Growth hormone responses to provocative tests in children with short stature

Metabolic Characteristics and Discriminative Diagnosis of Growth Hormone Deficiency and Idiopathic Short Stature in Preadolescents and Adolescents

Growth hormone deficiency (GHD) and idiopathic short stature (ISS) are the most common types of short stature (SS), but little is known about their pathogenesis, and even less is known about the study of adolescent SS. In this study, nuclear magnetic resonance (NMR)-based metabolomic analysis combined with least absolute shrinkage and selection operator (LASSO) were performed to identify the biomarkers of different types of SS (including 94 preadolescent GHD (PAG), 61 preadolescent ISS (PAI), 43 adolescent GHD (ADG), and 19 adolescent ISS (ADI)), and the receiver operating characteristic curve (ROC) was further used to evaluate the predictive power of potential biomarkers. The results showed that fourteen, eleven, nine, and fifteen metabolites were identified as the potential biomarkers of PAG, PAI, ADG, and ADI compared with their corresponding controls, respectively. The disturbed metabolic pathways in preadolescent SS were mainly carbohydrate metabolism and lipid metabolism, while disorders of amino acid metabolism played an important role in adolescent SS. The combination of aspartate, ethanolamine, phosphocholine, and trimethylamine was screened out to identify PAI from PAG, and alanine, histidine, isobutyrate, methanol, and phosphocholine gave a high classification accuracy for ADI and ADC. The differences in metabolic characteristics between GHD and ISS in preadolescents and adolescents will contribute to the development of individualized clinical treatments in short stature.

The association between idiopathic scoliosis and growth hormone treatment in short children

PURPOSE

Idiopathic scoliosis is the most common form of scoliosis, and the risk of onset and progression has been found to correlate with growth spurts. Therefore, treatment with recombinant human growth hormone (GH) treatment in short children may initiate and/or aggravate scoliosis. The aim of this study was to investigate the relationship between idiopathic scoliosis and GH treatment in short children.

METHODS

The medical records of 113 subjects seen at the participating institution between January 2010 and December 2020 and who were diagnosed with GH deficiency and small for gestational age, had idiopathic short stature, and were treated with GH for at least one year were reviewed. Scoliosis was defined as a Cobb angle greater than 10 degrees as assessed using a spine x-ray. Clinical data and laboratory findings before and 12 months after GH treatment were compared.

RESULTS

There was significant increase in height, height-standard deviation score, insulin-like growth factor 1, and insulin-like growth factor binding protein 3 (p<0.001) with GH treatment. However, there were no significant differences in the average Cobb angle (6.2°±3.3° vs. 6.1°±3.5°, p=0.842) and the prevalence of scoliosis (9.7% vs. 13.3%, p=0.481) before and after one year of GH treatment. A comparative analysis of both initial Cobb angle and change in Cobb angle during GH treatment showed no relationship with other factors.

CONCLUSION

Although GH treatment in short children increased height and growth velocity, it was not associated with development or aggravation of idiopathic scoliosis.

A Radiomics-Based Model with the Potential to Differentiate Growth Hormone Deficiency and Idiopathic Short Stature on Sella MRI

PURPOSE

We hypothesized that a radiomics approach could be employed to classify children with growth hormone deficiency (GHD) and idiopathic short stature (ISS) on sella magnetic resonance imaging (MRI). Accordingly, we aimed to develop a radiomics prediction model for differentiating GHD from ISS and to evaluate the diagnostic performance thereof.

MATERIALS AND METHODS

Short stature pediatric patients diagnosed with GHD or ISS from March 2011 to July 2020 at our institution were recruited. We enrolled 312 patients (GHD 210, ISS 102) with normal sella MRI and temporally split them into training and test sets (7:3). Pituitary glands were semi-automatically segmented, and 110 radiomic features were extracted from the coronal T2-weighted images. Feature selection and model development were conducted by applying mutual information (MI) and a light gradient boosting machine, respectively. After training, the model's performance was validated in the test set. We calculated mean absolute Shapley values for each of the selected input features using the Shapley additive explanations (SHAP) algorithm. Volumetric comparison was performed for GHD and ISS groups.

RESULTS

Ten radiomic features were selected by MI. The receiver operating characteristics curve of the developed model in the test set was 0.705, with an accuracy of 70.6%. When analyzing SHAP plots, root mean squared values had the highest impact in the model, followed by various texture features. In volumetric analysis, sagittal height showed a significant difference between GHD and ISS groups.

CONCLUSION

Radiomic analysis of sella MRI may be able to differentiate between GHD and ISS in clinical practice for short-statured children.

Growth Responses During 3 Years of Growth Hormone Treatment in Children and Adolescents With Growth Hormone Deficiency: Comparison Between Idiopathic, Organic and Isolated Growth Hormone Deficiency, and Multiple Pituitary Hormone Deficiency

BACKGROUND

The study aimed to compare the growth responses to 3 years of growth hormone (GH) treatment in children and adolescents with GH deficiency (GHD) according to idiopathic, organic, isolated (IGHD), and multiple pituitary hormone deficiency (MPHD).

METHODS

Total 163 patients aged 2-18 years (100 males and 63 females; 131 idiopathic and 32 organic GHD; 129 IGHD and 34 MPHD) were included from data obtained from the LG Growth Study. Parameters of growth responses and biochemical results were compared during the 3-year GH treatment.

RESULTS

The baseline age, bone age (BA), height (Ht) standard deviation score (SDS), weight SDS, mid-parental Ht SDS, predicted adult Ht (PAH) SDS, and insulin like growth factor-1 (IGF-1) SDS were significantly higher in the organic GHD patients than in the idiopathic GHD patients, but peak GH on the GH-stimulation test, baseline GH dose, and mean 3-year-GH dosage were higher in the idiopathic GHD patients than in the organic GHD patients. The prevalence of MPHD was higher in the organic GHD patients than in the idiopathic GHD patients. Idiopathic MPHD subgroup showed the largest increase for the ΔHt SDS and ΔPAH SDS during GH treatment, and organic MPHD subgroup had the smallest mean increase after GH treatment, depending on ΔIGF-1 SDS and ΔIGF binding protein-3 (IGFBP-3) SDS. The growth velocity and the parental-adjusted Ht gain were greater in the idiopathic GHD patients than the organic GHD patients during the 3-year GH treatment, which may have been related to the different GH dose, ΔIGF-1 SDS, and ΔIGFBP-3 SDS between two groups. Multiple linear regression analysis revealed that baseline IGF-1 SDS, BA, and MPH SDS in idiopathic group and baseline HT SDS in organic group are the most predictable parameters for favorable 3-year-GH treatment.

CONCLUSION

The 3-year-GH treatment was effective in both idiopathic and organic GHD patients regardless of the presence of MPHD or underlying causes, but their growth outcomes were not constant with each other. Close monitoring along with appropriate dosage of GH and annual growth responses, not specific at baseline, are more important in children and adolescents with GHD for long-term treatment.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01604395.

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.

Etiological Profile of Short Stature in Children and Adolescents

CONTEXT

The delayed growth of a child is a major cause of concern for the parents. There is a multitude of etiological factors which must be considered in relation to this common aspect of healthcare.

AIM

The study was done to evaluate the etiological profile of short stature in children and adolescents.

SETTINGS AND DESIGN

The cross-sectional study was conducted for 12 months including 111 cases of short stature (out of the 1,058 cases screened), at the endocrinology outpatient department (OPD) of a tertiary care institute in Haryana.

SUBJECTS AND METHODS

As per the inclusion criteria, cases with age <18 years were enrolled. The examination and anthropometric measurements were performed in the presence of parents/guardians.

RESULTS

Out of the 1,058 cases screened; 111 cases of short stature were recruited as per the inclusion and exclusion criteria. The prevalence was about 10.49% of the total population. The mean age of the sample was 12.34 ± 3.19 years. The endocrine causes were the most common followed by normal variants of growth and delay, chronic systemic illness, and nutritional and skeletal causes. Among the endocrine causes, hypothyroidism was the most common followed by growth hormone deficiency and type 1 diabetes mellitus (T1DM).

CONCLUSIONS

The mean chronological age of 12.34 ± 3.19 years suggests the delayed detection of short stature in the population. This highlights the importance of educating parents so that timely therapeutic intervention can be done to achieve the potential height.

Peak Growth Hormone Response to Combined Stimulation Test in 315 Children and Correlations with Metabolic Parameters

BACKGROUND/AIMS

Studies are lacking regarding the timing of peak growth hormone (PGH) response. We aim to elucidate the timing of PGH response to arginine and levodopa (A-LD) and evaluate the influence of body mass index (BMI) and other metabolic parameters on PGH.

METHODS

During growth hormone (GH) stimulation testing (ST) with A-LD, serum GH was measured at baseline and every 30 min up to 180 min. The PGH cut-off was defined as &amp;#x3c;10 ng/mL. IGF-1, IGF BP3, BMI, and metabolic parameters were obtained in a fasting state at baseline.

RESULTS

In the 315 tested children, stimulated PGH levels occurred at or before 120 min in 97.8% and at 180 min in 2.2%. GH area under the curve (AUC) positively correlated with PGH in all patients and with IGF-1 in pubertal males and females. BMI negatively correlated with PGH in all subjects. GH AUC negatively correlated with HOMA-IR and total cholesterol.

CONCLUSION

We propose termination of the GH ST with A-LD at 120 min since omission of GH measurement at 180 min did not alter the diagnosis of GH deficiency based on a cut-off of &amp;#x3c; 10 ng/mL. BMI should be considered in the interpretation of GH ST with A-LD. The relationships between GH AUC and metabolic parameters need further study.

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.

New Insights in Growth Hormone Stimulation Tests Protocols

Objective: The objective of this study was to analyze the performance of 2 stimulation tests used in the diagnosis of growth hormone deficiency.

Method: A retrospective study was conducted on a non-random sample of 310 patients, between 2 and 20 years old, who were hospitalized in the Mureș County Hospital’s Endocrinology Department and in the National Institute of Endocrinology C.I. Parhon with short stature between 2009-2015. Inclusion criteria: all subjects who underwent growth hormone stimulation tests in accordance with the national protocol. Microsoft Office Excel was used for data collection and MedCalc v 12.5 was used for statistical analysis.

Results: From the total of 310 patients, 102 were diagnosed in Târgu Mureș and 208 in Bucharest. Sex ratio favored boys (boys:girls 1.64:1). In 173 subjects growth hormone deficiency was confirmed. For both tests the percentage of maximum response was the highest for the 60 minutes blood sample regardless if the test were positive or not. Both tests have 100% sensitivity and negative predictive value, with the highest specificity for the 60 minutes clonidine and 30 minutes insulin. The false positive rate was 60% for the insulin test and 27.2% for clonidine for Târgu Mureș sample and 86.9% for the insulin test and 62.5% for clonidine for Bucharest sample. The concordance of the 2 tests was 49.36%.

Conclusions: Stimulating growth hormone testing has a number of limitations but is still needed in some auxological circumstances. We recommend performing the clonidine test first to exclude idiopathic short stature and then the insulin tolerance test for the diagnosis of growth hormone deficiency.

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.

Etiological factors of short stature in children and adolescents: experience at a tertiary care hospital in Egypt

BACKGROUND

Accurate anthropometric measurements and critical analysis of growth data allow the clinician to promptly recognize children with short stature. The aim of this study was to determine the frequency of etiological factors causing short stature among children referred to the pediatric endocrinology clinic of Assiut University Children's Hospital, the main tertiary care center in Upper Egypt.

METHODS

We conducted this descriptive observational study from May 2012 to December 2015, to analyze 637 children (boys 354, girls 283) with short stature. Evaluation included: detailed medical history, physical examination, laboratory tests, bone age and chromosomal analysis.

RESULTS

Endocrinological causes accounted for 26% of short stature [of them, 11.8% had growth hormone deficiency (GHD)], 63.6% had normal variants of growth [of them, 42% had familial short stature (FSS), 15.8% had constitutional growth delay (CGD) and 5.5% a combination of both]. Interestingly, celiac disease (CD) constituted 6.6% of children with short stature in our cohort.

CONCLUSIONS

Although potentially treatable causes such as GHD, hypothyroidism and CD accounted for a considerable percentage of short stature in our study, the majority of short stature in children had normal variations of growth. Growth hormone treatment in children, however, should be promptly initiated with specific clinical indications. CD is a not uncommon cause of short stature.

Reversible Pharmacological Induction of Motor Symptoms in MPTP-Treated Mice at the Presymptomatic Stage of Parkinsonism: Potential Use for Early Diagnosis of Parkinson's Disease

A crucial event in the pathogenesis of Parkinson's disease is the death of dopaminergic neurons of the nigrostriatal system, which are responsible for the regulation of motor function. Motor symptoms first appear in patients 20-30 years after the onset of the neurodegeneration, when there has been a loss of an essential number of neurons and depletion of compensatory reserves of the brain, which explains the low efficiency of treatment. Therefore, the development of a technology for the diagnosing of Parkinson's disease at the preclinical stage is of a high priority in neurology. In this study, we have developed at an experimental model a fundamentally novel for neurology approach for diagnosis of Parkinson's disease at the preclinical stage. This methodology, widely used for the diagnosis of chronic diseases in the internal medicine, is based on the application of a challenge test that temporarily increases the latent failure of a specific functional system, thereby inducing the short-term appearance of clinical symptoms. The provocation test was developed by a systemic administration of α-methyl-p-tyrosine (αMpT), a reversible inhibitor of tyrosine hydroxylase to MPTP-treated mice at the presymptomatic stage of parkinsonism. For this, we first selected a minimum dose of αMpT, which caused a decrease of the dopamine level in the striatum of normal mice below the threshold at which motor dysfunctions appear. Then, we found the maximum dose of αMpT at which a loss of dopamine in the striatum of normal mice did not reach the threshold level, and motor behavior was not impaired. We showed that αMpT at this dose induced a decrease of the dopamine concentration in the striatum of MPTP-treated mice at the presymptomatic stage of parkinsonism below a threshold level that results in the impairment of motor behavior. Finally, we proved that αMpT exerts a temporal and reversible influence on the nigrostriatal dopaminergic system of MPTP-treated mice with no long-term side effects on other catecholaminergic systems. Thus, the above experimental data strongly suggest that αMpT-based challenge test might be considered as the provocation test for Parkinson's disease diagnosis at the preclinical stage in the future clinical trials.