Diagnosis of severe growth hormone deficiency in the newborn

Pituitary Disorders

In this article, we will review common pituitary disorders. There are 6 hormones secreted by the anterior pituitary gland: thyroid-stimulating hormone, adrenocorticotropic hormone, follicle-stimulating hormone, luteinizing hormone, growth hormone, and prolactin. The posterior pituitary gland stores and releases the hormones made in the hypothalamus, oxytocin and antidiuretic hormone, based on the body's needs. This article will discuss the role of these hormones, conditions and symptoms that occur with elevated or reduced hormone levels, as well as the evaluation and treatment of these pituitary disorders.

Estimation of the reference values and decision limits for growth hormone in newborns using dried blood spots

OBJECTIVES

Severe deficiency of growth hormone (GHD) of the newborn is a rare but potentially life-threatening disease. GH measured during the first week of life, using dried blood spots (DBS), may offer several advantages. Aim of the study was to estimate the reference values for GH in newborns by a new analytical method using DBS.

METHODS

Using a new developed analytical method, GH was estimated from DBS of 1,036 healthy newborns attending the Neonatology Unit of Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico of Milan in the period July-October 2021. Reference values for GH deficiency were estimated by the Harrell-Davis bootstrap method, with 90 %CI calculated by the bias-corrected and accelerated bootstrap method.

RESULTS

All GH measurements required 33 analytical sessions (8 months) with a CV% for calibration curve slopes equal to 6.9 %. Intermediate precision evaluated by measurement of low (3 μg/L) and high (10 μg/L) quality controls was, respectively, 14 and 6.5 %. GH reference values, estimated at percentiles 1.0st, 2.5th and 5.0th, and their 90 %CI, were, respectively, 4.5 μg/L (90 %CI 3.8-5.1), 5.9 μg/L (90 %CI 5.4-6.4) and 7.0 μg/L (90 %CI 6.7-7.3). GH levels were not associated with sex, standard deviation scores, birth weight, gestational age, type of delivery or mother's variables (age, smoking habit, gestational diabetes).

CONCLUSIONS

Validation data suggest that this method can be used to measured GH in newborns using DBS. The reference values estimated in this study are in accordance with previous published works using ELISA and may help confirming the clinical suspicion of neonatal GHD.

Factors associated with neonatal hyperinsulinemic hypoglycemia, a case-control study

OBJECTIVES

We aimed to identify perinatal risk factors associated with hyperinsulinemic hypoglycemia in neonates. Secondary objectives included an examination of clinical and biochemical characteristics at the time of diagnosis and an exploration of the duration of diazoxide therapy.

METHODS

A case-control study was conducted, involving individual chart reviews of inborn infants diagnosed with hyperinsulinemic hypoglycemia (the HH group) between 2014 and 2021. These cases were paired with controls (the non-HH group) belonging to the same gestational age (GA) strata who did not exhibit HH or only had transient postnatal hypoglycemia.

RESULTS

A total of 52 infants with HH were matched with corresponding controls. The mean GA in the HH group was 34.4 ± 3.1 weeks. Notably, the HH group exhibited lower mean minimum plasma glucose (PG) levels and required higher glucose infusion rates in comparison to the non-HH group (26.5 ± 15.6 vs. 49.1 ± 37.7 mg/dL and 12.9 ± 3.8 vs. 5.7 ± 2.1 mg/kg/min, respectively; p<0.001 for both). After adjusting for potential confounding factors, only two variables, fetal growth restriction (FGR) and neonatal sepsis, demonstrated significant associations with HH (adjusted odds ratio [95 % confidence interval]: 8.1 [2.1-31.0], p=0.002 and 6.3 [1.9-21.4], p=0.003, respectively). The median duration of diazoxide therapy for the HH group was 4 months.

CONCLUSIONS

FGR and neonatal sepsis emerged as notable risk factors for HH. These infants exhibited lower PG levels and necessitated higher glucose infusion rates compared to their non-HH counterparts. Importantly, a substantial proportion of the HH group received diazoxide therapy, with a median treatment duration of 4 months.

[Diagnostic significance and considerations of growth hormone stimulation testing and insulin-like growth factor 1 in growth hormone deficiency]

The growth hormone (GH)/insulin-like growth factor 1 (IGF-1) axis is an essential component of the hypothalamic-pituitary growth hormone axis and plays a crucial role in childhood growth and development. Disruptions and abnormalities in the GH/IGF-1 signaling pathway and its pathways typically manifest as short stature in children. Children with short stature often undergo GH stimulation testing and IGF-1 level measurements to differentiate growth hormone deficiency (GHD) from other causes of growth delay. This article aims to analyze and elucidate the values of GH stimulation testing and IGF-1 measurement, providing reference for the diagnosis of GHD in children.

Neonatal Endocrine Diseases

Endocrine diseases are rare and can present very subtly in the neonatal period. Most are diagnosed using newborn screening in the United States; however, some infants may present with false negatives or more subtle findings. Endocrine etiologies should be considered during the management of critically ill infants. This article will give an overview of endocrine emergencies encountered in the neonatal period, including disorders of glucose metabolism, thyroid disorders, adrenal disorders, and pituitary disorders.

Management of Neonatal Isolated and Combined Growth Hormone Deficiency: Current Status

Congenital growth hormone deficiency (GHD) is a rare disease caused by disorders affecting the morphogenesis and function of the pituitary gland. It is sometimes found in isolation but is more frequently associated with multiple pituitary hormone deficiency. In some cases, GHD may have a genetic basis. The many clinical signs and symptoms include hypoglycaemia, neonatal cholestasis and micropenis. Diagnosis should be made by laboratory analyses of the growth hormone and other pituitary hormones, rather than by cranial imaging with magnetic resonance imaging. When diagnosis is confirmed, hormone replacement should be initiated. Early GH replacement therapy leads to more positive outcomes, including reduced hypoglycaemia, growth recovery, metabolic asset, and neurodevelopmental improvements.

The Year in Growth and Short Stature

The papers and communications selected here, published in 2020-2021, report major advances in pathophysiology, diagnostics, treatment and patient care in the fields of growth hormones and disorders. © 2022 French Society of Pediatrics. Published by Elsevier Masson SAS. All rights reserved.

Diagnosis of GH Deficiency Without GH Stimulation Tests

Growth hormone deficiency (GHD) is the most commonly affected pituitary hormone in childhood with a prevalence of 1 in 4000-10000 live births. GH stimulation testing (GHST) is commonly used in the diagnostic workup of GHD. However, GHD can be diagnosed in some clinical conditions without the need of GHST. The diagnosis of GHD in newborns does not require stimulation testing. Likewise infants/children with delayed growth and/or short stature associated with neuroradiological abnormalities and one or more additional pituitary hormone deficiencies may not need GHST. This review summarizes the current evidence on the diagnosis of GHD without stimulation tests.

Advances in differential diagnosis and management of growth hormone deficiency in children

Growth hormone (GH) deficiency (GHD) in children is defined as impaired production of GH by the pituitary gland that results in growth failure. This disease might be congenital or acquired, and occurs in isolation or in the setting of multiple pituitary hormone deficiency. Isolated GHD has an estimated prevalence of 1 patient per 4000-10,000 live births and can be due to multiple causes, some of which are yet to be determined. Establishing the correct diagnosis remains key in children with short stature, as initiating treatment with recombinant human GH can help them attain their genetically determined adult height. During the past two decades, our understanding of the benefits of continuing GH therapy throughout the transition period from childhood to adulthood has increased. Improvements in transitional care will help alleviate the consequent physical and psychological problems that can arise from adult GHD, although the consequences of a lack of hormone replacement are less severe in adults than in children. In this Review, we discuss the differential diagnosis in children with GHD, including details of clinical presentation, neuroimaging and genetic testing. Furthermore, we highlight advances and issues in the management of GHD, including details of transitional care.

Short and Long-Term Effects of Growth Hormone in Children and Adolescents With GH Deficiency

The syndrome of impaired GH secretion (GH deficiency) in childhood and adolescence had been identified at the end of the 19th century. Its non-acquired variant (naGHD) is, at childhood onset, a rare syndrome of multiple etiologies, predominantly characterized by severe and permanent growth failure culminating in short stature. It is still difficult to diagnose GHD and, in particular, to ascertain impaired GH secretion in comparison to levels in normally-growing children. The debate on what constitutes an optimal diagnostic process continues. Treatment of the GH deficit via replacement with cadaveric pituitary human GH (pit-hGH) had first been demonstrated in 1958, and opened an era of therapeutic possibilities, albeit for a limited number of patients. In 1985, the era of recombinant hGH (r-hGH) began: unlimited supply meant that substantial long-term experience could be gained, with greater focus on efficacy, safety and costs. However, even today, the results of current treatment regimes indicate that there is still a substantial fraction of children who do not achieve adult height within the normal range. Renewed evaluation of height outcomes in childhood-onset naGHD is required for a better understanding of the underlying causes, whereby the role of various factors - diagnostics, treatment modalities, mode of treatment evaluation - during the important phases of child growth - infancy, childhood and puberty - are further explored.

20p11.23-p11.21 deletion in a child with hyperinsulinemic hypoglycemia and GH deficiency: A case report

Some neonatal hypoglycemias have genetic origins. For instance, mutation in forkhead box protein A2 (FOXA2), located on chromosome 20p11.21, has recently been reported to cause hyperinsulinemic hypoglycemia and hypopituitarism. Here, we report a case of hyperinsulinemic hypoglycemia and GH deficiency (GHD) with 20p11.23-p11.21 deletion, which included FOXA2. The boy was diagnosed with hyperinsulinemic hypoglycemia during the neonatal period and subsequently administered diazoxide for treatment. His blood glucose levels gradually stabilized, and the diazoxide dosage was slowly reduced and ultimately fully weaned. The patient was discharged at the age of 29 d. Unfortunately, the patient experienced recurrent hypoglycemia at 3 mo, and diazoxide administration was re-initiated. Further examination, including chromosomal microarray analysis, revealed a 2.48-Mb 20p11.23-p11.21 deletion that encompassed FOXA2. In addition, severe GHD was detected, and magnetic resonance imaging of the brain revealed pituitary stalk interruption. Accordingly, GH replacement therapy was started at 0.175 mg/kg/wk, and blood glucose levels were stabilized. Our report suggests that there are pathological conditions that can cause both hyperinsulinemic hypoglycemia and hypopituitarism and reaffirms the importance of evaluating not only insulin and congenital metabolic disorders but also pituitary function in patients with hypoglycemia.