Diagnosis of growth hormone deficiency in childhood

Development and Validation of a Prediction Model Using Sella Magnetic Resonance Imaging-Based Radiomics and Clinical Parameters for the Diagnosis of Growth Hormone Deficiency and Idiopathic Short Stature: Cross-Sectional, Multicenter Study

BACKGROUND

Growth hormone deficiency (GHD) and idiopathic short stature (ISS) are the major etiologies of short stature in children. For the diagnosis of GHD and ISS, meticulous evaluations are required, including growth hormone provocation tests, which are invasive and burdensome for children. Additionally, sella magnetic resonance imaging (MRI) is necessary for assessing etiologies of GHD, which cannot evaluate hormonal secretion. Recently, radiomics has emerged as a revolutionary technique that uses mathematical algorithms to extract various features for the quantitative analysis of medical images.

OBJECTIVE

This study aimed to develop a machine learning-based model using sella MRI-based radiomics and clinical parameters to diagnose GHD and ISS.

METHODS

A total of 293 children with short stature who underwent sella MRI and growth hormone provocation tests were included in the training set, and 47 children who met the same inclusion criteria were enrolled in the test set from different hospitals for this study. A total of 186 radiomic features were extracted from the pituitary glands using a semiautomatic segmentation process for both the T2-weighted and contrast-enhanced T1-weighted image. The clinical parameters included auxological data, insulin-like growth factor-I, and bone age. The extreme gradient boosting algorithm was used to train the prediction models. Internal validation was conducted using 5-fold cross-validation on the training set, and external validation was conducted on the test set. Model performance was assessed by plotting the area under the receiver operating characteristic curve. The mean absolute Shapley values were computed to quantify the impact of each parameter.

RESULTS

The area under the receiver operating characteristic curves (95% CIs) of the clinical, radiomics, and combined models were 0.684 (0.590-0.778), 0.691 (0.620-0.762), and 0.830 (0.741-0.919), respectively, in the external validation. Among the clinical parameters, the major contributing factors to prediction were BMI SD score (SDS), chronological age-bone age, weight SDS, growth velocity, and insulin-like growth factor-I SDS in the clinical model. In the combined model, radiomic features including maximum probability from a T2-weighted image and run length nonuniformity normalized from a T2-weighted image added incremental value to the prediction (combined model vs clinical model, P=.03; combined model vs radiomics model, P=.02). The code for our model is available in a public repository on GitHub.

CONCLUSIONS

Our model combining both radiomics and clinical parameters can accurately predict GHD from ISS, which was also proven in the external validation. These findings highlight the potential of machine learning-based models using radiomics and clinical parameters for diagnosing GHD and ISS.

Genetic variations, clinical presentation and treatment outcome of isolated growth hormone deficiency type I and II: case series and review of the literature

PURPOSE

To report a case series of four patients with isolated growth hormone deficiency (IGHD) type I from two Chinese pedigrees and to elucidate phenotype-genotype correlation of IGHD type I and II with GH1 gene alterations in the literature.

METHODS

Whole exome sequencing (WES) was performed and a literature review was conducted.

RESULTS

Four patients presented with extreme growth retardation (height -4.74 to -6.50 SDS) and undetectable peak growth hormone (GH) during GH stimulating test. WES revealed a novel homozygous nonsense mutation, c.316delC (p.L106Cfs*35), in GH1 gene in the the first pedigree. Deletions of exon 1-5 in GH1 gene were identified in the second pedigree. Ideal catch-up growth after GH treatment was achieved. 94 patients with IGHD type I and 240 patients with IGHD type II were included in literature review. Patients with IGHD type I exhibited younger age (3.2 vs 6.0 years, P < 0.001), more severe growth retardation (median height -6.50 vs -3.84 SDS, P < 0.001), lower peak GH levels (0.05 vs 1.70 ng/ml, P < 0.001) and a higher dosage of GH (0.22 vs 0.17 mg/kg/week, P = 0.012) compared to patients with IGHD type II. Gross deletions constituted 72.3% of IGHD type I cases, while splicing mutations and missense mutations comprised 54.2% and 45.0% of IGHD type II cases. In patients with IGHD type I harboring gross deletion, an early age of diagnosis correlated with both a higher height SDS at diagnosis and a better response after GH treatment. Height SDS after GH treatment in patients with IGHD type II carrying splicing mutations was negatively correlated with age at diagnosis.

CONCLUSION

We identified two GH1 gene mutations, c.316delC (p.L106Cfs*35) and deletions of exon 1-5 in four Chinese patients with IGHD type I. They had a good response to GH treatment and gained satisfactory height improvement. Early diagnosis and initiating treatment may lead to a better prognosis.

The interplay of immunity and growth: a case of combined variable immunodeficiency and growth hormone deficiency

Introduction

Common variable immunodeficiency (CVID) is one of the more common immunodeficiencies seen in clinical practice with a complex disease pathology; while growth hormone deficiency (GHD) is a disorder characterized by complete or relative absence of the human growth hormone.

Case presentation

This case report presents a 13-year-old female patient with a long history of recurrent respiratory tract and ear infections, along with a notable failure to hit her developmental milestones early in the second decade of her life. The diagnosis was based on a thorough investigation of serum immunoglobulins for CVID and a GH stimulation test for GHD. For these, the patient was placed on a tailored regimen of IVIGs, somatropin therapy, and antibiotics for the recurrent infections.

Case discussion

CVID patients characteristically present with recurrent respiratory and ear infections, showing a marked decrease in immunity. Often diagnosed in childhood, GHD typically presents as growth failure along with developmental delays in dentition. There has been a notable rise in the coexistence of immunodeficiency syndromes and endocrinopathies studied in the past few decades. The case highlights and discusses the complex underlying pathology at play that links the two conditions to each other, while also excluding the various differentials.

Conclusion

The report highlights the various challenges faced by both clinicians and patients when dealing with dual health conditions that may have a relatively nonspecific presentation. Some of which include the diagnostic difficulties, financial strains on the patient leading to poor follow-up, and in the long-term, the development of various complications. This emphasizes the importance of early disease diagnosis and strict management protocols for the said disease, for the overall betterment of the patient's quality of life.

L-DOPA Test in the Diagnosis of Childhood Short Stature: Evaluation of Growth Hormone Peaks Over Time

INTRODUCTION

In childhood, growth hormone (GH) deficiency (GHD) diagnosis is based on auxological assessment and biochemical provocative tests, whose reliability remains disputed. Recently, several papers have been published on standardising the duration of some tests. The aim of our study was to analyse the possible length reduction of the L-DOPA provocative test.

METHODS

We retrospectively investigated the response of GH to L-DOPA in 256 children, analysing 267 tests (some patients were retested over time for the persistence of severe auxopathy). We studied the same data considering GH peak threshold both at 8 ng/mL (Italian GHD cut-off) and at 10 ng/mL (international cut-off). Based on stimulation tests, patients were divided into two groups: GHD and no-GHD short children. We described the results in the whole population and then clustering for gender and pubertal stage. We termed as index the test stopped at 90 min.

RESULTS

The GH peak after L-DOPA mostly occurred at 60 min. The sensitivity of the index test was the highest, while the specificity was slightly higher using the 8 ng/mL threshold (specificity = 0.68; 95% CI 0.60-0.76) then using the 10 ng/mL threshold (specificity = 0.56; 95% CI 0.47-0.65) at 90 min. The two ROC curves showed moderate performance of the test at 90 min. While the negative predictive value was 100% in both tests, the positive predictive value was slightly better with 10 ng/mL cut-off. Considering the two groups established by GHD definition and placing a GH threshold at 10 ng/mL, stopping L-DOPA test time at 90 min would have changed the test result and subsequentially patient's classification in 3/267 of the analysed tests (1.1%), while with the Italian GH threshold value at 8 ng/mL in 7/267 of the tests (2.6%).

CONCLUSIONS

Our research shows that omitting 120-min time reduces L-DOPA test specificity, especially with GHD cut-off at 10 ng/mL.

Impact of Daily Growth Hormone Adherence on Height Velocity Among Children With Growth Hormone Deficiency (GHD)

OBJECTIVE

To describe adherence to daily somatropin treatment and impact on height velocity within 1 year of treatment start among patients with pediatric growth hormone deficiency in a real-world US population.

METHODS

This retrospective cohort study included pediatric patients aged ≥3 years to <16 years with pediatric growth hormone deficiency prescribed somatropin by a pediatric endocrinologist at a US-based center of excellence between January 1, 2015 and December 31, 2020. Patient data were collected using hospital electronic health records linked to a specialty pharmacy patient prescription records. Adherence, evaluated over 12 months, was measured using the proportion of days covered metric and patients were categorized as adherent if their proportion of days covered ≥80%. Height velocity was annualized to compare across adherent and nonadherent patients.

RESULTS

One hundred eighty-one patients were identified and included in this study, of which 70.2% were male,73.5% were white, and mean age (standard deviation [SD]) at index was 12.1 (2.8). In the height velocity analysis, 174 patients were included and the mean (SD) annualized change in height was 10.2 (5.7) cm/y in the adherent group (n = 108) and 9.8 (7.6) in the nonadherent group (n = 66). The difference in height velocity between the groups was not statistically significant.

CONCLUSIONS

Minor improvements in average height velocity were observed in the patient group who were adherent to somatropin therapy, although not statistically significant. Lack of observed significance may be due to small sample sizes, short observation period, a likely heterogenous population in terms of growth hormone prescribing, data bias due to single-center origin, or potential patient misclassification.

Efficacy, safety, and patient satisfaction of norditropin and sogroya in patients with growth hormone deficiency: a systematic review and meta-analysis of randomized controlled trials

INTRODUCTION

Growth hormone deficiency occurs when the pituitary gland does not produce enough growth hormone. Norditropin®, a recombinant human growth hormone, and Sogroya®, an albumin-binding growth hormone derivative, are prescribed for patients with growth hormone deficiency. This systematic review assesses the efficacy, safety, and patient satisfaction associated with Norditropin and Sogroya.

METHODS

We systematically searched PubMed, Web of Science, and Scopus databases to identify eligible comparative studies. All studies published until June 2023 were included in our analysis. Our outcomes for children included height velocity and height velocity standard deviation score. In contrast, adult outcomes included adverse events, insulin-like growth factor 1-standard deviation score (IGF-1 SDS), and the Treatment Satisfaction Questionnaire for Medication-9 (TSQM-9). Results are reported as odds ratio (OR) and mean difference (MD) with a 95% confidence interval (95% CI).

RESULTS

Ten studies involving 1058 participants (665 children and 393 adults) were included in the meta-analysis. In children, Norditropin at doses of 0.034 and 0.067 mg/kg/day was compared to Sogroya at doses of 0.04, 0.08, 0.16, and 0.24 mg/kg/week. The results showed that 0.034 mg/kg/day Norditropin had a favorable impact on height velocity (MD -2.01, 95% CI -3.7 to -2.12, p < 0.00001) and height velocity standard deviation score (Mean Difference -3.61, 95% CI -5.06 to -2.16, p < 0.00001) when compared to Sogroya 0.04 mg/kg/day. Other doses showed comparable results. In adults, the only significant side effect noted was rash, which favored Sogroya (OR 0.1, 95% CI 0.04-0.27, p < 0.00001). Additionally, IGF-1 SDS was significantly higher in the Sogroya group than in the Norditropin group (MD 0.25, 95% CI 0.02-0.48, p = 0.03). Furthermore, the overall score of the TSQM-9 questionnaire, which includes three domains: convenience, effectiveness, and satisfaction, was significantly higher in the Sogroya group compared to the Norditropin group (OR 6.36, 95% CI 3.92-8.8, p < 0.00001).

CONCLUSION

Norditropin and Sogroya showed comparable efficacy and safety profiles, except for the prevalence of rash in the Norditropin group, and Sogroya has higher satisfaction among adults. More high-quality studies with more patients are required to confirm these results.

GH provocative tests stimulate the growth in children with idiopathic short stature

CONTEXT

Growth hormone (GH) deficiency in a child with short stature is diagnosed by GH secretion provocative tests. When the test response is considered adequate, the short stature is considered idiopathic (ISS).

OBJECTIVE

To determine the effect of GH provocative tests on the growth rate in children with idiopathic short stature.

DESIGN

Children with short stature with a normal response to at least one GH provocative test were enrolled. Height and growth velocity were measured prior to and after stimulus tests during the follow-up.

METHODS

Height, mid-parental height, body weight, and body mass index were measured. The height and growth rate were converted to percentiles and Standard Deviation Scores (SDS) using reference ranges standardized by age and sex. GH provocative tests employed arginine or clonidine as secretagogues.

RESULTS

Fourty-six children of both genders were enrolled. In thirty-six children, height was measured at the time of testing and on an average time prior to and after the tests of 210 days and 180 days respectively. After testing the children displayed a 3.4-fold increase in their estimated 90-day growth rate. The median (inter-quartile range, IQR) 90 days growth of children pre-and post-tests were 0.7 (0.2-1.0) cm and 2.4 (1.7-3.1) cm respectively with a mean 3,4-fold increase (p < 0.0001). The median (IQR) 90 days growth of children pre- and post-tests calculated as standard deviation scores (SDS) were -4.0 (-5.4--2.1) SDS and 0.1 (-1.9-1.4) SDS respectively (p < 0.0001). Ten children with ISS were observed for about 5 months before the GH provocative tests. A small increase in the growth rate was seen only in 2 out of 10 children before testing while it increased in all of them after the tests. The difference in the median growth rate at the first and the second observation was not significant (p = 0.219).

CONCLUSIONS

Two sequential somatotropic axis provocative tests increase the growth rate in children with idiopathic short stature. The duration of this effect is yet to be determined.

Pediatric growth hormone deficiency: Understanding the patient and caregiver perspectives

Childhood growth hormone deficiency (GHD) is a rare disorder associated with significant burden on both patients and caregivers. Although previous reports have detailed aspects of the burden experienced by patients and their caregivers, there is a paucity of first-hand information on the patient and caregiver journeys from their respective voices. To address this need, an advisory board meeting was conducted on September 30, 2022, with 4 pediatric patients with GHD and their caregivers to discuss their experiences prior to GHD diagnosis, during the diagnostic process, and during ongoing treatment with recombinant growth hormone. Feedback from patients and caregivers was reviewed by pediatric endocrinologists, who provided their own perspectives on the patient and caregiver journeys based on the information reported. Despite the small sample size, important insights were obtained: patients and caregivers reported remarkable growth benefits achieved with treatment, which provided strong motivation to remain adherent to daily injection regimens. Patient and caregiver accounts reflected wide variability between families in time from suspicion to diagnosis and in treatment challenges faced, ranging from practical issues such as handling and administration of medication to broader concerns about treatment access and continuity, as well as key knowledge gaps among patients, caregivers, and clinicians. Recommendations are provided to enhance the patient and caregiver journeys, including increasing development and availability of educational materials, providing opportunities for patient advocacy by clinicians and health care providers, and encouraging institutional improvements to ensure that patients continue to receive uninterrupted treatment during their critical period of growth.

Tackling access and payer barriers for growth hormone therapy in Saudi Arabia: a consensus statement for the Saudi Working Group for Pediatric Endocrinology

Prompt diagnosis and early treatment are key goals to optimize the outcomes of children with growth hormone deficiency (GHD) and attain the genetically expected adult height. Nonetheless, several barriers can hinder prompt diagnosis and treatment of GHD, including payer-related issues. In Saudi Arabia, moderate-to-severe short stature was reported in 13.1 and 11.7 % of healthy boys and girls, respectively. Several access and payer barriers can face pediatric endocrinologists during the diagnosis and treatment of GHD in Saudi Arabia. Insurance coverage policies can restrict access to diagnostic tests for GHD and recombinant human growth hormone (rhGH) due to their high costs and lack of gold-standard criteria. Some insurance policies may limit the duration of treatment with rhGH or the amount of medication covered per month. This consensus article gathered the insights of pediatric endocrinologists from Saudi Arabia to reflect the access and payer barriers to the diagnostic tests and treatment options of children with short stature. We also discussed the current payer-related challenges endocrinologists face during the investigations of children with short stature. The consensus identified potential strategies to overcome these challenges and optimize patient management.

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.

Multisystem Involvement in a Pediatric Patient With Suspected Mucopolysaccharidosis: A Case Report

Mucopolysaccharidoses (MPS) are a group of inherited metabolic disorders characterized by the deficiency or malfunction of lysosomal enzymes responsible for glycosaminoglycan (GAG) degradation. We present the case of an 11-year-old male with a history of calcified mitral valve, rheumatic heart disease, and growth hormone deficiency who presented with dyspnea on exertion. Physical examination revealed dysmorphic facial features, short stature, and suboptimal weight and height parameters. Magnetic resonance imaging (MRI) of the brain showed cystic lesions in the white matter and corpus callosum, hydrocephalus, and cerebral atrophy, suggestive of MPS. This case highlights the importance of considering MPS in the differential diagnosis of patients with multisystemic involvement and the utility of advanced imaging techniques like MRI in guiding diagnosis and management. A multidisciplinary approach involving cardiology, endocrinology, genetics, and neurology is crucial for comprehensive management and improving patient outcomes. Early diagnosis and intervention are essential in optimizing the quality of life for patients with MPS.

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.

Complex relationship between growth hormone and sleep in children: insights, discrepancies, and implications

Growth hormone (GH) is crucial to growth and development. GH secretion is regulated by a complex feedback system involving the pituitary gland, hypothalamus, and other organs, and predominantly occurs during deep sleep. Isolated and idiopathic growth hormone deficiency (GHD) is a condition characterized by GHD without any other signs or symptoms associated with a specific syndrome or disease. The aim of this narrative review was to evaluate the relationship between GH and sleep in children using published data. Various databases (Medline/PubMed, Scopus, and Web of Science) were systematically searched for relevant English language articles published up to April 2023. Search strategies included the terms 'children/pediatric', 'growth hormone', 'growth hormone deficiency' and 'sleep'. Data were extracted by two independent reviewers; 185 papers were identified of which 58 were duplicates and 118 were excluded (unrelated n=83, syndromic/genetic GHD n=17, non-English n=13, abstract n=1, case report n=1). Overall, nine studies (six clinical studies, two case series, and one survey) were included. GHD appears to have an adverse effect on sleep in children, and GH therapy has only been shown to have a beneficial effect on sleep parameters in some individuals. Notably, identified data were limited, old/poor quality, and heterogenous/inconsistent. Further research of GHD in pediatric populations is necessary to improve the understanding of GHD impact on sleep and its underlying mechanisms, and to determine the specific impacts of GH therapy on sleep in children.

Does excessive body mass affect the rhGH therapy outcomes in GHD children?

INTRODUCTION

For 35 years, recombinant human growth hormone (rhGH) has been successfully used worldwide to treat children with short stature related to growth hormone deficiency (GHD). Growth hormone therapy requires an individual approach to the patient due to varying responses to the treatment. Excessive body weight is one of the factors influencing the response.

AIM OF THE STUDY

To evaluate the impact of excessive body mass on rhGH therapy effectiveness in GHD children.

MATERIAL AND METHODS

165 short-statured children with isolated GHD (mean age 10.72 ±3.33 years), treated with rhGH for at least one year (mean follow-up 4.32 ±1.80 years), were separated into 3 groups based on their BMI standard deviation score (SDS). Bone age, height, weight, insulin-like growth factor 1 level, and rhGH dose were obtained up to 10 years with one-year intervals.

RESULTS

The mean change in height SDS in the first year was 0.52 ±0.41 SD and 0.60 ±0.32 SD for normal and excessive body weight children, respectively. The mean height velocity, based on the height SDS measured over the consecutive 5 years, was 0.44±0.25 SD/year for the normal-weight group and 0.32 ±0.24 SD/year for the excessive body weight group (p < 0.1).

CONCLUSIONS

Excess body weight has a significant impact on rhGH therapy outcomes. This correlates with the height increase in the first year of observation; however, long-term observation has shown that children diagnosed with overweight or obesity achieve significantly worse results compared to their normal-weight peers.

Primary response in GHD children treatment as a predictor for long-term therapy effectiveness therapy effectiveness

INTRODUCTION

Short stature in growth hormone deficiency (GHD) can be treated with recombinant human growth hormone (rhGH), which is proven to be both safe and effective. However, a considerable number of patients does not achieve satisfying therapy outcomes.

AIM OF THE STUDY

To evaluate the predictive effect of height increase in the first year of rhGH treatment on long-term therapy outcomes.

MATERIAL AND METHODS

165 short-stature children (mean age 10.72 ±3.33 years; 63% males), diagnosed with GHD, treated with rhGH for at least one year (mean follow-up 4.32 ±1.80 years), divided into 2 groups according to the change in height standard deviation score (SDS) after the first year of rhGH treatment: good responders (GR) and poor responders (PR). Then, in one-year intervals, patient's chronological age, bone age, height, weight, insulin-like growth factor level, and rhGH dose were all assessed.

RESULTS

In the GR group, mean height velocity SDS up to five years of observation was 1.19 ±0.41/year and in the PR group 0.59 ±0.38/year. The differences were statistically significant (p < 0.05).

CONCLUSIONS

The primary response to the rhGH treatment in GHD children seems to be a good predictor for long-term therapy outcomes.

Diffusion tensor imaging of the physis: the ABC's

The physis, or growth plate, is the primary structure responsible for longitudinal growth of the long bones. Diffusion tensor imaging (DTI) is a technique that depicts the anisotropic motion of water molecules, or diffusion. When diffusion is limited by cellular membranes, information on tissue microstructure can be acquired. Tractography, the visual display of the direction and magnitude of water diffusion, provides qualitative visualization of complex cellular architecture as well as quantitative diffusion metrics that appear to indirectly reflect physeal activity. In the growing bones, DTI depicts the columns of cartilage and new bone in the physeal-metaphyseal complex. In this "How I do It", we will highlight the value of DTI as a clinical tool by presenting DTI tractography of the physeal-metaphyseal complex of children and adolescents during normal growth, illustrating variation in qualitative and quantitative tractography metrics with age and skeletal location. In addition, we will present tractography from patients with physeal dysfunction caused by growth hormone deficiency and physeal injury due to trauma, chemotherapy, and radiation therapy. Furthermore, we will delineate our process, or "DTI pipeline," from image acquisition to data interpretation.

Evaluation of the growth response of children with growth hormone deficiency according to the peak growth hormone levels in provocation tests

BACKGROUND

We aimed to evaluate the relation between the peak growth hormone (GH) levels in provocation tests and response to recombinant human GH (rhGH) therapy in patients with GH deficiency (GHD).

METHODS

This was a cross-sectional, single-center, and retrospective study. A total of 135 patients under the age of 16 years who were diagnosed with GHD through insulin tolerance tests and L-DOPA stimulation tests and who received rhGH therapy for at least 2 years in the Pediatric Endocrinology Clinic of Akdeniz University Hospital between 1997 and 2021 were included in the study.

RESULTS

The patients were divided into two groups: idiopathic GHD (group I, n = 119) and multiple pituitary hormone deficiencies or organic pathology on magnetic resonance imaging (group II, n = 16). The patients in group I were classified into three subgroups according to the peak GH values in the provocation tests (group Ia: peak GH <3 μg/L, n = 34; group Ib: peak GH between 3 and 7 μg/L, n = 71; group Ic: peak GH between 7 and 10 μg/L, n = 34). The median age was 11.5 years in group I (8.8 in group Ia, 12.1 in group Ib, 12.3 in group Ib) and 8.8 years in group II. The height standard deviation score (SDS) was -2.93 in group I (-2.85 in group Ia, -2.99 in group Ib, -2.94 in group Ic) and -3.79 in group II. The median Δheight SDS was 0.61 in group I and 1.05 in group II at the end of the first year of treatment and 0.31 in group I and 0.45 in group II at the end of the second year (p = 0.005 and p = 0.074, respectively). When the subgroups of group I were compared, height SDS, Δheight SDS, and height velocity (HV) SDS were all higher in group Ia at the end of the first year of rhGH therapy (p = 0.040, p = 0.029, and p = 0.005, respectively). The height SDS was still significantly higher in group Ia (p = 0.033) while the HV SDS and Δheight SDS were similar between the groups at the end of the second year of therapy (p = 0.164 and p = 0.522, respectively). There was a statistically significant association between the first-year HV SDS and the peak GH value in provocation tests in multiple regression analyses (p<0.001). In addition, the final model revealed that height SDS and weight SDS at the start of the treatment and the first-year HV SDS are the factors with a statistically significant effect on the second-year HV SDS (p = 0.022, p = 0.001, and p<0.001, respectively).

CONCLUSION

Our findings show that the lower the GH peak in provocation tests, the better the response to treatment. The best HV was observed in the first year of rhGH therapy, and the diagnosis should be checked in those patients who had a low first-year HV and did not have a severely low GH peak in provocation tests.

Physician experience with once-weekly somatrogon versus once-daily rhGH regimen in pediatric patients with growth hormone deficiency: a cross-sectional survey of physicians from the global phase 3 study

Introduction

The standard of care for pediatric growth hormone deficiency (pGHD) is once-daily recombinant human growth hormone (rhGH). Somatrogon, a long-acting rhGH, requires less frequent, once-weekly, dosing. We describe physicians' preference for, experiences, and satisfaction with once-weekly somatrogon vs once-daily rhGH.

Methods

English-speaking investigators from somatrogon's global phase III study (NCT02968004) with prior experience using once-daily rhGH were included. Participants answered an online survey containing 14 closed- and open-ended items.

Results

Twenty-four pediatric endocrinologists (41.7% men; 79.2% practiced at public/private hospitals) from 12 countries with 25.8 ± 12.0 years' experience treating pGHD completed the survey. In terms of the time and effort required to explain device instructions, injection regimen, procedure for missed injection, and address patients'/caregivers' concerns, a similar proportion of physicians chose once-weekly somatrogon and once-daily rhGH; 62.5% physicians indicated that once-daily rhGH required greater effort to monitor adherence. Overall, 75% preferred once-weekly somatrogon over once-daily rhGH, 79.2% considered once-weekly somatrogon to be more convenient and less burdensome, and 83.3% were likely to prescribe somatrogon in the future. Overall, 50% felt that once-weekly somatrogon was more beneficial to patients, while 50% chose "No difference". Most physicians (62.5%) felt both regimens were equally likely to support positive long-term growth outcomes and reduce healthcare utilization. More physicians were "very satisfied" with once-weekly somatrogon (62.5%) than with once-daily rhGH (16.7%). Reduced injection frequency, patient and caregiver burden, increased convenience, and improved adherence were reasons for these choices.

Conclusion

Physicians had a positive experience with, and perception of, treating pGHD with once-weekly somatrogon.

Long acting growth hormone (LAGH), an update

In 1957, Maurice Raben at Yale was able to isolate and purify growth hormone from cadaveric pituitary glands. Pituitary growth hormone was the only way to treat children with growth hormone (GH) deficiency, until 1985 when recombinant GH became available for daily subcutaneous injection. For many years, the pediatric endocrine community longed for a long-acting recombinant GH formulation that would decrease the inconvenience of daily injections. Several mechanisms were employed to develop a GH that is rapidly absorbed into the blood stream after subcutaneous injection, but provides slow removal from the circulatory system to potentially optimize patient adherence to GH therapy. Four long-acting growth hormones are currently available in the world, or are close to regulatory approval. They are: (1) Pegylated formulations, (2) Prodrug formulations which are converted into active drug, (3) Nonvalent transient albumin binding GH compounds and (4) GH fusion proteins where a protein si fused with GH. All four formulations have undergone detailed phase 3 studies and were found to show non-inferiority in these clinical studies. All four demonstrate a safety and tolerability profile that is comparable to that of daily somatropin with an excellent adherence profile.

Long-term Pegylated GH for Children With GH Deficiency: A Large, Prospective, Real-world Study

CONTEXT

The evidence of long-term polyethylene glycol recombinant human GH (PEG-rhGH) in pediatric GH deficiency (GHD) is limited.

OBJECTIVE

This study aimed to examine the effectiveness and safety of long-term PEG-rhGH in children with GHD in the real world, as well as to examine the effects of dose on patient outcomes.

DESIGN

A prospective, observational, posttrial study (NCT03290235).

SETTING, PARTICIPANTS AND INTERVENTION

Children with GHD were enrolled from 81 centers in China in 4 individual clinical trials and received weekly 0.2 mg/kg/wk (high-dose) or 0.1 to <0.2 mg/kg/wk (low-dose) PEG-rhGH for 30 months.

MAIN OUTCOMES MEASURES

Height SD score (Ht SDS) at 12, 24, and 36 months.

RESULTS

A total of 1170 children were enrolled in this posttrial study, with 642 patients in the high-dose subgroup and 528 in the low-dose subgroup. The Ht SDS improved significantly after treatment in the total population (P < 0.0001), with a mean change of 0.53 ± 0.30, 0.89 ± 0.48, 1.35 ± 0.63, 1.63 ± 0.75 at 6 months, 12 months, 24 months, and 36 months, respectively. In addition, the changes in Ht SDS from baseline were significantly improved in the high-dose subgroup compared with the low-dose subgroup at 6, 12, 24, and 36 months after treatment (all P < 0.05). A total of 12 (1.03%) patients developed serious adverse events. There was no serious adverse event related to the treatment, and no AEs leading to treatment discontinuation or death occurred.

CONCLUSIONS

PEG-rhGH showed long-term effectiveness and safety in treating children with GHD. Both dose subgroups showed promising outcomes, whereas PEG-rhGH 0.2 mg/kg/wk might show additional benefit.

Diagnostic Value of IGF-1 in Growth Hormone-Deficient Children: Is a Second Growth Hormone Stimulation Test Necessary?

Objective

we assessed the diagnostic accuracy of insulin-like growth factor (IGF) 1 measurements with 1 growth hormone stimulation test (GHST) vs performing 2 GHSTs as the standard test to confirm the diagnosis of growth hormone deficiency (GHD) in children.

Methods

We retrospectively analyzed the baseline characteristics, anthropometric measurements, and laboratory data of 703 children with short stature, aged 4-14 years (mean age, 8.46 ± 2.7 years), who had undergone 2 GHSTs. We compared the diagnostic values of IGF-1 levels by using a cut-off value of ≤0 SD score, along with results of a single clonidine stimulation test (CST). We evaluated the false-positive rate, specificity, likelihood ratio, and area under the curve (AUC) of the 2 diagnostic methods. GHD was diagnosed if the peak growth hormone level was <7 ng/mL on 2 GHSTs.

Results

Of the 724 children, 577 (79.7%) had a low IGF-1 level (mean 104.9 ± 61.4 ng/mL), and 147 (20.3%) had a normal IGF-1 level (mean 145.9 ± 86.9 ng/mL). GHD was diagnosed in 187 patients (25.8%), of whom 146 (25.3%) had a low IGF-1 level. An IGF-1 level reflecting ≤0 SDs in combination with results of a single CST had a specificity of 92.6%, a false-positive rate of 5.5%, and an AUC of 0.6088. Using an IFG-1 cut-off level of ≤-2 SDs did not alter the diagnostic accuracy.

Conclusion

Low IGF-1 values of ≤0 SDs or ≤-2 SDs in combination with results of a single CST had poor diagnostic accuracy for GHD.

Development and validation of a nomogram to predict poor short-term response to recombinant human growth hormone treatment in children with growth disorders

PURPOSE

The purpose of this study was to develop and validate a clinical predictive model for predicting the likelihood of a poor therapeutic response during the first year of recombinant human growth hormone (rhGH) treatment in children with growth disorders.

METHODS

A total of 627 pediatric patients with growth disorders (GHD, ISS, TS, SGA) from The LG Growth Study cohort were evaluated. Restricted cubic splines (RCS) were utilized to investigate the association between predictors and the risk of poor rhGH response. Variables were selected using LASSO regression, and multivariate logistics regression models were established. Receiver operating characteristic (ROC) curves, calibration curves, decision curve analysis (DCA), and clinical impact curves (CIC) were used to assess the predictive model's accuracy and clinical value. The predictive accuracy of the model was validated on the testing set.

RESULTS

Two predictive models containing 8 baseline predictors (diagnosis, age, height SDS, bone age minus chronological age, rhGH dosage, distance from mid-parental height in SDS, weight SDS, IGF-1 SDS) and 1 post-treatment predictor (height SDS gain at 6 months) were constructed by multivariate logistic regression analyses. The nomogram was built based on the multivariate predictive model and showed good discrimination and model fit effects in both the training set and the testing set. DCA and CIC analyses presented good clinical usability.

CONCLUSION

The clinical predictive model for predicting the probability of poor short-term response of rhGH treatment in pediatric patients with growth disorders is useful and can assist physicians in making clinical decisions.

Pharmacokinetics and pharmacodynamics of once-weekly administration of JR-142, a long-acting albumin-fused human growth hormone: A rondemized, placebo-controlled phase 1 study

OBJECTIVE

Under clinical development for patients with growth hormone deficiency, JR-142 is a long-acting growth hormone with a half-life extended by fusion with modified serum albumin. We conducted a Phase 1 study to investigate the safety, tolerability, and pharmacokinetic (PK) and pharmacodynamic (PD) profiles of once-weekly subcutaneous administrations of JR-142. The study consisted of two parts: an open-label single ascending dosing study (Part 1), and a randomized, placebo-controlled, assessor-blinded multiple ascending dosing study (Part 2).

DESIGN

A total of 31 healthy Japanese male participants were enrolled. In Part 1, seven of them received a single subcutaneous injection of JR-142 each at dosages of 0.15 mg/kg (n = 1), 0.25 mg/kg (n = 2), 0.5 mg/kg (n = 2), or 1.0 mg/kg (n = 2). In Part 2, one weekly subcutaneous injection of JR-142 at 0.25 mg/kg, 0.5 mg/kg, 1.0 mg/kg or a placebo were given for four weeks to each of the other 24 participants (six in each group). Plasma JR-142 and serum insulin-like growth factor-1 (IGF-1) concentrations were measured for PK and PD assessments. Safety was evaluated on the basis of adverse events (AEs), laboratory tests, and other measures.

RESULTS

JR-142 induced dose-dependent increases in the maximum plasma JR-142 concentration (C_max) and the area under the plasma concentration-time curve from time 0 to τ (AUC_0-τ). A similar dose-response relationship was observed in serum IGF-1 concentrations. All trough IGF-1 levels were well sustained one week after the final administrations of JR-142 at the three dosages, while the peak concentrations of IGF-1 remained mildly elevated. No serious AEs were observed, and laboratory tests, including assessment of anti-drug antibodies, uncovered no significant safety issues.

CONCLUSIONS

Once-weekly subcutaneous injections of JR-142 produced positive dose-dependent PK and PD profiles over the dosage range. Drug accumulation was observed after the four-week administration period but did not raise safety concerns, indicating that JR-142 is well-tolerated in healthy participants. The PD profiles observed in terms of IGF-1 concentrations were also positive, and we believe the encouraging results of this study warrant substantiation in further clinical trials in patients with GHD.

ETHICS

This clinical study was conducted at one investigational site in Osaka, Japan, where the clinical study and the non-clinical data of JR-142 were reviewed and approved by its Institutional Review Board on 9th May 2019. The study was conducted in compliance with the approved study protocol, the Declaration of Helsinki, 1964, as revised in 2013, and Good Clinical Practice.

Isolated growth hormone deficiency and amenorrhea - Case report

Introduction and importance

Growth hormone (GH) deficiency is the most common hypopituitarism disorder. We highlight the challenges to its diagnosis and management in the setting of a developing country.

Case description

A 14-year-old came with a chief complaint of inability to menstruate. Menarche was at 12-years old, lasted 7 days, soaking 2 pads/day which discontinued shortly after. Thelarche was at 12-years-old and her breast is at Tanner stage 3. Her axillary and pubic hair are at Tanner stage 1. Height was 120 cm, weight 34.8 kg, height for age z-score < -3. Her lab results were normal for estradiol, luteinizing hormone (LH), follicle-stimulating hormone (FSH) and prolactin. Bone age was suitable for age. Magnetic resonance imaging revealed pituitary gland hypoplasia (5.3 mm). A hormonal panel 3 years prior showed abnormally low GH level but normal cortisol and thyroid hormone levels. She was diagnosed with isolated growth hormone deficiency (IGHD) with delayed puberty. She was treated with medroxyprogesterone tablets once daily, after which her menstruation restarted. However, due to her economic background, she declined genetic tests, discontinued her medication and amenorrhea recurred.

Clinical discussion

Amenorrhea present after a brief menarche should alert gynaecologists of a possible multi-hormone disorder with an underlying structural abnormality. IGHD may be due to a structural abnormality, such as pituitary gland hypoplasia. Unfortunately, economic reasons prevented the patient from receiving optimal treatment.

Conclusion

IGHD rarely presents with a gynaecological complaint. Hormonal and genetic tests along with imaging should be undertaken. Growth hormone supplementation is the treatment of choice.

Epidemiology of Disorders Associated with Short Stature in Childhood: A 20-Year Birth Cohort Study in Finland

Background

Many primary and secondary disorders disturb growth and cause short stature (height below −2 SDS) in childhood. Growth monitoring programs aim at their early detection but are not evidence-based: epidemiology of childhood growth disorders is poorly characterized, and no consensus exists on priority target conditions. Herein, we describe population-based epidemiological data on several primary and secondary growth disorders associated with short stature in childhood.

Materials and Methods

This retrospective population-based 20-year birth cohort study examined 1 144 503 children (51% boys) born in Finland between 1998 and 2017, with 16.5 million care notifications including medical diagnoses. The first occurrences of key primary or secondary growth disorders were identified in multiple registers. Median ages at diagnosis (MAD), and age- and sex-specific cumulative incidences (CMI) from birth until 16 years of age were determined.

Results

Turner syndrome was the most common primary growth disorder (CMI 52 per 100 000 at 16 years, MAD 4.0 years). Most primary growth disorders were diagnosed before the age of 4 years, and thereafter, secondary growth disorders increased in number. MAD of growth hormone deficiency (GHD) was 8.7 (boys) and 7.2 years (girls). At 16 years, the CMI of GHD was higher in boys than in girls (127 versus 93 per 100 000, respectively), whereas the CMI of hypothyroidism was higher in girls (569 versus 306 per 100 000). Celiac disease was the most common secondary growth disorder and more common in girls than in boys (988 versus 546 per 100 000 at 16 years, respectively).

Conclusion

These population-based epidemiological data indicate that childhood growth monitoring should be age- and sex-specific. In the early childhood, the focus should be on primary growth disorders, and from preschool age also on secondary growth disorders. These results provide evidence for improving growth monitoring programs and diagnostic practices targeting on Turner syndrome, GHD, hypothyroidism, and celiac disease.

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.

Polyethylene glycol recombinant human growth hormone in Chinese prepubertal slow-growing short children: doses reported in a multicenter real-world study

BACKGROUND

To evaluate the effectiveness of individualized-dose polyethylene glycol recombinant human growth hormone (PEG-rhGH) for short stature.

METHODS

This real-world study enrolled children with short stature in 19 hospitals throughout China. They were treated with PEG-rhGH for 6 months. The starting dosage ranged from 0.10 to 0.20 mg/kg/week. The primary outcome was the change in height standard deviation score (ΔHt SDS).

RESULTS

Five hundred and ten patients were included and grouped based on dosage as A (0.10-0.14 mg/kg/week), B (0.15-0.16 mg/kg/week), C (0.17-0.19 mg/kg/week), and D (0.20 mg/kg/week). The mean 6-month ΔHt SDS for the total cohort was 0.49 ± 0.27, and the means differed among the four dose groups (P = 0.002). The ΔHt SDS was lower in group A than in groups B (LSM difference [95%CI], -0.09 [-0.17, -0.01]), C (LSM difference [95%CI], -0.10 [-0.18, -0.02]), and D (LSM difference [95%CI], -0.13 [-0.21, -0.05]) after adjusting baseline covariates. There were no significant differences among groups B, C, and D. When the baseline IGF-1 was < -2 SDS or > 0 SDS, the △Ht SDS was not different among the four groups (P = 0.931 and P = 0.400). In children with baseline IGF-1 SDS of -2 ~ 0 SDS, a higher dosage was associated with a better treatment effect (P = 0.003), and the △Ht SDS was lower in older children than in younger ones (P < 0.001).

CONCLUSIONS

PEG-rhGH could effectively increase height in prepubertal short children. When the baseline IGF-1 was < -2 SDS, 0.10 mg/kg/week could be a starting dose. In other IGF-1 statuses, 0.15-0.20 mg/kg/week might be preferred.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT03249480 , retrospectively registered.

Clinical Aspects of Genetic and Non-Genetic Cardiovascular Risk Factors in Familial Hypercholesterolemia

Familial hypercholesterolemia (FH) is the most common monogenic metabolic disorder characterized by considerably elevated low-density lipoprotein cholesterol (LDL-C) levels leading to enhanced atherogenesis, early cardiovascular disease (CVD), and premature death. However, the wide phenotypic heterogeneity in FH makes the cardiovascular risk prediction challenging in clinical practice to determine optimal therapeutic strategy. Beyond the lifetime LDL-C vascular accumulation, other genetic and non-genetic risk factors might exacerbate CVD development. Besides the most frequent variants of three genes (LDL-R, APOB, and PCSK9) in some proband variants of other genes implicated in lipid metabolism and atherogenesis are responsible for FH phenotype. Furthermore, non-genetic factors, including traditional cardiovascular risk factors, metabolic and endocrine disorders might also worsen risk profile. Although some were extensively studied previously, others, such as common endocrine disorders including thyroid disorders or polycystic ovary syndrome are not widely evaluated in FH. In this review, we summarize the most important genetic and non-genetic factors that might affect the risk prediction and therapeutic strategy in FH through the eyes of clinicians focusing on disorders that might not be in the center of FH research. The review highlights the complexity of FH care and the need of an interdisciplinary attitude to find the best therapeutic approach in FH patients.

Prevalence of endocrine disorders among children exposed to Lavender Essential Oil and Tea Tree Essential Oils

Background

Lavender essential oil and tea tree essential oil have become popular ingredients in personal care and household products in recent decades. Questions regarding the safety of these oils in pediatric populations have been raised, proposing a link between these essential oils and endocrine disruption in children, specifically prepubertal gynecomastia. To date, no epidemiological studies have been conducted to evaluate this proposed link.

Methods

This is a cross sectional study conducted among parents of children in the United States to identify the prevalence of endocrine disruption in children aged 2-15 years old. This study also evaluates the potential for a relationship between the exposure of lavender essential oil and tea tree essential oil products and endocrine disrupting outcomes.

Results

In 556 children with a mean age of 6.33 (SD = 3.92), prevalence of endocrine disruption was .016 (SD = 0.13). No cases of prepubertal gynecomastia were identified in either group, and prevalence of precocious puberty, delayed puberty, growth hormone deficiency, and hypothyroidism were all consistent with population norms. Total risk of endocrine disorders among those exposed (0.0194) did not differ from the risk of those unexposed (0.0069). The risk ratio was 2.796 (95% CI: 0.352, 22.163, P = .458).

Conclusion

Children who were regularly exposed to lavender or tea tree essential oils experienced the same risk of endocrine disorders as those who were not exposed.

Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Macimorelin in Children with Suspected Growth Hormone Deficiency: An Open-Label, Group Comparison, Dose-Escalation Trial

BACKGROUND/AIMS

Diagnosis of growth hormone deficiency (GHD) in children requires the use of provocative growth hormone (GH) stimulation tests, which can have limited reliability and are potentially contraindicated in some patients. This is the first paediatric study to test the safety, tolerability, and pharmacokinetics (PK)/pharmacodynamics (PD) of macimorelin, an oral GH secretagogue, approved for diagnosis of adult GHD.

METHODS

In this open-label, group comparison, single-dose escalation trial (EudraCT 2018-001988-23), sequential cohorts of patients (C1-C3) received ascending single doses of macimorelin: 0.25 (C1), 0.5 (C2), and 1.0 (C3) mg/kg. Primary endpoints were safety and tolerability, and secondary endpoints were PK/PD.

RESULTS

Twenty-four patients aged between 2 and <18 with suspected GHD participated in the study. No macimorelin-related adverse events were reported, and macimorelin was well tolerated. Plasma macimorelin concentrations increased with dose: mean areas under the curve were 6.69 (C1), 18.02 (C2), and 30.92 (C3) h × ng/mL; mean maximum concentrations were 3.46 (C1), 8.13 (C2), and 12.87 (C3) ng/mL. GH concentration increased following macimorelin administration: mean times of maximum measured concentration were 52.5 (C1), 37.5 (C2), and 37.5 (C3) min.

CONCLUSION

All 3 doses of macimorelin had excellent safety and tolerability with PK/PD profiles in expected ranges. These results support the use of 1.0 mg/mL macimorelin in a Phase 3 test validation trial in children.

Is Gadolinium Contrast Necessary for Pituitary MRI in the Evaluation of Pediatric Short Stature and Growth Hormone Deficiency?

INTRODUCTION

Short stature is a common concern that necessitates pediatric endocrinology evaluation. Growth hormone deficiency (GHD) is a commonly considered etiology. Brain and pituitary magnetic resonance imaging (MRI) with gadolinium-based contrast agents (GBCAs) is the most widely used imaging in assessing patients with GHD. Given the significant strides made in MRI technology, the need for contrast material should be reassessed.

METHOD

We performed a retrospective review of healthy patients with short stature and/or GHD who underwent brain and pituitary MRI with and without contrast to assess the added value of contrast administration.

RESULTS

227/318 identified patients underwent growth hormone (GH) stimulation testing; 28 (12.3%) with normal GH response and 62 (27.3%) with severe GHD. We found a low incidence of sellar and suprasellar pathologies. When comparing noncontrast and contrast MRI, we found perfect agreement in detecting abnormal posterior pituitary bright spots (kappa:1.0) and substantial agreement in detecting pars intermedia cysts and posterior superior sellar cysts (kappa: 0.74 and 0.71, respectively). Initially, only moderate agreement was found in detecting infundibular abnormalities (kappa: 0.51), although a revised noncontrast MRI protocol with high-resolution 3D images enabled visualization of the infundibulum.

CONCLUSION

The MRI evaluation of healthy patients with short stature and/or isolated GHD may be completed without the use of GBCAs. The slight overestimation of pituitary stalk interruption by noncontrast images can be overcome by adding newer high-resolution sequences.

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.

Suboptimal adherence to daily growth hormone in a US real-world study: an unmet need in the treatment of pediatric growth hormone deficiency

OBJECTIVE

To evaluate adherence to, and discontinuation of, somatropin treatment over 4 years in a US population-based study of children with pediatric growth hormone deficiency (pGHD).

METHODS

A retrospective cohort analysis of commercially insured patients ≥3 and <16 years, diagnosed with pGHD, newly treated with somatropin was conducted using Optum De-identified Clinformatics Data Mart. Index date was defined as the first prescription for somatropin between 01 July 2002 and 30 September 2019. Five non-exclusive patient cohorts were identified (>3, 12, 24, 36, and 48 months of post-index continuous enrollment). Suboptimal adherence was defined as medication possession ratio <80%. Discontinuation was defined as the date at which a gap of >60 days between somatropin fills first occurred. Cox proportional hazards regression was used to evaluate time to discontinuation.

RESULTS

In the 12-month cohort (n = 3091), mean age was 11.3 ± 2.9 years, 75.9% were male, 70.9% white, 9.4% Hispanic, 3.6% Asian, and 3.1% black. The proportion with suboptimal adherence at months 12 and 48 was 19.6% and 35.9%, respectively. Discontinuation occurred in 42.2% of patients. The rate of discontinuation (HR [95% CI]) was higher for age ≥10 (1.74 [1.53-1.98]), females (1.35 [1.21-1.50]), black and Hispanic race/ethnicity (1.50 [1.18-1.90] and 1.27 [1.09-1.49] compared to White) and obesity (1.69 [1.19-2.40]).

CONCLUSION

Suboptimal adherence increases with treatment duration, and risk of discontinuation is associated with age, female gender, black or Hispanic race/ethnicity, and obesity. Strategies that facilitate adherence among children at risk of discontinuation may improve clinical outcomes.

Noncontrast MRI Protocol for Selected Pediatric Pituitary Endocrinopathies: A Procedure with High Diagnostic Yield and Potential to Reduce Anesthesia and Gadolinium-Based Contrast Exposure

BACKGROUND AND PURPOSE

Although many pediatric neuroradiology practices empirically use noncontrast brain and pituitary MR imaging for evaluation of growth hormone deficiency, central precocious puberty, and short stature, there are currently insufficient published data to support this practice in an evidence-based fashion. Therefore, the use of contrast-enhanced MR imaging for all pediatric pituitary endocrinopathies remains widespread. We evaluated whether noncontrast MR imaging has adequate diagnostic yield for the evaluation of pediatric growth hormone deficiency, central precocious puberty, and short stature.

MATERIALS AND METHODS

Pituitary MR imaging studies obtained for growth hormone deficiency, central precocious puberty, or short stature in patients 0-18 years of age from 2010 to 2019 were analyzed. Separate blinded review of noncontrast images in cases with abnormalities on the original radiology report was performed by 2 subspecialty-trained pediatric neuroradiologists, with discrepancies resolved by consensus.

RESULTS

Of the 134/442 MR imaging studies obtained for growth hormone deficiency, central precocious puberty, or short stature with hypothalamic-pituitary region abnormalities, there was 70% concordance with the original reports on blinded review of noncontrast images. Twenty-two of 40 discrepancies were deemed unrelated to the indication, and 9 cases originally interpreted as possible microadenoma were read as having normal findings on blinded review. Only 9 of 40 discrepancies required contrast for further characterization.

CONCLUSIONS

In our study, most relevant radiologic findings in patients with growth hormone deficiency, central precocious puberty, and short stature were detectable without contrast, providing evidence that contrast can be avoided in routine MR imaging evaluation of these indications. We propose a "rapid noncontrast pituitary" MR imaging protocol for pediatric patients presenting with growth hormone deficiency, central precocious puberty, or short stature, which may increase efficiency and decrease contrast and anesthesia exposure.

Gene polymorphisms in leptin and its receptor and the response to growth hormone treatment in patients with idiopathic growth hormone deficiency

This study aimed to investigate the relationships between genetic polymorphisms of leptin/receptor genes and clinical/biochemical characteristics in children with growth hormone deficiency (GHD). Ninety-three GHD children and 69 age-matched normal controls were enrolled. Anthropometric measurements, bone age, and laboratory test results were obtained. Polymorphisms in the LEP gene promoter locus (LEP-2548, rs7799039) and LEPR genes (K109R, rs1137100 and Q223R, rs1137101) were analyzed using PCR-RFLP. The serum leptin levels were measured using an ELISA kit. The median height and BMI z-scores of all GHD subjects were -2.20 and -0.26, respectively, and those of normal controls were -0.30 and -0.13, respectively. The serum leptin levels were similar between GHD subjects and normal controls (p = 0.537), but those were different between the complete GHD (6.97 ng/mL) and partial GHD (4.22 ng/mL) groups (p = 0.047). There were no differences in the genotypic distributions of LEP-2548, LEPR K109R, and Q223R between GHD subjects and normal controls. However, GHD subjects with the G allele at LEP-2548 showed higher IGF-1 (p = 0.047) and IGFBP-3 SDSs (p = 0.027) than GHD subjects with the A allele. GHD subjects with the G allele at LEPR Q223R showed lower stimulated GH levels (p = 0.023) and greater height gain after 1 year of GH treatment (p = 0.034) than GHD subjects with the A allele. In conclusion, leptin/leptin receptor genes are suggested to have the role of growth-related factors, which can affect various growth responses in children who share the same disease entity.

Revisiting peak serum cortisol response to insulin-induced hypoglycemia in children

PURPOSE

To evaluate factors that could potentially affect the hypothalamic-pituitary adrenal (HPA) axis response to insulin-induced hypoglycemia in children without history or symptoms of adrenal insufficiency and to propose a cut-off value to define a normal response in this population.

METHODS

Exploratory single-center study involving 78 children that prospectively underwent insulin tolerance test (ITT) for suspected growth hormone (GH) deficiency.

METHODS

Glucose, cortisol, GH, adrenocorticotrophic hormone (ACTH), epinephrine and norepinephrine levels were measured at baseline and after insulin-induced hypoglycemia. Serum cortisol was measured using Access automated immunoassay.

RESULTS

Mean (range) basal morning serum cortisol of 8 (2.2-19.5) µg/dL/222 (61-542) nmol/L increased after hypoglycemia to 20.5 (14.6-29.5) µg/dL/570 nmol/L (405-819) nmol/L. Peak serum cortisol levels of 14.6 µg/dL (405 nmol/L) and 15.4 µg/dL (428 nmol/L) corresponded to the 2.5th and 5th percentiles, respectively. Peak serum cortisol correlated with peak plasma epinephrine (r = 0.367; P = 0.0014) but did not correlate with age, BMI-SD or peak serum GH. Children with intact and abnormal GH responses presented similar mean peak serum cortisol levels (20.0 vs. 20.6 µg/dL/555 vs. 572 nmol/L; P = 0.21).

CONCLUSION

Our data indicate that the current cut-off to define normal HPA axis response in children after insulin-induced hypoglycemia warrants reevaluation to avoid over-diagnosis of adrenal insufficiency. Our results suggest that peak serum cortisol levels ≥ 15.4 µg/dL (428 nmol/L) in children undergoing ITT might represent a normal cortisol response to stress, regardless of age, BMI or GH secretory capacity.

Incidental Pituitary Cysts in Children: Does Growth Hormone Treatment Affect Cyst Size?

OBJECTIVE

To evaluate the response of incidentally discovered pituitary cysts to growth hormone (GH) treatment.

METHODS

A retrospective chart review was performed of children with pituitary cysts on magnetic resonance imaging (MRI) over a 5-year period. Records and images were reviewed, and the results were analyzed using descriptive statistics. Children with pituitary cysts who received GH treatment were compared with those without.

RESULTS

We identified 109 children with pituitary cysts, 24 were treated with GH therapy. The average age was 8.5 ± 5.1 years. Children whose initial MRI scan was to evaluate growth hormone deficiency were more commonly male and non-Hispanic White compared with those with scans for other indications (male, 18 of 24 vs 35 of 85, P = .003; White, 23 of 24 vs 58 of 85, P = .004). Among patients who received GH treatment, 12 had follow-up MRI. Six had no change in cyst size and 6 had a decrease in cyst size. We observed no difference in the likelihood of cyst growth between those who received GH and those who did not (0 of 12 cysts with GH vs 1 of 15 cysts without GH showed growth at follow-up). No patient had neurologic deficits attributable to the pituitary cyst at any time.

CONCLUSION

In a single-institution, retrospective study, we find no evidence of growth in pituitary cysts in response to GH therapy.

When They're Done Growing, Don't Forget They May Still Need Growth Hormone

The effect of the growth hormone (GH) in promoting linear growth is well known; however, less recognized by practitioners especially pediatric, are its metabolic properties. This may be because the deleterious effects of improperly treated or untreated growth hormone deficiency (GHD) can present beyond the pediatric years. In addition, clinicians may lack familiarity with the potential issues that can arise due to inadequately treated GHD. Considering information from both the basic sciences research and clinical medicine, pediatric practitioners should be cognizant about the metabolic effects of GH. They should also be equipped to provide anticipatory guidance to patients regarding the importance of adherence to therapy in GHD and be prepared to transition patients with permanent GHD from pediatric GH supplementation to adult GH dosing. With a lack of proper transitioning, adverse outcomes may present beyond childhood.

Adult growth hormone deficiency: Optimizing transition of care from pediatric to adult services

OBJECTIVE

Most patients with childhood-onset growth hormone deficiency (CO-GHD) receive treatment with exogenous growth hormone (GH) to facilitate the attainment of their full potential adult height. Recent evidence suggests that continuing GH administration during the transition period between the end of linear growth and full adult maturity is necessary for proper body composition and bone and muscle health, and may also have beneficial effects on metabolic parameters, bone mineral density, and quality of life. The timing of this transition period coincides with the transfer of care from a pediatric to an adult endocrinologist, creating the potential for a care gap as a consequence of losing the patient to follow-up.

DESIGN

An advisory board comprising both pediatric and adult endocrinologists was assembled to address current clinical unmet needs and to collaborate on a structured transitional plan for optimal management of patients with CO-GHD.

INSIGHTS/CONCLUSION

The advisors suggest collaborative, multidisciplinary approaches to ensure continuity of care; ongoing testing and monitoring of GHD status into adulthood; and a clearly structured protocol that includes practical guidance for clinicians to establish best practices for transitioning older adolescents with persistent CO-GHD to adult care.

Growth, body composition, and endocrine issues in Williams syndrome

PURPOSE OF REVIEW

Williams syndrome is a multisystem disorder caused by a microdeletion on chromosome 7q. Throughout infancy, childhood, and adulthood, abnormalities in body composition and in multiple endocrine axes may arise for individuals with Williams syndrome. This review describes the current literature regarding growth, body composition, and endocrine issues in Williams syndrome with recommendations for surveillance and management by the endocrinologist, geneticist, or primary care physician.

RECENT FINDINGS

In addition to known abnormalities in stature, calcium metabolism, and thyroid function, individuals with Williams syndrome are increasingly recognized to have low bone mineral density, increased body fat, and decreased muscle mass. Furthermore, recent literature identifies a high prevalence of diabetes and obesity starting in adolescence, and, less commonly, a lipedema phenotype in both male and female individuals. Understanding of the mechanisms by which haploinsufficiency of genes in the Williams syndrome-deleted region contributes to the multisystem phenotype of Williams syndrome continues to evolve.

SUMMARY

Multiple abnormalities in growth, body composition, and endocrine axes may manifest in individuals with Williams syndrome. Individuals with Williams syndrome should have routine surveillance for these issues in either the primary care setting or by an endocrinologist or geneticist.

Discriminatory performance of insulin-like growth factor 1 and insulin-like growth factor binding protein-3 by correlating values to chronological age, bone age, and pubertal status for diagnosis of isolated growth hormone deficiency

PURPOSE

The discriminatory performance of insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) was investigated by correlating their values with chronological age (CA), bone age (BA), and pubertal status (PS) for diagnosis of isolated growth hormone deficiency (IGHD).

METHODS

We evaluated IGF-1 and IGFBP-3 levels in 310 short-stature subjects subdivided into 2 groups: IGHD (n=31) and non-IGHD (n=279). IGF-1 and IGFBP-3 were assayed using immune-radiometric assay and transformed into standard deviation score (SDS) according to CA, BA, and PS.

RESULTS

The highest sensitivity was found in IGF-1-SDS for CA and IGFBP-3-SDS for CA (22.6% and 30.0%, respectively). The highest specificity was found in IGF-1-SDS for PS and IGFBP-3-SDS for PS (98.2% and 94.4%, respectively). Groups with the highest positive predictive values were IGF-1-SDS for BA and IGFBP-3-SDS for BA (10.9% and 5.1%, respectively). Highest negative predictive values were seen in IGF-1-SDS for CA and IGFBP-3-SDS for CA (98.4% and 98.4%, respectively).

CONCLUSION

IGF-1-SDS for CA, instead of IGF-1-SDS for BA or PS, could be used as a standard variable for IGHD screening. The sufficiently high specificity of IGF-1-SDS for PS suggests that this value is a useful tool for identification of IGHD.

Measuring IGF-1 and IGFBP-3 Profiles in Women Seeking Assisted Reproduction; Relationship to Clinical Parameters (Study 1)

This study examines the IGF serum profile (IGF-1, IGFBP-3 and the IGF Ratio) from 1633 women who undertook an Assessment Cycle prior to any treatment by assisted reproduction. The idea is to progressively study the IGF profile with a view to identify those women who may be classified as having adult growth hormone deficiency (AGHD) and who may benefit from specific dynamic endocrinological testing to identify a potential benefit from growth hormone adjuvant treatment. This first study evaluates the IGF profile on clinical parameters, namely age, body mass index (BMI) and stature. The study shows a significant linear reduction in IGF-1 levels across the four age groups (<35 years, 35–39 years, 40–44 years and ≥45 years; p < 0.001). However, there was no variation in IGFBP-3 levels but the IGF Ratio showed a progressive linear elevation with advancing age (p < 0.001). With respect to both BMI and stature, none of the IGF profile parameters showed any variation. We conclude that further studies are warranted to examine the notion of underlying AGHD in the causation of the well-known feature of age-related poor prognosis in assisted reproduction.

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.

A novel diagnostic tool for the evaluation of hypothalamic-pituitary region and diagnosis of growth hormone deficiency: pons ratio

Backgrounds Limitations in the evaluation of the pituitary size and changes according to pubertal status make its validity questionable. Recently, in a small-scale study, pons ratio (PR) has been suggested as a more sensitive tool for diagnosis and etiological evaluation of growth hormone deficiency (GHD). The aim of the study is to evaluate the diagnostic value of PR in the diagnosis of GHD. Methods We retrospectively evaluated the pituitary magnetic resonance imaging (MRI) of 133 patients with a diagnosis of GHD. Primary axis (PA) was assigned as a line crossing the mid-sagittal dorsum sella and fourth ventricle. PR was defined as the pons height above the PA divided by total pons height. The PR of patients with GHD was compared to subjects without GHD. Results Study included 133 patients with GHD and 47 controls. In total, 121 (91%) patients had isolated GHD and 12 (9%) patients had multiple pituitary hormone deficiency. The PR of the patient group (mean: 0.32 ± 0.89; range: 0.14-0.63) was significantly higher than controls (mean: 0.26 ± 0.067; range 0.19-0.44) (p: 0.000). The optimal cut-off value of PR for GHD diagnosis was 0.27 (sensitivity 71% specificity 56%). There was a negative correlation between anterior pituitary height (APH)-SDS and PR (p: 0.002; r: -0.27). APH was increased, but PR remained unchanged in pubertal patients (p: 0.089). Conclusions PR measurement is a noninvasive, practical method with a cost-benefit clinical value. As it is not affected by pubertal status, PR is potentially a more sensitive tool for evaluation of pituitary gland in GHD patients compared to APH.

Early Recovery of Height Velocity in Prepubertal Children With Acute Lymphoblastic Leukemia Treated by a Short Intensive Phase Without Cranial Radiation Therapy

PURPOSE

There have been few reports on height disturbance in childhood acute lymphoblastic leukemia (ALL) patients treated without cranial radiation therapy (CRT). Our study aimed to clarify the critical period of growth in pediatric patients who were treated by the Japan Childhood Leukemia Study (JACLS) ALL-02 protocol, which involved short-term intensive treatment without CRT.

PATIENTS AND METHODS

A retrospective, cohort study was conducted for prepubertal children with B-precursor ALL who were diagnosed from July 2002 to November 2011 and treated by the JACLS ALL-02 protocol at Oita University Hospital. The heights were chronologically measured at pretreatment, after the intensive phase (INT), at the end of treatment (END), and at 1 to 5 year(s) posttreatment (POST 1 to 5).

RESULTS

Nine boys and 4 girls were enrolled. Z score of the height was reduced at INT and END. Delta Z scores of the height and Z score of height velocity were reduced from pretreatment to INT, and they demonstrated an early recovery during maintenance treatment in INT to END.

CONCLUSIONS

Early recovery of delta Z scores of the height and Z score of height velocity was observed during the INT to END period. The shortened intensive phase without CRT may result in an adequate height in prepubertal ALL patients.

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.

Anthropometric and biochemical correlates of PAPP-A2, free IGF-I, and IGFBP-3 in childhood

OBJECTIVE

Pregnancy-associated plasma protein-A2 (PAPP-A2) is a metalloproteinase that cleaves IGFBP-3 and IGFBP-5. Human mutations in PAPPA2 result in short stature with a low percentage of free IGF-I. Little is known about PAPP-A2 levels and the regulation of free IGF-I throughout childhood. We examined PAPP-A2 and intact IGFBP-3 levels in childhood and explored associations between PAPP-A2, free and total IGF-I, and total and intact IGFBP-3 and their relationship to the percentage of free to total IGF-I and anthropometric factors.

DESIGN

Cross-sectional study at a single center.

METHODS

PAPP-A2, free IGF-I, and intact IGFBP-3 levels were measured in childhood (3-18 years old) and an evaluation of the relationship between these proteins and anthropometric factors.

RESULTS

In 838 children, PAPP-A2 consistently decreased throughout childhood. In contrast, free IGF-I increased. A pubertal peak in free IGF-I was present in females but was less evident in males. Intact and total IGFBP-3 increased throughout childhood; however, intact IGFBP-3 had a more marked rise than total IGFBP-3. Percent free IGF-I decreased with no distinct pubertal peak. PAPP-A2 levels positively correlated with the percent free IGF-I (Male, Female; r = 0.18, 0.38; P < 0.001) and negatively with intact IGFBP-3 (Male, Female; r = -0.58, -0.65; P < 0.0001).

CONCLUSIONS

This is the first study to describe serum PAPP-A2 and intact IGFBP-3 in children between 3 and 18 years of age. Our correlative findings suggest that PAPP-A2 is an important regulator of the percent free IGF-I which can be a marker of perturbations in the GH/IGF-I axis.