GH Response Research Articles

Abstract 2695: Transcriptomic profiling of human patients with acute myeloid leukemia reveals critical effects of growth hormone responsiveness on patient survival and mechanisms of tumor therapy resistance

Abstract Growth hormone (GH) has been reported to drive leukemia cell proliferation as early as 1977, while downstream effectors of the GH signaling pathway (i.e., insulin-like growth factor 1; IGF1) have more recently been widely implicated in the aggressive pathology and robust therapy resistance phenotypes of acute myeloid leukemia (AML). It is also known that patients with acromegaly (high levels of circulating GH and IGF1) develop AML at a significantly higher rate than the general population, while individuals with GH resistance remain completely resistant to all types of cancer. Despite all of the aforementioned evidence pointing to a critical role of GH in AML progression and prognosis, a detailed transcriptomic analysis of human patients is lacking. We aim to address this gap by thorough in silico studies aimed at revealing the nature and extent to which the GH axis can be suitable targeted in AML. Here, we present a summary of our analyses of clinical and transcriptomic data from 200 human patients with AML from The Cancer Genome Atlas database, using multiple bioinformatics software programs in the public domain. Our study revealed that GH receptor (GHR) is expressed more highly in AML than in normal myeloid cells, and a robust correlation exists between GH responsiveness and patient survival. A sex-specific profiling of the patient transcriptomic data identified critical pathways related to therapy resistance, extracellular matrix remodeling, metastasis, and immune evasion to be upregulated differentially in male and female AML patients with relatively elevated GHR expression compared to patients with relatively lower GHR expression. Furthermore, we identified microRNAs which are differentially expressed in AML patients with higher than median GHR expression. We validated these miRNAs to be effective indicators of disease progression and prognosis and can be valuable markers in liquid biopsy approaches. Acknowledgement: This work was supported in part by the State of Ohio’s Eminent Scholar Program that includes a gift from Milton and Lawrence Goll, by the AMVETS, and Ohio University’s Edison Biotechnology Institute. Citation Format: Emily Davis, Reetobrata Basu, John J. Kopchick. Transcriptomic profiling of human patients with acute myeloid leukemia reveals critical effects of growth hormone responsiveness on patient survival and mechanisms of tumor therapy resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2695.

GH Responsiveness Is not Correlated to IGF1 P2 Promoter Methylation in Children With Turner Syndrome, GHD and SGA Short Stature.

BackgroundThe methylation of IGF1 promoter P2 was reported to negatively correlate with serum IGF-1 concentration and rhGH treatment response in children with idiopathic short stature. These findings have not yet been confirmed.ObjectiveThis study aimed to determine IGF1 promoter P2 methylation in short children treated with rhGH and correlate clinical parameters with the methylation status. In addition, long-term stability of methylation during rhGH treatment was studied.DesignThis was a single tertiary center study analyzing clinical GH response and IGF-1 serum concentration changes in patients with GHD (n=40), SGA short stature (n=36), and Turner syndrome (n=16) treated with rhGH. Data were correlated to the methylation of two cytosine residues (-137, +97) of the P2 promoter of IGF1 in blood cells measured by pyrosequencing in 443 patient samples.ResultsBasal and stimulated IGF-1 concentrations, first year increment in height velocity and studentized residuals of a prediction model did not correlate to the methylation of -137 und +97 in IGF1 P2 promoter. The methylation of these two sites was relatively stable during treatment.ConclusionsThis study did not confirm IGF1 P2 promotor being a major epigenetic locus for GH responsiveness in patients treated with a normal dose of rhGH. Additional studies are warranted.

The cut-off limits of GH response to GHRH + arginine test related to body mass index for the diagnosis of adult GH deficiency: do we need to review our diagnostic criteria?

The cut-off limits of GH response to GHRH + arginine test related to body mass index for the diagnosis of adult GH deficiency: do we need to review our diagnostic criteria?

Association between overweight and growth hormone secretion in patients with non-functioning pituitary tumors.

IntroductionGrowth hormone (GH) deficiency (GHD) is often complicated by non-functioning pituitary tumors (NFPTs); however, its prevalence remains unclear because preoperative screening for GHD with provocative tests is not recommended. Accordingly, we attempted to clarify the characteristics of GHD in unoperated patients with NFPT.Materials and methodsWe retrospectively reviewed adult patients with non-functioning pituitary adenoma (NFPA) and Rathke’s cyst who underwent preoperative GH-releasing peptide-2 (GHRP-2) tests from January 2013 to December 2016. We investigated the association between peak GH response to GHRP-2 and background characteristics.ResultsAmong 104 patients (85 NFPA and 19 Rathke’s cysts), 45 (43%) presented severe GHD, as diagnosed using GHRP-2 tests. Body mass index (β = -0.210, P = 0.007), free thyroxine (β = 0.440, P < 0.001), and tumor height (β = -0.254, P < 0.001) were significant variables for determining the peak GH response to GHRP-2 in multiple regression analyses. Overweight (odds ratio, 3.86; 95% confidence interval, 1.02–14.66) was significantly associated with severe GHD after adjustment for age, sex, creatinine, free thyroxine, tumor height and clinical diagnosis. The regression slopes between tumor height and peak GH response to GHRP-2 significantly differed between overweight patients and non-overweight individuals, as determined by analysis of covariance (P = 0.040). In the 48 patients who underwent postoperative GHRP-2 tests, severe postoperative GHD was significantly more common in overweight patients than non-overweight individuals (100% vs. 48%, P < 0.001).ConclusionWe observed a negative synergistic effect between overweight and tumor size on GH secretion in patients with NFPTs, indicating that GH provocation tests for diagnosing underestimated GHD could be considered in overweight unoperated patients with large NFPTs.

Sleep deprivation prevents counterregulatory adaptation to recurrent hypoglycaemia

Aims/hypothesisAttenuated counterregulation after recurrent hypoglycaemia is a major complication of diabetes treatment. As there is previous evidence for the relevance of sleep in metabolic control, we assessed the acute contribution of sleep to the counterregulatory adaptation to recurrent hypoglycaemia.MethodsWithin a balanced crossover design, 15 healthy, normal-weight male participants aged 18–35 years underwent three hyperinsulinaemic–hypoglycaemic clamps with a glucose nadir of 2.5 mmol/l, under two experimental conditions, sleep and sleep deprivation. Participants were exposed to two hypoglycaemic episodes, followed by a third hypoglycaemic clamp after one night of regular 8 h sleep vs sleep deprivation. The counterregulatory response of relevant hormones (glucagon, growth hormone [GH], ACTH, cortisol, adrenaline [epinephrine] and noradrenaline [norepinephrine]) was measured, and autonomic and neuroglycopenic symptoms were assessed.ResultsSleep deprivation compared with sleep dampened the adaptation to recurrent hypoglycaemia for adrenaline (p=0.004), and this pattern also emerged in an overall analysis including adrenaline, GH and glucagon (p=0.064). After regular sleep, the counterregulatory responses of adrenaline (p=0.005), GH (p=0.029) and glucagon (p=0.009) were attenuated during the 3rd clamp compared with the 1st clamp, but were preserved after sleep deprivation (all p>0.225). Neuroglycopenic and autonomic symptoms during the 3rd clamp compared with the 1st clamp were likewise reduced after sleep (p=0.005 and p=0.019, respectively). In sleep deprivation, neuroglycopenic symptoms increased (p=0.014) and autonomic symptoms were unchanged (p=0.859).Conclusions/interpretationThe counterregulatory adaptation to recurrent hypoglycaemia is compromised by sleep deprivation between hypoglycaemic episodes, indicating that sleep is essential for the formation of a neurometabolic memory, and may be a potential target of interventions to treat hypoglycaemia unawareness syndrome.Graphical abstract

A GH Secretagogue Receptor Agonist (LUM-201) Elicits Greater GH Responses than Standard GH Secretagogues in Subjects of a Pediatric GH Deficiency Trial

Introduction: LUM-201 (ibutamoren, formerly MK-0677) is an orally administered GH secretagogue receptor agonist under development for treatment of pediatric growth hormone deficiency (PGHD). Methods: The GH response to a single dose of LUM-201 and to other GH secretagogues used for diagnosis of PGHD were compared in 68 pediatric subjects participating in a trial for growth hormone deficiency. Results: LUM-201 elicited greater GH responses than observed in GHD diagnostic tests with arginine, glucagon, clonidine, L-dopa, and insulin-induced hypoglycemia [median and interquartile ranges 15.0 ng/mL (3.5, 49) vs. 5.5 ng/mL (1.8, 7.6) (p < 0.0001)]. The difference between responses was greatest in subjects with higher baseline IGF-I concentrations and higher GH responses to standard GH stimuli. Conclusion: LUM-201 elicits greater GH responses than standard stimuli in subjects with higher peak GH in response to conventional testing and is potentially an orally administered treatment alternative to injectable rhGH in a subset of patients with adequate responses to an acute dose of LUM-201.

A COMPARISON OF L-DOPA AND CLONIDINE GROWTH HORMONE STIMULATION TESTS IN CHILDREN WITH SHORT STATURE

Aim: The purpose of this study was to compare the results of L-dopa and clonidine GH stimulation tests applied in children with short stature and to identify which of these tests should be primarily selected. Materials and Methods: The records of 68 patients aged between 2.5 and 16.6 years presenting to the pediatric endocrinology clinic with short stature and undergoing GH stimulation tests between September 2016 and February 2021 were evaluated retrospectively. Cases with GH levels &lt;10 ng/dl following the first GH stimulation test then underwent the other GH stimulation test. Thirty-four (50%) of the cases in the study consisted of individuals beginning with the clonidine test, while the other 34 (50%) started with the L-dopa test. Results: Thirty-five patients (51.5%) were girls and 33 (48.5%) were boys. Twenty-seven (79.4%) of the individuals in whom L-dopa was employed as the first test had insufficient GH responses, while a sufficient GH response could not be achieved in 18 cases (66.7%) with the clonidine test. Insufficient growth hormone responses were observed in 17 (50%) of the patients undergoing the clonidine test as the first test, and sufficient growth hormone response was also not achieved at the L-dopa test performed as the second test in 15 (88.2%) of these cases (p&lt; 0.001). A cut-off point of 8.9 ng/dl was determined for 50% sensitivity and 100% specificity for the L-dopa test, and a cut-off point of 9.76 for 88% sensitivity and 94% specificity for the clonidine test. Conclusion: GH stimulation tests performed to investigate GHD are laborious and time-consuming. The first stimulation test to be applied to differentiate GHD from ISS must therefore be well selected. The clonidine stimulation test, with higher sensitivity than but similar specificity to the L-dopa test, can be employed as the first test.

Molecular diagnosis for growth hormone deficiency in Chinese children and adolescents and evaluation of impact of rare genetic variants on treatment efficacy of growth hormone

BackgroundGrowth hormone is an effective therapy for growth hormone deficiency (GHD) but with a rather variable individual sensitivity. It is unclear whether rare genetic variants may contribute to the differential GH responsiveness. MethodsThe present study aims to investigate the molecular etiology of GHD in Chinese children and adolescents and evaluate the impact of rare variants on therapeutic efficacies of GH. ResultsTwenty-one rare heterozygous variant were classified as promising uncertain significance (n = 14), pathogenic (n = 5) or likely pathogenic (n = 2) for 21 of the 93 GHD patients. After GHD patients harboring these rare variants were excluded, inter-individual variability in the response to GH therapy obviously reduced and the negative correlation between initiation age of treatment and height SDS change became stronger in the group without rare variants. Among rare variants, 7 (likely) pathogenic variants (7.5%, 7/93) involved a total of 6 genes not only associated with GH secretion (PROKR2, LZTR1), but also growth plate chondrocyte signaling (ACAN, FBN1, COL9A1) or genetic syndromes (PTPN11). ConclusionsRare genetic variants are an important factor contributing to differential GH responsiveness and genetic testing should be factored into accurate diagnosis and treatment decision making in the future.Clinical Trial Registration Number: ChiCTR1900026510.

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

BackgroundThe 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.MethodsEighty 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.ResultsAn 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.ConclusionThis 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.

SNORD116 and growth hormone therapy impact IGFBP7 in Prader–Willi syndrome

PurposePrader–Willi syndrome (PWS) is a neurodevelopmental disorder with hypothalamic dysfunction due to deficiency of imprinted genes located on the 15q11-q13 chromosome. Among them, the SNORD116 gene appears critical for the expression of the PWS phenotype. We aimed to clarify the role of SNORD116 in cellular and animal models with regard to growth hormone therapy (GHT), the main approved treatment for PWS. MethodsWe collected serum and induced pluripotent stem cells (iPSCs) from GH-treated PWS patients to differentiate into dopaminergic neurons, and in parallel used a Snord116 knockout mouse model. We analyzed the expression of factors potentially linked to GH responsiveness. ResultsWe found elevated levels of circulating IGFBP7 in naive PWS patients, with IGFBP7 levels normalizing under GHT. We found elevated IGFBP7 levels in the brains of Snord116 knockout mice and in iPSC-derived neurons from a SNORD116-deleted PWS patient. High circulating levels of IGFBP7 in PWS patients may result from both increased IGFBP7 expression and decreased IGFBP7 cleavage, by downregulation of the proconvertase PC1. ConclusionSNORD116 deletion affects IGFBP7 levels, while IGFBP7 decreases under GHT in PWS patients. Modulation of the IGFBP7 level, which interacts with IGF1, has implications in the pathophysiology and management of PWS under GHT. [Display omitted]

Characteristics and treatment responsiveness of patients with acromegaly and a paradoxical GH increase to oral glucose load.

We aimed to investigate the clinical, biochemical, histological and radiological characteristics as well as the response to somatostatin analogs (SSA) in a large cohort of acromegaly patients with a paradoxical GH response (PR) to oral glucose tolerance test (OGTT). Retrospective study. Of 110 patients with acromegaly included in our study, 30 (PR+; 27%) had a paradoxical GH increase of more than 25% relative to basal GH levels during OGTT. At diagnosis, PR+ patients were older than PR- patients (52 ± 16 years vs 44 ± 14 years, P < 0.05) and had smaller pituitary tumors (40% microadenomas vs 19%, P < 0.05), which were less often invasive (17% vs 35%, P < 0.05), overall more secreting (insulin-like growth factor-1 (IGF-1)/tumoral surface: 2.35 ULN/cm2 (0.28-9.06) vs 1.08 (0.17-7.87), P = 0.011), and more often hypointense on T2-weighted MRI (92% vs 48%, P = 0.001). While the rate of remission after surgery was similar in the two groups (69%), a better response to SSA treatment was observed in PR+ patients, either before (IGF-1 reduction of > 50% after 3-6 months in 77% vs 49%, P = 0.023) or after surgery (normalization of IGF-1 in 100% vs 44%, P = 0.011). Our study demonstrates that in acromegaly, a paradoxical GH increase during OGTT is associated with particular features of somatotroph adenomas and with a better prognosis in terms of response to SSA.

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

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

LUM-201 Elicits Greater GH Response than Standard GH Secretagogues in Pediatric Growth Hormone Deficiency

Presentation Type: OralScience Type and Topic: Clinical Trial Introduction: LUM-201 (ibutamoren, formerly MK-0677) is an orally administered GH-secretagogue that stimulates the GH secretagogue receptor (GHSR1a) in the hypothalamus and pituitary. LUM-201 is in development for long-term use in a subset of PGHD patients with moderate growth deficiencies. A diagnosis of PGHD is confirmed by low GH responses to standard GH secretagogues (clonidine, arginine, L-dopa, glucagon, insulin) so it is somewhat counter-intuitive to suggest that children who cannot respond to one GH secretagogue might have favorable responses to LUM-201. Objective: To determine if LUM-201 stimulates GH responses differently than standard GH secretagogues. Methods: 68 naïve-to-treatment, prepubertal children with GHD received two standard GH stimulation tests and a test with a single 0.8 mg/kg dose of LUM-201. The 68 subjects included 20 girls and 48 boys. The median (interquartile range) age was 9.2 years (7.2,10.8), bone age 6.0 years (4.5, 7.9), height SDS -3.3 (-4.5, -2.5), pretreatment height velocity 4.0 cm/y (3.2, 4.6), and baseline IGF-1 51 ng/mL (24,111). Results: The median (interquartile range) of maximal GH response to single dose LUM-201 was 15.0 ng/mL (3.5, 49) and to various pairs of standard stimuli was 5.4 ng/mL (1.8-7.6) (p< 0.00001). The median (IQR) for the difference between GH responses to LUM-201 and standard stimuli was 9.6 ng/ml (1.9, 42). In a multivariate analysis (r2 =0.73) differential GH increased with higher values of baseline IGF-I (p < 0.00001) and standard GH stimulation test (p = 0.047) but was not influenced by age (p = 0.16), sex (p = 0.28), baseline HV (p = 0.24), age-bone age differences (p = 0.33) or height-SDS (p = 0.75). Conclusion: In GHD children, the GH response to single dose LUM-201 greatly exceeds that observed with standard GH testing agents. The difference is greatest among patients with higher baseline values of IGF-I and higher GH responses to standard stimuli. The synergistic actions of LUM-201 on the physiological mechanisms regulating GH release explain why GH responses are greater in response to LUM-201 compared to traditional tests used to diagnose PGHD. Key words: LUM-201, GH deficiency, GH secretagogues, pediatrics, stimulation tests, short stature, pituitary, hypothalamus

Two Cases of Anti-PIT-1 Hypophysitis Exhibited as a Form of Paraneoplastic Syndrome

Abstract Background: Anti-pituitary-specific transcription factor 1 (PIT-1) hypophysitis (anti-PIT-1 antibody syndrome) is a newly defined clinical entity, demonstrating an adult-onset hypopituitarism, and is a thymoma-associated autoimmune disease characterized by acquired GH, PRL, and TSH deficiencies due to autoimmunity against PIT-1 (1, 2). This disease is defined by an acquired specific GH, PRL, and TSH deficiencies and the presence of circulating anti-PIT-1 antibody and/or PIT-1-specific T cells (2). As the etiology, ectopic expression of PIT-1 in thymoma plays a causal role in the development of the disease (3); however, it is unknown whether this disease is involved in other conditions. Here, we report two PIT-1 hypophysitis cases, exhibiting as a form of paraneoplastic syndrome with malignancies other than thymoma. Clinical Case: A 79-year-old woman (case 1) and an 86-year-old man (case 2) were referred to us on suspicion of anti-PIT-1 hypophysitis because of acquired GH, PRL, and TSH deficiencies. In both patients, the endocrinological evaluation revealed extremely low basal levels and blunted responses of GH, PRL, and TSH to the provocative stimuli. In contrast, the secretion of HPA and HPG axis were preserved in both patients. Magnetic resonance imaging of the pituitary gland showed slight atrophy in case 1 and normal size in case 2. Interestingly, computed tomography imaging revealed no evidence for thymomas in both patients. On the other hand, case 1 was complicated with diffuse large B-cell lymphoma (DLBCL) of the bladder with multiple bilateral cervicals, axillary, para-aorta, and internal and external peri iliac lymphadenopathies. Case 2 was diagnosed with malignancy with multiple metastases of unknown origin with para-aortic and para-gastric lymphadenopathies, and vertebral body infiltrates. Because circulating anti-PIT-1 antibody was detected, both patients were diagnosed with anti-PIT-1 hypophysitis. Circulating PIT-1-reactive T cells were detected in case 1 using Enzyme-Linked Immunospot assay. Interestingly, the PIT-1 protein was ectopically expressed in the DLBCL tissue of case 1, while DLBCL tissues derived from control patients without anti-PIT-1 hypophysitis were negative for PIT-1. In case 2, the materials were not available because of the situation of the best supportive care. Conclusion: These data show that anti-PIT-1 hypophysitis is associated not only with thymoma but also with other malignancies. Additionally, the ectopic expression of PIT-1 in the DLBCL tissues and presence of PIT-1- reactive T cells suggested that the underlying mechanisms were similar to those observed in thymoma (3). Thus, anti-PIT-1 hypophysitis is defined as a form of paraneoplastic syndrome. Reference: (1) J Clin Invest. 2011;121(1):113-119., (2) Endocr Rev. 2020;41(2)., (3) Sci Rep. 2017;7:43060.

The Arginine Stimulation Test Allows Rapid Diagnosis of Central Diabetes Insipidus in Children

Introduction: Water deprivation testing (H2O-dep) is usually required to distinguish between diabetes insipidus (DI) and primary polydipsia (PP) in children with polydipsia-polyuria syndrome (PP-S). The H2O-dep is challenging for children and their families. The prolonged fasting may provoke hypoglycemia and dehydration, particularly in younger children. Serum concentrations of copeptin (COP) (a surrogate marker of AVP, which is easier to measure by a robust assay), are known to increase in adults and children undergoing IV arginine (ARG) stimulation testing (ASTT). Objective: To test the hypothesis that COP levels during ASTT would differentiate between DI and PP. Methods: Serum COP responses to ARG were measured in 13 healthy short children being tested for GH deficiency (controls); and in 4 patients with PP-S. Arginine-HCl (500 mg/Kg) was infused IV from 0 to 30 min, with blood sampling at 0, 15, 30, 45, 60 min; seven of 13 controls also received clonidine PO (150 mcg/m2) at 0 min. COP was measured with a 2-site immunometric assay (BRAHMS Platform, Quest Diagnostics). Results: A-Controls. As the COP values at each time point were similar in the ARG and ARG-Clonidine controls, the data from both groups were combined. COP peaked at 45-60 min post ARG in the 13 controls. COP (Mean+SD; pMol/l)) increased from 9.7+4.3, (range 3-17) to a peak of 12.4+5.0 (range 6-21) at 60 min; Δ% increase 47+50 % (range 0-133). The peak COP values on ASTT showed no correlation with subjects’ age or peak GH response. Results B: Subjects with PP-S: On the basis of H2O-dep, MRI findings, and long-term response to desmopressin therapy, 3 of 4 children were diagnosed with central DI, and 1 with PP. Abbreviations: S[Osm], U[Osm]= serum, urine osmolality (mOsm/Kg); values obtained at the end of the H2O Dep: Subject 1. 3 y-old male, diagnosed with PP. After H2O-dep S[Osm] / U[Osm] 286 / 615. On ASTT COP (base vs. peak) 15 vs.116 pMol/l. Subject 2. 8 y-old male, diagnosed with central DI with Langerhans cell histiocytosis (LCH). MRI: absent bright spot. After H2O-dep S[Osm] / U[Osm] 318/202; On ASTT COP (base vs. peak) 2 vs. 2 pMol/l. Subject 3. 2 y-old male. diagnosed with central DI, possible LCH; MRI: absent bright spot. No H2O-dep; On ASTT COP (base vs. peak) 3 vs 3 pMol/l. Subject 4. Male, 3 y-old. Diagnosed with partial DI with LCH. MRI: absent bright spot. After H2O-dep S[Osm] / U[Osm] 297/569. On ASTT COP (base vs. peak) 5 vs. 6 pMol/l. Comment: In all DI patients, COP concentrations remained flat in the ASTT, at 2-3 pmol/L in 2 subjects with complete DI, and 5-6 pmol/L in 1 subject with partial DI. The latter response overlapped with that of 1 of 13 control subjects. Conclusions: These preliminary data support the hypothesis that ASTT is an easy, minimally invasive test, valuable for differentiating the etiology of PP-S in children. However, patients with partial DI may have low-normal COP responses at ASTT that overlap with values in normal children.

Clinical and Biochemical Phenotype of Indian Children with Different Types of Idiopathic Growth Hormone Deficiency and their Association with Pituitary Height on MRI.

Background and Objectives:Differentiation of growth hormone deficiency (GHD) into various types has been made based on peak stimulated growth hormone levels and other hormone axis involvement. The data regarding how this classification is associated with variation in clinical and biochemical phenotype and how these findings associate with pituitary morphology remains sparse, especially in the Indian population. Therefore, we aimed to ascertain the differences in the pattern of auxological, clinical features including pituitary hypoplasia, and endocrinological profile among patients with severe GHD, partial GHD, and MPHD in the Indian population and to evaluate the association of pituitary height with various clinical and hormonal parameters.Materials and Methods:We conducted a cross-sectional study in 100 patients with idiopathic GHD. Patients were grouped into severe GHD, partial GHD, and MPHD to observe the differences in clinical, biochemical, and MRI findings. The pituitary height findings were correlated clinical and biochemical presentation.Results:MPHD subjects had a significantly higher frequency of breech delivery, neonatal jaundice, neonatal hypoglycemia, and micropenis. A significant difference was observed in the chronological age, bone age retardation (CA-BA), height SDS, weight SDS, peak GH response, IGF-1, IGF-1 SDS, and prevalence of pituitary hypoplasia, pituitary height, and pituitary height SDS among these three groups. In the composite population of GHD, pituitary height SDS was correlated with peak GH, basal IGF-I SDS, and body height SDS.Conclusion:The clinical and biochemical phenotype differs significantly among the various types of GHD. Pituitary height correlates with these findings and is helpful in further assessment of these patients.

Can plasma antioxidants prevent DNA damage in oxidative stress condition induced by growth hormone deficiency? A pilot study.

Adult growth hormone deficiency (GHD), a condition characterized by increased oxidative stress, is related to augmented cardiovascular, metabolic and oncological risk. A case-control observational study has been performed to evaluate DNA oxidative damage analysing the production of thymidine-glycol in lymphocytes and its correlation with plasma antioxidant levels, evaluated as Total Antioxidant Capacity (TAC). GHD was diagnosed using GHRH 50μg iv+arginine 0,5 g/Kg test, with peak GH response <9 μg/L when BMI was <30 kg/m2 or <4 μg/L when BMI was >30 kg/m2. Three groups were identified: total GHD (n = 16), partial GHD (n = 11), and controls (n = 12). Thymidine-glycol, TAC and IGF-1 have been determined respectively in lymphocytes, plasma and serum samples. When considering thymidine-glycol, we found a significant difference between total vs partial GHD and controls. Unexpectedly thymidine-glycol was lower in total GHD, also accompanied with a significant increase in plasmatic TAC. Our results showed that in adult GHD condition, the production of antioxidant species, in response to increased oxidative stress, could exert a protective effect on thymidine-glycol formation, and consequently on DNA intracellular damages. This pilot study could be inserted in the complex scenario of oxidative damage of GHD, a subtle, yet poorly defined condition, worthy of further insights.

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

ContextRecombinant 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.ObjectivesEvaluate 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.DesignData on children with GHD were analyzed in a legacy data base (GeNeSIS data).Participants514 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 MeasuresChildren 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.ResultsCohorts 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.ConclusionsThe combination of peak GH to GH stimulation testing and baseline IGF-I concentration are predictive enrichment markers for annualized HV responses to rhGH therapy.

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.

Transcriptome profiling of insulin sensitive tissues from GH deficient mice following GH treatment.

Most studies that have examined the transcriptional response to GH have been performed with a single tissue. Thus, the current study performed RNASeq across three insulin-sensitive tissues of GH-treated GH deficient (GHKO) mice. GHKO mice were injected with recombinant human GH (hGH) or vehicle daily for 5 days and adipose, liver, and muscle tissues were collected 4 h after the final injection. RNA was isolated from the tissues and sequenced. Genes that were differentially expressed between GH and vehicle treatments were further analyzed. Enrichment analysis and topology-aware pathway analysis were performed. GHKO mice treated with hGH had expected phenotypic alterations, with increased body, fat, fluid, liver, and muscle mass, and increased serum IGF-1 and insulin. 55 Genes were differentially expressed in all three tissues, including the canonical GH targets Igf1, Igfals, and Cish. Enrichment analysis confirmed the canonical GH response in select tissues, such as cell proliferation, metabolism, and fibrosis. The JAK/STAT pathway was the only pathway significantly altered in all three tissues. As expected, GH caused expression changes of many known target genes, although new candidate GH targets were identified. Liver and muscle appear to be more GH sensitive than adipose tissue due to the larger number of DEG and pathways significantly altered, but adipose still has a characteristic GH response. The diversity of changes uncovered in all three tissues after 5 days of GH treatment highlights the multiplicity of GH's effects in its target tissues.