Pragmatic Evaluation of Growth Hormone Stimulation Tests in Short Stature.

Introduction: To assess the performance of growth hormone stimulation tests (GHSTs) in the evaluation of short stature. Methods: It was a single-centre retrospective study carried out in children evaluated for short stature between January 2005 to March 2020. The clonidine stimulation test (CST) and glucagon stimulation test (GST) were used to assess growth hormone (GH) reserve (GST was performed only when peak GH levels were between 5 to ≤10 ng/mL on CST). A GH level of <5 ng/mL on CST or ≤10 ng/ml on both was used to corroborate GH deficiency. Results: A total of 556 children were eligible for this study. The mean (SD) age was 12.9 (3.5) years, and 66.3% were male. The peak GH level [median (IQR)] was 5.50 ng/ml (1.90 - 7.50) on CST (at 60 minutes) and 7.45 ng/ml (2.15 - 10.77) on GST (at 120 minutes). On restricting sampling to two time points, the false positive rate was 13.6% on CST (60, 90 minutes) and 11.5% on GST (120, 150 minutes). Similarly, restricting to three time points was associated with a false positive rate of 8.5% on CST (60, 90, 120 minutes) and 3.8% on GST (90, 120, 150 minutes). Using the treating clinician-determined diagnosis of GHD as a reference standard, the optimal cut-off of peak GH on CST was 7.79 ng/ml (sensitivity: 83.8%; specificity: 89.4%). Conclusion: Restricting the GH sampling to fewer time points is associated with an increase in the false positivity rate (FPR).

Evolving growth hormone deficiency: proof of concept.

Introduction: We present the evolution of GHD in adolescent males with persistent growth failure, in whom the diagnosis was established after a second GH stimulation test (GST). Methods: We performed a retrospective chart review of children who presented for short stature (height less < 2SD for mean/mid-parental height) and/or growth failure (sustained growth velocity < 0 SD) to pediatric endocrinology at Mount Sinai Kravis Children's Hospital, New York and who had 2 GSTs. Data collected from electronic medical records were analyzed using SPSS v28.0. Results: Of 53 patients included, 42 were males. Average GH peak on initial GST was 15.48 ± 4.92 ng/ml, at 10.07 ± 2.65 years, mean height -1.68 ± 0.56SD(28% had <2SD), IGF-1 -1.00 ± 0.88SD. After 2.23 ± 1.22 years, at 12.04 ± 2.41years, height SDs decreased to -1.82 ± 0.63SD and IGF-1 was -1.08 ± 0.84SD. At repeat GST, average GH peak was 7.59 ± 2.12 ng/dL, with 36% ≤7 ng/dl and 32% in puberty. 12 males reached adult height of 0.08 ± 0.69 SD with a mean height gain of 1.83 ± 0.56SD(p<0.005), IGF-1 of -1.15 ± 0.81SD after 4.64 ± 1.4 years of GH. Conclusion: We offer evidence for Evolving Growth Hormone Deficiency (EGHD) through repeat GST in children with persistent growth slowdown, even with pubertal progression; emphasizing the need for careful longitudinal follow-up to make accurate diagnosis.

Acute Effects of Growth Hormone on the Cellular Immunologic Landscape in Pediatric Patients.

INTRODUCTION: Growth hormone (GH) and the immune system have multiple bidirectional interactions. Data about the acute effects of GH on the immune system are lacking. The objective of our study was to evaluate the acute effects of GH on the immune system using time-of-flight mass cytometry. METHODS: This was a prospective study of pediatric patients who were being evaluated for short stature and underwent a GH stimulation test at a tertiary care center. Blood samples for immunologic markers, i.e., complete blood count (CBC) and time of flight mass cytometry (CyTOF), were collected at baseline (T0) and over the course of three hours (T3) of the test. Differences in immune profiling in patients by timepoint (T0, T3) and GH response (growth hormone sufficient (GHS) versus growth hormone deficient (GHD)) were calculated using a two-way ANOVA test.  Results: A total of 54 patients (39 boys and 15 girls) aged five to 18 years were recruited. Twenty-two participants tested GHD (peak GH <10 ng/ml). The CyTOF analysis showed a significant increase from T0 to T3 in granulocyte percentage, monocyte count, and dendritic cell (DC) count; in contrast, a significant decrease was seen in T lymphocytes (helper and cytotoxic) and IgD+ B lymphocytes. The CBC analysis supported these findings: an increase in total white blood cell count, absolute neutrophil count, and neutrophil percentage; a decrease in absolute lymphocyte count, lymphocyte percentage, absolute eosinophil count, and absolute monocyte count. No significant differences were found between CBC/CyTOF measurements and GH status at either time. CONCLUSIONS: This study provides the first high-resolution map of acute changes in the immune system with GH stimulation. This implies a key role for GH in immunomodulatory function.

Russell-Silver Syndrome With Growth Hormone Deficiency.

Russell-Silver syndrome (RSS) is a rare genetic disorder characterized by intrauterine growth restriction (IUGR), postnatal growth failure, and distinctive dysmorphic features. We present a case of a four-year-old male presenting with a slow growth velocity with a history of IUGR and surgical interventions, exhibiting classic RSS features. Laboratory investigations revealed low insulin-like growth factor 1 (IGF-1) and low growth hormone (GH) levels on stimulation tests. Clinical exome sequencing revealed a de novo mutation in the insulin-like growth factor 2 (IGF2) gene. Additionally, a variant of uncertain significance in the DHX37 gene was noted in the patient and the asymptomatic father. After genetic counseling, recombinant GH therapy was initiated. This case underscores the genetic complexity of RSS and highlights the importance of early diagnosis, genetic testing, and multidisciplinary management in optimizing outcomes for patients with RSS.

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

Introduction: Growth hormone stimulation tests (GHST) remain the cornerstone for diagnosing growth hormone deficiency (GHD), yet they can be lengthy and costly. We aimed to examine whether the combined clonidine and glucagon stimulation test (CGST) and l-dopa and glucagon stimulation test (LDGST) can be shortened without compromising the test's specificity. Material and methods: We retrospectively analyzed the baseline characteristics, auxological and laboratory data of children with short stature who had undergone a CGST and an LDGST for GHD. We compared the diagnostic accuracy for the standard test and shortened test, eliminating time points of 0 and 210 min. Results: We reviewed 830 charts (8.17 ± 2.92 years old; 56.27% males), with 431 (57.0%) children in the CGST group, and 38 (51.35%) in the LDGST group who tested negative for GHD. The peak and maximum GH levels occurred at the 60-min time point for both the CGST and LDGST. Eliminating the 0-min time point was the only time that did not affect the specificity of the CGST, with a false-positive rate of 2 (2.99%), specificity of 0.99 (0.99-0.99), and p value of 0.25. Eliminating the 0- and 210-min time points did not affect the specificity of the LDGST, with a false-positive rate of 2 (5.26%), specificity of 0.95 (0.95-0.95), and p value of 0.24. Conclusions: We concluded that 0-min time point could be eliminated without compromising the combined GHST diagnostic value, thus resulting in cost reduction. Larger studies are needed for the combined LDGST to explore whether the 30- and 210-min time points could be eliminated, thus resulting in cost and time savings.

Late-Onset Isolated Growth Hormone Deficiency.

Two male patients, who presented at 13.5 and 13.9 years of age with growth failure and short stature, were ultimately diagnosed with isolated growth hormone deficiency (GHD). Patient 1 was first evaluated when his height declined from -0.67 SD to -1.3 SD. He had a peak growth hormone (GH) concentration to GH stimulation test (GHST) of 16.9 ng/mL (16.9 µg/L) and remained untreated. As puberty advanced, his height decreased further to -1.65 SD. A second GHST while his serum testosterone was 79 ng/dL (2.74 nmol/L) had a peak GH of 5.4 ng/mL (5.4 µg/L), consistent with GHD. He was treated with GH for 4.8 years and reached adult height of 180.5 cm (0.57 SD), gaining 2.22 SDS. Patient 2, height -2.63 SD, had an unstimulated peak GH concentration of 19 ng/mL (19 µg/L). As puberty advanced, his height decreased further to -2.96 SD. Repeat peak GH concentration was 9.2 ng/mL (9.2 µg/L) when serum testosterone was 83.9 ng/dL (2.91 nmol/L). GH treatment resulted in rapid increase of height velocity from 1.8 cm/year to 11.3 cm/year in 6 months, consistent with GHD. Both patients demonstrate that GHD may develop over time and cannot be excluded by a single GHST. Longitudinal monitoring of children with poor growth as puberty progresses is essential to uncover GHD.

Growth Hormone Treatment in Children with Perthes Disease and Growth Hormone Deficiency: A Case Report and Literature Review.

BACKGROUND: Perthes disease is an idiopathic femoral head necrosis disease in children. Although it is believed that the prognosis after surgery within 5 years of age is good, there are very few reports in the literature regarding concurrent growth hormone deficiency and the outcome of growth hormone treatment. We retrospectively analyzed and summarized the clinical data of patients with Perthes disease and GHD in a child treated with rhGH for four years. CASE PRESENTATION: We reported the case of an 11.9-year-old boy diagnosed with "Perthes disease" at 2.7 years. He underwent surgery at the age of 4.8 years and recovered well. At 6.7 years old, he was admitted for "slow growth in height for more than four years." Physical examination demonstrated severe short stature with a height of 108.8 cm (< 3rd percentile, -2.45 standard deviation (SD)). The major abnormalities observed in the auxiliary examinations included low insulin-like growth factor-1 (IGF-1) (-1.73SD) and low GH peak levels (< 5 µg/L) in the growth hormone stimulation test. A diagnosis of complete GHD was confirmed, and low-dose rhGH treatment was administered. After four years of rhGH treatment, his height reached 152.3 cm (50th-75th percentile, + 0.29 SD). The annual growth rate was approximately 9.1 cm per year, and the curative effect was significant. No adverse reactions were observed during the treatment. CONCLUSION: The benefits of rhGH in children with Perthes disease and GHD may outweigh its risks. However, its safety requires long-term follow-up evaluation.

The Influence of Body Mass Index on the Growth Hormone Peak Response regarding Growth Hormone Stimulation Tests in Children.

INTRODUCTION: Several studies have analyzed the association between the maximal growth hormone serum level obtained during a growth hormone stimulation test (GHMax) and the body mass index-standard deviation score (BMI-SDS). However, as sample sizes were quite small, our study aimed to analyze the association between GHMax and BMI-SDS within a large cohort of 991 children. Further, we investigated other influencing factors, like test type, age, sex, puberty, and preterm birth. METHODS: Children with short stature (height <10th percentile) received growth hormone stimulation tests with arginine or glucagon at the Department of Paediatric Endocrinology of the University of Leipzig Medical Center. The study population included a total of 1,438 tests (633 tests on girls, 805 tests on boys), with the majority consisting of prepubertal children (tests = 1,138). The mean age at testing was 7.74 years. Analyses were carried out on the entire cohort as well as stratified by test types. We performed univariate and multivariate analyses using linear mixed-effect models to assess the effects on GHMax. RESULTS: GHMax and BMI-SDS were significantly negatively associated with an effect size of ß = -1.10 (p < 0.001), independent from the test type. The GHMax values were significantly (p < 0.001) higher for glucagon (mean value: 9.65 ng/mL) than those for arginine tests (mean value: 8.50 ng/mL). Age, sex, premature birth, and puberty were not significantly related to GHMax values. CONCLUSION: We confirmed the negative association between GHMax and weight status of short children found in previous studies. Therefore, considering BMI-SDS may be helpful in the assessment of growth hormone stimulation tests in short-statured children, but it should not be the determining factor for a treatment decision.

Sex steroid priming in short stature children unresponsive to GH stimulation tests: Why, who, when and how.

Despite decades of experience, the diagnosis of growth hormone deficiency (GHD) remains challenging, especially in peripubertal children. Failure to respond to GH stimulation tests (GHSTs) is needed to confirm GHD, but long-standing controversies regarding the number of tests needed and the interpretation of GH peaks are still a matter of debate worldwide. Diagnostic workup is even more problematic in short children with slow growth and delayed sexual development: they often exhibit low GH peaks under GHST, which often normalize as puberty progresses. Consequently, this transient suboptimal response to GHST may result in GH overtreatment, carrying both health and economic concerns. Considering the complex and bound link between GH axis and sex steroids, the use of sex steroid priming prior to GHST might be helpful in peripubertal setting. However, its use is still controversial. There is no consensus regarding patient selection, timing, dose, and preparation of sex steroids. In this review, we aim to overview the use of sex steroid priming in clinical practice, highlighting the need to develop appropriate guidelines in order to overcome diagnostic pitfalls in peripubertal age.

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

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

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

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

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

OBJECTIVE: To evaluate the variability of growth hormone stimulation tests results and factors affecting it in short children suspected of having growth hormone deficiency. DESIGN: The cohort included patients with short stature suspected of having growth hormone deficiency, and who underwent a second stimulation test, after the first stimulation test was positive. Testing was done at a single center from May 2014 to October 2017. Patients' weight, height, age, sex, stimulating agents and test results were recorded. RESULTS: The study population comprised 200 patients, 108 males and 92 females, average age 9.2 years (2.2-16.6 years). The average peak growth hormone was 5.2 µg/L and 7.8 µg/L in the first and second tests respectively and the concordance rate was 56.5%. The probability of a second positive test was increased if the peak growth hormone level in the first test was below 5 µg/L. In the second test, Clonidine and Glucagon led to higher peak growth levels than Arginine with averages of 9.02, 9.97 and 6.88 µg/L respectively. Younger children and children with higher BMI SDS only had lower peaks of growth hormone in the second test. The effect of height SDS on peak growth hormone levels was equivocal. CONCLUSION: The reproducibility rate of GH simulation tests in our study was low. A few factors may affect the peak levels of growth hormone in the second test, the most prominent being the peak of growth hormone in the first test.

GHD Diagnostics in Europe and the US: An Audit of National Guidelines and Practice.

INTRODUCTION: Almost 20 years after the first international guidelines on the diagnosis and treatment of GHD have been published, clinical practice varies significantly. The low accuracy of endocrine tests for GHD and the burden caused by ineffective treatment of individual patients were strong motives for national endocrine societies to set up national guidelines regarding how to diagnose GHD in childhood. This audit aims to review the current state and identify common changes, which may improve the diagnostic procedure. METHODS: A group of eight German pediatric endocrinologists contacted eight pediatric endocrinologists from Spain, France, Poland, the UK, the Netherlands, Denmark, Italy, and the US. Each colleague responded as a representative for the own country to a detailed questionnaire containing 22 open questions about national rules, guidelines, and practice with respect to GHD diagnostics and GH prescription. The results were presented and discussed in a workshop and then documented in this study which was reviewed by all participants. RESULTS: National guidelines are available in 7 of 9 countries. GH is prescribed by pediatric endocrinologists in most countries. Some countries have established boards that review and monitor prescriptions. Preferred GH stimulation tests and chosen cutoffs vary substantially. Overall, a trend to lowering the GH cutoff was identified. Priming is becoming more popular and now recommended in 5 out of 9 countries; however, with different protocols. The definition of pretest-conditions that qualify the patient to undergo GH testing varies substantially in content and strictness. The most frequently used clinical sign is low height velocity, but definition varies. Height, IGF-1, and bone age are additional parameters recommended in some countries. CONCLUSIONS: GHD diagnostics varies substantially in eight European countries and in the US. It seems appropriate to undertake further efforts to harmonize endocrine diagnostics in Europe and the US based on available scientific evidence.

The prevalence and volumetry of pituitary cysts in children with growth hormone deficiency and idiopathic short stature.

Background Pituitary cysts have been speculated to cause endocrinopathies. We sought to describe the prevalence and volumetry of pituitary cysts in patients with growth hormone deficiency (GHD) and idiopathic short stature (ISS). Methods Six hundred and eighteen children evaluated for growth failure at the Division of Pediatric Endocrinology at New York Medical College between the years 2002 and 2012, who underwent GH stimulation testing and had a brain magnetic resonance imaging (MRI) prior to initiating GH treatment were randomly selected to be a part of this study. High resolution MRI was used to evaluate the pituitary gland for size and the presence of a cyst. Cyst prevalence, cyst volume and percentage of the gland occupied by the cyst (POGO) were documented. Results Fifty-six patients had a cyst, giving an overall prevalence of 9.1%. The prevalence of cysts in GHD patients compared to ISS patients was not significant (13.5% vs. 5.7%, p=0.46). Mean cyst volume was greater in GHD patients than ISS patients (62.0 mm3 vs. 29.4 mm3, p=0.01). POGO for GHD patients was significantly greater (p=0.003) than for ISS patients (15.3%±12.8 vs. 7.1%±8.0). Observers were blinded to patient groups. Conclusions GHD patients had a significantly greater volume and POGO compared to ISS patients. This raises the question of whether cysts are implicated in the pathology of growth failure.

The Relationship between Subnormal Peak-Stimulated Growth Hormone Levels and Auxological Characteristics in Obese Children.

CONTEXT: The hypothesis that obese children are overdiagnosed with growth hormone deficiency (GHD) has not been adequately investigated in the context of adiposity-related differences in auxology. AIM: To investigate the differences in auxological parameters between short, prepubertal, obese children, and normal-weight peers who underwent growth hormone stimulation testing (GHST). HYPOTHESIS: Over-weight/obese children with GHD [peak growth hormone (GH) < 10 µg/L] will have higher values for growth velocity (GV) standard deviation score (SDS), bone age minus chronological age (BA - CA), and child height SDS minus mid-parental height (MPTH) SDS when compared to normal-weight GHD peers. SUBJECTS AND METHODS: A retrospective review of anthropometric and provocative GHST data of 67 prepubertal, GH-naïve children of age 10.21 ± 2.56 years (male n = 45, age 10.8 ± 2.60 years; female n = 22, age 8.94 ± 2.10). INCLUSION CRITERIA: GHST using arginine and clonidine. EXCLUSION CRITERIA: hypopituitarism, abnormal pituitary magnetic resonance imaging scan, syndromic obesity, or syndromic short stature. Data were expressed as mean ± SD. RESULTS: The over-weight/obese children with peak GH of <10 µg/L had significantly lower value for natural log (ln) peak GH (1.45 ± 0.09 vs. 1.83 ± 0.35, p = 0.022), but similar values for GV SDS, insulin-like growth factor-I, insulin-like growth factor binding protein-3, bone age, BA - CA, MPTH, and child height SDS minus MPTH SDS compared to normal-weight peers with GHD. After adjusting for covariates, the over-weight/obese children (BMI ≥ 85th percentile) were >7 times more likely than normal-weight subjects (BMI < 85th percentile) to have a peak GH of <10 µg/L, and 23 times more likely to have a peak GH of <7 µg/L (OR = 23.3, p = 0.021). There was a significant inverse relationships between BMI SDS and the ln of peak GH (ß = -0.40, r (2) = 0.26, p = 0.001), but not for BMI SDS vs. GV SDS, ln peak GH vs. BA, or ln peak GH vs. GV SDS. CONCLUSION: Subnormal peak GH levels in obese prepubertal children are not associated with unique pre-GHST auxological characteristics.

Consensus document of the Neuroendocrinology area of the Spanish Society of Endocrinology and Nutrition on management of hypopituitarism during transition.

The transition period from child to adult represents a crucial phase in the growth process where multiple physical and psychosocial changes occur. It has been arbitrarily defined as the period extending from late puberty to full adult maturity (i.e., from mid to late teenage years until 6-7 years after achievement of final height). The aim of this guideline is to emphasize the importance of adequate hormone replacement during this period and to review reassessment of pituitary function. In patients with GH deficiency diagnosed in childhood, an attempt is made to answer when to retest GH secretion, when to treat and how they should be monitored. Thyroxine, glucocorticoid, and sex steroid replacement are also reviewed.

Optimizing the method in calculating the insulin dosages in the insulin hypoglycemia-growth hormone stimulation test:preliminary exploration / 中华内分泌代谢杂志

Objective To explore more suitable calculation method of the insulin dosage in insulin hypoglycemia-growth hormone stimulation test(insulin tolerance test, ITT). Methods Fifty-six subjects suspected of growth hormone deficiency were divided into primary and secondary onset groups. All the patients took oral glucose tolerance test and ITT. Homeostasis model of assessment for insulin resistance index ( HOMA-IR) and insulin sensitivity index ( ISI), area under insulin curve ( AUCINS ) and the area under glucose curve ( AUCPG ) were calculated. The insulin dosages during ITT between two groups were compared and the main factors influencing the insulin dosage were analyzed. Results There was no difference in the insulin dosage during ITT between primary and secondary groups. The actual dosage of insulin in this cohort study revealed a significant difference from the initial insulin dosage recommended by the guideline. Multiple linear regression analysis found that AUCINS and body mass index were the independent factors affecting the insulin dosage. Then the optimized coefficient of ITT ( γ) were found. Conclusion The insulin dosage used in our study was inconsistent with the guidelines-recommended ones. In order to make ITT more efficient and safer, a more optimized calculation method to improve the successful rate of insulin-induced hypoglycemia in ITT is proposed.

Reappraisal of bovril as a source of arginine in the arginine stimulation test for growth hormone deficiency

The purpose of this case study is to report the use of oral Bovril (a food supplement which contains arginine) as an alternative test for growth hormone stimulation test. We performed oral Bovril test in 3 patients -- one with suspected growth hormone deficiency in whom insulin tolerance test could not be performed (subject A), one sex-matched control (subject B), and one with confirmed growth hormone deficiency (subject C). 14g/m2 of oral Bovril was mixed with 150ml of warm water and was given to all three subjects. Blood for growth hormone was taken at baseline, and every 30 minutes till 150 minutes after ingestion of oral Bovril. The ingestion of oral Bovril showed a positive response in subjects A and B, with highest growth hormone levels of 28.4mIU/L and 42.0mIU/L respectively at 150 minutes. Subject C had suppressed growth hormone throughout the test. Oral Bovril is readily available and is a safe alternative for standard growth hormone stimulation test.