Sensitivity and specificity of six tests for the diagnosis of adult GH deficiency

Hypopituitarism

Partial or complete deficiency of anterior or posterior pituitary hormone production leads to central hypoadrenalism, central hypothyroidism, hypogonadotropic hypogonadism, growth hormone deficiency, or arginine vasopressin deficiency depending on the hormones affected. Hypopituitarism is rare and likely to be underdiagnosed, with an unknown but rising incidence and prevalence. The most common cause is compressive growth or ablation of a pituitary or hypothalamic mass. Less common causes include genetic mutations, hypophysitis (especially in the context of cancer immunotherapy), infiltrative and infectious disease, and traumatic brain injury. Clinical features vary with timing of onset, cause, and number of pituitary axes disrupted. Diagnosis requires measurement of basal circulating hormone concentrations and confirmatory hormone stimulation testing as needed. Treatment is aimed at replacement of deficient hormones. Increased mortality might persist despite treatment, particularly in younger patients, females, and those with arginine vasopressin deficiency. Patients with complex diagnoses, pregnant patients, and adolescent pituitary-deficient patients transitioning to adulthood should ideally be managed at a pituitary tumour centre of excellence.

Clinical and laboratory characteristics but not response to treatment can distinguish children with definite growth hormone deficiency from short stature unresponsive to stimulation tests

Introduction

It has been proposed that not all children with short stature displaying an inadequate response to tests for growth hormone (GH) secretion truly suffer from GH deficiency (GHD). Only children with a monogenic cause of GHD or an identifiable combined hormonal deficiency or anatomical anomaly in the hypothalamic-pituitary axis should be considered definite GHD (dGHD). The remaining patients can be defined as a separate group of patients, "short stature unresponsive to stimulation tests" (SUS). The aim of this proof-of-concept study, was to assess whether SUS patients treated with rhGH exhibit any differences compared to GHD patients undergoing the same treatment.

Methods

Retrospective analysis on 153 consecutive patients with short stature and pathological response to two GH stimulation tests. Patients with dGHD were defined as those with a clear genetic or anatomical hypothalamic-pituitary anomaly, as well as those with combined pituitary hormone deficiencies and those with a known insult to the hypothalamic-pituitary axis (i.e. total brain irradiation) (n=38, 25%); those without any of the previous anomalies were defined as SUS (n=115, 75%).

Results

At diagnosis, dGHD and SUS populations did not differ significantly in sex (F 32% vs 28%, p=0.68), age (11.9 vs 12.1, p=0.45), height SDS at diagnosis (-2.2 vs. -2.0, p=0.35) and prevalence of short stature (height <-2 SDS) (56% vs 51%, p=0.45). IGF-1 SDS were significantly lower in dGHD (-2.0 vs -1.3, p<0.01). After 1 year of treatment, the prevalence of short stature was significantly reduced in both groups (31% in dGHD vs. 21% in SUS, p<0.01) without any significant differences between groups (p=0.19), while the increase in IGF-1 SDS for bone age was greater in the dGHD category (+1.9 vs. +1.5, p<0.01), with no further difference in IGF-1 SDS between groups. At the last available follow-up, 59 patients had reached the near adult height (NAH) and underwent retesting for GHD. No differences in NAH were found (-0.3 vs. -0.4 SDS, 0% vs. 4% of short stature). The prevalence of pathological retesting was higher in dGHD (60% vs. 10%, p<0.01) as well as of overweight and obesity (67% vs. 26%).

Conclusion

Stimulation tests and the equivalent benefit from rhGH therapy, cannot distinguish between dGHD and SUS populations. In addition, lower IGF-1 concentrations at baseline and their higher increase during treatment in dGHD patients, and the lack of pathological retesting upon reaching NAH in SUS patients, are facts that suggest that deficient GH secretion may not be the cause of short stature in the SUS studied population.

Growth hormone replacement in adults with cured acromegaly: Efficacy and safety

Between 2% and 60% of patients with cured acromegaly may eventually develop growth hormone deficiency. In adults, growth hormone deficiency is associated with abnormal body composition, decreased exercise capacity and quality of life, dyslipidemia, insulin resistance and increased cardiovascular risk. Similar to patients with other sellar lesions, the diagnosis of growth hormone deficiency in adults with cured acromegaly generally requires stimulation testing, with the exception of patients with very low serum insulin-like growth factor I levels and multiple additional pituitary hormone deficiencies. In adults with cured acromegaly, growth hormone replacement may have beneficial effects on body adiposity, muscle endurance, serum lipids and quality of life. Growth hormone replacement is generally well-tolerated. Arthralgias, edema, carpal tunnel syndrome and hyperglycemia may occur in patients with cured acromegaly, as is true of patients with growth hormone deficiency of other etiologies. However, there is evidence of increased cardiovascular risk in some studies of growth hormone replacement in adults with cured acromegaly. More studies are needed to fully establish the beneficial effects and elucidate the risks of growth hormone replacement in adults with cured acromegaly. Until then, growth hormone replacement can be considered in these patients on a case-by-case basis.

A decade of approved first-in-class small molecule orphan drugs: Achievements, challenges and perspectives

In the past decade (2011-2020), there was a growing interest in the discovery and development of orphan drugs for the treatment of rare diseases. However, rare diseases only account for a population of 0.65‰-1‰ which usually occur with previously unknown biological mechanisms and lack of specific therapeutics, thus to increase the demands for the first-in-class (FIC) drugs with new biological targets or mechanisms. Considering the achievements in the past 10 years, a total of 410 drugs were approved by U.S. Food and Drug Administration (FDA), which contained 151 FIC drugs and 184 orphan drugs, contributing to make up significant numbers of the approvals. Notably, more than 50% of FIC drugs are developed as orphan drugs and some of them have already been milestones in drug development. In this review, we aim to discuss the FIC small molecules for the development of orphan drugs case by case and highlight the R&D strategy with novel targets and scientific breakthroughs.

Dynamic Tests in Pituitary Endocrinology: Pitfalls in Interpretation during Aging

Aging and age-related diseases represent hot topics of current research. Progressive damage in morphology and function of cells and tissue characterizes the normal process of aging that is influenced by both genetic and environmental factors. The ability of each individual to adapt to these stressors defines the type of aging and the onset of age-related diseases (i.e., metabolic syndrome, inflammatory disorders, cancer, and neurodegenerative diseases). The endocrine system plays a critical role in this process because of its complex relationships with brain, immune system, and skeletal muscle; thus, alterations in hormonal networks occur during aging to maintain homeostasis, with consequent under- or overactivity of specific hypothalamic-pituitary-peripheral hormone axes. On the other hand, the increase in life expectancy has led to increasing incidence of age-related diseases, including endocrine disorders, which may prompt assessment of endocrine function in aging individuals. In this context, there is growing awareness that natural changes of endocrine physiology and physiopathology occurring with increasing age may necessitate age-driven diagnostic cutoffs requiring validation in the elderly. This review aims to analyze the available literature on the hormone response to the most important dynamic tests currently used in the clinical practice for the screening of anterior pituitary-related diseases to underline pitfalls in interpretation during aging.

Prevalence of growth hormone deficiency in patients with unexplained chronic fatigue after undergoing bone marrow transplantation in adulthood

PURPOSE

Many patients who undergo bone marrow transplantation (BMT) in adulthood experience unexplained chronic fatigue which can have a major impact on their health-related quality of life (QoL). Pre-BMT treatment regimens increase the risk of developing acquired growth hormone deficiency (GHD), which results in a clinical syndrome with decreased energy and has additionally been linked to metabolic syndrome.

METHODS

Using the gold-standard insulin hypoglycemic test (IHT), we evaluated the prevalence of GHD in 18 post-BMT adult patients with unexplained chronic fatigue, as well as the correlation between peak serum GH response and QoL scores, the metabolic syndrome, and insulin resistance. Peak serum GH cut-point less than 3.0 ug/L was used for the diagnosis of severe GHD. The Fatigue Severity Scale and Quality of Life in Adult GHD Assessment questionnaires were used to quantify fatigue symptoms.

RESULTS

The prevalence of severe GHD within this sample of 18 patients was 50%. A trend between lower peak serum GH response and higher fatigue and QoL-AGHDA scores was observed.

CONCLUSIONS

GHD may represent a remediable contributor to post-BMT chronic fatigue in adults, further studies are needed to evaluate the potential role of screening and GH replacement therapy in this vulnerable patient population.

IMPLICATIONS FOR CANCER SURVIVORS

GHD may be a treatable explanation for disabling post-BMT fatigue pending results of intervention studies.

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.

Metabolomics as a potential tool for the diagnosis of growth hormone deficiency (GHD): a review

Metabolomics uses several analytical tools to identify the chemical diversity of metabolites present in organisms. These metabolites are low molecular weight molecules (<1500 Da) classified as a final or intermediary product of metabolic processes. The application of this omics technology has become prominent in inferring physiological conditions through reporting on the phenotypic state; therefore, the introduction of metabolomics into clinical studies has been growing in recent years due to its efficiency in discriminating pathophysiological states. Regarding endocrine diseases, there is a great interest in verifying comprehensive and individualized physiological scenarios, in particular for growth hormone deficiency (GHD). The current GHD diagnostic tests are laborious and invasive and there is no exam with ideal reproducibility and sensitivity for diagnosis neither standard GH cut-off point. Therefore, this review was focussed on articles that applied metabolomics in the search for new biomarkers for GHD. The present work shows that the applications of metabolomics in GHD are still limited, since the little complementarily of analytical techniques, a low number of samples, GHD combined to other deficiencies, and idiopathic diagnosis shows a lack of progress. The results of the research are relevant and similar; however, their results do not provide an application for clinical practice due to the lack of multidisciplinary actions that would be needed to mediate the translation of the knowledge produced in the laboratory, if transferred to the medical setting.

Anterior pituitary function in Rathke's cleft cysts versus nonfunctioning pituitary adenomas

Although Rathke's cleft cysts (RCCs) are common sellar/parasellar lesions, studies examining pituitary function in patients with nonsurgical RCC are limited. This study aimed to clarify the importance of RCCs, including small nonsurgical ones, as a cause of hypopituitarism by determining the prevalence of pituitary hormone secretion impairment and its relationship to cyst/tumor size in patients with RCC and in those with nonfunctioning pituitary adenoma (NFA). We retrospectively investigated the basal levels of each anterior pituitary hormone, its responses in the stimulation test(s), and cyst/tumor size in patients with RCC (n = 67) and NFA (n = 111) who were consecutively admitted to our hospital for endocrinological evaluation. RCCs were much smaller than NFAs (median height, 12 vs. 26 mm). The prevalence of gonadotropin, PRL, and GH secretion impairment in RCC was lower in comparison to NFA (19% vs. 44%, 34% vs. 61%, and 24% vs. 46%, respectively), whereas the prevalence of TSH and ACTH secretion impairment was comparable (21-27% and 17-24%, respectively). A significant positive relationship between cyst/tumor size and number of impaired hormones was observed in both groups, but smaller cysts could cause hormone secretion impairment in RCC. Stimulation tests suggested that most hormone secretion impairment was attributable to the interrupted hypothalamic-pituitary axis in both groups. Therefore, RCC, even small ones, can cause pituitary dysfunction. Different mechanisms may underlie hypothalamic-pituitary interruption in RCC and NFA.

Contribution of Ghrelin to the Pathogenesis of Growth Hormone Deficiency

In this review we described the interactions between ghrelin and the growth hormone (GH)-insulin-like growth factor 1 (IGF-1) axis in children and adults with growth hormone deficiency (GHD). A possible involvement of these interactions in the pathogenesis of unexplained cases of GHD was suggested. Current research provides more and more details to the knowledge on the circadian rhythm of ghrelin. We gathered reports on the decreasing effect of Helicobacter pylori-related chronic gastritis on the number of ghrelin immunopositive cells and the consequent decrease in ghrelin serum concentration. The gastrointestinal tract microflora modification of the ghrelin action, by the mechanism of molecular mimicry, was also stressed. Moreover, the mutual relationships between ghrelin and the TSH-FT4/FT3 axis in growth and metabolic processes are described. It is to be recalled that FT4 and FT3 exert a permissive impact on IGF-1 action and, in turn, GH, in reaction mediated by IGF-1, enhances the monodeiodination of FT4 to FT3. Finally, we discussed the latest attempts to use the GH secretagogue receptor (GHS-R) analogues for possible diagnostic and therapeutic purposes.

Experience of a Pituitary Clinic for US Military Veterans With Traumatic Brain Injury

Context

Traumatic brain injury (TBI) is considered the "signature" injury of veterans returning from wartime conflicts in Iraq and Afghanistan. While moderate/severe TBI is associated with pituitary dysfunction, this association has not been well established in the military setting and in mild TBI (mTBI). Screening for pituitary dysfunction resulting from TBI in veteran populations is inconsistent across Veterans Affairs (VA) institutions, and such dysfunction often goes unrecognized and untreated.

Objective

This work aims to report the experience of a pituitary clinic in screening for and diagnosis of pituitary dysfunction.

Methods

A retrospective analysis was conducted in a US tertiary care center of veterans referred to the VA Puget Sound Healthcare System pituitary clinic with a history of TBI at least 12 months prior. Main outcome measures included demographics, medical history, symptom burden, baseline hormonal evaluation, brain imaging, and provocative testing for adrenal insufficiency (AI) and adult-onset growth hormone deficiency (AGHD).

Results

Fatigue, cognitive/memory problems, insomnia, and posttraumatic stress disorder were reported in at least two-thirds of the 58 patients evaluated. Twenty-two (37.9%) were diagnosed with at least one pituitary hormone deficiency, including 13 (22.4%) AI, 12 (20.7%) AGHD, 2 (3.4%) secondary hypogonadism, and 5 (8.6%) hyperprolactinemia diagnoses; there were no cases of thyrotropin deficiency.

Conclusion

A high prevalence of chronic AI and AGHD was observed among veterans with TBI. Prospective, larger studies are needed to confirm these results and determine the effects of hormone replacement on long-term outcomes in this setting.

Growth hormone deficiency in adults with Cushing's disease

Growth hormone deficiency (GHD) generally occurs in patients with Cushing's disease (CD) as a consequence of cortisol excess. Mass effect may contribute to the development of GHD in the minority of patients with CD due to corticotroph macroadenomas. Patients with CD in remission are at considerable risk of GH deficiency as a consequence of pituitary surgery or radiation therapy. The purpose of the present review is to summarize data on GH deficiency in adults with CD. Untreated GH deficiency is associated with increased visceral adiposity, decreased lean mass, bone mass, and exercise capacity, impaired linear growth (in children), dyslipidemia, insulin resistance and impaired quality of life. Evaluation and treatment of GHD should be considered in patients with CD in remission. Serum insulin-like growth factor I (IGF-I) can be helpful in the diagnosis of GHD among patients with multiple additional pituitary hormone deficiencies. The diagnosis of GHD generally requires dynamic testing, including insulin, glucagon or macimorelin stimulation. Growth hormone replacement may improve body composition, bone density, linear growth (in children), exercise capacity, dyslipidemia and quality of life. While generally safe, GH replacement requires careful monitoring to assure effectiveness and tolerance in treated patients.

Current concepts of the diagnosis of adult growth hormone deficiency

In adults, growth hormone (GH) deficiency is associated with increased visceral adiposity, decreased lean body mass, bone mineral density and exercise capacity, dyslipidemia, insulin resistance, increased cardiometabolic and fracture risk, and impaired quality of life. The aim of the present article is to review the diagnosis of GH deficiency in adults. To avoid overdiagnosis of GH deficiency, it is critical to evaluate only patients at risk for pituitary dysfunction, including those who have had sellar masses, pituitary surgery, radiation therapy, traumatic brain injury, subarachnoid hemorrhage or childhood onset GH deficiency. Evaluation for GH deficiency should be undertaken after testing and replacement of other pituitary hormone deficits. Since GH secretion is pulsatile, measuring serum GH levels randomly is not helpful in establishing the diagnosis of GH deficiency. Serum insulin-like growth factor I (IGF-I) levels lack substantial diurnal variation but also lack sufficient sensitivity and specificity in the diagnosis of GH deficiency in adults. However, adults with multiple (≥3) additional pituitary hormone deficiencies, risk factors for hypopituitarism and low serum IGF-I levels are very likely to be GH deficient. In most cases, the diagnosis of GH deficiency requires stimulation testing. These tests involve the administration of a pharmacologic agent that normally stimulates GH release from pituitary somatotrophs, including insulin, glucagon, growth hormone releasing hormone-arginine or macimorelin, followed by sampling of serum specimens at regular intervals for GH assay. Patients with a peak GH level that is below a predetermined cutpoint are classified as GH deficient. A systematic approach to the diagnosis of GH deficiency is essential in order to accurately identify adults who may benefit from GH replacement.

Sensitivity and specificity of the macimorelin test for diagnosis of AGHD

OBJECTIVE

The macimorelin test is approved for the diagnosis of adult growth hormone deficiency (AGHD) based on its efficacy vs the insulin tolerance test (ITT). Macimorelin has a significant advantage over ITT in avoiding hypoglycemia. Analyses were conducted to determine whether macimorelin performance is affected by age, BMI, or sex, and evaluate its performance vs ITT over a range of GH cutpoints.

DESIGN

Post hoc analyses of data from a previous randomized phase 3 study included participants aged 18-66 years with BMI <37 kg/m2 and high (Group A), intermediate (Group B), or low (Group C) likelihood for AGHD based on pituitary history, and matched controls (Group D).

METHODS

Probability of AGHD was estimated using unadjusted, age-adjusted, BMI-adjusted, and sex-adjusted logistic models. Area under the curve (AUC) of the estimated receiver operating characteristic (ROC) curve (range, 0-1; 1 = perfect) was compared for adjusted vs unadjusted models. Separate analyses evaluated agreement, sensitivity, and specificity for macimorelin and ITT using cutpoints of 2.8, 4.0, 5.1, and 6.5 ng/mL.

RESULTS

For participants in Group A (n = 41) and Group D (n = 29), unadjusted, age-adjusted, BMI-adjusted, and sex-adjusted models had ROC AUCs (95% CIs) of 0.9924 (0.9807-1), 0.9924 (0.9807-1), 0.9916 (0.9786-1), and 0.9950 (0.9861-1), respectively.

CONCLUSIONS

Macimorelin performance was not meaningfully affected by age, BMI, or sex, indicating robustness for AGHD diagnosis. Of the 4 GH cutpoints evaluated, the cutpoint of 5.1 ng/mL provided maximal specificity (96%) and high sensitivity (92%) and was in good overall agreement with the ITT at the same cutpoint (87%).

The Cut-off Limits of Growth Hormone Response to the Insulin Tolerance Test Related to Body Mass Index for the Diagnosis of Adult Growth Hormone Deficiency

INTRODUCTION

The diagnosis of growth hormone deficiency (GHD) in adults is based on a reduced GH response to provocative tests, such as the insulin tolerance test (ITT) and the GH-releasing hormone (GHRH) + arginine (ARG) test. However, the cut-off limits of peak GH response in lean subjects are not reliable in obese patients; this is noteworthy since adult GHD is often associated with obesity. To date, there are no ITT cut-offs related to body mass index (BMI).

OBJECTIVE

We aimed to evaluate the diagnostic cut-offs of GH response to the ITT in the function of BMI.

METHODS

The GH response to the ITT was studied in 106 patients with a history of hypothalamic-pituitary disease, a mean age of 48.2 ± 12.4 years, and a mean BMI of 26.8 ± 6.1 kg/m2). Patients were divided into lean, overweight, and obese groups according to their BMI. The lack of GH response to GHRH + ARG test was considered the gold standard for the diagnosis of GHD. The best GH cut-off in the ITT, defined as the one with the best sensitivity (SE) and specificity (SP), was identified using receiver-operating characteristics curve (ROC) analysis.

RESULTS

The best GH cut-off in the ITT was 3.5 μg/L in lean subjects (SE 82.1%; SP 85.7%), 1.3 μg/L in overweight subjects (SE 74.1%; SP 85.7%), and 2.2 μg/L in obese subjects (SE 90.0%; SP 50.0%). The diagnostic accuracy was 97.2, 76.5, and 76.7%, respectively.

CONCLUSIONS

Our data show that the ITT represents a reliable diagnostic tool for the diagnosis of adult GHD in lean subjects if an appropriate cut-off limit is assumed. Overweight and obesity strongly reduce the GH response to the ITT, GH BMI-related cut-off limits, and the diagnostic reliability of the test.

Development and Internal Validation of a Predictive Model for Adult GH Deficiency Prior to Stimulation Tests

BACKGROUND

The diagnosis of adult GH deficiency (GHD) relies on a reduced GH response to provocative tests. Their diagnostic accuracy, however, is not perfect, and a reliable estimation of pre-test GHD probability could be helpful for a better interpretation of their results.

METHODS

Eighty patients showing concordant GH response to two provocative tests, i.e. the insulin tolerance test and the GHRH + arginine test, were enrolled. Data on IGF-I values and on the presence/absence of other pituitary deficits were collected and integrated for the estimation of GHD probability prior to stimulation tests.

RESULTS

An independent statistically significant association with the diagnosis of GHD was found both for IGF-I SDS (OR 0.34, 95%-CI 0.18-0.65, p=0.001) and for the presence of other pituitary deficits (OR 6.55, 95%-CI 2.06-20.83, p=0.001). A low (<25%) pre-test GHD probability could be predicted when IGF-I SDS > +0.91 in the presence of other pituitary deficits or IGF-I SDS > -0.52 in the absence of other pituitary deficits. A high (>75%) pre-test GHD probability could be predicted when IGF-I SDS < -0.82 in the presence of other pituitary deficits or IGF-I SDS < -2.26 in the absence of other pituitary deficits.

CONCLUSION

This is the first study that proposes a quantitative estimation of GHD probability prior to stimulation tests. Our risk class stratification represents a simple tool that could be adopted for a Bayesian interpretation of stimulation test results, selecting patients who may benefit from a second stimulation test and possibly reducing the risk of wrong GHD diagnosis.

Interleukin-6 response to insulin-induced hypoglycemia is associated with hypothalamic-pituitary-adrenal axis activation

Increased plasma levels of interleukin-6 (IL-6) in response to acute hypoglycemia have been well documented. Aiming to study the interaction between IL-6 and counter-regulatory hormones during hypoglycemic stress we conducted an exploratory single center study involving 26 adult patients undergoing insulin tolerance test. Insulin-induced hypoglycemia elicited a significant dynamic response of IL-6, adrenaline, noradrenaline, GH, prolactin, ACTH and serum and salivary cortisol (P < 0.001 for all variables). Patients with insufficient HPA axis response had lower hypoglycemia-induced IL-6 increase (median: 0.88 pg/mL) compared with individuals with intact HPA axis response (2.03 pg/mL, P = 0.007). IL-6 maximal increase correlated with the maximal increase of serum cortisol (rs = 0.48; P = 0.013), salivary cortisol (rs = 0.66; P = 0.012), plasma ACTH (rs = 0.48; P = 0.013) and with the increase in procedure-related symptoms of anxiety and hypoglycemia (rs = 0.57; P = 0.003). In conclusion, hypoglycemic stress-induced IL-6 increase is associated with activation of the HPA axis, suggesting that IL-6 response to hypoglycemic stress may be regarded as part of the counter-regulatory response, possibly contributing to the maintenance of glucose homeostasis.

Axis-specific analysis and predictors of endocrine recovery and deficits for non-functioning pituitary adenomas undergoing endoscopic transsphenoidal surgery

PURPOSE

Endoscopic transsphenoidal surgery (ETSS) is a well-established treatment for patients with nonfunctioning pituitary adenomas (NFPAs). Data on the rates of pituitary dysfunction and recovery in a large cohort of NFPA patients undergoing ETSS and the predictors of endocrine function before and after ETSS are scarce. This study is purposed to analyze the comprehensive changes in hormonal function and identify factors that predict recovery or worsening of hormonal axes following ETSS for NFPA.

METHODS

A retrospective review of 601 consecutive patients who underwent ETSS between 2010 and 2018 at one institution was performed. Recovery or development of new hypopituitarism was analyzed in 209 NFPA patients who underwent ETSS.

RESULTS

Patients with preoperative endocrine deficits (59.8%) in one or more pituitary axes had larger tumor volumes (P = 0.001) than those without preoperative deficits. Recovery of preoperative pituitary deficit occurred in all four axes, with overall mean recovery of 29.7%. The cortisol axis showed the highest recovery whereas the thyroid axis showed the lowest, with 1-year cumulative recovery rates of 44.3% and 6.1%, respectively. Postoperative hypopituitarism occurred overall in 17.2%, most frequently in the thyroid axis (24.3%, 27/111) and least frequently in the cortisol axis (9.7%, 16/165). Axis-specific predictors of post-operative recovery and deficiency were identified.

CONCLUSIONS

Dynamic alterations in pituitary hormones were observed in a proportion of patients following ETSS in NFPA patients. Postoperative endocrine vulnerability, recovery, and factors that predicted recovery or loss of endocrine function depended on the hormonal system, necessitating an axis-specific surveillance strategy postoperatively.

A Novel Syndrome With Short Stature, Mandibular Hypoplasia, and Osteoporosis May Be Associated With a PRRT3 Variant

Context

Despite considerable progress in elucidating the molecular basis of various progeroid syndromes, some rare patients remain unexplained.

Objective

To elucidate molecular genetic basis of a novel autosomal recessive progeroid syndrome.

Participants

A 24-year-old male and his 18-year-old sister with short stature, mandibular hypoplasia, pointed nose, shrill voice, severe osteoporosis, and short eyebrows and their unaffected siblings and parents belonging to a consanguineous Arab family.

Results

Using exome and Sanger sequencing, we report a novel homozygous p.Glu394Lys disease-causing variant in proline-rich transmembrane protein 3 (PRRT3). PRRT3 belongs to the family of proline-rich proteins containing several repeats of a short proline-rich sequence, but its function remains to be determined. Preliminary observations showing colocalization of Prrt3 and synaptophysin support its role in vesicle exocytosis. Consistent with the highest messenger ribonucleic acid expression of PRRT3 in the pituitary, both the patients had mild growth hormone deficiency but had near normal reproductive development.

Conclusions

We conclude that the homozygous p.Glu394Lys variant in PRRT3 may be associated with a novel autosomal recessive, progeroid syndrome with short stature, mandibular hypoplasia, osteoporosis, short eyebrows, and mild growth hormone (GH) deficiency. Our findings extend the spectrum of progeroid syndromes and elucidate important functions of PRRT3 in human biology, including secretion of GH from the pituitary.

Safety, tolerability, pharmacokinetics, and pharmacodynamics of macimorelin in healthy adults: Results of a single-dose, randomized controlled study

OBJECTIVE

Macimorelin is an orally active ghrelin receptor agonist indicated for the diagnosis of adult growth hormone (GH) deficiency in the United States. This phase 1 study evaluated the safety, tolerability, pharmacokinetics, and pharmacodynamics of single ascending doses of macimorelin (including a supratherapeutic dose to be used in a thorough QT trial) in healthy adults.

DESIGN

Participants were randomized to receive macimorelin 0.5, 1.0, or 2.0 mg/kg or placebo in 1 of 3 sequential ascending-dose cohorts. Blood samples for pharmacokinetic and pharmacodynamic assays were collected pre-dose and at specified time points over a 24-h period. Pharmacokinetic parameters assessed included area under the concentration-time curve (AUC), maximum concentration (C_max) of macimorelin in plasma, time to C_max (t_max), and terminal elimination half-life (t_1/2). Pharmacodynamic assessments evaluated levels of GH, adrenocorticotropic hormone, thyroid-stimulating hormone, cortisol, and prolactin. Safety was assessed based on treatment-emergent adverse events (TEAEs), vital signs, 12‑lead electrocardiograms, and laboratory parameters.

RESULTS

A total of 28 healthy adults were enrolled and completed the study. Macimorelin AUC and C_max showed less than dose-proportional increases following administration of 0.5 and 1.0 mg/kg. Mean t_1/2 was 3.51 h for macimorelin 0.5 and 1.0 mg/kg and 8.29 h for macimorelin 2.0 mg/kg; median t_max occurred at 0.5 to 0.75 h. GH levels increased after dosing, with a t_max of 0.75 h to 1.0 h. Mean GH C_max was similar with the macimorelin 0.5- and 1.0-mg/kg doses (31.9 and 37.8 ng/mL, respectively) and was ~50% lower with macimorelin 2.0 mg/kg (18.4 ng/mL). Transient increases were observed in adrenocorticotropic hormone, cortisol, and prolactin, which were not dose related. A total of 19 TEAEs were reported in 35.7% (10/28) of participants; all TEAEs were mild or moderate and resolved. A total of 12 drug-related TEAEs were reported in 8 participants. Headache was the most common drug-related TEAE. All doses of macimorelin prolonged mean QTcF by 10 to 11 ms. There were no clinically meaningful changes in vital signs or laboratory parameters.

CONCLUSIONS

Single-dose administration of macimorelin 0.5 to 2.0 mg/kg was well tolerated. Macimorelin exposure was less than dose-proportional over the dose range studied. Administration of macimorelin stimulated GH production, with the greatest increases observed in the macimorelin 0.5- and 1.0-mg/kg groups.

Diagnosis and Treatment of Growth Hormone Deficiency: A Position Statement from Korean Endocrine Society and Korean Society of Pediatric Endocrinology

Growth hormone (GH) deficiency is caused by congenital or acquired causes and occurs in childhood or adulthood. GH replacement therapy brings benefits to body composition, exercise capacity, skeletal health, cardiovascular outcomes, and quality of life. Before initiating GH replacement, GH deficiency should be confirmed through proper stimulation tests, and in cases with proven genetic causes or structural lesions, repeated GH stimulation testing is not necessary. The dosing regimen of GH replacement therapy should be individualized, with the goal of minimizing side effects and maximizing clinical improvements. The Korean Endocrine Society and the Korean Society of Pediatric Endocrinology have developed a position statement on the diagnosis and treatment of GH deficiency. This position statement is based on a systematic review of evidence and expert opinions.

Dexamethasone Stimulation Test in the Diagnostic Work-Up of Growth Hormone Deficiency in Childhood: Clinical Value and Comparison With Insulin-Induced Hypoglycemia

CONTEXT

dexamethasone has been demonstrated to elicit GH secretion in adults, but few data are available about its effectiveness as a provocative stimulus in the diagnostic work-up of GH deficiency (GHD) in childhood.

OBJECTIVE

to assess the clinical value of dexamethasone stimulation test (DST) as a diagnostic tool for pediatric GHD.

DESIGN AND SETTING

retrospective single-center analysis. The study population included 166 patients with a pathological response to arginine stimulation test (AST, first-line test) and subsequently tested with either insulin tolerance test (ITT) or DST as a second-line investigation between 2008 and 2019.

MAIN OUTCOME MEASURES

comparison between GH peaks and secretory curves induced by ITT and DST; degree of agreement between DST and AST versus ITT and AST.

RESULTS

the pathological response to AST (GH peak < 8 ng/mL) was confirmed by an ITT in 80.2% (89/111) of patients and by a DST in 76.4% (42/55), with no statistical difference between the two groups (p value 0.69). Mean GH peaks achieved after ITT and DST were entirely comparable (6.59 ± 3.59 versus 6.50 ± 4.09 ng/ml, respectively, p 0.97) and statistically higher than those elicited by arginine (p < 0.01 for both), irrespectively of the average GH peaks recorded for each patient (Bland-Altman method). Dexamethasone elicited a longer lasting and later secretory response than AST and ITT. No side effects were recorded after DST.

CONCLUSIONS

DST and ITT confirmed GHD in a superimposable percentage of patients with a pathological first-line test. DST and ITT share a similar secretagogue potency, overall greater than AST.

From JMV-1843 to Macrilen

Growth hormone deficiency (GHD) is a severe pathology that greatly affects the quality of life, and increases morbidity and mortality of patients owing to the augmentation of cardiovascular events. Treatment of GHD is challenging, mainly because there is no specific characteristic sign or symptom that can be used to make a clear diagnosis. There is need for an unequivocal diagnosis of GHD to avoid unnecessary treatment with GH, because the available provocative tests (GH stimulation tests) are not specific and sensitive enough, and are contraindicated in some patients. Ghrelin is an endogenous peptide that stimulates GH secretion by interacting with a G-protein-coupled receptor named ghrelin receptor (GH secretagogue receptor 1a, GHS-R1a). Given this, a GH stimulation test using ghrelin or its analogues appears to be attractive. In this paper, a modified tripeptide first named JMV-1843 in the laboratory is briefly presented. It is potent and selective in stimulating the release of GH and is orally active. It has been recently commercialised for the diagnosis of adult GH deficiency under the tradename Macrilen. The test using this compound appears to be reliable, well tolerated, and simple.

AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS AND AMERICAN COLLEGE OF ENDOCRINOLOGY GUIDELINES FOR MANAGEMENT OF GROWTH HORMONE DEFICIENCY IN ADULTS AND PATIENTS TRANSITIONING FROM PEDIATRIC TO ADULT CARE

Objective: The development of these guidelines is sponsored by the American Association of Clinical Endocrinologists (AACE) Board of Directors and American College of Endocrinology (ACE) Board of Trustees and adheres with published AACE protocols for the standardized production of clinical practice guidelines (CPG). Methods: Recommendations are based on diligent reviews of clinical evidence with transparent incorporation of subjective factors, according to established AACE/ACE guidelines for guidelines protocols. Results: The Executive Summary of this 2019 updated guideline contains 58 numbered recommendations: 12 are Grade A (21%), 19 are Grade B (33%), 21 are Grade C (36%), and 6 are Grade D (10%). These detailed, evidence-based recommendations allow for nuance-based clinical decision-making that addresses multiple aspects of real-world care of patients. The evidence base presented in the subsequent Appendix provides relevant supporting information for the Executive Summary recommendations. This update contains 357 citations of which 51 (14%) are evidence level (EL) 1 (strong), 168 (47%) are EL 2 (intermediate), 61 (17%) are EL 3 (weak), and 77 (22%) are EL 4 (no clinical evidence). Conclusion: This CPG is a practical tool that practicing endocrinologists and regulatory bodies can refer to regarding the identification, diagnosis, and treatment of adults and patients transitioning from pediatric to adult-care services with growth hormone deficiency (GHD). It provides guidelines on assessment, screening, diagnostic testing, and treatment recommendations for a range of individuals with various causes of adult GHD. The recommendations emphasize the importance of considering testing patients with a reasonable level of clinical suspicion of GHD using appropriate growth hormone (GH) cut-points for various GH-stimulation tests to accurately diagnose adult GHD, and to exercise caution interpreting serum GH and insulin-like growth factor-1 (IGF-1) levels, as various GH and IGF-1 assays are used to support treatment decisions. The intention to treat often requires sound clinical judgment and careful assessment of the benefits and risks specific to each individual patient. Unapproved uses of GH, long-term safety, and the current status of long-acting GH preparations are also discussed in this document. LAY ABSTRACT This updated guideline provides evidence-based recommendations regarding the identification, screening, assessment, diagnosis, and treatment for a range of individuals with various causes of adult growth-hormone deficiency (GHD) and patients with childhood-onset GHD transitioning to adult care. The update summarizes the most current knowledge about the accuracy of available GH-stimulation tests, safety of recombinant human GH (rhGH) replacement, unapproved uses of rhGH related to sports and aging, and new developments such as long-acting GH preparations that use a variety of technologies to prolong GH action. Recommendations offer a framework for physicians to manage patients with GHD effectively during transition to adult care and adulthood. Establishing a correct diagnosis is essential before consideration of replacement therapy with rhGH. Since the diagnosis of GHD in adults can be challenging, GH-stimulation tests are recommended based on individual patient circumstances and use of appropriate GH cut-points. Available GH-stimulation tests are discussed regarding variability, accuracy, reproducibility, safety, and contraindications, among other factors. The regimen for starting and maintaining rhGH treatment now uses individualized dose adjustments, which has improved effectiveness and reduced reported side effects, dependent on age, gender, body mass index, and various other individual characteristics. With careful dosing of rhGH replacement, many features of adult GHD are reversible and side effects of therapy can be minimized. Scientific studies have consistently shown rhGH therapy to be beneficial for adults with GHD, including improvements in body composition and quality of life, and have demonstrated the safety of short- and long-term rhGH replacement. Abbreviations: AACE = American Association of Clinical Endocrinologists; ACE = American College of Endocrinology; AHSG = alpha-2-HS-glycoprotein; AO-GHD = adult-onset growth hormone deficiency; ARG = arginine; BEL = best evidence level; BMD = bone mineral density; BMI = body mass index; CI = confidence interval; CO-GHD = childhood-onset growth hormone deficiency; CPG = clinical practice guideline; CRP = C-reactive protein; DM = diabetes mellitus; DXA = dual-energy X-ray absorptiometry; EL = evidence level; FDA = Food and Drug Administration; FD-GST = fixed-dose glucagon stimulation test; GeNeSIS = Genetics and Neuroendocrinology of Short Stature International Study; GH = growth hormone; GHD = growth hormone deficiency; GHRH = growth hormone-releasing hormone; GST = glucagon stimulation test; HDL = high-density lipoprotein; HypoCCS = Hypopituitary Control and Complications Study; IGF-1 = insulin-like growth factor-1; IGFBP = insulin-like growth factor-binding protein; IGHD = isolated growth hormone deficiency; ITT = insulin tolerance test; KIMS = Kabi International Metabolic Surveillance; LAGH = long-acting growth hormone; LDL = low-density lipoprotein; LIF = leukemia inhibitory factor; MPHD = multiple pituitary hormone deficiencies; MRI = magnetic resonance imaging; P-III-NP = procollagen type-III amino-terminal pro-peptide; PHD = pituitary hormone deficiencies; QoL = quality of life; rhGH = recombinant human growth hormone; ROC = receiver operating characteristic; RR = relative risk; SAH = subarachnoid hemorrhage; SDS = standard deviation score; SIR = standardized incidence ratio; SN = secondary neoplasms; T3 = triiodothyronine; TBI = traumatic brain injury; VDBP = vitamin D-binding protein; WADA = World Anti-Doping Agency; WB-GST = weight-based glucagon stimulation test.

Impact of BMI on peak growth hormone responses to provocative tests and therapeutic outcome in children with growth hormone deficiency

This study investigated the relationship between peak stimulated growth hormone (GH) and body mass index (BMI), as well as the impact of BMI on therapeutic response in patients with GH deficiency (GHD). A total of 460 patients were enrolled in the study. The patients were divided into four groups as per the etiology and peak GH values: idiopathic (n = 439), organic (n = 21), complete (n = 114), and partial (n = 325) GHD groups. Subsequently, they were classified as normal, overweight, or obese based on their BMI. There was no difference in BMI between complete and partial GHD. A significant negative relationship between peak GH and BMI were found. Moreover, obese GHD children had a considerably better therapeutic response in height increase and BMI decrease during 2 years of GH treatment compared to non-obese children with GHD. There was no difference between peak GH and type of GH stimulation test (GHST), except the clonidine test, which showed a much lower peak GH in obese GHD children. In conclusion, BMI had a negative impact on peak GH response, and therapeutic outcome was more favorable in the obese group. Despite no difference in GH response by type of GHST, the degree of obesity differentially affected the results.

Adult growth hormone deficiency: clinical advances and approaches to improve adherence

Introduction: There have been significant clinical advances in the understanding of the diagnosis and benefits of long-term recombinant human growth hormone (rhGH) replacement in adults with GH deficiency (GHD) since its approval in 1996 by the United States Food and Drug Administration.Areas covered: We searched PubMed, Medline, CINAHL, EMBASE and PsychInfo databases between January 2000 and June 2019 for published studies evaluating adults with GHD. We reviewed the data of the oral macimorelin test compared to the GHRH plus arginine and the insulin tolerance tests that led to its approval by the United States FDA and European Medicines Agency for adult diagnostic testing. We summarize the clinical advances of long-term benefits of rhGH therapy and the potential effects of GH receptor polymorphisms on individual treatment responsiveness. We identify that non-adherence and discontinuation rates are high and recommend strategies to support patients to improve adherence. We also provide an overview of several long-acting GH (LAGH) preparations currently under development and their potential role in improving treatment adherence.Expert opinion: This article summarizes recent clinical advances in rhGH replacement therapy, the biological and molecular aspects that may influence rhGH action, and offers practical strategies to enhance adherence in adults with GHD.

Non-functioning pituitary adenomas: indications for pituitary surgery and post-surgical management

PURPOSE

Non-functioning pituitary adenomas (NFPAs) are associated with impaired well-being, increased comorbidities, and reduced long-term survival. Data on optimal management of NFPAs around surgical treatment are scarce, and postoperative treatment and follow-up strategies have not been evaluated in prospective trials. Here, we review the preoperative, perioperative, and early postoperative management of patients with NFPAs.

METHODS

We searched Medline and the Cochrane Library for articles published in English with the following items "Pituitary neoplasms AND Surgery" and "Surgery AND Hypopituitarism". Studies containing detailed analyses of the management of NFPAs in adult patients, including pituitary surgery, endocrine care, imaging, ophthalmologic assessment and long-term outcome were reviewed.

RESULTS

Treatment options for NFPAs include active surveillance, surgical resection, and radiotherapy. Pituitary surgery is currently recommended as first-line treatment in patients with visual impairment due to adenomas compressing the optic nerves or chiasma. Radiotherapy is reserved for large tumor remnants or tumor recurrence following one or more surgical attempts. There is no consensus of optimal pre-, peri-, and postoperative management such as timing, frequency, and duration of endocrine, radiologic, and ophthalmologic assessments as well as management of smaller tumor remnants or tumor recurrence.

CONCLUSIONS

In clinical practice, there is a great variation in the treatment and follow-up of patients with NFPAs. We have, based on available data, suggested an optimal management strategy for patients with NFPAs in relation to pituitary surgery. Prospective trials oriented at drawing up strategies for the management of NFPAs are needed.

Epilepsy, depression, and growth hormone

Depression affects a large proportion of patients with epilepsy, and is likely due in part to biological mechanism. Hormonal dysregulation due to the disruptive effects of seizures and interictal epileptiform discharges on the hypothalamic-pituitary-adrenal axis likely contributes to high rates of depression in epilepsy. This paper reviews the largely unexplored role of neuroendocrine factors in epilepsy-related depression, focusing on Growth Hormone (GH). While GH deficiency is traditionally considered a childhood disorder manifested by impaired skeletal growth, GH deficiency in adulthood is now recognized as a serious disorder characterized by impairments in multiple domains including mood and quality of life. Could high rates of depression in patients with epilepsy relate to subtle GH deficiency? Because GH replacement therapy has been shown to improve mood and quality of life in patients with GH deficiency, this emerging area may hold promise for patients suffering from epilepsy-related depression.

Decreased plasma l-arginine levels in organic acidurias (MMA and PA) and decreased plasma branched-chain amino acid levels in urea cycle disorders as a potential cause of growth retardation: Options for treatment

BACKGROUND AND AIM

Patients with methylmalonic acidemia (MMA) and propionic acidemia (PA) and urea cycle disorders (UCD), treated with a protein restricted diet, are prone to growth failure. To obtain optimal growth and thereby efficacious protein incorporation, a diet containing the essential and functional amino acids for growth is necessary. Optimal growth will result in improved protein tolerance and possibly a decrease in the number of decompensations. It thus needs to be determined if amino acid deficiencies are associated with the growth retardation in these patient groups. We studied the correlations between plasma L-arginine levels, plasma branched chain amino acids (BCAA: L-isoleucine, L-leucine and L-valine) levels (amino acids known to influence growth), and height in MMA/PA and UCD patients.

METHODS

We analyzed data from longitudinal visits made in stable metabolic periods by patients registered at the European Registry and Network for Intoxication Type Metabolic Diseases (E-IMD, Chafea no. 2010 12 01).

RESULTS

In total, 263 MMA/PA and 311 UCD patients were included, all aged below 18 years of age. In patients with MMA and PA, height z-score was positively associated with patients' natural-protein-to-energy prescription ratio and their plasma L-valine and L-arginine levels, while negatively associated with the amount of synthetic protein prescription and their age at visit. In all UCDs combined, height z-score was positively associated with the natural-protein-to-energy prescription ratio. In those with carbamylphosphate synthetase 1 deficiency (CPS1-D), those with male ornithine transcarbamylase deficiency (OTC-D), and those in the hyperornithinemia-hyperammonemia-homocitrullinuria (HHH) syndrome subgroup, height z-score was positively associated with patients' plasma L-leucine levels. In those with argininosuccinate synthetase deficiency (ASS-D) and argininosuccinate lyase deficiency (ASL-D), height was positively associated with patients' plasma L-valine levels.

CONCLUSION

Plasma L-arginine and L-valine levels in MMA/PA patients and plasma L-leucine and L-valine levels in UCD patients, as well as the protein-to-energy prescription ratio in both groups were positively associated with height. Optimization of these plasma amino acid levels is essential to support normal growth and increase protein tolerance in these disorders. Consequently this could improve the protein-to-energy intake ratio.

Auxological characteristics of pediatric patients with permanent or transient isolated growth hormone deficiency. Response to treatment and final height

INTRODUCTION

Treatment with recombinant human growth hormone (rhGH) has been shown to improve adult height in pediatric patients with GH deficiency (GHD). However, reassessment of patients after they reach their final height shows some of them have permanent GH deficiency (PGHD), while others had a transient deficiency (TGHD). The study objective was to assess, in a cohort of pediatric patients with GHD, potential differences in response to treatment with rhGH depending on whether deficiency is permanent or transient.

MATERIALS AND METHODS

A retrospective study of 89 patients with GHD, who were monitored from diagnosis to adult height. Clinical, auxological, radiographic and laboratory variables were collected at diagnosis, after the first year of treatment, and when they had reached their adult height.

RESULTS

PGHD was found in 28% of patients. Initial height was -2.46 ± 0.86 SD and -2.24 ± 0.68 SD in subjects with PGHD and TGHD respectively. Peak GH level at diagnosis was 4.26 ± 2.78 and 6.20 ± 2.01 ng/mL (p < 0.01) in the PGHD and TGHD groups respectively. After the first year of treatment, increase in growth velocity was greater in the PGHD group: 4.33 ± 3.53 SD vs. 2.95 ± 2.54 SD in the PGHD group (p = 0.043). Final height was -0.81 ± 0.87 SD in the PGHD and -0.95 ± 0.83 SD in the TGHD group (p = 0.47).

CONCLUSIONS

Patients with PGHD had a better short- and long-term response to rhGH. They also showed lower GH levels in stimulation tests at diagnosis, as previously reported.

Macimorelin as a Diagnostic Test for Adult GH Deficiency

PURPOSE

The diagnosis of adult GH deficiency (AGHD) is challenging and often requires confirmation with a GH stimulation test (GHST). The insulin tolerance test (ITT) is considered the reference standard GHST but is labor intensive, can cause severe hypoglycemia, and is contraindicated for certain patients. Macimorelin, an orally active GH secretagogue, could be used to diagnose AGHD by measuring stimulated GH levels after an oral dose.

MATERIALS AND METHODS

The present multicenter, open-label, randomized, two-way crossover trial was designed to validate the efficacy and safety of single-dose oral macimorelin for AGHD diagnosis compared with the ITT. Subjects with high (n = 38), intermediate (n = 37), and low (n = 39) likelihood for AGHD and healthy, matched controls (n = 25) were included in the efficacy analysis.

RESULTS

After the first test, 99% of macimorelin tests and 82% of ITTs were evaluable. Using GH cutoff levels of 2.8 ng/mL for macimorelin and 5.1 ng/mL for ITTs, the negative agreement was 95.38% (95% CI, 87% to 99%), the positive agreement was 74.32% (95% CI, 63% to 84%), sensitivity was 87%, and specificity was 96%. On retesting, the reproducibility was 97% for macimorelin (n = 33). In post hoc analyses, a GH cutoff of 5.1 ng/mL for both tests resulted in 94% (95% CI, 85% to 98%) negative agreement, 82% (95% CI, 72% to 90%) positive agreement, 92% sensitivity, and 96% specificity. No serious adverse events were reported for macimorelin.

CONCLUSIONS

Oral macimorelin is a simple, well-tolerated, reproducible, and safe diagnostic test for AGHD with accuracy comparable to that of the ITT. A GH cutoff of 5.1 ng/mL for the macimorelin test provides an excellent balance between sensitivity and specificity.

Diagnosis of GH Deficiency as a Late Effect of Radiotherapy in Survivors of Childhood Cancers

BACKGROUND

Limited guidance exists for selecting a laboratory method for diagnosing GH deficiency (GHD) when it occurs as a late effect of radiotherapy in childhood cancer survivors (CCSs).

METHODS

We searched Medline, Embase, Cochrane Central Register of Controlled Trials and Database of Systematic Reviews, and Scopus for studies evaluating GHD that used IGF-1 or IGF-binding protein 3 (IGFBP-3) measurements compared with GH dynamic testing.

RESULTS

We included 15 studies [IGF-1 (8 studies) and IGFBP-3 (7 studies)] enrolling 477 patients. Comparator tests varied widely. Overall, both IGF-1 and IGFBP-3 had suboptimal diagnostic accuracy but were strongly correlated. The use of both tests simultaneously in the same cohort did not improve the diagnostic accuracy. Despite high variability in the testing protocols, dynamic tests remained the most accurate for appropriately identifying patients with GHD. The insulin tolerance test (ITT) appears to be the most accepted reference test when used alone or in combination with arginine; however, standardized testing strategies among practice groups are absent. GHRH and arginine stimulation performed almost similarly to the ITT; however, in one study GHRH with arginine stimulation had 66% sensitivity and 88% specificity compared with the ITT. Insufficient data were available to assess the accuracy of serial GH testing (nocturnal or over 24 hours).

CONCLUSION

The diagnostic accuracy of various dynamic tests for GHD in CCSs appears to follow the same patterns as those in non-CCSs. Interpreting GHRH stimulation is a challenge given the primarily hypothalamic dysfunction in CCSs. IGF-1 and IGFBP-3 perform poorly in this population.

Natural history of Rathke's cleft cysts: A retrospective analysis of a two centres experience

OBJECTIVE

Rathke's cleft cyst (RCC) is a common sellar lesion which may cause visual impairment, hypopituitarism and headaches from mass effect. The natural history of these lesions is currently unclear. We investigated the natural history of RCCs and compared surgically treated patients with those treated conservatively.

METHODS

We performed a retrospective cohort study of patients diagnosed with a RCC between 1996 and 2016 at Stanford University and Ospedale Maggiore Policlinico di Milano.

RESULTS

Patients were divided into 2 cohorts: Group A, 72 subjects who underwent surgical resection of a symptomatic RCC, and Group B, 62 subjects managed conservatively. Compared to Group B, Group A subjects had larger RCCs (79% vs 22% had a largest diameter >10 mm, P < .001) and were more likely (41.5% vs 16%, P < .001) to present with hypopituitarism and diabetes insipidus (DI) (18% vs 1.6%, P = .002). In Group A, after a mean follow-up of 53.7 months, 12.5% of patients had recurrence and a second surgery. After surgery, 35% of patients recovered pituitary function. Hyperprolactinemia (26.6%) and hypogonadism (66.6%) resolved more commonly that did DI (20.1%). New pituitary deficits appeared in 16.6% of patients after surgery. In Group B, with a mean follow-up of 41 months, only 6.4% had cyst enlargement, none underwent surgery, and none developed a pituitary deficit.

CONCLUSION

Our data offer guidance in decision-making regarding the management of RCC patients and confirm the safety of conservative treatment in asymptomatic patients.

Biomarkers of GH action in children and adults

Growth hormone (GH) and IGF-I levels in serum are used as biomarkers in the diagnosis and management of GH-related disorders but have not been subject to structured validation. Auxological parameters in children and changes in body composition in adults, as well as metabolic parameters and patient related outcomes are used as clinical and surrogate endpoints. New treatment options, such as long acting GH and GH antagonists, require reevaluation of the currently used biochemical biomarkers. This article will review biomarkers, surrogate endpoints and clinical endpoints related to GH treatment in children and adults as well as in acromegaly.

Hypopituitarism 3 and 12 months after traumatic brain injury and subarachnoid haemorrhage

OBJECTIVE

High prevalence of hypopituitarism (HP) has been reported after traumatic brain injury (TBI) and subarachnoid haemorrhage (SAH). The aim of the study was to prospectively evaluate the prevalence and progression of HP in patients after TBI and SAH in Icelandic population.

DESIGN

A 12 month prospective single-centre study.

METHODS AND PROCEDURES

A total of 27 patients were included, 15 patients with TBI and 12 patients with SAH. Pituitary function was evaluated with baseline hormone measurements and diagnostic tests. An insulin tolerance test was used unless contraindicated, then the GHRH-arginine test and Synachten test were used.

RESULTS

At three months, 16.7% (2/12) of the patients had HP after TBI and 33.3% (4/12) after SAH. At 12 months, 21.4% (3/14) of patients had HP after TBI and 9.1% (1/11) after SAH. Gonadotropin deficiency was the most common deficiency at 3 months and GH and gonadotropin deficiency at 12 months.

CONCLUSIONS

There is a considerable risk of HP after TBI and reason to study pituitary function further in patients with SAH. We believe that neuroendocrine evaluation is important in these patients. Since recovery commonly occurs 12 months after the event, evaluation should be performed after that time if not clinically indicated earlier.

The prevalence of growth hormone deficiency in survivors of subarachnoid haemorrhage: results from a large single centre study

OBJECTIVE

The variation in reported prevalence of growth hormone deficiency (GHD) post subarachnoid haemorrhage (SAH) is mainly due to methodological heterogeneity. We report on the prevalence of GHD in a large cohort of patients following SAH, when dynamic and confirmatory pituitary hormone testing methods are systematically employed.

DESIGN

In this cross-sectional study, pituitary function was assessed in 100 patients following SAH. Baseline pituitary hormonal profile measurement and glucagon stimulation testing (GST) was carried out in all patients. Isolated GHD was confirmed with an Arginine stimulation test and ACTH deficiency was confirmed with a short synacthen test.

RESULTS

The prevalence of hypopituitarism in our cohort was 19% and the prevalence of GHD was 14%. There was no association between GHD and the clinical or radiological severity of SAH at presentation, treatment modality, age, or occurrence of vasospasm. There were statistically significant differences in terms of Glasgow Outcome Scale (GOS; p = 0.03) between patients diagnosed with GHD and those without. Significant inverse correlations between GH peak on GST with body mass index (BMI) and waist hip ratio (WHR) was also noted (p < 0.0001 and p < 0.0001 respectively).

CONCLUSION

Using the current testing protocol, the prevalence of GHD detected in our cohort was 14%. It is unclear if the BMI and WHR difference observed is truly due to GHD or confounded by the endocrine tests used in this protocol. There is possibly an association between the development of GHD and worse GOS score. Routine endocrine screening of all SAH survivors with dynamic tests is time consuming and may subject many patients to unnecessary side-effects. Furthermore the degree of clinical benefit derived from growth hormone replacement in this patient group, remains unclear. Increased understanding of the most appropriate testing methodology in this patient group and more importantly which SAH survivors would derive most benefit from GHD screening is required.

Pituitary insufficiency following traumatic thoracic injury in an adolescent male patient: A case report and literature review

RATIONALE

Traumatic thoracic injuries in adolescents are rare but could be connected with traumatic brain injuries (TBI) and development of chronic hypopituitarism. Early recognition of these endocrine problems is a significant challenge to clinicians. We present difficulties in diagnosis of hypothalamic-pituitary insufficiency following traumatic thoracic injury in adolescence. We also review the literature of similar cases.

PATIENT CONCERNS

We present a case of a 24-years-old male. In 2007, at the age of 15 he underwent a severe traffic accident followed by thoracic injury with concussion, hemothorax and dissection of the aorta requiring aortic stent-graft implantation.

DIAGNOSES

During the post-traumatic period, transient polydipsia and polyuria symptoms were observed. The patient had no medical history of any serious disease before the accident, his growth and pubertal development was normal. After the accident the patient did not undergo any routine medical check-ups. In 2013 gonadal axis deficiency was diagnosed during investigation of libido problems. Following the diagnosis testosterone replacement therapy was initiated.

INTERVENTIONS

Further endocrinological investigation was carried out in 2016. The patient's main complaints were decreased mood and poor physical fitness. BMI was 27.34 kg/m, with a tendency to abdominal fat distribution. The patient's height is 160 cm, while Mid Parental Height (MPH) is 173.5 cm. Decreased bone density was found in DEXA examination. Serum growth hormone level (GH) was normal while insulin-like growth factor-1 (IGF-1) level was below normal. Insulin tolerance test (ITT) and low levels of IGF-1 confirmed somatotropic axis deficiency. Nuclear magnetic resonance (NMR) of the hypothalamo-pituitary region showed no abnormalities. PROP 1 and other common genetic mutations associated with GH deficits were excluded. Testosterone treatment was continued. The patient increased physical activity and implemented diet.

OUTCOMES

The patient has lost weight, improved physical activity performance and is feeling better. The procedure to start GH supplementation is now in process.

LESSONS

Based on our case and available literature we suggest that adolescent patients after traumatic brain injuries may require precise investigation and strict monitoring due to the possibility of unrecognized hypopituitarism.

A patient with van Maldergem syndrome with endocrine abnormalities, hypogonadotropic hypogonadism, and breast aplasia/hypoplasia

Background

We report a female patient with endocrine abnormalities, hypogonadotropic hypogonadism and amazia (breasts aplasia/hypoplasia but normal nipples and areolas) in a rare syndrome: Van Maldergem syndrome (VMS).

Case presentation

Our patient was first evaluated at age 4 for intellectual disability, craniofacial features, and auditory malformations. At age 15, she presented with no breast development and other findings consistent with hypogonadotropic hypogonadism. At age 37, she underwent whole exome sequencing (WES) to identify pathogenic variants. WES revealed compound heterozygous variants in DCHS1 (rs145099391:G > A, p.P197L & rs753548138:G > A, p.T2334 M) [RefSeq NM_003737.3], diagnostic of Van Maldergem syndrome (VMS-1). VMS is a rare autosomal disorder reported in only 13 patients, characterized by intellectual disability, typical craniofacial features, auditory malformations, hearing loss, skeletal and limb malformations, brain abnormalities with periventricular neuronal heterotopia and other variable anomalies. Our patient had similar phenotypic abnormalities. She also had hypogonadotropic hypogonadism and amazia. Based on the clinical findings reported, two previously published patients with VMS may also have been affected by hypogonadotropic hypogonadism, but endocrine abnormalities were not evaluated or mentioned.

Conclusion

This case highlights an individual with VMS, characterized by compound heterozygous variants in DCHS1. Our observations may provide additional information on the phenotypic spectrum of VMS, including hypogonadotropic hypogonadism and amazia. However, the molecular genetic basis for endocrine anomalies observed in some VMS patients, including ours, remains unexplained.

Electronic supplementary material

The online version of this article (10.1186/s13633-017-0052-z) contains supplementary material, which is available to authorized users.

Growth hormone deficiency and hypopituitarism in adults after complicated mild traumatic brain injury

PURPOSE

Traumatic brain injury is considered the main cause of hypopituitarism in adults, and GH deficiency appears to be the most frequent pituitary deficit. Most of the available studies have included all degrees of severity of trauma. We aimed to assess pituitary function and GH deficiency in adult patients at different time lengths after complicated mild TBI according to Glasgow Coma Scale. We also aimed to evaluate whether mild TBI patients with GH deficiency had developed alterations in the glycolipid profile.

METHODS

Forty-eight patients (34 men and 14 women) with complicated mild TBI were included in the study. Twenty-three patients were evaluated at 1 year (Group A) and 25 patients at 5 years or longer after the injury (Group B). All patients underwent basal hormonal evaluation for pituitary function. GH deficiency was investigated by the combined test (GH releasing hormone + arginine). The glycolipid profile was also evaluated.

RESULTS

GH deficiency occurred in 8/23 patients (34.7 %) of Group A and in 12/25 patients (48 %) of Group B. In addition, two patients, one in each group, showed evidence of central hypothyroidism. Patients with GH deficiency, especially in Group A, presented a higher frequency of visceral adiposity and adverse metabolic profile as compared to no-GH deficiency patients.

CONCLUSIONS

Patients examined at 1 year or several years from complicated mild TBI had a similarly high occurrence of isolated GH deficiency, which was associated with visceral adiposity and metabolic alterations. Our findings suggest that patients undergone complicated mild TBI should be evaluated for GH deficiency even after several years from trauma.

Oral glucose-stimulated growth hormone (GH) test in adult GH deficiency patients and controls: Potential utility of a novel test

CONTEXT

The diagnosis of adult GH deficiency requires confirmation with a GH stimulation test. Oral glucose (OG) administration affects GH secretion, initially decreasing and subsequently stimulating GH secretion.

OBJECTIVE

The aim of this study was to investigate the diagnostic efficacy and safety of a long OG test (LOGT) as a stimulus of GH secretion for the diagnosis of adult GH deficiency (AGHD).

DESIGN

Prospective experimental cross-sectional study.

SETTINGS

The study was conducted at the Endocrinology department of the University Hospital of a Coruña, Spain.

PARTICIPANTS AND METHODS

We included 60 (40 women) AGHD patients (15) and controls (45) paired 1:3, of similar age, sex and BMI. The area under the curve (AUC) and peak were calculated for GH. The Mann-Whitney test was used to compare the different groups. ROC curve analyses were used. p-Values<0.05 were considered as statistically significant.

INTERVENTIONS

The intervention consisted of orally administering 75g oral glucose administration; GH was obtained every 30min for a total of 300min.

MAIN OUTCOME MEASUREMENT

Peak GH area under receiver operating characteristic curve (ROC-AUC) following LOGT.

RESULTS

Peak GH (μg/L) levels were lower in the AGHD patients (0.26±0.09) than in the controls (4.00±0.45), p<0.001. After LOGT, with the ROC plot analysis the best peak GH cut-point was 1.0μg/L, with 100% sensitivity, 78% specificity, ROC-AUC of 0.9089 and 81.82% accuracy. There were no relevant adverse events during any of the LOGT.

CONCLUSIONS

The LOGT could be a cheap, safe, convenient and effective test for the diagnosis of AGHD.

Gender has to be taken into account in diagnosing adult growth hormone deficiency by the GHRH plus arginine test

OBJECTIVE

Data on the effect of gender on the interpretation of the GHRH plus arginine stimulation test (GHRH+ARG test) is controversial. We validated the GHRH+ARG stimulation test in control subjects and patients with organic or idiopathic pituitary disease and a suspicion of adult growth hormone deficiency (AGHD) using the Immulite 2000 XPi GH assay.

DESIGN

We studied 126 apparently healthy adults (median age 38.8years) and 34 patients with a suspicion of AGHD (median age 42.2years). Identification of AGHD with the GHRH+ARG test was investigated with commonly accepted BMI-related consensus cut-off limits for peak GH concentrations. Serum samples collected during the GHRH+ARG test were analysed for GH in 2014-2015. Serum IGF-1 concentrations were studied as a reference.

RESULTS

In 14 of 65 (22%) control males the GH peak value was below the BMI-related cut-off limits for GH sufficiency indicating a false diagnosis of AGHD. All control females had a normal GHRH+ARG response. Median peak GH response was significantly (p<0.001) higher in female (39.3μg/L) than in male controls (21μg/L). According to consensus cut-offs all but one young female patient had a deficient response compatible with a diagnosis of AGHD.

CONCLUSIONS

The GH response to stimulation by GHRH+ARG is gender-dependent, being lower in healthy males than in females. Gender should be considered when defining cut-off limits for peak GH concentrations in the GHRH+ARG test. The presently used BMI-related cut-off levels will lead to a significant misclassification of males as GH deficient.

Pituitary Hypoplasia

This article summarizes pituitary development and function as well as specific mutations of genes encoding the following transcription factors: HESX1, LHX3, LHX4, POU1F1, PROP1, and OTX2. Although several additional genetic defects related to hypopituitarism have been identified, this article focuses on these selected factors, as they have been well described in the literature in terms of clinical characterization of affected patients and molecular mechanisms of action, and therefore, are very relevant to clinical practice.

Sensitivity of various body indices and visceral adiposity index in predicting metabolic syndrome among Chinese patients with adult growth hormone deficiency

AIM

Adult growth hormone deficiency (AGHD) refers to decreased secretion of growth hormones in the adults, which is associated with increased clustering of conventional cardiovascular risk factors such as central obesity, insulin resistance and dyslipidemia. Metabolic syndrome (MetS), a recognized risk factor of cardiovascluar diseases, shares some clinical features. Given that the prevalence of MetS is on the rise in patients with AGHD, and that cardiovascular disease (CVD) is an important cause of morbidity and mortality in that population, the alternative, simple, non-invasive methods of assessing MetS among this population are needed. This study aims to determine the sensitivity of five anthropometric indices [Body mass index (BMI), Waist circumference (WC), Waist-to-hip ratio (WHR), Waist-to-height ratio (WHtR) and Visceral adiposity index (VAI)] in predicting metabolic syndrome in Chinese population-based patients with adult growth hormone deficiency.

MATERIALS AND METHODS

A total of 96 Chinese patients with adult growth hormone deficiency were included in this study. They were compared with equal number of apparently healthy persons with similar characteristics (matched with age and gender) to the previous group. Anthropometric measurements including weight, height, serum lipids indices, blood pressure (BP), fasting plasma glucose (FPG), WC were measured. BMI, WHR, WHtR, and VAI were calculated.

RESULTS AND DISCUSSION

AGHD patients with MetS had higher WC (91.00 ± 8.28 vs 78.01 ± 7.12), BMI (24.95 ± 2.91 VS 23.30 ± 2.80), WHR (0.92 ± 0.06 VS 0.87 ± 0.07), WHtR (0.53 ± 0.06 VS 0.47 ± 0.05), VAI [(5.59 (4.02, 7.55) VS 1.69 (0.87, 3.05)] levels in comparison to those without MetS. Meantime WC, BMI, WHR, WHtR, VAI was positively correlated to MetS components. ROC curve for participants with AGHD showed that VAI had the highest SS of 92% (BMI 0.812; WHR 0.706; WHtR 0.902; VAI 0.920, respectively) for prediction of MetS in AGHD. The optimal cutoff values for different adiposity markers in predicting MetS were as follows: WC (79.65), BMI (23.46); WHR (0.89); WHtR (0.54); VAI (2.29).

CONCLUSION

In conclusion, our study showed all adiposity measures of interest present themselves as easy and practical tools for use in population studies and clinical practice for evaluating MetS in AGDH and VAI was identified as the best in Chinese AGHD patients among them.

Hormonal Replacement in Hypopituitarism in Adults: An Endocrine Society Clinical Practice Guideline

OBJECTIVE

To formulate clinical practice guidelines for hormonal replacement in hypopituitarism in adults.

PARTICIPANTS

The participants include an Endocrine Society-appointed Task Force of six experts, a methodologist, and a medical writer. The American Association for Clinical Chemistry, the Pituitary Society, and the European Society of Endocrinology co-sponsored this guideline.

EVIDENCE

The Task Force developed this evidence-based guideline using the Grading of Recommendations, Assessment, Development, and Evaluation system to describe the strength of recommendations and the quality of evidence. The Task Force commissioned two systematic reviews and used the best available evidence from other published systematic reviews and individual studies.

CONSENSUS PROCESS

One group meeting, several conference calls, and e-mail communications enabled consensus. Committees and members of the Endocrine Society, the American Association for Clinical Chemistry, the Pituitary Society, and the European Society of Endocrinology reviewed and commented on preliminary drafts of these guidelines.

CONCLUSIONS

Using an evidence-based approach, this guideline addresses important clinical issues regarding the evaluation and management of hypopituitarism in adults, including appropriate biochemical assessments, specific therapeutic decisions to decrease the risk of co-morbidities due to hormonal over-replacement or under-replacement, and managing hypopituitarism during pregnancy, pituitary surgery, and other types of surgeries.

Eliciting an antibody response against a recombinant TSH containing fusion protein

Designing novel antigens to rise specific antibodies for Thyroid Stimulating Hormone (TSH) detection is of great significance. A novel fusion protein consisting of the C termini sequence of TSH beta subunit and a fusion sequence was designed and produced for rabbit immunization. Thereafter, the produced antibodies were purified and characterized for TSH detection. Our results indicate that the produced antibody is capable of sensitive and specific detection of TSH with low cross reactivity. This study underscores the applicability of designed fusion protein for specific and sensitive polyclonal antibody production and the importance of selecting an amenable region of the TSH for immunization.

IGF-I levels reflect hypopituitarism severity in adults with pituitary dysfunction

PURPOSE

To evaluate the utility of Insulin-like growth factor I (IGF-I) standard deviation score (SDS) as a surrogate marker of severity of hypopituitarism in adults with pituitary pathology.

METHODS

We performed a retrospective data analysis, including 269 consecutive patients with pituitary disease attending a tertiary endocrine clinic in 1990-2015. The medical files were reviewed for the complete pituitary hormone profile, including IGF-I, and clinical data. Age-adjusted assay reference ranges of IGF-I were used to calculate IGF-I SDS for each patient. The main outcome measures were positive and negative predictive values of low and high IGF-I SDS, respectively, for the various pituitary hormone deficiencies.

RESULTS

IGF-I SDS correlated negatively with the number of altered pituitary axes (p < 0.001). Gonadotropin was affected in 76.6 % of cases, followed by thyrotropin (58.4 %), corticotropin (49.1 %), and prolactin (22.7 %). Positive and negative predictive values yielded a clear trend for the probability of low/high IGF-I SDS for all affected pituitary axes. Rates of diabetes insipidus correlated with IGF-I SDS values both for the full study population, and specifically for patients with non-functioning pituitary adenomas.

CONCLUSIONS

IGF-I SDS can be used to evaluate the somatotroph function, as a valid substitute to absolute IGF-I levels. Moreover, IGF-I SDS predicted the extent of hypopituitarism in adults with pituitary disease, and thus can serve as a marker of hypopituitarism severity.

AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS AND AMERICAN COLLEGE OF ENDOCRINOLOGY DISEASE STATE CLINICAL REVIEW: A NEUROENDOCRINE APPROACH TO PATIENTS WITH TRAUMATIC BRAIN INJURY

OBJECTIVE

Traumatic brain injury (TBI) is now recognized as a major public health concern in the United States and is associated with substantial morbidity and mortality in both children and adults. Several lines of evidence indicate that TBI-induced hypopituitarism is not infrequent in TBI survivors and may contribute to the burden of illness in this population. The goal of this article is to review the published data and propose an approach for the neuroendocrine evaluation and management of these patients.

METHODS

To identify pertinent articles, electronic literature searches were conducted using the following keywords: "traumatic brain injury," "pituitary," "hypopituitarism," "growth hormone deficiency," "hypogonadism," "hypoadrenalism," and "hypothyroidism." Relevant articles were identified and considered for inclusion in the present article.

RESULTS

TBI-induced hypopituitarism appears to be more common in patients with severe TBI. However, patients with mild TBI or those with repeated, sports-, or blast-related TBI are also at risk for hypopituitarism. Deficiencies of growth hormone and gonadotropins appear to be most common and have been associated with increased morbidity in this population. A systematic approach is advised in order to establish the presence of pituitary hormone deficiencies and implement appropriate replacement therapies.

CONCLUSION

The presence of traumatic hypopituitarism should be considered during the acute phase as well as during the rehabilitation phase of patients with TBI. All patients with moderate to severe TBI require evaluation of pituitary function. In addition, symptomatic patients with mild TBI and impaired quality of life are at risk for hypopituitarism and should be offered neuroendocrine testing.