Likelihood of persistent GH deficiency into late adolescence: relationship to the presence of an ectopic or normally sited posterior pituitary gland

Clinical and laboratory characteristics but not response to treatment can distinguish children with definite growth hormone deficiency from short stature unresponsive to stimulation tests

Introduction

It has been proposed that not all children with short stature displaying an inadequate response to tests for growth hormone (GH) secretion truly suffer from GH deficiency (GHD). Only children with a monogenic cause of GHD or an identifiable combined hormonal deficiency or anatomical anomaly in the hypothalamic-pituitary axis should be considered definite GHD (dGHD). The remaining patients can be defined as a separate group of patients, "short stature unresponsive to stimulation tests" (SUS). The aim of this proof-of-concept study, was to assess whether SUS patients treated with rhGH exhibit any differences compared to GHD patients undergoing the same treatment.

Methods

Retrospective analysis on 153 consecutive patients with short stature and pathological response to two GH stimulation tests. Patients with dGHD were defined as those with a clear genetic or anatomical hypothalamic-pituitary anomaly, as well as those with combined pituitary hormone deficiencies and those with a known insult to the hypothalamic-pituitary axis (i.e. total brain irradiation) (n=38, 25%); those without any of the previous anomalies were defined as SUS (n=115, 75%).

Results

At diagnosis, dGHD and SUS populations did not differ significantly in sex (F 32% vs 28%, p=0.68), age (11.9 vs 12.1, p=0.45), height SDS at diagnosis (-2.2 vs. -2.0, p=0.35) and prevalence of short stature (height <-2 SDS) (56% vs 51%, p=0.45). IGF-1 SDS were significantly lower in dGHD (-2.0 vs -1.3, p<0.01). After 1 year of treatment, the prevalence of short stature was significantly reduced in both groups (31% in dGHD vs. 21% in SUS, p<0.01) without any significant differences between groups (p=0.19), while the increase in IGF-1 SDS for bone age was greater in the dGHD category (+1.9 vs. +1.5, p<0.01), with no further difference in IGF-1 SDS between groups. At the last available follow-up, 59 patients had reached the near adult height (NAH) and underwent retesting for GHD. No differences in NAH were found (-0.3 vs. -0.4 SDS, 0% vs. 4% of short stature). The prevalence of pathological retesting was higher in dGHD (60% vs. 10%, p<0.01) as well as of overweight and obesity (67% vs. 26%).

Conclusion

Stimulation tests and the equivalent benefit from rhGH therapy, cannot distinguish between dGHD and SUS populations. In addition, lower IGF-1 concentrations at baseline and their higher increase during treatment in dGHD patients, and the lack of pathological retesting upon reaching NAH in SUS patients, are facts that suggest that deficient GH secretion may not be the cause of short stature in the SUS studied population.

The Growth Hormone Deficiency (GHD) Reversal Trial: effect on final height of discontinuation versus continuation of growth hormone treatment in pubertal children with isolated GHD-a non-inferiority Randomised Controlled Trial (RCT)

BACKGROUND

Growth hormone deficiency (GHD) is the commonest endocrine cause of short stature and may occur in isolation (I-GHD) or combined with other pituitary hormone deficiencies. Around 500 children are diagnosed with GHD every year in the UK, of whom 75% have I-GHD. Growth hormone (GH) therapy improves growth in children with GHD, with the goal of achieving a normal final height (FH). GH therapy is given as daily injections until adult FH is reached. However, in many children with I-GHD their condition reverses, with a normal peak GH detected in 64-82% when re-tested at FH. Therefore, at some point between diagnosis and FH, I-GHD must have reversed, possibly due to increase in sex hormones during puberty. Despite increasing evidence for frequent I-GHD reversal, daily GH injections are traditionally continued until FH is achieved.

METHODS/DESIGN

Evidence suggests that I-GHD children who re-test normal in early puberty reach a FH comparable to that of children without GHD. The GHD Reversal study will include 138 children from routine endocrine clinics in twelve UK and five Austrian centres with I-GHD (original peak GH < 6.7 mcg/L) whose deficiency has reversed on early re-testing. Children will be randomised to either continue or discontinue GH therapy. This phase III, international, multicentre, open-label, randomised controlled, non-inferiority trial (including an internal pilot study) will assess whether children with early I-GHD reversal who stop GH therapy achieve non-inferior near FH SDS (primary outcome; inferiority margin 0.55 SD), target height (TH) minus near FH, HRQoL, bone health index and lipid profiles (secondary outcomes) than those continuing GH. In addition, the study will assess cost-effectiveness of GH discontinuation in the early retesting scenario.

DISCUSSION

If this study shows that a significant proportion of children with presumed I-GHD reversal generate enough GH naturally in puberty to achieve a near FH within the target range, then this new care pathway would rapidly improve national/international practice. An assumed 50% reversal rate would provide potential UK health service cost savings of £1.8-4.6 million (€2.05-5.24 million)/year in drug costs alone. This new care pathway would also prevent children from having unnecessary daily GH injections and consequent exposure to potential adverse effects.

TRIAL REGISTRATION

EudraCT number: 2020-001006-39.

The landscape of retesting in childhood-onset idiopathic growth hormone deficiency and its reversibility: a systematic review and meta-analysis

OBJECTIVE

Children diagnosed with idiopathic isolated growth hormone deficiency (IGHD) are frequently observed to no longer be GH-deficient at a later stage of growth as a result of 'GHD reversal'. Reevaluation of GH status by stimulation test is currently incorporated into management guidelines at attainment of final height (FH). Over the past three decades, numerous studies have evaluated reversal rates using different methodologies including crucial parameters like GHD aetiology, GH cut-off and retesting time point, with heterogeneous results. We aimed to systematically analyse the reversibility of childhood-onset IGHD dependent on retesting GH cut-offs and retesting time points.

METHODS

PubMed, Cochrane Library, TRIP database and NHS Evidence were searched for publications investigating the reversibility of IGHD from database initiation to 30 June 2020 following PRISMA recommendations. Study cohorts were pooled according to retesting GH cut-off and time point. Reversal rates were calculated using random-effects models.

RESULTS

Of the 29 studies initially identified, 25 provided sufficient detail for IGHD analysis, resulting in 2030 IGHD patient data. Reversal rates decreased significantly as the retesting GH cut-off increased (P = 0.0013). Pooled (95% CI) reversal rates were 80% (59-92%, n = 227), 73% (62-81%, n = 516) and 55% (41-68%, n = 1287) for cohorts using retesting GH cut-offs of 3-4 ng/mL, 5-6 ng/mL and 7.7-10 ng/mL, respectively. Individuals retested at FH (n = 674) showed a pooled reversal rate of 74% (64-82%) compared to 48% (25-71%) when retested before FH (n = 653).

CONCLUSION

Provided evidence supports reevaluation of current IGHD management guidelines. The high reversal rates should instigate consideration of early retesting.

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.

Differential diagnosis between constitutional delay of growth and puberty, idiopathic growth hormone deficiency and congenital hypogonadotropic hypogonadism: a clinical challenge for the pediatric endocrinologist

INTRODUCTION

Differential diagnosis between constitutional delay of growth and puberty (CDGP), partial growth hormone deficiency (pGHD) and congenital hypogonadotropic hypogonadism (cHH) may be difficult. All these conditions usually present with poor growth in pre- or peri-pubertal age and they may recur within one familial setting, constituting a highly variable, but somehow common, spectrum of pubertal delay.

EVIDENCE ACQUISITION

Narrative review of the most relevant English papers published between 1981 and march 2020 using the following search terms "constitutional delay of growth and puberty," "central hypogonadism," "priming," "growth hormone deficiency," "pituitary," "pituitary magnetic resonance imaging," with a special regard to the latest scientific acquisitions.

EVIDENCE SYNTHESIS

CDGP is by far the most prevalent entity in boys and recurs within families. pGHD is a rare, often idiopathic and transient condition, where hypostaturism presents more severely. Specificity of pGHD diagnosis is increased by priming children before growth hormone stimulation test (GHST); pituitary MRI and genetic analysis are recommended to personalize future follow-up. Diagnosing cHH may be obvious when anosmia and eunuchoid proportions concomitate. However, cHH can either overlap with pGHD in forms of multiple pituitary hormone deficiencies (MPHD) or syndromic conditions either with CDGP in family pedigrees, so endocrine workup and genetic investigations are necessary. The use of growth charts, bone age, predictors of adult height, primed GHST and low dose sex steroids (LDSS) treatment are recommended.

CONCLUSIONS

Only a step-by-step diagnostic process based on appropriate endocrine and genetic markers together with LDSS treatment can help achieving the correct diagnosis and optimizing outcomes.

Role of MRI T2-DRIVE in the assessment of pituitary stalk abnormalities without gadolinium in pituitary diseases

OBJECTIVE

To investigate the role of T2-DRIVE MRI sequence in the accurate measurement of pituitary stalk (PS) size and the identification of PS abnormalities in patients with hypothalamic-pituitary disorders without the use of gadolinium.

DESIGN

This was a retrospective study conducted on 242 patients who underwent MRI due to pituitary dysfunction between 2006 and 2015. Among 135 eligible patients, 102 showed eutopic posterior pituitary (PP) gland and 33 showed 'ectopic' PP (EPP).

METHODS

Two readers independently measured the size of PS in patients with eutopic PP at the proximal, midpoint and distal levels on pre- and post-contrast T1-weighted as well as T2-DRIVE images; PS visibility was assessed on pre-contrast T1 and T2-DRIVE sequences in those with EPP. The length, height, width and volume of the anterior pituitary (AP), PP height and length and PP area were analyzed.

RESULTS

Significant agreement between the two readers was obtained for T2-DRIVE PS measurements in patients with 'eutopic' PP; a significant difference was demonstrated between the intraclass correlation coefficient calculated on the T2-DRIVE and the T1-pre- and post-contrast sequences. The percentage of PS identified by T2-DRIVE in EPP patients was 72.7% compared to 30.3% of T1 pre-contrast sequences. A significant association was found between the visibility of PS on T2-DRIVE and the height of AP.

CONCLUSION

T2-DRIVE sequence is extremely precise and reliable for the evaluation of PS size and the recognition of PS abnormalities; the use of gadolinium-based contrast media does not add significant information and may thus be avoided.

Classical and non-classical causes of GH deficiency in the paediatric age

Growth hormone deficiency (GHD) may result from a failure of hypothalamic GHRH production or release, from congenital disorders of pituitary development, or from central nervous system insults including tumors, surgery, trauma, radiation or infiltration from inflammatory diseases. Idiopathic, isolated GHD is the most common sporadic form of hypopituitarism. GHD may also occur in combination with other pituitary hormone deficiencies, and is often referred to as hypopituitarism, combined pituitary hormone deficiency (CPHD), multiple pituitary hormone deficiency (MPHD) or panhypopituitarism. Children without any identifiable cause of their GHD are commonly labeled as having idiopathic hypopituitarism. MRI imaging is the technique of choice in the diagnosis of children with hypopituitarism. Marked differences in MRI pituitary gland morphology suggest different etiologies of GHD and different prognoses. Pituitary stalk agenesis and ectopic posterior pituitary (EPP) are specific markers of permanent GHD, and patients with these MRI findings show a different clinical and endocrine outcome compared to those with normal pituitary anatomy or hypoplastic pituitary alone. Furthermore, the classic triad of ectopic posterior pituitary gland, pituitary stalk hypoplasia/agenesis, and anterior pituitary gland hypoplasia is generally associated with permanent GHD. T2 DRIVE images aid in the identification of pituitary stalk without the use of contrast medium administration. Future developments in imaging techniques will undoubtedly reveal additional insights. Mutations in a number of genes encoding transcription factors - such as HESX1, SOX2, SOX3, LHX3, LHX4, PROP1, POU1F1, PITX, GLI3, GLI2, OTX2, ARNT2, IGSF1, FGF8, FGFR1, PROKR2, PROK2, CHD7, WDR11, NFKB2, PAX6, TCF7L1, IFT72, GPR161 and CDON - have been associated with pituitary dysfunction and abnormal pituitary gland development; the correlation of genetic mutations to endocrine and MRI phenotypes has improved our knowledge of pituitary development and management of patients with hypopituitarism, both in terms of possible genetic counseling, and of early diagnosis of evolving anterior pituitary hormone deficiencies.

Diagnosis of growth hormone deficiency in the paediatric and transitional age

Growth hormone deficiency is a rare cause of childhood short stature, but one for which treatment exists in the form of recombinant human growth hormone. A diagnosis of growth hormone deficiency is made based on auxology, biochemistry and imaging. Although no diagnostic gold standard exists, growth hormone provocation tests are considered the mainstay of diagnostic investigations. However, these must be interpreted with caution in view of issues with variability and reproducibility, as well as the limited evidence-base for cut-off values used to distinguish growth hormone deficient and non-growth hormone deficient subjects. In addition, nutritional and pubertal status can affect results, with no consensus on the role of priming with sex steroid hormones. Difficulties with assays exist both for growth hormone as well as insulin-like growth factor-1. Pituitary magnetic resonance imaging is a useful diagnostic, and possibly prognostic, aid. Although genetic testing is not routine, the discovery of more relevant mutations makes it an increasingly important investigation. Children with growth hormone deficiency are retested biochemically on completion of growth, to assess whether they remain so into adulthood.

Brain Magnetic Resonance Imaging as First-Line Investigation for Growth Hormone Deficiency Diagnosis in Early Childhood

BACKGROUND/AIMS

The diagnosis of growth hormone (GH) deficiency (GHD) in infancy and early childhood is not straightforward. GH stimulation tests are unsafe and unreliable in infants, and normative data are lacking. This study aims to investigate whether brain magnetic resonance imaging (MRI) may replace GH stimulation tests in the diagnosis of GHD in children younger than 4 years.

METHODS

We examined a retrospective cohort, with longitudinal follow-up, of 68 children consecutively diagnosed with GHD before the age of 4 years. The prevalence of hypothalamic-pituitary (HP) alterations at MRI and the associations with age and either isolated GHD (IGHD) or multiple pituitary hormone deficiency (MPHD) were assessed.

RESULTS

The prevalences of IGHD and MPHD were 54.4 and 45.6%, respectively. In the first group, brain MRI showed abnormalities in 83.8%: isolated pituitary hypoplasia in 48.7% and complex defects in 35.1%. In patients with MPHD, MRI showed complex alterations in 100%. All children younger than 24 months showed HP MRI abnormalities, regardless of the diagnosis. Complex defects were found in 94% of patients younger than 12 months and in 75% of patients between 13 and 24 months.

CONCLUSION

Our data suggest that brain MRI may represent the first-line investigation for diagnosing GHD in infancy and early childhood.

Natural history of growth hormone deficiency in a pediatric cohort

BACKGROUND/AIMS

Controversies still exist regarding the evaluation of growth hormone deficiency (GHD) in childhood at the end of growth. The aim of this study was to describe the natural history of GHD in a pediatric cohort.

METHODS

This is a retrospective study of a cohort of pediatric patients with GHD. Cases of acquired GHD were excluded. Univariate logistic regression was used to identify predictors of GHD persisting into adulthood.

RESULTS

Among 63 identified patients, 47 (75%) had partial GHD at diagnosis, while 16 (25%) had complete GHD, including 5 with multiple pituitary hormone deficiencies. At final height, 50 patients underwent repeat stimulation testing; 28 (56%) recovered and 22 (44%) remained growth hormone (GH) deficient. Predictors of persisting GHD were: complete GHD at diagnosis (OR 10.1, 95% CI 2.4-42.1), pituitary stalk defect or ectopic pituitary gland on magnetic resonance imaging (OR 6.5, 95% CI 1.1-37.1), greater height gain during GH treatment (OR 1.8, 95% CI 1.0-3.3), and IGF-1 level <-2 standard deviation scores (SDS) following treatment cessation (OR 19.3, 95% CI 3.6-103.1). In the multivariate analysis, only IGF-1 level <-2 SDS (OR 13.3, 95% CI 2.3-77.3) and complete GHD (OR 6.3, 95% CI 1.2-32.8) were associated with the outcome.

CONCLUSION

At final height, 56% of adolescents with GHD had recovered. Complete GHD at diagnosis, low IGF-1 levels following retesting, and pituitary malformation were strong predictors of persistence of GHD.

Pituitary Stalk Interruption Syndrome from Infancy to Adulthood: Clinical, Hormonal, and Radiological Assessment According to the Initial Presentation

Background

Patients with pituitary stalk interruption syndrome (PSIS) are initially referred for hypoglycemia during the neonatal period or growth retardation during childhood. PSIS is either isolated (nonsyndromic) or associated with extra-pituitary malformations (syndromic).

Objective

To compare baseline characteristics and long-term evolution in patients with PSIS according to the initial presentation.

Study Design

Sixty-seven patients with PSIS were included. Data from subgroups were compared: neonates (n = 10) versus growth retardation patients (n = 47), and syndromic (n = 32) versus nonsyndromic patients (n = 35).

Results

Neonates displayed a more severe hormonal and radiological phenotype than children referred for growth retardation, with a higher incidence of multiple hormonal deficiencies (100% versus 34%; P = 0.0005) and a nonvisible anterior pituitary lobe (33% versus 2%; P = 0.0017). Regular follow-up of growth might have allowed earlier diagnosis in the children with growth retardation, as decreased growth velocity and growth retardation were present respectively 3 and 2 years before referral. We documented a progressive worsening of endocrine impairment throughout childhood in these patients. Presence of extra-pituitary malformations (found in 48%) was not associated with more severe hormonal and radiological characteristics. Growth under GH treatment was similar in the patient groups and did not vary according to the pituitary MRI findings.

Conclusions

PSIS diagnosed in the neonatal period has a particularly severe hormonal and radiological phenotype. The progressive worsening of endocrine impairment throughout childhood justifies periodic follow-up to check for additional hormonal deficiencies.

Associations between pituitary imaging abnormalities and clinical and biochemical phenotypes in children with congenital growth hormone deficiency: data from an international observational study

BACKGROUND/AIMS

Magnetic resonance imaging (MRI) is used to investigate the etiology of growth hormone deficiency (GHD). This study examined relationships between MRI findings and clinical/hormonal phenotypes in children with GHD in the observational Genetics and Neuroendocrinology of Short Stature International Study, GeNeSIS.

METHODS

Clinical presentation, hormonal status and first-year GH response were compared between patients with pituitary imaging abnormalities (n = 1,071), patients with mutations in genes involved in pituitary development/GH secretion (n = 120) and patients with idiopathic GHD (n = 7,039).

RESULTS

Patients with hypothalamic-pituitary abnormalities had more severe phenotypes than patients with idiopathic GHD. Additional hormonal deficiencies were found in 35% of patients with structural abnormalities (thyroid-stimulating hormone > adrenocorticotropic hormone > luteinizing hormone/follicle-stimulating hormone > antidiuretic hormone), most frequently in patients with septo-optic dysplasia (SOD). Patients with the triad [ectopic posterior pituitary (EPP), pituitary aplasia/hypoplasia and stalk defects] had a more severe phenotype and better response to GH treatment than patients with isolated abnormalities. The sex ratio was approximately equal for patients with SOD, but there was a significantly higher proportion of males (approximately 70%) in the EPP, pituitary hypoplasia, stalk defects, and triad categories.

CONCLUSION

This large, international database demonstrates the value of classification of GH-deficient patients by the presence and type of hypothalamic-pituitary imaging abnormalities. This information may assist family counseling and patient management.

Magnetic resonance imaging of CNS in 15,043 children with GH deficiency in KIGS (Pfizer International Growth Database)

OBJECTIVES

Neuroimaging has become an essential part of the diagnostic process in children with GH deficiency (GHD). The aim of the study was to document the frequency of neuroanatomical abnormalities in a very large cohort of children with GHD and to relate these findings to patient clinical characteristics.

DESIGN AND METHODS

Results of magnetic resonance imaging (MRI) were reported in 15,043 of 43,725 children with non-acquired GHD (idiopathic, neurosecretory dysfunction (NSD) and known congenital cause) who were enrolled in KIGS (Pfizer International Growth Database) between 1987 and 2011. Clinical characteristics of patients before GH treatment with normal MRI (idiopathic GHD (IGHD) and NSD) were compared with those of patients with abnormal pituitaries (hypoplasia, empty sella (ES), HME (hypoplastic anterior pituitary, missing pituitary stalk and ectopic posterior pituitary)).

RESULTS

Abnormal MRIs were found in 4032 (26.8%) children, within which ES (N=1178 (7.8%)) and HME (N=1019 (6.8%)) were the most frequent findings. In 2361 children diagnosed as IGHD or NSD before MRI examination, anatomical abnormalities ((pituitary hypoplasia: n=974); (HME: n=459)) were documented. Patients with anatomical abnormalities had more severe characteristics of GHD: normal MRI < pituitary hypoplasia < ES < HME.

CONCLUSIONS

GHD is associated with a great variety of neuroanatomical abnormalities as identified by MRI. The investigation and evaluation of MRI need to be conducted in a structured mode. There is an association between anatomical and functional abnormalities of the pituitary.

The use of neuroimaging for assessing disorders of pituitary development

Magnetic resonance imaging (MRI) is the radiological examination method of choice for evaluating hypothalamo-pituitary-related endocrine disease and is considered essential in the assessment of patients with suspected hypothalamo-pituitary pathology. Physicians involved in the care of such patients have, in MRI, a valuable tool that can aid them in determining the pathogenesis of their patients' underlying pituitary conditions. Indeed, the use of MRI has led to an enormous increase in our knowledge of pituitary morphology, improving, in particular, the differential diagnosis of hypopituitarism. Specifically, MRI allows detailed and precise anatomical study of the pituitary gland by differentiating between the anterior and posterior pituitary lobes. MRI recognition of pituitary hyperintensity in the posterior part of the sella, now considered a marker of neurohypophyseal functional integrity, has been the most striking finding in the diagnosis and understanding of certain forms of 'idiopathic' and permanent growth hormone deficiency (GHD). Published data show a number of correlations between pituitary abnormalities as observed on MRI and a patient's endocrine profile. Indeed, several trends have emerged and have been confirmed: (i) a normal MRI or anterior pituitary hypoplasia generally indicates isolated growth hormone deficiency that is mostly transient and resolves upon adult height achievement; (ii) patients with multiple pituitary hormone deficiencies (MPHD) seldom show a normal pituitary gland; and (iii) the classic triad of ectopic posterior pituitary, pituitary stalk hypoplasia/agenesis and anterior pituitary hypoplasia is more frequently reported in MPHD patients and is generally associated with permanent GHD. Pituitary abnormalities have also been reported in patients with hypopituitarism carrying mutations in several genes encoding transcription factors. Establishing endocrine and MRI phenotypes is extremely useful for the selection and management of patients with hypopituitarism, both in terms of possible genetic counselling and in the early diagnosis of evolving anterior pituitary hormone deficiencies. Going forward, neuroimaging techniques are expected to progressively expand and improve our knowledge and understanding of pituitary diseases.