above -2.0 SD; 50% had IGF-1 concentration above -1.5 SD and 58% above -2.0 SD; 59% had pituitary anomalies demonstrated by MRI. Fourteen patients harbored the heterozygous R183H mutation, one patient had the N47D mutation and one had a novel F25Y mutation in GH-1. Using cut-off levels of -1.5 SD for height, IGF-I and IGFBP-3 excluded the diagnosis of GHD in 17, 68 and 79% of the children, respectively; a cut-off of -2 SD excluded 28, 88 and 96%, respectively. Further brain MRI and genetic tests excluded 81-96% and 96-100%, respectively, of children currently diagnosed with GH.

CONCLUSION

Use of the tested approach, which avoids carrying out two GHSTs, would exclude most children currently diagnosed with GHD. Until better tools become available, we recommend identifying GHD in children by an integrated approach combining phenotype, auxological parameters, hormonal measurements and two separate GHSTs, with MRI and genetic tests to support the diagnosis.