Approach to the growth hormone-deficient child during transition to adulthood

Diagnosis and therapeutic approach to bone health in patients with hypopituitarism

The results of many studies in recent years indicate a significant impact of pituitary function on bone health. The proper function of the pituitary gland has a significant impact on the growth of the skeleton and the appearance of sexual dimorphism. It is also responsible for achieving peak bone mass, which protects against the development of osteoporosis and fractures later in life. It is also liable for the proper remodeling of the skeleton, which is a physiological mechanism managing the proper mechanical resistance of bones and the possibility of its regeneration after injuries. Pituitary diseases causing hypofunction and deficiency of tropic hormones, and thus deficiency of key hormones of effector organs, have a negative impact on the skeleton, resulting in reduced bone mass and susceptibility to pathological fractures. The early appearance of pituitary dysfunction, i.e. in the pre-pubertal period, is responsible for failure to achieve peak bone mass, and thus the risk of developing osteoporosis in later years. This argues for the need for a thorough assessment of patients with hypopituitarism, not only in terms of metabolic disorders, but also in terms of bone disorders. Early and properly performed treatment may prevent patients from developing the bone complications that are so common in this pathology. The aim of this review is to discuss the physiological, pathophysiological, and clinical insights of bone involvement in pituitary disease.

The influence of growth hormone deficiency on bone health and metabolisms

Growth hormone (GH) is a key peptide hormone in the regulation of bone metabolism, through its systemic and paracrine action mediated directly as well as by insulin-like growth factor-1 (IGF-1). Growth hormone exerts pleiotropic effects leading to an increase in linear bone growth, accumulation of bone mineral content and preservation of peak bone mass. Furthermore, it influences protein, lipid, and carbohydrate metabolism.Growth hormone deficiency (GHD) causes a low bone turnover rate leading to reduced bone mineral density (BMD) and increased bone fragility. The results of GH insufficiency are the most pronounced among children as it negatively affects longitudinal bone growth, causing short stature and in adolescents, in whom it hinders the acquisition of peak bone mass. Most studies show that treatment with recombinant human growth hormone (rhGH) in GHD patients could improve BMD and decrease fracture risk. This review aims to summarize the pathophysiology, clinical picture and management of bone complications observed in GHD.

Osteometabolic profile and bone mass in the transition phase: ethnic differences in Brazilians treated with somatropin during childhood

OBJECTIVE

The main growth hormone action is to promote linear growth increasing protein synthesis stimulation and osteoblastic activity. Peak bone mass extends from adolescence to 30 years of age. Several factors may influence this acquisition and prevent fracture risk in adulthood, such as genetic potential, GH, ethnicity, and lifestyle factors. This study aims to compare bone mass and osteometabolic profile of white and Afro-descendant Brazilian adolescents in the transition phase, who were treated with human recombinant growth hormone in childhood.

METHODS

The authors selected 38 adolescents from the Transition Outpatient Clinic of the University of São Paulo. Lumbar spine and total body bone mineral density (BMD) and bone mineral content (BMC), serum calcium, 25-OH-vitamin D and bone markers were analyzed at the rhGH withdrawal.

RESULTS

The mean age was 16.8 ± 1.6 years. There were 21 Afro-descendant and 17 whites. Thirty-four percent of the sample presented vitamin D insufficiency, 66% inadequate calcium intake and 44.7% physical inactivity. The Afro-descendants showed a lower lumbar spine and total body Z scores than those of the whites (p = 0.04 and p = 0.03, respectively), as well as their mean body weight (p = 0.03). There were no differences in the remaining osteometabolic parameters.

CONCLUSION

As most adolescents had vitamin D insufficiency, low calcium intake, and physical inactivity, calcium, and cholecalciferol supplementation and lifestyle changes should be encouraged. The Brazilian Afro-descendant may be a vulnerable group for low bone mass, requiring special strategies to increase bone accrual and body weight. More studies are necessary to compare ethnic differences in this population.

Safety of growth hormone replacement in survivors of cancer and intracranial and pituitary tumours: a consensus statement

Growth hormone (GH) has been used for over 35 years, and its safety and efficacy has been studied extensively. Experimental studies showing the permissive role of GH/insulin-like growth factor 1 (IGF-I) in carcinogenesis have raised concerns regarding the safety of GH replacement in children and adults who have received treatment for cancer and those with intracranial and pituitary tumours. A consensus statement was produced to guide decision-making on GH replacement in children and adult survivors of cancer, in those treated for intracranial and pituitary tumours and in patients with increased cancer risk. With the support of the European Society of Endocrinology, the Growth Hormone Research Society convened a Workshop, where 55 international key opinion leaders representing 10 professional societies were invited to participate. This consensus statement utilized: (1) a critical review paper produced before the Workshop, (2) five plenary talks, (3) evidence-based comments from four breakout groups, and (4) discussions during report-back sessions. Current evidence reviewed from the proceedings from the Workshop does not support an association between GH replacement and primary tumour or cancer recurrence. The effect of GH replacement on secondary neoplasia risk is minor compared to host- and tumour treatment-related factors. There is no evidence for an association between GH replacement and increased mortality from cancer amongst GH-deficient childhood cancer survivors. Patients with pituitary tumour or craniopharyngioma remnants receiving GH replacement do not need to be treated or monitored differently than those not receiving GH. GH replacement might be considered in GH-deficient adult cancer survivors in remission after careful individual risk/benefit analysis. In children with cancer predisposition syndromes, GH treatment is generally contraindicated but may be considered cautiously in select patients.

Growth hormone deficiency and the transition from pediatric to adult care

OBJECTIVE

To discuss the approach to patients diagnosed with growth hormone deficiency (GHD) in childhood during the transition period from puberty to adulthood, focusing on the following: (1) physiology; (2) effects of recombinant human GH (rhGH) interruption/reinstitution after adult height achievement; (3) re-evaluation of somatrotropic axis; (4) management of rhGH reinstitution, when necessary.

SOURCE OF DATA

Narrative review of the literature published at PubMed/MEDLINE until September 2020 including original and review articles, systematic reviews and meta-analyses.

SYNTHESIS OF DATA

Growth hormone is crucial for the attainment of normal growth and for adequate somatic development, which does not end concomitantly with linear growth. Retesting adolescents who already meet the criteria that predict adult GHD with high specificity is not necessary. Patients with isolated GHD have a high likelihood of normal response to GH testing after puberty. Adolescents with confirmed GHD upon retesting should restart rhGH replacement and be monitored according to IGF-I levels, clinical parameters, and complementary exams.

CONCLUSION

Patients with isolated idiopathic GHD in childhood are a special group who must be reevaluated for GHD as many of them have normal GH provocative tests upon retesting after puberty. Patients who confirm the persistence of GHD in the transition period should maintain rhGH replacement in order to reach an ideal peak bone mass, satisfactory body composition, lipid and glucose profiles, and quality of life.

Vasculometabolic effects in patients with congenital growth hormone deficiency with and without GH replacement therapy during adulthood

PURPOSE

To evaluated the metabolic profiles and vascular properties in congenital growth hormone (GH) deficiency (GHD) and its replacement in adults.

PATIENTS AND METHODS

Cross-sectional study conducted in a single tertiary center for pituitary diseases. Eighty-one adult subjects were divided into three groups: (1) 29 GHD patients with daily subcutaneous GH replacement therapy (GHRT) during adulthood; (2) 20 GHD patients without GHRT during adulthood and (3) 32 controls. Only patients with adequate adherence to others pituitary hormone deficiencies were included. Anthropometric parameters, body composition by dual-energy X-ray absorptiometry, metabolic profiles and vascular properties (carotid intima media thickness, pulse wave velocity and flow-mediated dilation) were compared among the groups.

RESULTS

Waist-to-height ratio (WHR), body fat percentages and fat mass index (FMI) were lower in patients with GHRT than patients without GHRT during adulthood (0.49 ± 0.06 vs. 0.53 ± 0.06 p = 0.026, 30 ± 10 vs. 40 ± 11 p = 0.003 and 7.3 ± 4 vs. 10 ± 3.5 p = 0.041, respectively). In addition, association between longer GHRT and lower body fat percentage was observed (r =  - 0.326, p = 0.04). We found higher triglyceride (113.5 ± 62 vs. 78 ± 36, p = 0.025) and lower HDL cholesterol (51 ± 17 vs. 66 ± 23, p = 0.029) levels in patients without GHRT during adulthood in comparison to controls. No statistical differences were observed for vascular properties among the groups.

CONCLUSIONS

No differences in vascular properties were observed in congenital GHD adult patients with or without GHRT despite patients without GHRT had an unfavorable body composition. GHRT currently remains an individualized decision in adults with GHD and these findings bring new insight into the treatment and follow-up of these patients.

3D DXA Hip Differences in Patients with Acromegaly or Adult Growth Hormone Deficiency

The skeleton is regulated by and responds to pituitary hormones, especially when the circulating levels are perturbed in disease. This study aims to analyse the between-group differences in 3D dual-energy X-ray absorptiometry (DXA) parameters at the hip site among patients with acromegaly or adult growth hormone deficiency (AGHD) and a healthy control group. The current cross-sectional study includes data for 67 adults, 20 with acromegaly, 14 with AGHD and 33 healthy controls. We obtained the areal bone mineral density (aBMD) outcomes using DXA and cortical and trabecular parameters using 3D-DXA software (3D-SHAPER). The mean-adjusted 3D-DXA parameters did not differ between acromegaly patients and the controls (p > 0.05); however, we found cortical bone impairment (−7.3% to −8.4%; effect size (ES) = 0.78) in AGHD patients (p < 0.05). Differences in the cortical bone parameters were more evident when comparing AGHD patients (−8.5% to −16.2%; ES = 1.22 to 1.24) with acromegaly patients (p < 0.05). In brief, the 3D mapping highlighted the trochanter as the site with greater cortical bone differences between acromegaly patients and the controls. Overall, AGHD patients displayed lower cortical parameters at the trochanter, femoral neck and intertrochanter compared to the controls and acromegaly patients. To sum up, 3D-DXA provided useful information about the characteristics of bone involvement in growth hormone (GH)-related disorders. Patients with AGHD showed distinct involvement of the cortical structure.

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.

Clinical, Diagnostic, and Therapeutic Aspects of Growth Hormone Deficiency During the Transition Period: Review of the Literature

The role of growth hormone (GH) during childhood and adulthood is well established. Once final stature is reached, GH continues to act during the transition, the period between adolescence and adulthood in which most somatic and psychological development is obtained. The achievement of peak bone mass represents the most relevant aspect of GH action during the transition period; however, equally clear is its influence on body composition and metabolic profile and, probably, in the achievement of a complete gonadal and sexual maturation. Despite this, there are still some aspects that often make clinical practice difficult and uncertain, in particular in evaluating a possible persistence of GH deficiency once final stature has been reached. It is also essential to identify which subjects should undergo re-testing and, possibly, replacement therapy, and the definition of unambiguous criteria for therapeutic success. Moreover, even during the transition phase, the relationship between GH substitution therapy and cancer survival is of considerable interest. In view of the above, the aim of this paper is to clarify these relevant issues through a detailed analysis of the literature, with particular attention to the clinical, diagnostic and therapeutic aspects.

GH deficiency in cancer survivors in the transition age: diagnosis and therapy

BACKGROUND

Survival rates among childhood cancer survivors (CCSs) have significantly risen in the last 40 years due to substantial improvements in treatment protocols. However, this improvement has brought with it serious late effects that frequently involve the endocrine system. Of the endocrine disorders, GH deficiency (GHD) is the most common among CCSs as a consequence of a history of cancers, surgery, and/or radiotherapy involving the hypothalamo-pituitary region.

METHODS

A comprehensive search of English language articles regardless of age was conducted in the MEDLINE database between December 2018 and October 2019. We selected all studies on GH therapy in CCSs during the transition age regarding the most challenging topics: when to retest; which diagnostic tests and cut-offs to use; when to start GH replacement therapy (GHRT); what GH dose to use; safety; quality of life, compliance and adherence to GHRT; interactions between GH and other hormonal replacement treatments.

RESULTS

In the present review, we provide an overview of the current clinical management of challenges in GHD in cancer survivors in the transition age.

CONCLUSIONS

Endocrine dysfunction among CCSs has a high prevalence in the transition age and increase with time. Many endocrine disorders, including GHD, are often not diagnosed or under-diagnosed, probably due to the lack of specialized centers for the long-term follow-up. Therefore, it is crucial that transition specialized clinics should be increased in terms of number and specific skills in order to manage endocrine disorders in adolescence, a delicate and complex period of life. A multidisciplinary approach, also including psychological counseling, is essential in the follow-up and management of these patients in order to minimize their disabilities and maximize their quality of life.

Childhood-onset growth hormone deficiency and the transition to adulthood: current perspective

Childhood-onset growth hormone deficiency (CO-GHD) is an endocrine condition associated with a broad range of health issues from childhood through to adulthood, which requires particular attention during the transition period from adolescence to young adulthood. There is uncertainty in the clinical practice of the management of CO-GHD during transition regarding the clinical assessment and management of individual patients during and after transition to obtain optimal follow-up and improved health outcomes. Despite the availability of clinical guidelines providing the framework for transition of young adults with CO-GHD, there remains substantial variation in approaching transitional care among pediatric and adult services. A well-structured and coordinated transitional plan with clear communication and direct collaboration between pediatric and adult health care to ensure optimal management of adolescents with CO-GHD during transition is needed.

Pituitary Diseases and Bone

Neuroendocrinology of bone is a new area of research based on the evidence that pituitary hormones may directly modulate bone remodeling and metabolism. Skeletal fragility associated with high risk of fractures is a common complication of several pituitary diseases such as hypopituitarism, Cushing disease, acromegaly, and hyperprolactinemia. As in other forms of secondary osteoporosis, pituitary diseases generally affect bone quality more than bone quantity, and fractures may occur even in the presence of normal or low-normal bone mineral density as measured by dual-energy X-ray absorptiometry, making difficult the prediction of fractures in these clinical settings. Treatment of pituitary hormone excess and deficiency generally improves skeletal health, although some patients remain at high risk of fractures, and treatment with bone-active drugs may become mandatory. The aim of this review is to discuss the physiological, pathophysiological, and clinical insights of bone involvement in pituitary diseases.

Pattern of Use of Biosimilar and Originator Somatropin in Italy: A Population-Based Multiple Databases Study During the Years 2009-2014

PURPOSE

Somatropin [recombinant growth hormone (rGH)] is approved in children and adults for several conditions involving growth disturbances and the corresponding biosimilar is available in Italy since 2006. No population-based data are available on the pattern of rGH use in Italian clinical practice. This study aimed at exploring the pattern of biosimilar and originator rGH use in six Italian centers, where different policy interventions promoted biosimilar use.

METHODS

This population-based, drug-utilization study was conducted in the years 2009-2014, using administrative databases of Umbria, Tuscany, and Lazio Regions and Local Health Units of Caserta, Treviso, and Palermo. Naïve rGH users were characterized, and prevalence of use and discontinuation were assessed over time.

RESULTS

Among 6,785 patients treated with rGH during the study years, 4,493 (66.2%) were naïve users (males/females = 1.3), mostly affected by GH deficiency. The prevalence of rGH use increased from 2009 to 2010, remaining stable thereafter, but it was heterogeneous across centers (twofold higher prevalence of use in center n.2 than centers n.4 and 1 in 2014). Biosimilar rGH uptake increased over time but was low (7.8% in 2014) and heterogeneous as well. Discontinuation of rGH therapy occurred in 54.0% of naïve users, more frequently in females than males (58.1 vs. 50.9%). During the first year of treatment, discontinuation was frequent (39.9%), but no statistically significant differences were observed in treatment persistence for biosimilar vs. originator rGH (p > 0.05).

CONCLUSION

Geographical heterogeneity in the prevalence of rGH use was observed. Similarly, the biosimilar rGH uptake was low and variable across centers. Post-marketing monitoring is required to continuously monitor the benefit-risk profile of rGH, thus guaranteeing greater savings than only promoting lowest cost rGH.

Clinical and laboratory parameters predicting a requirement for the reevaluation of growth hormone status during growth hormone treatment: Retesting early in the course of GH treatment

OBJECTIVE

We aimed to define the predictive criteria, in the form of specific clinical, hormonal and radiological parameters, for children with growth hormone deficiency (GHD) who may benefit from the reevaluation of GH status early in the course of growth hormone (GH) treatment.

DESIGN AND METHODS

Two hundred sixty-five children with growth hormone deficiency were retested by GH stimulation at the end of the first year of GH treatment. The initial clinical and laboratory characteristics of those with a normal (GH≥10ng/ml) response and those with a subnormal (GH<10ng/ml) response were compared to predict a normal GH status during reassessment.

RESULTS

Sixty-nine patients (40.6%) out of the 170 patients with isolated growth hormone deficiency (IGHD) had a peak GH of ≥10ng/ml during the retest. None of the patients with multiple pituitary hormone deficiency (MPHD) had a peak GH of ≥10ng/ml. Puberty and sex steroid priming in peripubertal cases increased the probability of a normal GH response. Only one patient with IGHD who had an ectopic posterior pituitary without stalk interruption on MRI analysis showed a normal GH response during the retest. Patients with a peak GH between 5 and 10ng/ml, an age at diagnosis of ≥9years or a height gain below 0.61 SDS during the first year of treatment had an increased probability of having a normal GH response at the retest.

CONCLUSION

Early reassessment of GH status during GH treatment is unnecessary in patients who have MPHD with at least 3 hormone deficiencies. Retesting at the end of the first year of therapy is recommended for patients with IGHD who have a height gain of <0.61 SDS in the first year of treatment, especially those with a normal or 'hypoplastic' pituitary on imaging. Priming can increase the likelihood of a normal response in patients in the pubertal age group who do not show overt signs of pubertal development.

Evaluation of growth hormone stimulation testing in children

OBJECTIVE

To evaluate the use and interpretation of growth hormone (GH) stimulation tests used across the UK for diagnosing GH deficiency.

BACKGROUND

Previous studies show poor consensus on the use of GH stimulation tests. Sex steroid priming and retesting in the transition period are areas not previously surveyed.

DESIGN

Data were collected from tertiary paediatric endocrinologists, paediatricians with a specialist interest in endocrinology and biochemists across the UK over 6 months through distributing electronic surveys.

RESULTS

At least three different GH stimulation tests were used by 33% of departments. Glucagon and insulin doses varied most, and sampling frequency varied most using insulin. All laboratories use a recommended chemiluminescence immunoassay with an acceptable coefficient of variability. The GH peak for diagnosing GH deficiency varied from 6 to 8 μg/l. A wide range of clinical scenarios prompted retesting in the transition period, suggesting nonstandardized current practice. Seventy-five per cent of departments use sex steroid priming, but follow criteria variously combining bone age, chronological age and pubertal stage, together with variations in steroid type and dose.

CONCLUSIONS

Although a contentious diagnostic test, GH stimulation tests remain the gold standard for diagnosing GH deficiency. Our data suggest that together with variation in indication, protocol and interpretation, there is considerable variation in current practices pertaining to priming and retesting in transition. Given the current financial climate and the need for careful resource management, this study emphasizes the considerable need for consensus in the investigation, diagnosis and long-term follow-up of these children, at least nationally if not internationally.

An audit of the management of childhood-onset growth hormone deficiency during young adulthood in Scotland

Background

Adolescents with childhood onset growth hormone deficiency (CO-GHD) require re-evaluation of their growth hormone (GH) axis on attainment of final height to determine eligibility for adult GH therapy (rhGH).

Aim

Retrospective multicentre review of management of young adults with CO-GHD in four paediatric centres in Scotland during transition.

Patients

Medical records of 130 eligible CO-GHD adolescents (78 males), who attained final height between 2005 and 2013 were reviewed. Median (range) age at initial diagnosis of CO-GHD was 10.7 years (0.1–16.4) with a stimulated GH peak of 2.3 μg/l (0.1–6.5). Median age at initiation of rhGH was 10.8 years (0.4–17.0).

Results

Of the 130 CO-GHD adolescents, 74/130(57 %) had GH axis re-evaluation by stimulation tests /IGF-1 measurements. Of those, 61/74 (82 %) remained GHD with 51/74 (69 %) restarting adult rhGH. Predictors of persistent GHD included an organic hypothalamic-pituitary disorder and multiple pituitary hormone deficiencies (MPHD). Of the remaining 56/130 (43 %) patients who were not re-tested, 34/56 (61 %) were transferred to adult services on rhGH without biochemical retesting and 32/34 of these had MPHD. The proportion of adults who were offered rhGH without biochemical re-testing in the four centres ranged between 10 and 50 % of their total cohort.

Conclusions

A substantial proportion of adults with CO-GHD remain GHD, particularly those with MPHD and most opt for treatment with rhGH. Despite clinical guidelines, there is significant variation in the management of CO-GHD in young adulthood across Scotland.

An analysis of product wastage arising from dosing increment granularity in four modern growth hormone administration devices

OBJECTIVE

Human growth hormone (hGH) delivery systems differ in the size of the dose increments that can be set by the patient, affecting proximity to the target (i.e., prescribed) dose which can be attained. We investigated differences in dosing increment granularity in NordiFlex®, FlexPro®, NordiPen® (all multiple dose devices) and MiniQuick® (single dose) delivery systems.

METHODS

A simulation model was developed to project hGH dosing in pediatric patients with growth hormone deficiency, small for gestational age or Turner syndrome, calculating the nearest dose above the target dose administrable by each device in typical EU and US cohorts and projecting the excess dose (hGH wastage) over 1 year of typical use.

RESULTS

The device with the smallest dosing increment (FlexPro 5 mg; 0.025 mg dosing increment) was projected to administer doses < 1% above the target across all indications. MiniQuick (0.2 mg dosing increment) was projected to deliver between 5 and 6% above the target dose. None of the sensitivity analyses changed the conclusion that larger dosing increments result in more hGH wastage.

CONCLUSIONS

In addition to increasing dosing accuracy, finer dosing increments may result in reductions in unnecessary hGH usage, which may in turn result in reductions in the cost of hGH treatment borne by the health-care payer.

Adult mortality or morbidity is not increased in childhood-onset growth hormone deficient patients who received pediatric GH treatment: an analysis of the Hypopituitary Control and Complications Study (HypoCCS)

BACKGROUND

The French Safety and Appropriateness of Growth Hormone treatments in Europe (SAGhE) cohort has raised concern of increased mortality risk during follow-up into adulthood in certain patients who had received growth hormone (GH) treatment during childhood. The Hypopituitary Control and Complications Study monitored mortality and morbidity of adult GH-deficient patients including those with childhood-onset GH deficiency (COGHD) who received GH treatment as children.

PURPOSE

Evaluate risk of mortality, cancer, myocardial infarction (MI) and stroke in a prospective observational study.

METHODS

COGHD patients [n = 1,204, including 389 diagnosed with idiopathic COGHD (ICOGHD)] had received pediatric GH treatment. Standardized mortality ratios (SMRs), and cancer standardized incidence ratios (SIRs) in patients without a prior cancer were estimated relative to reference populations. Crude incidence rates were estimated for MI and stroke.

RESULTS

No increased mortality or cancer incidence was observed, as compared with reference populations, during a follow-up of 3.7 ± 3.3 years (mean ± SD). The overall SMR for COGHD was 1.14 [95 % confidence interval (CI) 0.55-2.10], and for ICOGHD, 0.33 (0.01-1.84). The overall cancer SIR for COGHD was 0.27 (0.01-1.50), and for ICOGHD, 0.00 (0.00-2.45). No incident case of MI was reported. The crude stroke incidence rate [181.3 per 100,000 person-years] in COGHD patients was consistent with the rates reported in reference populations. No incident case of stroke was identified in ICOGHD patients who are presumed to have no increased stroke risk factors.

CONCLUSIONS

The results indicate no increased risk of mortality or incidence of cancer, stroke, or MI in adult GH-deficient patients who had previously received pediatric GH treatment.

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

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

Understanding the growth hormone therapy adherence paradigm: a systematic review

INTRODUCTION

Growth hormone (GH) therapy is used to treat a variety of growth disorders in childhood/adolescence. Its efficacy is thought to be dependent on patients' adherence to their treatment regimen.

METHODS

PubMed was searched using the keywords 'growth hormone', 'child'[Mesh], 'adolescent'[Mesh], and 'patient compliance'[Mesh].

RESULTS

Most studies of adherence to paediatric GH therapy have used either issued/encashed GH prescriptions or questionnaires. Estimates of prevalence of non-adherence vary from 5-82%, depending on the methods and definitions used. Different studies have variously demonstrated an association (or lack thereof) between adherence and age, socioeconomic status, treatment duration, injection device used and injection-giver. A number of interventions have been proposed to improve adherence, including offering a choice of injection device, but none are supported by trials. Poor adherence is associated with reduced height velocity and likely increased economic costs; evidence for other effects is circumstantial.

CONCLUSION

Adherence to paediatric GH therapy is suboptimal, which may partially explain why the mean final height attained is below that of the general population. Analysis of the causes of non-adherence is complicated by conflicting evidence from different studies. Multifactorial interventions are most likely to be successful in improving adherence. We make recommendations for further research.

Monocentric study of 112 consecutive patients with childhood onset GH deficiency around and after transition

OBJECTIVES

Our aim was to analyze a large cohort of childhood onset GH deficiency (CO-GHD) adults from a unique adult center, in order to analyze their clinical management and to study the metabolic and bone status in relation to GHD and to the other pituitary deficits, and to evaluate these parameters during the long-term follow-up.

DESIGN AND METHODS

Observational retrospective cohort study on 112 consecutive CO-GHD adults transferred to our unit from 1st January 1994 to 1st March 2012. Evaluation of GHD in pediatrics and after transition was conducted following consensus guidelines. Data recorded from pediatric and adult files were GH doses, pituitary magnetic resonance imaging and function, and metabolic and bone status.

RESULTS

Most patients presented with severe CO-GHD (64%) associated with other pituitary deficits (66%). CO-GHD was acquired in 56%, congenital in 33%, and idiopathic in 11% cases. Most patients (83%) stopped GH before transfer, at 16.3 years (median), despite persistence of GHD. Median age at transfer was 19.4 years. After transfer, GHD persisted in 101 patients and four of the 11 resolutive GHD were non idiopathic. IGF1 level was <-2 SDS in 70% of treated patients at transfer and in 34% of them after 3 years of treatment. Follow-up showed improvement in lipid profile and bone mineral density in severely persistent GHD patients under GH therapy. In multivariate analysis, the associated pituitary deficits seemed stronger determinant factors of metabolic and bone status than GHD.

CONCLUSIONS

This study raises concern about discontinuation of GH replacement therapy in pediatrics in severely persistent GHD patients and about the often insufficient dose of GH in the treatment of adult patients.

Product wastage from modern human growth hormone administration devices: a laboratory and computer simulation analysis

BACKGROUND

Treatment of growth hormone disorders typically involves daily injections of human growth hormone (GH) over many years, incurring substantial costs. We assessed the extent of undesired GH loss due to leakage in the course of pen preparation prior to injection, and differences between the prescribed dose, based on patient weight, and the actual delivered dose based on pen dosing increments in five GH administration devices.

METHODS

Norditropin® prefilled FlexPro®, NordiFlex®, NordiLet®, and durable NordiPen®/SimpleXx® 5 mg pens (Novo Nordisk A/S, Bagsværd, Denmark) and durable Omnitrope® Pen-5 devices (Sandoz, Holzkirchen, Germany) were tested (n = 40 for each device type). Product wastage was measured in accordance with validated protocols in an ISO (International Organization for Standardization) 11608-1 and Good Manufacturing Practice compliant laboratory. The average mass of wasted GH from each device type was measured in simulations of dripping with the needle attached prior to injection and while setting a dose. Statistical significance (P < 0.05) was confirmed by Student's t-test, and a model was constructed to estimate mean annual GH wastage per patient in cohorts of pediatric patients with GH disorders.

RESULTS

Mean GH mass wasted with the needle on prior to injection was 0.0 μg with Norditropin pens, relative to 98 μg with Omnitrope Pen-5. During dose dialing, 0.0-2.3 μg of GH was lost with Norditropin pens versus 0.8 μg with Omnitrope Pen-5. All Norditropin and Omnitrope device comparisons were statistically significant. Modeling GH wastage in a US cohort showed 5.5 mg of annual GH wastage per patient with FlexPro versus 43.6 mg with Omnitrope, corresponding to 7-8 additional pens per patient annually.

CONCLUSION

Overall, Norditropin pens resulted in significantly less wastage than the Omnitrope Pen-5. The study suggests that GH devices of the same nominal volume exhibit differences that may affect the frequency of GH prescription refills required to remain adherent to therapy.

United States multicenter study of factors predicting the persistence of GH deficiency during the transition period between childhood and adulthood

Background

Many patients with childhood-onset growth hormone (GH) deficiency do not fulfill diagnostic criteria for GH deficiency (GHD) after attainment of adult height and may not require long-term GH treatment. Patients with history of idiopathic GHD (IGHD) pose the greatest management dilemma, as data regarding factors predictive of persistent GHD in this group are lacking.

Objectives

The objective of this study was to assess potential predictors of persistent GHD in a US patient cohort during transition from childhood to adulthood, particularly in patients with history of IGHD.

Methods

We studied 73 US patients with history of childhood-onset GHD screened at 21 US pediatric endocrine centers for a randomized clinical trial of GH replacement after attainment of adult height. The cohort comprised 42 boys/men and 31 girls/women aged14–22 years, who had received ≥1 year of GH treatment and had completed linear growth. The main outcome measures were sensitivity, specificity, positive and negative predictive values (PPV, NPV) of clinical and hormonal factors for persistent GHD (defined a priori in this study as peak GH < 5 μg/L).

Results

For the cohort as a whole, the best predictors of persistent GHD (100% PPV) were history of organic hypothalamic-pituitary disorder or ≥2 additional pituitary hormone deficiencies (PHD). Best predictors of persistent GHD in patients with childhood history of IGHD were standard deviation scores (SDS) for serum insulin-like growth factor binding protein-3 (IGFBP-3) below -2.0, and for insulin-like growth factor-I (IGF-I) below -5.3 (measured ≥6 weeks after completion of GH treatment; PPV 100% for both), and age <4 years at original diagnosis (PPV 89%). IGF-I above -1.6 SDS had 100% NPV.

Conclusions

US patients with an organic cause of childhood-onset GHD or ≥2 additional PHDs may not require GH stimulation testing to reconfirm GHD after completion of childhood treatment. In contrast, patients with idiopathic childhood-onset GHD almost invariably require retesting, as GHD persists in only a minority (those who were very young at initial diagnosis and those who have subnormal IGFBP-3 or extremely low IGF-I after completion of childhood treatment). Subnormal posttreatment IGF-I (<-2.0 SDS) lacked predictive power for persistent GHD, whereas IGF-I > -1.6 SDS was 100% predictive of GH sufficiency.

Bone density in post-pubertal adolescent survivors of childhood brain tumors

BACKGROUND

Childhood cancer survivors are at high risk for reduced bone mineral density (BMD). Our objective was to determine whether post-pubertal adolescent survivors of brain tumors, whose tumor or treatments placed them at risk for pituitary hormone deficiencies, have low BMD near time of peak bone mass accrual, and to assess risk factors for decreased BMD.

PROCEDURE

Chart review of 36 post-pubertal adolescents with history of tumor or radiation therapy (RT) of the hypothalamic-pituitary area who had undergone BMD screening via dual-energy X-ray absorptiometry (DXA).

RESULTS

Age at DXA was 16.9 ± 1.9 years (mean ± SD). Time since diagnosis was 8.5 ± 3.6 years. Median BMD Z scores were -0.95 (range -2.7 to 1.7) at the femoral neck, -1.20 (-3.6 to 1.8) at the hip, and -0.90 (-3.7 to 1.8) at the spine. Bone mineral apparent density (BMAD) Z scores were -0.23 (-2.7 to 1.9) at the femoral neck and -0.45 (-3.0 to 2.3) at the spine. Those with history of ≥1 fracture had lower BMD Z scores of the femoral neck, total hip, and spine (P < 0.05). Those with treated GH deficiency (GHD) had a higher BMD Z-score at the femoral neck, total hip, and spine (P < 0.05) than those not treated. There was no difference in BMD with respect to treatment with chemotherapy, cranial or spinal RT, or hypogonadism. Spontaneous menarche and regular periods did not correlate with BMD.

CONCLUSIONS

In post-pubertal adolescent survivors of childhood brain tumors, fracture history and untreated GHD are risk factors for decreased BMD.

GH deficiency during the transition period: clinical characteristics before and after GH replacement therapy in two different subgroups of patients

OBJECTIVE

To study two subsets of patients with GH deficiency (GHD) during the transition period: childhood onset GHD (CO-GHD) and patients who develop GHD during the transition phase (TO-GHD) before and after GH replacement.

PATIENTS AND MEASUREMENTS

In 1340 GHD subjects from KIMS (Pfizer International Metabolic Database), CO (n=586) or TO (n=754), background characteristics, anthropometric measurements, IGF-1, lipids and quality of life (QoL) were evaluated at baseline and after 3 years of GH replacement.

RESULTS

Both groups responded similarly to GH treatment. Changes of clinical outcomes were mainly determined by their value at baseline. Onset of the disease in childhood or transition period did not appear to be a significant predictor of response in any of the clinical outcomes.

CONCLUSIONS

Age at GHD diagnosis was a significant predictor for many outcomes at baseline, but disease onset did not appear as an independent predictor concerning changes after 3 years of GH treatment. The results suggest that GH replacement during the transition period should be considered independently of the onset of the deficiency.

Growth hormone deficiency in the transition period: body composition and gonad function

Recombinant GH therapy is normally administered to GH-deficient children in order to achieve a satisfactory height - the main target during childhood and adolescence. However, the role of GH does not end once final height has been reached, but continues during the so-called transition period. In this phase of life, the body undergoes several changes, both physical and psychological, that culminate in adulthood. During this period, GH has a part in numerous metabolic functions. These include the lipid profile, where it increases HDL and reduces LDL, with the global effect of cardiovascular protection. It also has important effects on body composition (improved muscle strength and lean body mass and reduced body fat), the achievement of proper peak bone density, and gonad maturation. Retesting during the transition period, involving measurement of IGF-I plus a provocative test (insulin tolerance test or GHRH + arginine test), is thus necessary to establish any persistent GH deficiency requiring additional replacement therapy. The close cooperation of the medical professionals involved in the patient's transition from a pediatric to an adult endocrinologist is essential. The aim of this review is to point out the main aspects of GH treatment on body composition, metabolic and gonad functions in the transition period.

Treatment of adult growth hormone deficiency: who, why and how? A review

Adult growth hormone deficiency (AGHD) is nowadays recognized as a distinct clinical entity and replacement therapy has become a standard practice. Reflecting on the accumulated evidence, questions nevertheless arise. Should all AGHD patients be treated? What dose of GH should be given and for how long? What are the real long-term benefits, in particular regarding life expectancy? if the diagnosis of severe GHD is firmly established and if there is no contra-indication (such as an active cancer or uncontrolled diabetes), it is worthwile initiating GH replacement therapy. Treatment can indeed correct the abnormal body composition, improve various adverse cardiovascular parameters and risk factors, increase muscle strength and bone mineral density and, although to a variable degree, improve the patient's quality of life and psychological well-being. Treatment should be started with very low doses to avoid side-effects related to fluid retention and should then be gradually titrated against IGF-I values, clinical response and individual tolerance.There is unfortunately no confirmed predictive factor for the overall therapeutic response in a given individual. Thus, the decision to whether or not pursue the therapy will depend on the ratio of perceived and expected benefits over cost and risks of treatment, as well as on the persistent motivation of the patient.

Growth hormone replacement therapy: transition from adolescence to adulthood

Consideration of GH re-testing should be performed in all adolescents reaching the transition period (if not at start of puberty) who had been previously diagnosed with idiopathic, isolated GH deficiency. In the presence of multiple hormone deficiencies and/or clear-cut evidence of organic disease, persistence of severe GH deficiency is much more likely. Thus, GH deficiency may be "confirmed" by a low serum IGF-I concentration. During the transition period, the optimal time to reassess the integrity of the GH-IGF-I axis after prior GH treatment, the specific testing protocol to use, and the definition of GH deficiency all remain unknown. During the transition period, patients should have their GH dose lowered with (upward) adjustments made on the basis of age-and gender-adjusted serum IGF-I concentrations. GH treatment during the transition period has been shown in most, but not all, studies to be beneficial in preventing development of the features of the adult GH deficiency syndrome. It is important to remember that, during the transition period in teenagers with GH deficiency, there must be initiation of a careful plan for transfer of care to an intermist-endocrinologist with expertise in management of hypothalamic-pituitary disease in young adults.

Transitioning of children with GH deficiency to adult dosing: changes in body composition

As more evidence gathers regarding the beneficial effect of growth hormone replacement therapy (GHRT) on body composition and other parameters in adults with childhood-onset growth hormone deficiency (GHD), questions emerge regarding whether or not GHRT should be discontinued following cessation of statural growth, and the effect of GHRT during the transition period on body composition and related parameters. This review discusses the effect of discontinuation of GHRT following attainment of adult stature, and the treatment and dose effect when GHRT is reinstated. We also review data regarding who should receive GHRT, the criteria for diagnosing persistent GHD, dosing of GHRT and the possibility of a GH 'holiday'.

Evaluation of permanent growth hormone deficiency (GHD) in young adults with childhood onset GHD: a multicenter study

BACKGROUND

Reconfirming the diagnosis of childhood onset growth hormone deficiency (GHD) in young adults is necessary to demonstrate the need for continuation of GH therapy.

OBJECTIVE

This nationally-based study was planned to establish GH status during adulthood in childhood-onset GH deficient patients and to evaluate factors that would predict persistency of the GHD.

METHODS

In this multicenter study, 70 GH deficient patients who had reached final height were evaluated after completion of GH treatment. Fifty-two patients (74%) had isolated GHD and 18 patients (26%) had multiple pituitary hormone deficiency (MPHD). Patients who had reached final height and the pubertal Tanner stage 5 were reevaluated for GH status. After at least 6 weeks of cessation of GH treatment, patients were retested with insulin induced hypoglycemia.

RESULTS

GHD was found to be transient in 64.3% of all patients. Of the isolated GH deficient patients 82.7% had transient GHD, whereas 88.9% of the MPHD patients showed persistent GHD. Comparison of isolated GH deficient and multiple hormone deficient patients indicated higher peak GH, IGF-I and IGFBP-3 levels in isolated GH deficient patients. No parameter was significantly different in the transiently and persistently GH deficient patients with respect to gender. Although specificity of IGF-I value of less than -2 SD showing persistency of GHD was lower than the specificity of IGFBP-3 value of less than -2 SD (65.7% vs 84%), negative predictive values were similar for the two parameters (85.2% and 84%, respectively).

CONCLUSION

Most of the cases of childhood onset GHD are idiopathic and the GHD is transient. In patients with MPHD, GHD is generally permanent. Low IGF-I and IGFBP-3 levels are supporting findings to show persistency of the GHD.

Growth hormone, insulin-like growth factors, and the skeleton

GH and IGF-I are important regulators of bone homeostasis and are central to the achievement of normal longitudinal bone growth and bone mass. Although GH may act directly on skeletal cells, most of its effects are mediated by IGF-I, which is present in the systemic circulation and is synthesized by peripheral tissues. The availability of IGF-I is regulated by IGF binding proteins. IGF-I enhances the differentiated function of the osteoblast and bone formation. Adult GH deficiency causes low bone turnover osteoporosis with high risk of vertebral and nonvertebral fractures, and the low bone mass can be partially reversed by GH replacement. Acromegaly is characterized by high bone turnover, which can lead to bone loss and vertebral fractures, particularly in patients with coexistent hypogonadism. GH and IGF-I secretion are decreased in aging individuals, and abnormalities in the GH/IGF-I axis play a role in the pathogenesis of the osteoporosis of anorexia nervosa and after glucocorticoid exposure.

[Management of the growth hormone (GH)-treated patients with diagnosis of GH deficiency (DGH) during transition from childhood to adulthood]

Growth hormone (GH) has many beneficial effects in patients with childhood-onset GH deficiency (GHD) in addition to its promotion of linear growth. The discontinuation of GH treatment in GHD patients, during the transition from childhood to adulthood, induces significant unfavorable changes in body composition, skeletal integrity, exercise capacity, and an adverse cardiovascular risk profile. These changes are reversed after the resumption of GH treatment. As the benefits of continuing GH therapy into adulthood has been well established, it is possible that GH replacement therapy will not be stopped once growth has been completed, but it will continue into adult life. Considering that a high proportion of patients with diagnosis of DGH in childhood are no longer GHD in adolescence, the GH status must be retested when growth is completed. Other factors such as clinical history, GH response in childhood, hipotalamic-pituitary MRI and IGF-1 concentration must be considered. Reconfirmation of GHD diagnosis through stimulation testing is usually required, unless there is a proven genetic or structural lesion persistent from childhood.

Deterioration of growth hormone (GH) response and anterior pituitary function in young adults with childhood-onset GH deficiency and ectopic posterior pituitary: a two-year prospective follow-up study

CONTEXT

The current criteria for definition of partial GHD in young adults are still a subject of debate.

OBJECTIVES

The objective of the study was to reinvestigate anterior pituitary function in young adults with congenital childhood-onset GHD associated with structural hypothalamic-pituitary abnormalities and normal GH response at the time of first reassessment of GH secretion.

DESIGN AND SETTING

This was a prospective explorative study conducted in a university research hospital.

PATIENTS AND METHODS

Thirteen subjects with a mean age of 17.2 +/- 0.7 yr and a peak GH after insulin tolerance test (ITT) higher than 5 microg/liter were recruited from a cohort of 42 patients with childhood-onset GHD and ectopic posterior pituitary at magnetic resonance imaging. GH secretion after ITT and GHRH plus arginine, IGF-I concentration, and body mass index, waist circumference, blood pressure, total cholesterol, and fibrinogen were evaluated at baseline and at 2-yr follow-up.

RESULTS

At mean age of 19.2 +/- 0.7 yr, the mean peak GH response decreased significantly after ITT (P = 0.00001) and GHRH plus arginine (P = 0.0001). GH peak values after ITT and GHRH plus arginine were less than 5 and 9 microg/liter in 10 and eight patients, respectively. Additional pituitary defects were documented in eight patients. Significant changes were found in the values of IGF-I sd score (P = 0.0026), waist circumference (P = 0.00001), serum total cholesterol (P = 0.00001), and serum fibrinogen (P = 0.0004).

CONCLUSIONS

The results of this study underline the importance of further reassessment of pituitary function in young adults with GHD of childhood-onset and poststimulation GH responses suggestive of partial GHD.