The diagnosis of growth hormone deficiency in children and adults

Can Growth Hormone Stimulation Tests in Children Predict the Response to Growth Hormone Treatment?

OBJECTIVE

The efficacy of growth hormone (GH) treatment in short, healthy children diagnosed with growth hormone deficiency (GHD) or idiopathic short stature (ISS) suggests an overlap between these 2 conditions. Although imperfect and inconsistent, GH stimulation testing (GHST) remains the primary diagnostic tool for differentiating GHD and ISS, influencing GH treatment eligibility and dosing. This study aims to assess the clinical significance of GHST by comparing the response to GH treatment in children diagnosed with GHD or ISS based on their GHST results.

METHODS

A retrospective study in an endocrine clinic at a tertiary pediatric referral center comparing the response to GH treatment over 3 years in children diagnosed with GHD or ISS.

RESULTS

Two hundred ninty-one children treated with GH, 97 children diagnosed with GHD, and 194 with ISS are included in the analysis. Height significantly improved, and insulin-like growth factor-1 levels increased independent of the GHST results, gender, or pubertal status (P < .001). When adjusting for dosage, height gain was not associated with the treatment indication, GHD or ISS, or GHST peak levels.

CONCLUSIONS

Our findings indicate similar responses to GH treatment in children classified as GHD or ISS based on GHST. These results suggest that the pivotal role of GHST in diagnosing and treating short children should be reconsidered.

Exploring height outcomes with adjuvant aromatase inhibition in growth hormone-deficient male survivors of childhood cancer

BACKGROUND

Aromatase inhibitors (AI) may improve height in short stature conditions; however, the effect in childhood cancer survivors (CCS) is unknown. We assessed final adult height (FAH) in CCS treated with AI and GH compared with those treated with GH alone.

METHODS

Retrospective cohort study of GH-deficient male CCS treated between 2007 and 2023. FAH was noted as the height at the fusion of growth plates or 18 years of age. Multivariable linear regression was used to examine treatment association with FAH, adjusting for other risk factors.

RESULTS

Ninety-two patients were included; 70 were treated with GH and 22 with combination AI/GH. The mean age at GH initiation did not differ between groups. The mean age at AI initiation was 13.7 ± 1.9 years. A greater proportion of patients in the AI/GH group were treated with stem cell transplantation, abdominal radiation, total body irradiation, and cis-retinoic acid (p < .01). Multivariable linear regression demonstrated no significant treatment association with FAH Z-score (β = 0.04, 95% CI: -0.9 to 0.9). History of spinal radiation (β = -0.93, 95% CI: -1.7 to -0.2), lower starting height Z-score (β = -0.8, 95% CI: -1.2 to -0.4), and greater difference between bone age and chronological age (β = -0.3, 95% CI: -0.5 to -0.07) were associated with lower FAH Z-score.

CONCLUSIONS

Adjuvant AI was not associated with increased FAH in male CCS compared with GH monotherapy. Future work is needed to determine the optimal adjunctive treatment to maximize FAH for this population.

Baseline Clinical Factors Associated with Cessation of Growth Hormone Therapy in Patients with Severe Growth Hormone Deficiency - Real World Evidence

Background

Growth hormone replacement is indicated in adults with severe growth hormone (GH) deficiency, adult growth hormone deficiency assessment (AGHDA) score of at least 11 and are receiving treatment for other pituitary hormone deficiencies. There are no data looking at the cessation of GH replacement in adult patients with severe GH deficiency and the factors that predict the likelihood of patients continuing or stopping growth hormone replacement.

Methods

We audited patients on the GH register between January 2006 and January 2023 in Hull University Teaching Hospitals NHS foundation Trust, a UK tertiary hospital. Baseline characteristics, the cause of GH deficiency, AGHDA score at diagnosis and the reason for stopping GH were collected. Proportions were compared between patients adhering to GH replacement and those who had ceased it. Logistic regression analysis was used to identify factors independently associated with cessation of GH.

Results

The study comprised 141 adult patients with a mean age of 52 years, of which 75 (53%) were female. 54 (38%) individuals had discontinued GH replacement therapy. Predominant reasons for discontinuation were lack of therapeutic benefit (46%) and a change in clinical indication (26%). Among patients who discontinued GH therapy, the most frequent cause of GH deficiency was idiopathic (57%), while for those on GH replacement, pituitary surgery was the leading cause of GH deficiency (53%). Logistic regression analysis showed no baseline factor was statistically significantly associated with GH cessation, except female gender which had a borderline significance (P = 0.05).

Conclusions

In this real-world investigation of patients with severe GH deficiency, over two in five individuals who discontinued GH therapy cited the absence of perceived benefits. We show a borderline association of female gender with GH cessation and large population-based studies will be needed to investigate this and other causes of GH cessation.

International recommendations for screening and preventative practices for long-term survivors of transplantation and cellular therapy: a 2023 update

As hematopoietic cell transplantation (HCT) and cellular therapy expand to new indications and international access improves, the volume of HCT performed annually continues to rise. Parallel improvements in HCT techniques and supportive care entails more patients surviving long-term, creating further emphasis on survivorship needs. Survivors are at risk for developing late complications secondary to pre-, peri- and post-transplant exposures and other underlying risk-factors. Guidelines for screening and preventive practices for HCT survivors were originally published in 2006 and updated in 2012. To review contemporary literature and update the recommendations while considering the changing practice of HCT and cellular therapy, an international group of experts was again convened. This review provides updated pediatric and adult survivorship guidelines for HCT and cellular therapy. The contributory role of chronic graft-versus-host disease (cGVHD) to the development of late effects is discussed but cGVHD management is not covered in detail. These guidelines emphasize special needs of patients with distinct underlying HCT indications or comorbidities (e.g., hemoglobinopathies, older adults) but do not replace more detailed group, disease, or condition specific guidelines. Although these recommendations should be applicable to the vast majority of HCT recipients, resource constraints may limit their implementation in some settings.

International Recommendations for Screening and Preventative Practices for Long-Term Survivors of Transplantation and Cellular Therapy: A 2023 Update

As hematopoietic cell transplantation (HCT) and cellular therapy expand to new indications and international access improves, the number of HCTs performed annually continues to rise. Parallel improvements in HCT techniques and supportive care entails more patients surviving long term, creating further emphasis on survivorship needs. Survivors are at risk for developing late complications secondary to pretransplantation, peritransplantation, and post-transplantation exposures and other underlying risk factors. Guidelines for screening and preventive practices for HCT survivors were originally published in 2006 and then updated in 2012. An international group of experts was convened to review the contemporary literature and update the recommendations while considering the changing practices of HCT and cellular therapy. This review provides updated pediatric and adult survivorship guidelines for HCT and cellular therapy. The contributory role of chronic graft-versus-host disease (cGVHD) to the development of late effects is discussed, but cGVHD management is not covered in detail. These guidelines emphasize the special needs of patients with distinct underlying HCT indications or comorbidities (eg, hemoglobinopathies, older adults) but do not replace more detailed group-, disease-, or condition-specific guidelines. Although these recommendations should be applicable to the vast majority of HCT recipients, resource constraints may limit their implementation in some settings.

Pituitary function at presentation and following therapy in patients with non-functional pituitary macroadenomas: a single centre retrospective cohort study

BACKGROUND

Non-functioning pituitary macroadenomas (NFPMs) may present with hypopituitarism. Pituitary surgery and radiotherapy pose an additional risk to pituitary function.

OBJECTIVES

To assess the incidence of hypopituitarism at presentation, the impact of treatment, and the likelihood of endocrine recovery during follow-up.

METHODS

All patients treated surgically with and without radiotherapy for NFPMs between 1987 and 2018 who had longer than six months follow-up were identified. Demographics, presentation, investigation, treatment, and outcomes were collected.

RESULTS

In total, 383 patients were identified. The median age was 57 years, with a median follow-up of 8 years. Preoperatively, 227 patients (227/375; 61%) had evidence of at least one pituitary deficiency. Anterior panhypopituitarism was more common in men (p = 0.001) and older patients (p = 0.005). Multiple hormone deficiencies were associated with large tumours (p = 0.03). Patients treated with surgery and radiotherapy had a higher incidence of all individual pituitary hormone deficiency, anterior panhypopituitarism, and significantly lower GH, ACTH, and TSH deficiencies free survival probability than those treated with surgery alone. Recovery of central hypogonadism, hypothyroidism, and anterior panhypopituitarism was also less likely to be reported in those treated with surgery and radiotherapy. Those with preoperative hypopituitarism had a higher risk of pituitary impairment at latest review than those presented with normal pituitary function (p = 0.001).

CONCLUSION

NFPMs are associated with a significant degree of hypopituitarism at time of diagnosis and post-therapy. The combination of surgery and radiotherapy is associated with a higher risk of pituitary dysfunction. Recovery of pituitary hormone deficit may occur after treatment. Patients should have regular ongoing endocrine evaluation post-treatment to assess changes in pituitary function and the need for long-term replacement therapy.

Post-Operative Medium- and Long-Term Endocrine Outcomes in Patients with Non-Functioning Pituitary Adenomas-Machine Learning Analysis

Post-operative endocrine outcomes in patients with non-functioning pituitary adenoma (NFPA) are variable. The aim of this study was to use machine learning (ML) models to better predict medium- and long-term post-operative hypopituitarism in patients with NFPAs. We included data from 383 patients who underwent surgery with or without radiotherapy for NFPAs, with a follow-up period between 6 months and 15 years. ML models, including k-nearest neighbour (KNN), support vector machine (SVM), and decision tree models, showed a superior ability to predict panhypopituitarism compared with non-parametric statistical modelling (mean accuracy: 0.89; mean AUC-ROC: 0.79), with SVM achieving the highest performance (mean accuracy: 0.94; mean AUC-ROC: 0.88). Pre-operative endocrine function was the strongest feature for predicting panhypopituitarism within 1 year post-operatively, while endocrine outcomes at 1 year post-operatively supported strong predictions of panhypopituitarism at 5 and 10 years post-operatively. Other features found to contribute to panhypopituitarism prediction were age, volume of tumour, and the use of radiotherapy. In conclusion, our study demonstrates that ML models show potential in predicting post-operative panhypopituitarism in the medium and long term in patients with NFPM. Future work will include incorporating additional, more granular data, including imaging and operative video data, across multiple centres.

Growth Hormone Deficiency following Traumatic Brain Injury in Pediatric and Adolescent Patients: Presentation, Treatment, and Challenges of Transitioning from Pediatric to Adult Services

Traumatic brain injury (TBI) is increasingly recognized, with an incidence of approximately 110 per 100,000 in pediatric populations and 618 per 100,000 in adolescent and adult populations. TBI often leads to cognitive, behavioral, and physical consequences, including endocrinopathies. Deficiencies in anterior pituitary hormones (e.g., adrenocorticotropic hormone, thyroid-stimulating hormone, gonadotropins, and growth hormone [GH]) can negatively impact health outcomes and quality of life post-TBI. This review focuses on GH deficiency (GHD), the most common post-TBI pituitary hormone deficiency. GHD is associated with abnormal body composition, lipid metabolism, bone mineral density, executive brain functions, behavior, and height outcomes in pediatric, adolescent, and transition-age patients. Despite its relatively frequent occurrence, post-TBI GHD has not been well studied in these patients; hence, diagnostic and treatment recommendations are limited. Here, we examine the occurrence and diagnosis of TBI, retrospectively analyze post-TBI hypopituitarism and GHD prevalence rates in pediatric and adolescent patients, and discuss appropriate GHD testing strategies and GH dosage recommendations for these patients. We place particular emphasis on the ways in which testing and dosage recommendations may change during the transition phase. We conclude with a review of the challenges faced by transition-age patients and how these may be addressed to improve access to adequate healthcare. Little information is currently available to help guide patients with TBI and GHD through the transition phase and there is a risk of interrupted care; therefore, a strength of this review is its emphasis on this critical period in a patient's healthcare journey.

Comparison of glucagon stimulation test and low dose ACTH test in assessing hypothalamic-pituitary-adrenal (HPA) axis in children

INTRODUCTION

Children with a pituitary hormone deficiency are at risk for secondary adrenal insufficiency (AI). A stimulation test is usually performed for diagnosing AI, evaluating both the hypothalamic-pituitary-adrenal and growth hormone (GH)-IGF-1 axes. This single test is preferred by clinicians and is considerably more tolerable by patients. The objective of this study was to evaluate the glucagon stimulation test (GST), which is commonly used to assess both axes. Its diagnostic capability for GH deficiency is high and well accepted, however its utility for determining secondary AI has not been well established.

METHODS

This retrospective study involved 120 patients under 18 years of age with short stature who had undergone both a GST and low dose ACTH stimulation test (LDACTH test). Twenty-six children who had more than 6 months elapsed between the two tests were excluded from the study. The study was conducted on patients of the Pediatric Endocrinology Department at Soroka University Hospital, a tertiary medical centre in Beer Sheva, Israel. Statistical analyses were carried out via IBM SPSS (v. 22), with a significance level determined at p < .05.

RESULTS

Different cortisol cut-off values were assessed for GST and it was determined that the highest combined sensitivity and specificity yielded a cut-off point of 320 nmol/L (56% sensitivity and 83% specificity) while the currently accepted cut-off value (500 nmol/L) yielded 100% sensitivity and 6% specificity.

CONCLUSION

The results of this study show that GST is not an optimal tool for diagnosing secondary AI. Therefore, clinicians using this test should interpret its results with caution.

Isolated anterior pituitary dysfunction in adulthood

Hypopituitarism is defined as a complete or partial deficiency in one or more pituitary hormones. Anterior hypopituitarism includes secondary adrenal insufficiency, central hypothyroidism, hypogonadotropic hypogonadism, growth hormone deficiency and prolactin deficiency. Patients with hypopituitarism suffer from an increased disability and sick days, resulting in lower health status, higher cost of care and an increased mortality. In particular during adulthood, isolated pituitary deficits are not an uncommon finding; their clinical picture is represented by vague symptoms and unclear signs, which can be difficult to properly diagnose. This often becomes a challenge for the physician. Aim of this narrative review is to analyse, for each anterior pituitary deficit, the main related etiologies, the characteristic signs and symptoms, how to properly diagnose them (suggesting an easy and reproducible step-based approach), and eventually the treatment. In adulthood, the vast majority of isolated pituitary deficits are due to pituitary tumours, head trauma, pituitary surgery and brain radiotherapy. Immune-related dysfunctions represent a growing cause of isolated pituitary deficiencies, above all secondary to use of oncological drugs such as immune checkpoint inhibitors. The diagnosis of isolated pituitary deficiencies should be based on baseline hormonal assessments and/or dynamic tests. Establishing a proper diagnosis can be quite challenging: in fact, even if the diagnostic methods are becoming increasingly refined, a considerable proportion of isolated pituitary deficits still remains without a certain cause. While isolated ACTH and TSH deficiencies always require a prompt replacement treatment, gonadal replacement therapy requires a benefit-risk evaluation based on the presence of comorbidities, age and gender of the patient; finally, the need of growth hormone replacement therapies is still a matter of debate. On the other side, prolactin replacement therapy is still not available. In conclusion, our purpose is to offer a broad evaluation from causes to therapies of isolated anterior pituitary deficits in adulthood. This review will also include the evaluation of uncommon symptoms and main etiologies, the elements of suspicion of a genetic cause and protocols for diagnosis, follow-up and treatment.

Growth Hormone Response to L-Arginine Alone and Combined with Different Doses of Growth Hormone-Releasing Hormone: A Systematic Review and Meta-Analysis

Background

Arginine (ARG) can modulate growth hormone (GH) release by suppressing its endogenous inhibitory regulator, somatostatin. ARG also induces the release of the GH-releasing hormone (GHRH). This study aims to review the effects of L-arginine supplementation alone and combined with GHRH in different doses on GH secretion.

Methods

In this systematic review and meta-analysis, an electronic literature search was conducted on Medline database (PubMed), Scopus, and Web of Science databases. All eligible studies were randomized clinical trials that reported the effects of ARG supplementation alone or with GHRH on GH levels. Mean difference (MD) and 95% confidence intervals (CI) were computed as the effect size.

Results

Meta-analyses showed significant effects of ARG alone on GH release (MD = 10.07, 95% CI: 7.87, 12.28). Moreover, the response of GH was greater with ARG in combination with GHRH (MD = 24.96, 95% CI: 17.51, 32.42). There was no significant difference between the patients and healthy individuals and between oral and injection use of ARG. The systematic review revealed the important role of ARG in combination with other amino acids on GH secretion in patients with GH deficiency.

Conclusion

This study revealed that in GH-deficient individuals, high doses of ARG supplementation in combination with GHRH and/or other amino acids might have potential therapeutic effects on increasing GH concentrations. These findings propose that ARG supplementation can be considered as a potential stimulator in management of GH deficiency.

Growth Hormone Deficiency

Short stature is a common reason for a child to visit the endocrinologist, and can be a variant of normal or secondary to an underlying pathologic cause. Pathologic causes include growth hormone deficiency (GHD), which can be congenital or acquired later. GHD can be isolated or can occur with other pituitary hormone deficiencies. The diagnosis of GHD requires thorough clinical, biochemical, and radiographic investigations. Genetic testing may also be helpful in some patients. Treatment with recombinant human growth hormone (rhGH) should be initiated as soon as the diagnosis is made and patients should be monitored closely to evaluate response to treatment and for potential adverse effects.

Predictive factors for recovery from adult growth hormone deficiency after transsphenoidal surgery for nonfunctioning pituitary adenoma

OBJECTIVE

Recovery from adult growth hormone deficiency (AGHD) after transsphenoidal surgery (TSS) has not been well discussed because of the lack of examinations including pituitary provocation tests (PPTs) before and after the procedure. This study aimed to evaluate the growth hormone (GH) axis function of patients with nonfunctioning pituitary adenoma (NFPA) via pre- and postoperative PPTs. Moreover, the predictive factors for recovery from AGHD after TSS were validated to facilitate surgery for AGHD in patients with NFPA.

METHODS

In total, 276 patients (median age 60.0 years) who underwent TSS for NFPA were included in this study. PPTs were performed before and 3 months after TSS. Then, the relationships between recovery from AGHD after TSS and clinical, surgical, and hormonal factors, including peak GH level based on PPTs, were evaluated statistically.

RESULTS

In this study, 114 patients were diagnosed with preoperative AGHD. Approximately 25.4% recovered from AGHD after TSS. In contrast, among the 162 patients without preoperative AGHD, 13 (8.0%) had newly developed postoperative AGHD. The predictive factors for recovery from AGHD were younger age, female sex, initial TSS, and high peak GH level based on preoperative PPT. According to the receiver operating characteristic curve analysis, patients who were aged ≤ 62.2 years and had a peak GH level of ≥ 0.74 μg/L based on preoperative PPT were likely to recover from AGHD (sensitivity: 82.8%, specificity: 72.9%, and area under the curve: 0.8229).

CONCLUSIONS

AGHD caused by NFPA can improve after initial TSS among young patients with certain peak GH levels assessed by preoperative PPT. Whether TSS for NFPA can promote recovery from AGHD is worth considering in some patients.

Growth hormone deficiency in adults with hypopituitarism-What are the risks and can they be eliminated by therapy?

Growth hormone (GH) deficiency develops early in patients with hypothalamic-pituitary disorders and is therefore common among these patients. GH deficiency in adults is associated with increased morbidity, increased body fat mass, abdominal obesity, dyslipidaemia, reduced exercise capacity, impaired cardiac function as well as reduced self-reported well-being and impaired quality of life. Since recombinant human GH became available as replacement therapy more than 25 years ago, randomised controlled trials and long-term studies, together with meta-analyses, have shown improved outcomes in adult patients with hypopituitarism receiving GH. Many of the features associated with GH deficiency in adults improve, or even normalize, and the safety profile is reassuring. The increased interest in GH deficiency in adults with hypothalamic-pituitary disorders has also contributed to the identification of other factors of importance for an outcome such as the replacement of other pituitary hormone deficiencies, and the management of the underlying hypothalamic-pituitary disease, most commonly a pituitary tumour. In this narrative review, we summarize the burden of GH deficiency in adults with hypopituitarism, the impact of GH replacement on the outcome, as well as safety. Based on currently available data, GH replacement should be considered routine management of adults with hypopituitarism.

Diagnosis of Growth Hormone Deficiency in Children: The Efficacy of Glucagon versus Clonidine Stimulation Test

INTRODUCTION

The diagnosis of childhood growth hormone deficiency (GHD) requires a failure to respond to 2 GH stimulation tests (GHSTs) performed with different stimuli. The most commonly used tests are glucagon stimulation test (GST) and clonidine stimulation test (CST). This study assesses and compares GST and CST's diagnostic efficacy for the initial evaluation of short children.

METHODS

Retrospective, single-center, observational study of 512 short children who underwent GHST with GST first or CST first and a confirmatory test with the opposite stimulus in cases of initial GH peak <7.5 ng/mL during 2015-2018. The primary outcome measure was the efficacy of the GST first or CST first in diagnosing GHD.

RESULTS

Population characteristics include median age of 9.3 years (interquartile range 6.2, 12.1), 78.3% prepubertal, and 61% boys. Subnormal GH response in the initial test was recorded in 204 (39.8%) children: 148 (45.5%) in GST first and 56 (30%) in CST first, p < 0.001. Confirmatory tests verified GHD in 75/512 (14.6%) patients. Divergent results between the initial and confirmatory tests were more prevalent in GST first than CST first (103/148 [69.6%] vs. 26/56 [46.4%], p < 0.001) indicating a significantly lower error rate for the CST first compared to the GST first. In multivariate analysis, the only significant predictive variable for divergent results between the tests was the type of stimulation test (OR = 0.349 [95% CI 0.217, 0.562], p < 0.001).

CONCLUSIONS

Screening of GH status with CST first is more efficient than that with GST first in diagnosing GHD in short children with suspected GHD. It is suggested that performing CST first may reduce the need for a second provocative test and avoid patients' inconvenience of undergoing 2 serial tests.

Growth Hormone Deficiency and Treatment in Childhood Cancer Survivors

Growth hormone (GH) deficiency is a common pituitary hormone deficiency in childhood cancer survivors (CCS). The identification, diagnosis, and treatment of those individuals at risk are important in order to minimize associated morbidities that can be ameliorated by treatment with recombinant human GH therapy. However, GH and insulin-like growth factor-I have been implicated in tumorigenesis, so there has been concern over the use of GH therapy in patients with a history of malignancy. Reassuringly, GH therapy has not been shown to increase risk of tumor recurrence. These patients have an increased risk for development of meningiomas, but this may be related to their history of cranial irradiation rather than to GH therapy. In this review, we detail the CCS who are at risk for GHD and the existing evidence on the safety profile of GH therapy in this patient population.

Towards Understanding the Direct and Indirect Actions of Growth Hormone in Controlling Hepatocyte Carbohydrate and Lipid Metabolism

Growth hormone (GH) is critical for achieving normal structural growth. In addition, GH plays an important role in regulating metabolic function. GH acts through its GH receptor (GHR) to modulate the production and function of insulin-like growth factor 1 (IGF1) and insulin. GH, IGF1, and insulin act on multiple tissues to coordinate metabolic control in a context-specific manner. This review will specifically focus on our current understanding of the direct and indirect actions of GH to control liver (hepatocyte) carbohydrate and lipid metabolism in the context of normal fasting (sleep) and feeding (wake) cycles and in response to prolonged nutrient deprivation and excess. Caveats and challenges related to the model systems used and areas that require further investigation towards a clearer understanding of the role GH plays in metabolic health and disease are discussed.

Short and Long-Term Effects of Growth Hormone in Children and Adolescents With GH Deficiency

The syndrome of impaired GH secretion (GH deficiency) in childhood and adolescence had been identified at the end of the 19th century. Its non-acquired variant (naGHD) is, at childhood onset, a rare syndrome of multiple etiologies, predominantly characterized by severe and permanent growth failure culminating in short stature. It is still difficult to diagnose GHD and, in particular, to ascertain impaired GH secretion in comparison to levels in normally-growing children. The debate on what constitutes an optimal diagnostic process continues. Treatment of the GH deficit via replacement with cadaveric pituitary human GH (pit-hGH) had first been demonstrated in 1958, and opened an era of therapeutic possibilities, albeit for a limited number of patients. In 1985, the era of recombinant hGH (r-hGH) began: unlimited supply meant that substantial long-term experience could be gained, with greater focus on efficacy, safety and costs. However, even today, the results of current treatment regimes indicate that there is still a substantial fraction of children who do not achieve adult height within the normal range. Renewed evaluation of height outcomes in childhood-onset naGHD is required for a better understanding of the underlying causes, whereby the role of various factors - diagnostics, treatment modalities, mode of treatment evaluation - during the important phases of child growth - infancy, childhood and puberty - are further explored.

Diagnosing Growth Hormone Deficiency: Can a Combined Arginine and Clonidine Stimulation Test Replace 2 Separate Tests?

OBJECTIVE

Given the large number of false-positive growth hormone deficiency (GHD) diagnoses from a single growth hormone (GH) stimulation test in children, 2 different pharmacologic tests, performed on separate days or sequentially, are required. This study aimed to assess the reliability and safety of a combined arginine-clonidine stimulation test (CACST).

METHODS

This was a retrospective, single-center, observational study. During 2017-2019, 515 children aged >8 years underwent GH stimulation tests (CACST: n = 362 or clonidine stimulation test [CST]: n = 153). The main outcome measures used to compare the tests were GH response (sufficiency/deficiency) and amplitude and timing of peak GH and safety parameters.

RESULTS

Population characteristics were as follows: median age of 12.2 years (interquartile range [IQR]: 10.7, 13.4), 331 boys (64%), and 282 prepubertal children (54.8%). The GHD rate was comparable with 12.7% for CACST and 14.4% for CST followed by a confirmatory test (glucagon or arginine) (P = .609). Peak GH was higher and occurred later in response to CACST compared with CST (14.6 ng/mL [IQR: 10.6, 19.4] vs 11.4 ng/mL [IQR: 7.0, 15.8], respectively, P < .001; 90 minutes [IQR: 60, 90] vs 60 minutes [IQR: 60, 90], respectively, P < .001). No serious adverse events occurred following CACST.

CONCLUSION

Our findings demonstrate the reliability and safety of CACST in detecting GHD in late childhood and adolescence, suggesting that it may replace separate or sequential GH stimulation tests. By diminishing the need for the second GH stimulation test, CACST saves time, is more cost-effective, and reduces discomfort for children, caregivers, and medical staff.

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.

Corroboration of Height Velocity Prediction Markers for rhGH With an Oral GH Secretagogue Treatment in Children With GHD

Context

Recombinant human growth hormone (rhGH) is approved for treatment of pediatric growth hormone deficiency (GHD), with greatest growth responses observed in those with severe GHD. Orally administered GH secretagogues (GHS) may be useful treatment in patients with moderate GHD. Distinguishing children with severe vs moderate GHD could identify children who would be better treated with rhGH or GHS.

Objectives

Evaluate baseline insulin-like growth factor-I (IGF-I) and stimulated peak GH response as predictors of 12-month height velocity (HV) in children with GHD.

Design

Data on children with GHD were analyzed in a legacy data base (GeNeSIS data).

Participants

514 naïve to rhGH-treatment, prepubertal children with idiopathic isolated GHD for whom stimulated GH, baseline serum IGF-I, and first-year HV during rhGH treatment data are available.

Outcome Measures

Children with severe or moderate GHD were categorized based on GH and IGF-I data and evaluated based on baseline auxologic and hormone profiles and first-year growth response to rhGH.

Results

Cohorts of severe and moderate GHD were 81/514 (15.8%) and 433/514 (84.2%). Cohorts differed significantly with regard to indicators of GHD [eg, baseline height SD score (SDS), height SDS minus target height SDS, HV, HV SDS, and change in height SDS during rhGH treatment]. Multiple regression analysis showed IGF-I and stimulated GH were significant predictors of HV independent of other known variables. Expected first-year HV in moderate GHD was 8.3 cm/y.

Conclusions

The combination of peak GH to GH stimulation testing and baseline IGF-I concentration are predictive enrichment markers for annualized HV responses to rhGH therapy.

Effectiveness and Overall Safety of NutropinAq® for Growth Hormone Deficiency and Other Paediatric Growth Hormone Disorders: Completion of the International Cooperative Growth Study, NutropinAq® European Registry (iNCGS)

Objective

The International Cooperative Growth Study, NutropinAq® European Registry (iNCGS) (NCT00455728) monitored long-term safety and effectiveness of recombinant human growth hormone (rhGH; NutropinAq® [somatropin]) in paediatric growth disorders.

Methods

Open-label, non-interventional, post-marketing surveillance study recruiting children with growth disorders. Endpoints included gain in height standard deviation score (SDS), adult height, and occurrence of adverse events (AEs).

Results

2792 patients were enrolled. 2082 patients (74.6%) had growth hormone deficiency (GHD), which was isolated idiopathic in 1825 patients (87.7%). Non-GHD diagnoses included Turner syndrome (TS) (n=199), chronic renal insufficiency (CRI) (n=10), other non-GHD (n=498), and missing data for three participants. Improvements from baseline height SDS occurred at all time points to Month 132, and in all subgroups by disease aetiology. At Month 12, mean (95% CI) change in height SDS by aetiology was: idiopathic GHD 0.63 (0.61;0.66), organic GHD 0.71 (0.62;0.80), TS 0.59 (0.53; 0.65), CRI 0.54 (-0.49;1.56), and other non-GHD 0.64 (0.59;0.69). Mean height ( ± SD) at the last visit among the 235 patients with adult or near-adult height recorded was 154.0 cm ( ± 8.0) for girls and 166.7 cm ( ± 8.0) for boys. The most frequent biological and clinical non-serious drug-related AEs were increased insulin-like growth factor concentrations (314 events) and injection site haematoma (99 events). Serious AEs related to rhGH according to investigators were reported (n=30); the most frequent were scoliosis (4 events), epiphysiolysis (3 events), and strabismus (2 events).

Conclusions

There was an improvement in mean height SDS in all aetiology subgroups after rhGH treatment. No new safety concerns were identified.

Economic burden of growth hormone deficiency in a US pediatric population

BACKGROUND: Pediatric growth hormone deficiency (GHD) is a rare disorder of short stature that is currently treated with daily injections of somatropin. In addition to short stature, GHD is associated with other comorbidities such as impaired musculoskeletal development, cardiovascular disease, and decreased quality of life. OBJECTIVE: To analyze somatropin utilization, adherence, and health care costs among children with GHD who had either Medicaid or commercial health insurance. METHODS: Children (aged < 18 years) with a GHD diagnosis between January 1, 2008, and December 31, 2017, were identified in the IBM MarketScan Commercial and Medicaid databases. Patients with at least 12- and 6-month continuous enrollment pre- and postdiagnosis were eligible. Children with GHD were direct matched (1:3) to controls without GHD (or other short stature-related disorders) on age, gender, plan type, region, and race (Medicaid only). Index date was the date of the first GHD diagnosis during the selection window for GHD patients and using random assignment for controls. Patients were followed until the end of continuous database enrollment or December 31, 2018. Baseline comorbidities and medications were measured during the 12 months pre-index, whereas somatropin treatment patterns along with all-cause and GHD-related health care costs were measured during the variable follow-up period. Multivariable modeling was used to compare costs between GHD patients and controls and between somatropin-treated and -untreated GHD patients while adjusting for baseline characteristics. RESULTS: There were 6,820 Medicaid and 14,070 commercial patients with GHD who met the study inclusion criteria. Mean (SD) age at index was 9.5 (4.5) years for Medicaid patients and 11.1 (3.7) years for commercial patients. The majority of patients were male (> 65%), and mean follow-up time for all cases and controls was 3-4 years. Overall, 63.2% of Medicaid and 68.4% of commercial GHD patients were treated with somatropin at some point during follow-up. Among Medicaid GHD patients, the treatment rate was highest among White males and lowest among Black females. Adherence was low as the proportion of days covered was ≥ 80% for only 18.4% of Medicaid patients and 32.3% of commercial patients and 49.1% of treated Medicaid and 24.3% of treated commercial patients discontinued before turning age 13. After adjusting for baseline characteristics, all-cause non-somatropin annualized costs were 5.67 times higher (Δ$19,309) for Medicaid GHD patients and 5.46 times higher (Δ$12,305) for commercial GHD patients than matched non-GHD controls. Adjusted all-cause non-somatropin annualized costs were 0.59 times lower (Δ$14,416) for treated Medicaid patients and 0.69 times lower (Δ$7,650) for treated commercial patients than for untreated patients. CONCLUSIONS: Pediatric GHD presents a significant health care burden, and many patients remain untreated or undertreated. Untreated GHD was associated with higher non-somatropin health care costs than treated GHD. Strategies to optimize treatment and improve adherence may reduce the health care burden faced by these patients. DISCLOSURES: This study was funded by Ascendis Pharma, Inc. Smith and Pitukcheewanont are employed by Ascendis Pharma, Inc. Manjelievskaia, Lopez-Gonzalez, and Morrow are employed by IBM Watson Health, which received funding from Ascendis Pharma, Inc., to conduct this study. Kaplowitz is a paid consultant of Ascendis Pharma, Inc.

Temporal trends in craniopharyngioma management and long-term endocrine outcomes: A multicentre cross-sectional study

BACKGROUND

The optimal management of craniopharyngiomas remains controversial.

OBJECTIVES

To examine temporal trends in the management of craniopharyngioma with a focus on endocrine outcomes.

METHODS

This was a cross-sectional, multicentre study. Patients treated between 1951 and 2015 were identified and divided into four quartiles. Demographics, presentation, treatment and outcomes were collected.

RESULTS

In total, 142 patients with childhood-onset craniopharyngioma (48/142; 34%) and adult-onset disease (94/142; 66%) were included. The median follow-up was 15 years (IQR 5-23 years). Across quartiles, there was a significant trend towards using transsphenoidal surgery (P < .0001). The overall use of radiotherapy was not different among the four quartiles (P = .33). At the latest clinical review, the incidence of GH, ACTH, gonadotrophin deficiencies and anterior panhypopituitarism fell significantly across the duration of the study. Anterior panhypopituitarism was not affected by treatment modality (surgery vs surgery and radiotherapy) (P = .23). There was no difference in the incidence of high BMI (≥25 kg/m² ) among the four quartiles (P = .14). BMI was higher in patients who treated with surgery and radiotherapy than those treated with surgery only (P = .006). Tumour regrowth occurred in 51 patients (51/142; 36%) with no difference in regrowth among quartiles over the time course of the study (P = .15).

CONCLUSION

We demonstrate a significant reduction in panhypopituitarism in craniopharyngioma patients over time, most likely because of a trend towards more transsphenoidal surgery. However, long-term endocrine sequelae remain common and lifelong follow-up is required.

Use of the Growth Hormone Stimulation Test Result in the Management of Patients With a Short Stature

Introduction A proportionate short stature (SS) assessment involves the documentation of normal growth hormone secretion via a growth hormone (GH) stimulation test. All available GH stimulation tests have some disadvantages. The decision to initiate GH therapy is dependent on multiple factors, including the GH stimulation test result. However, many patients receive GH therapy, even if they have a normal GH stimulation test result, with the indication of a presumed idiopathic SS. Objective In this study, we investigated the use of the GH stimulation test result in initiating GH therapy. Method A cross-sectional study was conducted with patients diagnosed with proportionate SS. Age, gender, insulin-like growth factor 1 (IGF-1) level, and GH stimulation test results were collected retrospectively from the electronic medical records. The main outcome variable was the decision related to prescribing GH therapy. Results A total of 286 patient charts were reviewed, and the majority (n = 201, 64.6%) were male. For just less than half (n = 136, 47.6%), the result of the GH stimulation test was ≥ 10 ng/mL, in a small proportion (n = 53, 18.5%) the result was < 5 ng/mL, and for the rest of the cohort, the result was 5.0 - 9.9 ng/mL. The majority (n = 219, 70.4%) received GH therapy, irrespective of the GH stimulation test result. The odds ratio (OR) for GH treatment was 3.9 (CI: 1.79 - 8.49) and 3.0 (CI: 1.21 - 7.42) for patients with a result < 5 ng/mL and 5.0 - 9.9 ng/mL, respectively, compared to the group with a result of ≥ 10 ng/mL. Conclusion GH therapy is frequently prescribed for patients with SS, irrespective of the GH stimulation test result. However, the group with SS with a result of < 9.9 ng/mL was more likely to receive GH therapy. The question of whether a GH stimulation test is required, in the context of SS, is debatable.

Growth hormone therapy in adults with growth hormone deficiency: a critical assessment of the literature

PURPOSE

Growth hormone (GH) therapy has been studied as treatment for clinical manifestations of adult-onset growth hormone deficiency (AO-GHD), including cardiovascular risk, bone health, and quality of life. Patients with AO-GHD typically also have significant history of pituitary pathology and hypopituitarism, which raises the question of what proportion of their clinical presentation can be attributed to GHD alone. Currently, much of the existing data for GH therapy in AO-GHD come from uncontrolled retrospective studies and observational protocols. These considerations require careful reassessment of the role of GH as a therapeutic agent in adult patients with hypopituitarism.

METHODS

We contrast results from placebo-controlled trials with those from uncontrolled and retrospective studies for GH replacement in patients with hypopituitarism. We also examine the evidence for the manifestations of AO-GHD being attributed to GHD alone, as well as the data on adults with congenital, life-long untreated isolated GHD.

RESULTS

The evidence for increased morbidity and mortality in hypopituitary patients with GHD, and for the benefits of GH therapy, are conflicting. There remains the possibility that the described clinical manifestations of AO-GHD may not be due to GHD alone, but may also be related to underlying pituitary pathology, treatment history and suboptimal hormone replacement.

CONCLUSIONS

In the setting of inconsistent data on the benefits of GH therapy, treatment of AO-GHD remains an individualized decision. There is a need for more randomized, placebo-controlled studies to evaluate the long-term outcomes of GH therapy in adults with hypopituitarism.

The heart in growth hormone (GH) deficiency and the cardiovascular effects of GH

Besides its effects on longitudinal growth in childhood and its metabolic effects with consequences on body composition and lipid levels, growth hormone (GH) has important roles on maintaining the structure and function of the normal adult heart. GH/insulin like growth factor-I (IGF-I) also interacts with the vascular system and plays a role in the regulation of vascular tone. GH deficiency (GHD) in adulthood is associated with increased fat mass (particularly visceral) and abnormal lipid profile, which may contribute to the excess cardiovascular mortality observed in patients with panhypopituitarism. Treatment with GH improved body composition (by increasing lean mass and decreasing fat mass) and improved lipid profile. It also has beneficial effects on vascular walls. The improvement in cardiovascular morbidity and mortality induced by GH is less clear as data are scarce and obtained on small populations. The importance of alteration in cardiac morphology and function observed in GHD is debated, particularly when cardiac magnetic resonance is used rather than echocardiography. The effects of treatment with GH on heart function and morphology are modest when studied by echocardiography.

Basal characteristics and first year responses to human growth hormone (GH) vary according to diagnostic criteria in children with non-acquired GH deficiency (naGHD): observations from a single center over a period of five decades

Background Children with non-acquired (na) growth hormone deficiency (GHD) diagnosed over decades in one center may provide perspective insight. Methods naGHD is divided into idiopathic GHD (IGHD), GHD of known cause (cGHD) and GHD neurosecretory dysfunction (NSD); time periods: <1988 (I); 1988-1997 (II); 1998-2007 (III); 2008-2015 (IV). Descriptive analyses were performed at diagnosis and during first year GH treatment. Results Patients (periods, N): I, 87; II, 141; III, 356; IV, 51. In cGHD (all), age, maximum GH, insulin-like growth factor-I (IGF-I), and insulin-like growth factor-binding protein-3 (IGFBP-3) (5.1 years, 3.6 μg/L, -5.3 standard deviation score [SDS], -3.7 SDS) were lower than in IGHD (all) (6.8 years 5.8 μg/L, -2.5 SDS, -1.0 SDS), but not height (-3.1 vs. -3.2 SDS). Characteristics of NSD were similar to that of IGHD. Patients with IGHD - not cGHD - diagnosed during 2008-2015 (IV) were the youngest with most severe GHD (maxGH, IGF-I, IGFBP-3), and first year height velocity (HV) and ∆ IGF-I (10.5 cm/year, 4.0 SDS) but not ∆ height SDS were the highest on recombinant human growth hormone (rhGH) (27 μg/kg/day). Conclusions Although during 1988-2007 patient characteristics were similar, the recently (>2008) stipulated more stringent diagnostic criteria - HV before testing, sex steroid priming, lower GH cut-off - have restricted diagnoses to more severe cases as they were observed before the rhGH era.

Adult-Onset Hepatocyte GH Resistance Promotes NASH in Male Mice, Without Severe Systemic Metabolic Dysfunction

Nonalcoholic fatty liver disease (NAFLD), which includes nonalcoholic steatohepatitis (NASH), is associated with reduced GH input/signaling, and GH therapy is effective in the reduction/resolution of NAFLD/NASH in selected patient populations. Our laboratory has focused on isolating the direct vs indirect effects of GH in preventing NAFLD/NASH. We reported that chow-fed, adult-onset, hepatocyte-specific, GH receptor knockdown (aHepGHRkd) mice rapidly (within 7 days) develop steatosis associated with increased hepatic de novo lipogenesis (DNL), independent of changes in systemic metabolic function. In this study, we report that 6 months after induction of aHepGHRkd early signs of NASH develop, which include hepatocyte ballooning, inflammation, signs of mild fibrosis, and elevated plasma alanine aminotransferase. These changes occur in the presence of enhanced systemic lipid utilization, without evidence of white adipose tissue lipolysis, indicating that the liver injury that develops after aHepGHRkd is due to hepatocyte-specific loss of GH signaling and not due to secondary defects in systemic metabolic function. Specifically, enhanced hepatic DNL is sustained with age in aHepGHRkd mice, associated with increased hepatic markers of lipid uptake/re-esterification. Because hepatic DNL is a hallmark of NAFLD/NASH, these studies suggest that enhancing hepatocyte GH signaling could represent an effective therapeutic target to reduce DNL and treat NASH.

Evaluation of growth hormone response to GHRH plus arginine test in children with idiopathic short stature: role of peak time

PURPOSE

To describe the course of growth hormone response to growth hormone releasing hormone (GHRH) plus arginine provocative test in children with idiopathic short stature (ISS) and to evaluate the role of peak time.

METHODS

A retrospective study was performed analyzing 344 GHRH plus arginine provocative tests performed in children and adolescents with short stature. Serum GH levels were measured at four-time points (T0', T30', T45' and T60') and GH peak was defined as the maximum value at any time point. Mean (T30'-T60') GH value and area under the curve (AUC) were calculated.

RESULTS

When analyzing the time of peak at the provocative test, the most frequent peak time was T45' (53.8%) in the ISS group, with no differences in gender, age, and pubertal stage. Analyzing GHD subjects, the most frequent time of peak was T30 (50%). Analyzing the whole population, the GH T0' levels were significantly lower in subjects with the GH peak at T45' than those with the GH peak at T30' (1.7 ± 2.0 vs. 3.2 ± 4.0, p < 0.001). In subjects with GH peak at T45', the value of GH peak, AUC and mean GH were significantly higher than in those with GH peak at T30' and T60'. A direct correlation was found between the value of GH peak and growth velocity SDS (r = 0.127, p = 0.04) and a negative one between GH peak and GH level at T0' (r = - 0.111, p = 0.04), even when adjusted for gender, age, pubertal stage and BMI Z score.

CONCLUSIONS

The time peak at 45 min seems to be associated with a better response to the test considering GH peak, mean and AUC. Patients with a GH peak at 30 min more probably could have a derangement in GH secretion showing worst growth pattern and/or a GH deficiency and should be carefully observed.

Growth hormone - past, present and future

Growth hormone (GH) research and its clinical application for the treatment of growth disorders span more than a century. During the first half of the 20th century, clinical observations and anatomical and biochemical studies formed the basis of the understanding of the structure of GH and its various metabolic effects in animals. The following period (1958-1985), during which pituitary-derived human GH was used, generated a wealth of information on the regulation and physiological role of GH - in conjunction with insulin-like growth factors (IGFs) - and its use in children with GH deficiency (GHD). The following era (1985 to present) of molecular genetics, recombinant technology and the generation of genetically modified biological systems has expanded our understanding of the regulation and role of the GH-IGF axis. Today, recombinant human GH is used for the treatment of GHD and various conditions of non-GHD short stature and catabolic states; however, safety concerns still accompany this therapeutic approach. In the future, new therapeutics based on various components of the GH-IGF axis might be developed to further improve the treatment of such disorders. In this Review, we describe the history of GH research and clinical use with a particular focus on disorders in childhood.

Hepatic lipid metabolism and non-alcoholic fatty liver disease in aging

Aging is associated with dysregulation of glucose and lipid metabolism. Various factors that contribute to the dysregulation include both modifiable (e.g. obesity, insulin resistance) and non-modifiable risk factors (age-associated physiologic changes). Although there is no linear relationship between aging and prevalence of non-alcoholic fatty liver disease, current data strongly suggests that advanced age leads to more severe histological changes and poorer clinical outcomes. Hepatic lipid accumulation could lead to significant hepatic and systemic consequences including steatohepatitis, cirrhosis, impairment of systemic glucose metabolism and metabolic syndrome, thereby contributing to age-related diseases. Insulin, leptin and adiponectin are key regulators of the various physiologic processes that regulate hepatic lipid metabolism. Recent advances have expanded our understanding in this field, highlighting the role of novel mediators such as FGF 21, and mitochondria derived peptides. In this review, we will summarize the mediators of hepatic lipid metabolism and how they are altered in aging.

Body Mass Disorders in Healthy Short Children and in Children with Growth Hormone Deficiency

The aim of the study was to determine the degree of adiposity and the incidence of body mass disorders, including abdominal obesity, in healthy short children and children with growth hormone deficiency. The study included 134 short children (height < 10th percentile) aged 7-15. In this cohort there were 63 (31 boys and 32 girls) children without diagnosed hormonal disorders and 71 patients (35 boys and 36 girls) with growth hormone deficiency. Basic somatic features were assessed and the study participants were categorized according to the percentage of body fat (%FAT), body mass index (BMI), and waist-to-height ratio (WHtR). We found that there were no significant differences in %FAT and the incidence of body weight disorders depending on gender or diagnosis. %FAT deficit was observed in 12-21% of the participants and underweight in almost every fourth child. Overweight involved 3-14% of the participants and obesity was diagnosed in isolated cases (0-3%); both were considerably lower compared to the estimates based on %FAT. Using the cut-off points of WHtR, abdominal adiposity was observed in 3-15% of the participants. In conclusion, quite a large number of short children (between 25 and 50%) are characterized by abnormal body fat or body mass index values. The results indicate a limited usefulness of BMI in evaluating the incidence of overweight and obesity in children characterized by a height deficit.

Clinical and laboratory parameters predicting a requirement for the reevaluation of growth hormone status during growth hormone treatment: Retesting early in the course of GH treatment

OBJECTIVE

We aimed to define the predictive criteria, in the form of specific clinical, hormonal and radiological parameters, for children with growth hormone deficiency (GHD) who may benefit from the reevaluation of GH status early in the course of growth hormone (GH) treatment.

DESIGN AND METHODS

Two hundred sixty-five children with growth hormone deficiency were retested by GH stimulation at the end of the first year of GH treatment. The initial clinical and laboratory characteristics of those with a normal (GH≥10ng/ml) response and those with a subnormal (GH<10ng/ml) response were compared to predict a normal GH status during reassessment.

RESULTS

Sixty-nine patients (40.6%) out of the 170 patients with isolated growth hormone deficiency (IGHD) had a peak GH of ≥10ng/ml during the retest. None of the patients with multiple pituitary hormone deficiency (MPHD) had a peak GH of ≥10ng/ml. Puberty and sex steroid priming in peripubertal cases increased the probability of a normal GH response. Only one patient with IGHD who had an ectopic posterior pituitary without stalk interruption on MRI analysis showed a normal GH response during the retest. Patients with a peak GH between 5 and 10ng/ml, an age at diagnosis of ≥9years or a height gain below 0.61 SDS during the first year of treatment had an increased probability of having a normal GH response at the retest.

CONCLUSION

Early reassessment of GH status during GH treatment is unnecessary in patients who have MPHD with at least 3 hormone deficiencies. Retesting at the end of the first year of therapy is recommended for patients with IGHD who have a height gain of <0.61 SDS in the first year of treatment, especially those with a normal or 'hypoplastic' pituitary on imaging. Priming can increase the likelihood of a normal response in patients in the pubertal age group who do not show overt signs of pubertal development.

Pituitary dysfunction after traumatic brain injury: are there definitive data in children?

In the past decade, several studies in adults and children have described the risk of pituitary dysfunction after traumatic brain injury (TBI). As a result, an international consensus statement recommended follow-up on the survivors. This paper reviews published studies regarding hypopituitarism after TBI in children and compares their results. The prevalence of hypopituitarism ranges from 5% to 57%. Growth hormone (GH) and ACTH deficiency are the most common, followed by gonadotropins and thyroid-stimulating hormone. Paediatric studies have failed to identify risk factors for developing hypopituitarism, and therefore we have no tools to restrict screening in severe TBI. In addition, the present review highlights the lack of a unified follow-up and the fact that unrecognised pituitary dysfunction is frequent in paediatric population. The effect of hormonal replacement in patient recovery is important enough to consider baseline screening and reassessment between 6 and 12 months after TBI. Medical community should be aware of the risk of pituitary dysfunction in these patients, given the high prevalence of endocrine dysfunction already reported in the studies. Longer prospective studies are needed to uncover the natural course of pituitary dysfunction, and new studies should be designed to test the benefit of hormonal replacement in metabolic, cognitive and functional outcome in these patients.

MRI features of growth hormone deficiency in children with short stature caused by pituitary lesions

We verified the advantages of using magnetic resonance imaging (MRI) for improving the diagnostic quality of growth hormone deficiency (GHD) in children with short stature caused by pituitary lesions. Clinical data obtained from 577 GHD patients with short stature caused by pituitary lesions were retrospectively analyzed. There were 354 cases (61.3%) with anterior pituitary dysplasia; 45 cases (7.8%) of pituitary stalk interruption syndrome (PSIS); 15 cases (2.6%) of pituitary hyperplasia due to primary hypothyroidism; 38 cases (6.6%) of Rathke cleft cyst; 68 cases (11.8%) of empty sella syndrome; 16 cases (2.8%) of pituitary invasion from Langerhans cell histiocytosis; 2 cases (0.3%) of sellar regional arachnoid cyst and 39 cases (6.8%) of craniopharyngioma. MRI results showed that the height of anterior pituitary in patients was less than normal. Location, size and signals of posterior pituitary and pituitary stalk were normal in anterior pituitary dysplasia. In all cases pituitary hyperplasia was caused by hypothyroidism. MRI results showed that anterior pituitary was enlarged, and we detected upward apophysis and obvious homogeneous enhancement. There were no pituitary stalk interruption and abnormal signal. We also observed that after hormone replacement therapy the size of pituitary gland was reduced. Anterior pituitary atrophy was observed in Rathke cleft cyst, empty sella syndrome, sellar regional arachnoid cyst and craniopharyngioma. The microstructure of hypophysis and sellar region was studied with MRI. We detected pituitary lesions, and the characteristics of various pituitary diseases of GHD in children with short stature. It was concluded that in children with GHD caused by pituitary lesions, MRI was an excellent method for early diagnosis. This method offers clinical practicability and we believe it can be used for differential diagnosis and to monitor the therapeutic effects.

Long-Term Outcomes, Genetics, and Pituitary Morphology in Patients with Isolated Growth Hormone Deficiency and Multiple Pituitary Hormone Deficiencies: A Single-Centre Experience of Four Decades of Growth Hormone Replacement

BACKGROUND

Growth hormone (GH) has been used to treat children with GH deficiency (GHD) since 1966.

AIMS

Using a combined retrospective and cross-sectional approach, we explored the long-term outcomes of patients with GHD, analysed factors influencing therapeutic response, determined persistence into adulthood, investigated pituitary morphology, and screened for mutations in causative genes.

METHODS

The files of 96 GH-deficient children were reviewed. In a subset of 50 patients, re-assessment in adulthood was performed, including GHRH-arginine testing, pituitary magnetic resonance imaging (MRI), and mutational screening for the growth hormone-1 gene (GH1) and the GHRH receptor gene (GHRHR) in isolated GHD (IGHD), and HESX1, PROP1, POU1F1, LHX3, LHX4, and GLI2 in multiple pituitary hormone deficiency (MPHD) patients.

RESULTS

GH was started at a height SDS of -3.2 ± 1.4 in IGHD patients and of -4.1 ± 2.1 in MPHD patients. Relative height gain was 0.3 SDS/year, absolute gain 1.6 SDS, and 1.2/2.6 SDS in IGHD/MPHD, respectively. Mid-parental target height was reached in 77%. Initial height SDS, bone age retardation and duration of GH replacement were correlated with height SDS gain. GHD persisted into adulthood in 19 and 89% of subjects with IGHD and MPHD, respectively. In 1/42 IGHD patients a GH1 mutation was detected; PROP1 mutations were found in 3/7 MPHD subjects. Anterior pituitary hypoplasia, combined with posterior pituitary ectopy and pituitary stalk invisibility on MRI, was an exclusive finding in MPHD patients.

CONCLUSIONS

GH replacement successfully corrects the growth deficit in children with GHD. While the genetic aetiology remains undefined in most cases of IGHD, PROP1 mutations constitute a major cause for MPHD. Persistence of GHD into adulthood is related to abnormal pituitary morphology.

Clinical features of girls with short stature among inv (9), Turner (45, X) and control individuals

BACKGROUND

The clinical significance of pericentric inversion of chromosome 9 [inv (9)] remains unclear.

METHODS

This case control study assessed girls with short stature. According to karyotypes, the subjects were divided into inv (9) [46,XX,inv (9)(p12q13) and 46,XX,inv (9)(p11q13)], Turner syndrome (45, X) and control (normal 46, XX) groups, respectively. Detailed clinical features were compared.

RESULTS

Height standard deviation score (SDS) values at diagnosis were -2.51±0.58, -3.71±2.12 and -2.5±1.24 for inv (9), (45, X) and control groups, respectively (p=0.022). The inv (9) group showed lower body mass index (BMI) values compared with the (45, X) and control groups (F=5.097, p=0.008). Similar growth hormone deficiency (GHD) incidences were found in all groups. Interestingly, height SDS was positively correlated with mother height and patient BMI SDS (r=0.51, p=0.036; r=0.576, p=0.023, respectively) in the inv (9) group. In the (45, X) group, height SDS was positively correlated with birth weight (r=0.392, p=0.039).

CONCLUSIONS

Short stature in inv (9) girls was correlated with low birth weight (LBW) and mother height.

Growth Hormone Control of Hepatic Lipid Metabolism

In humans, low levels of growth hormone (GH) and its mediator, IGF-1, associate with hepatic lipid accumulation. In mice, congenital liver-specific ablation of the GH receptor (GHR) results in reductions in circulating IGF-1 and hepatic steatosis, associated with systemic insulin resistance. Due to the intricate relationship between GH and IGF-1, the relative contribution of each hormone to the development of hepatic steatosis is unclear. Our goal was to dissect the mechanisms by which hepatic GH resistance leads to steatosis and overall insulin resistance, independent of IGF-1. We have generated a combined mouse model with liver-specific ablation of GHR in which we restored liver IGF-1 expression via the hepatic IGF-1 transgene. We found that liver GHR ablation leads to increases in lipid uptake, de novo lipogenesis, hyperinsulinemia, and hyperglycemia accompanied with severe insulin resistance and increased body adiposity and serum lipids. Restoration of IGF-1 improved overall insulin sensitivity and lipid profile in serum and reduced body adiposity, but was insufficient to protect against steatosis-induced hepatic inflammation or oxidative stress. We conclude that the impaired metabolism in states of GH resistance results from direct actions of GH on lipid uptake and de novo lipogenesis, whereas its actions on extrahepatic tissues are mediated by IGF-1.

Functional Changes after Recombinant Human Growth Hormone Replacement in Patients with Chronic Traumatic Brain Injury and Abnormal Growth Hormone Secretion

We explored the effects of recombinant human growth hormone (rhGH) replacement on physical and cognitive functioning in subjects with a moderate-to-severe traumatic brain injury (TBI) with abnormal growth hormone (GH) secretion. Fifteen individuals who sustained a TBI at least 12 months prior to study enrollment were identified as having abnormal GH secretion by glucagon stimulation testing (maximum GH response less than 8 ng/mL). Peak cardiorespiratory capacity, body composition, and muscle force testing were assessed at baseline and one year after rhGH replacement. Additionally, standardized neuropsychological tests that assess memory, processing speed, and cognitive flexibility, as well as self-report inventories related to depression and fatigue, were administered at baseline and 1 year after rhGH replacement. Comparison tests were performed with proper post hoc analyses. All analyses were carried out at α < 0.05. Peak O₂ consumption, peak oxygen pulse (estimate of cardiac stroke volume), and peak ventilation all significantly increased (p < 0.05). Maximal isometric and isokinetic force production were not altered. Skeletal muscle fatigue did not change but the perceptual rating of fatigue was reduced by ∼25% (p = 0.06). Cognitive performance did not change significantly over time, whereas self-reported symptoms related to depression and fatigue significantly improved. The observed changes suggest that rhGH replacement has a positive impact on cardiorespiratory fitness and a positive impact on perceptual fatigue in survivors of TBI with altered GH secretion.

Skeletal assessment and secular changes in knee development: a radiographic approach

OBJECTIVES

The purpose of this study is to conduct an analysis of ossification patterns in the distal femoral, proximal tibial, and proximal fibular epiphyses, and the patella. The results generated from this analysis will be compared with previous standards published by Elgenmark () and Garn et al. () to determine if clinical and skeletal age assessment standards should be updated for contemporary Americans.

MATERIALS AND METHODS

Using the Pediatric Radiology Interactive Atlas (Patricia), a total of 1,317 epiphyses were scored for presence or absence from radiographs of 1,056 white individuals born in or after 1990. Statistical modeling of epiphyseal appearance was conducted for all major percentiles, including the 5th and 95th percentiles through logistic regression.

RESULTS

Compared with Elgenmark () and Garn et al. (), our data suggest that the distal femoral and proximal tibial epiphyses show overall earlier ossification, while the proximal fibular epiphysis shows later ossification. When examining the pooled sex 50th percentile for our data, we found that ossification timing differences are 1.2 weeks earlier in the distal femoral epiphysis, 2.1 weeks earlier in the proximal tibial epiphysis, and 1.4 years later in the proximal fibular epiphysis.

DISCUSSION

The epiphyses that appear early in life, for example the distal femoral epiphysis, require gestational age information to accurately estimate appearance times. There are considerable differences between the ossification timing patterns presented in this study and those of previous standards, which did not include gestational ages. Several factors may explain the observed differences in the epiphyses of the knee including: the availability of gestational age information, the analysis of longitudinal versus cross-sectional data, differences in socioeconomic status and prenatal care, and secular change. KEYWORDS age estimation, growth standards, ossification, skeletal maturation, subadult/juvenile growth.

Is insulin-like growth factor-I a good marker for treatment adherence in growth hormone deficiency in adulthood?

OBJECTIVE

There is a paucity of studies on adherence to growth hormone treatment in growth hormone deficient (GHD) adults. Therefore, this study reports on adherence to GH-replacement therapy in adults with GHD, with a special focus on the course and potential predictors of nonadherence.

DESIGN

Retrospective single-centre cohort study.

PATIENTS

From the local patient database, 179 suitable patients with GHD were identified.

MEASUREMENTS

The primary outcome was adherence assessed by calculating the percentage of available prescription data in comparison with recommended GH dosages over a mean follow-up period of 92·4 months. Patients were categorized into five adherence categories ranging from <20% to >80%.

RESULTS

Mean overall adherence was 74·0%, with 52·9% of patients falling into the adherence group of >80% and 8·8% of <20%. There was a significant drop in adherence (9·8%) between the first and second years of treatment (P < 0·001). Patients with childhood-onset GHD were significantly less adherent to GH treatment than patients with adult-onset GHD (62·0% vs 77·0%, P = 0·012); however, this finding was no longer significant after including age as a covariate. Frequency of IGF-1 levels lying outside the age- and sex-specific reference range was not a good indicator for adherence.

CONCLUSION

Although overall adherence was relatively high in our study sample, there is a significant amount of patients who should be regarded as nonadherent. This applies in particular to younger patients. Treating physicians should be aware of the fact that IGF-1 levels do not seem to be a good indicator for adherence.

Challenges in the Diagnosis and Management of Growth Hormone Deficiency in India

In clinical practice, every year approximately 150,000 children are referred with short stature (SS) based on a cut-off of fifth percentile. The most important endocrine and treatable cause of SS is growth hormone deficiency (GHD). The lack of reliable data on the prevalence of GHD in India limits estimation of the magnitude of this problem. The diagnosis and treatment of GHD are hurdled with various challenges, restricting the availability of growth hormone (GH) therapy to only a very limited segment of the children in India. This review will firstly summarize the gaps and challenges in diagnosis and treatment of GHD based on literature analysis. Subsequently, it presents suggestions from the members at advisory board meetings to overcome these challenges. The advisory board suggested that early initiation of the therapy could better the chances of achieving final adult height within the normal range for the population. Education and awareness about growth disorders among parents, regular training for physicians, and more emphasis on using the Indian growth charts for growth monitoring would help improve the diagnosis and treatment of children with GHD. Availability of an easy-to-use therapy delivery system could also be beneficial in improving adherence and achieving satisfactory outcomes.

Diagnosis and Treatment of Hypopituitarism

Hypopituitarism is a chronic endocrine illness that caused by varied etiologies. Clinical manifestations of hypopituitarism are variable, often insidious in onset and dependent on the degree and severity of hormone deficiency. However, it is associated with increased mortality and morbidity. Therefore, early diagnosis and prompt treatment is necessary. Hypopituitarism can be easily diagnosed by measuring basal pituitary and target hormone levels except growth hormone (GH) and adrenocorticotropic hormone (ACTH) deficiency. Dynamic stimulation tests are indicated in equivocal basal hormone levels and GH/ACTH deficiency. Knowledge of the use and limitations of these stimulation tests is mandatory for proper interpretation. It is necessary for physicians to inform their patients that they may require lifetime treatment. Hormone replacement therapy should be individualized according to the specific needs of each patient, taking into account possible interactions. Long-term endocrinological follow-up of hypopituitary patients is important to monitor hormonal replacement regimes and avoid under- or overtreatment.

Frequency of genetic defects in combined pituitary hormone deficiency: a systematic review and analysis of a multicentre Italian cohort

OBJECTIVE

Combined pituitary hormonal deficiency (CPHD) can result from mutations within genes that encode transcription factors. This study evaluated the frequency of mutations in these genes in a cohort of 144 unrelated Italian patients with CPHD and estimated the overall prevalence of mutations across different populations using a systematic literature review.

MATERIAL AND METHODS

A multicentre study of adult and paediatric patients with CPHD was performed. The PROP1, POU1F1, HESX1, LHX3 and LHX4 genes were analysed for the presence of mutations using direct sequencing. We systematically searched PubMed with no date restrictions for studies that reported genetic screening of CPHD cohorts. We only considered genetic screenings with at least 10 individuals. Data extraction was conducted in accordance with the guidelines set by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA).

RESULTS

Global mutation frequency in Italian patients with CPHD was 2·9% (4/136) in sporadic cases and 12·5% (1/8) in familial cases. The worldwide mutation frequency for the five genes calculated from 21 studies was 12·4%, which ranged from 11·2% in sporadic to 63% in familial cases. PROP1 was the most frequently mutated gene in sporadic (6·7%) and familial cases (48·5%).

CONCLUSION

The frequency of defects in genes encoding pituitary transcription factors is quite low in Italian patients with CPHD and other western European countries, especially in sporadic patients. The decision of which genes should be tested and in which order should be guided by hormonal and imaging phenotype, the presence of extrapituitary abnormalities and the frequency of mutation for each gene in the patient-referring population.

Endocrine sequelae beyond 10 years in survivors of medulloblastoma

INTRODUCTION

Survival following treatment of paediatric medulloblastomas has significantly improved over the past few decades, but as a consequence, late effects, particularly endocrine sequelae, have been recognized. The complete picture of late effects, however, has been limited by short duration of follow-up.

AIM

To establish the evolution of endocrine sequelae in patients treated for medulloblastoma.

METHODS

Single-centre analysis of medulloblastoma treatment and endocrine sequelae in patients diagnosed between 1982 and 2002.

RESULTS

A total of 109 patients were treated for medulloblastoma, with various treatment modalities involving radio- and chemotherapy. Only 45 (41%) patients remained alive, and details of treatment and late effects were available for 35 (25 m). The median age at diagnosis was 8 (range 2-14) years, and the median follow-up was 18 (range 10-28) years. Growth hormone deficiency (GHD) was the most prevalent hormone deficiency (97%), followed by primary hypothyroidism (60%) and adrenocorticotrophic hormone (ACTH) deficiency (45·5%). The median time from end of treatment to loss of growth hormone was 1·7 (range 0·7-15) years, ACTH deficiency 2·9 (range 0·75-7·5) years and hypothyroidism 4·1 (range 0·7-11·4) years. Twenty-three percentage developed hypogonadism (17% primary and 6% secondary), whilst precocious puberty was seen in 20%. Endocrinopathies appeared to be more prevalent in those treated with concomitant chemotherapy and radiotherapy.

CONCLUSIONS

Prevalence of endocrine sequelae in medulloblastoma survivors is high, and evolution of endocrine dysfunction can occur as late as 15 years from treatment completion; hence, long-term close monitoring of growth, puberty and gonadal function is essential.

Effect of summer daylight exposure and genetic background on growth in growth hormone-deficient children

The response to growth hormone in humans is dependent on phenotypic, genetic and environmental factors. The present study in children with growth hormone deficiency (GHD) collected worldwide characterised gene–environment interactions on growth response to recombinant human growth hormone (r-hGH). Growth responses in children are linked to latitude, and we found that a correlate of latitude, summer daylight exposure (SDE), was a key environmental factor related to growth response to r-hGH. In turn growth response was determined by an interaction between both SDE and genes known to affect growth response to r-hGH. In addition, analysis of associated networks of gene expression implicated a role for circadian clock pathways and specifically the developmental transcription factor NANOG. This work provides the first observation of gene–environment interactions in children treated with r-hGH.

Insulin-like growth factor binding-protein-3 (IGFBP-3)

The IGF system comprises two IGFs (IGF-1, IGF-2), two IGF-receptors (IGF-R1, IGF-R2), and six IGF binding proteins (IGFBPs) with a high affinity for IGFs. The IGFBPs, of which IGFBP-3 is the most abundant in postnatal blood, link with IGFs and prevent them from being degraded; they also facilitate IGF transport through body compartments. The interaction between IGFs and their specific receptors is partly regulated by structural modifications inherent to the IGFBPs. IGFBPs also have IGF-independent biological effects. Since serum IGFBP-3 is GH-dependent and correlates quantitatively with GH secretion, its measurement is useful in tests of abnormal GH secretion. Particularly during childhood, IGFBP-3 values play an important role in ascertaining alterations in GH secretion and action (i.e., primary IGF deficiency states). A new role for IGFBP-3 and other IGFBPs with natural or altered structures is likely to be established through current studies investigating their application in promoting apoptotic processes in malignancies.

Reference ranges for an automated chemiluminescent assay for serum insulin-like growth factor I (IGF-I) in a large population of healthy adults from Buenos Aires

PURPOSE

Insulin-like growth factor I (IGF-I) represents an essential tool in the diagnostic work-up and in the monitoring of treatment efficacy for somatotrophic axis disorders both in children and adults. A large number of factors including, but not limited to, age, sex and weight as well as analytical variables influence IGF-I serum levels; therefore, reliable normative data are essential for a correct interpretation of results. The aim of the present study was to establish reference range values for serum IGF-I, in a large population of healthy adults from Buenos Aires city.

METHODS

The study included serum samples from 1044 healthy subjects aged 21-87 years (423 females and 621 males) divided into groups by sex at 5-year intervals from 21 to >75 years. Serum IGF-I concentrations were determined by a fully automated two-site, solid-phase, enzyme-labeled chemiluminescent immunometric assay (Immulite 2000, Siemens Healthcare Diagnostics). IGF-BP interferences are circumvented by blocking IGF-BP binding sites with excess IGF-II in the on-board predilution step.

RESULTS

Results show the age dependence of circulating IGF-I levels, with a smooth and steady decrease in levels with age. No sex differences were found in subjects >26 years; however, in the group aged 21-25 years, IGF-I levels were significantly higher in females. In conclusion, this study provides age- and gender-adjusted normal reference ranges for IGF-I levels obtained with an automated immunometric chemiluminescent assay Immulite 2000 in healthy adult subjects.