Reassessment of the optimal growth hormone cut-off level in insulin tolerance testing for growth hormone secretion in patients with childhood-onset growth hormone deficiency during transition to adulthood

Isolated anterior pituitary dysfunction in adulthood

Hypopituitarism is defined as a complete or partial deficiency in one or more pituitary hormones. Anterior hypopituitarism includes secondary adrenal insufficiency, central hypothyroidism, hypogonadotropic hypogonadism, growth hormone deficiency and prolactin deficiency. Patients with hypopituitarism suffer from an increased disability and sick days, resulting in lower health status, higher cost of care and an increased mortality. In particular during adulthood, isolated pituitary deficits are not an uncommon finding; their clinical picture is represented by vague symptoms and unclear signs, which can be difficult to properly diagnose. This often becomes a challenge for the physician. Aim of this narrative review is to analyse, for each anterior pituitary deficit, the main related etiologies, the characteristic signs and symptoms, how to properly diagnose them (suggesting an easy and reproducible step-based approach), and eventually the treatment. In adulthood, the vast majority of isolated pituitary deficits are due to pituitary tumours, head trauma, pituitary surgery and brain radiotherapy. Immune-related dysfunctions represent a growing cause of isolated pituitary deficiencies, above all secondary to use of oncological drugs such as immune checkpoint inhibitors. The diagnosis of isolated pituitary deficiencies should be based on baseline hormonal assessments and/or dynamic tests. Establishing a proper diagnosis can be quite challenging: in fact, even if the diagnostic methods are becoming increasingly refined, a considerable proportion of isolated pituitary deficits still remains without a certain cause. While isolated ACTH and TSH deficiencies always require a prompt replacement treatment, gonadal replacement therapy requires a benefit-risk evaluation based on the presence of comorbidities, age and gender of the patient; finally, the need of growth hormone replacement therapies is still a matter of debate. On the other side, prolactin replacement therapy is still not available. In conclusion, our purpose is to offer a broad evaluation from causes to therapies of isolated anterior pituitary deficits in adulthood. This review will also include the evaluation of uncommon symptoms and main etiologies, the elements of suspicion of a genetic cause and protocols for diagnosis, follow-up and treatment.

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

PURPOSE

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

METHODS

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

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

Clinical benefits of sex steroids given as a priming prior to GH provocative test or as a growth-promoting therapy in peripubertal growth delays: Results of a retrospective study among ENDO-ERN centres

OBJECTIVES

Sex steroids, administered as a priming before GH stimulation tests (GHST) to differentiate between growth hormone deficiency (GHD) and constitutional delay of growth and puberty (CDGP) or as growth-promoting therapy using low-dose sex steroids (LDSS) in CDGP, are much debated. We aimed to compare auxological outcomes of CDGP or GHD children undergoing primed or unprimed GHST and to evaluate LDSS treatment in CDGP.

DESIGN

Retrospective study among three paediatric University Hospitals in Italy and UK.

METHODS

184 children (72 females) aged 12.4 ± 2.08 years underwent primed (/P⁺ ) or unprimed (/P^- ) GHST and were followed up until final height (FH). CDGP patients were untreated (CDG P^- ) or received LDSS (CDGP⁺ ). The cohort included 34 CDG P^- /P⁺ , 12 CDGP⁺ /P⁺ , 51 GHD/P⁺ , 29 CDG P^- /P^- , 2 CDGP⁺ /P^- and 56 GHD/P^- . FH standard deviation score (SDS), Δ SDS FH-target height (TH) and degree of success (-1 ≤ Δ SDS FH-SDS TH ≤ +1) were outcomes of interest.

RESULTS

GHD/P⁺ had better FH-SDS (-0.87 vs -1.49; P = .023) and ΔSDS FH-TH (-0.35 vs -0.77; P = .002) than CDGP^- /P⁺ . Overall, GHD/P⁺ showed the highest degree of success (90%, P = .006). Regardless of priming, both rhGH and LDSS improved degree of success compared to no treatment (89% and 86% vs 63%, P = .0009). GHD/P⁺ showed a trend towards a higher proportion of permanent GHD compared to GHD/P^- (30.43% vs 15.09%; P = .067).

CONCLUSION

In peripubertal children, priming before GHST improves diagnostic accuracy of GHST for idiopathic GHD. LDSS treatment improves auxological outcomes in CDGP.

Copeptin response to hypoglycemic stress is linked to prolactin activation in children

PURPOSE

The physiological role of arginine vasopressin (AVP) in the acute stress response in humans and especially in children is unclear. The aim of this study was to explore the interaction between copeptin, a well-established surrogate marker of AVP release, and anterior pituitary hormone activation in response to acute hypoglycemic stress in children and adolescents.

METHODS

We conducted an exploratory single center study involving 77 children and adolescents undergoing insulin-induced hypoglycemia. Blood levels of copeptin, ACTH, cortisol, GH, prolactin, interleukin-6 (IL-6), adrenaline and noradrenaline were determined at baseline and after insulin-induced hypoglycemia.

RESULTS

Basal plasma levels of copeptin (median: 5.2 pmol/L) increased significantly after hypoglycemia (median 9.7 pmol/L; P < 0.0001). Subjects with insufficient HPA axis response or severe GH deficiency had lower hypoglycemia-induced copeptin increase (median: 2.3 pmol/L) compared with individuals with intact pituitary response (median: 5.2 pmol/L, P = 0.02). Copeptin increase correlated significantly with the maximal increase of ACTH (r_s = 0.30; P = 0.010), cortisol (r_s = 0.33; P = 0.003), prolactin (r_s = 0.25; P = 0.03), IL-6 (r_s = 0.35; P = 0.008) and with BMI-SDS (r_s = - 0.28, P = 0.01). In multivariate regression analysis, prolactin increase was the only independent variable associated with copeptin increase (P = 0.0004).

CONCLUSION

Our data indicate that: (1) hypoglycemic stress elicits a marked copeptin response in children and adolescents, pointing out its role as an acute stress marker in this population; (2) stress-induced AVP/copeptin release is associated with anterior pituitary activation, mainly a prolactin response.

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.

AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS AND AMERICAN COLLEGE OF ENDOCRINOLOGY GUIDELINES FOR MANAGEMENT OF GROWTH HORMONE DEFICIENCY IN ADULTS AND PATIENTS TRANSITIONING FROM PEDIATRIC TO ADULT CARE

Objective: The development of these guidelines is sponsored by the American Association of Clinical Endocrinologists (AACE) Board of Directors and American College of Endocrinology (ACE) Board of Trustees and adheres with published AACE protocols for the standardized production of clinical practice guidelines (CPG). Methods: Recommendations are based on diligent reviews of clinical evidence with transparent incorporation of subjective factors, according to established AACE/ACE guidelines for guidelines protocols. Results: The Executive Summary of this 2019 updated guideline contains 58 numbered recommendations: 12 are Grade A (21%), 19 are Grade B (33%), 21 are Grade C (36%), and 6 are Grade D (10%). These detailed, evidence-based recommendations allow for nuance-based clinical decision-making that addresses multiple aspects of real-world care of patients. The evidence base presented in the subsequent Appendix provides relevant supporting information for the Executive Summary recommendations. This update contains 357 citations of which 51 (14%) are evidence level (EL) 1 (strong), 168 (47%) are EL 2 (intermediate), 61 (17%) are EL 3 (weak), and 77 (22%) are EL 4 (no clinical evidence). Conclusion: This CPG is a practical tool that practicing endocrinologists and regulatory bodies can refer to regarding the identification, diagnosis, and treatment of adults and patients transitioning from pediatric to adult-care services with growth hormone deficiency (GHD). It provides guidelines on assessment, screening, diagnostic testing, and treatment recommendations for a range of individuals with various causes of adult GHD. The recommendations emphasize the importance of considering testing patients with a reasonable level of clinical suspicion of GHD using appropriate growth hormone (GH) cut-points for various GH-stimulation tests to accurately diagnose adult GHD, and to exercise caution interpreting serum GH and insulin-like growth factor-1 (IGF-1) levels, as various GH and IGF-1 assays are used to support treatment decisions. The intention to treat often requires sound clinical judgment and careful assessment of the benefits and risks specific to each individual patient. Unapproved uses of GH, long-term safety, and the current status of long-acting GH preparations are also discussed in this document. LAY ABSTRACT This updated guideline provides evidence-based recommendations regarding the identification, screening, assessment, diagnosis, and treatment for a range of individuals with various causes of adult growth-hormone deficiency (GHD) and patients with childhood-onset GHD transitioning to adult care. The update summarizes the most current knowledge about the accuracy of available GH-stimulation tests, safety of recombinant human GH (rhGH) replacement, unapproved uses of rhGH related to sports and aging, and new developments such as long-acting GH preparations that use a variety of technologies to prolong GH action. Recommendations offer a framework for physicians to manage patients with GHD effectively during transition to adult care and adulthood. Establishing a correct diagnosis is essential before consideration of replacement therapy with rhGH. Since the diagnosis of GHD in adults can be challenging, GH-stimulation tests are recommended based on individual patient circumstances and use of appropriate GH cut-points. Available GH-stimulation tests are discussed regarding variability, accuracy, reproducibility, safety, and contraindications, among other factors. The regimen for starting and maintaining rhGH treatment now uses individualized dose adjustments, which has improved effectiveness and reduced reported side effects, dependent on age, gender, body mass index, and various other individual characteristics. With careful dosing of rhGH replacement, many features of adult GHD are reversible and side effects of therapy can be minimized. Scientific studies have consistently shown rhGH therapy to be beneficial for adults with GHD, including improvements in body composition and quality of life, and have demonstrated the safety of short- and long-term rhGH replacement. Abbreviations: AACE = American Association of Clinical Endocrinologists; ACE = American College of Endocrinology; AHSG = alpha-2-HS-glycoprotein; AO-GHD = adult-onset growth hormone deficiency; ARG = arginine; BEL = best evidence level; BMD = bone mineral density; BMI = body mass index; CI = confidence interval; CO-GHD = childhood-onset growth hormone deficiency; CPG = clinical practice guideline; CRP = C-reactive protein; DM = diabetes mellitus; DXA = dual-energy X-ray absorptiometry; EL = evidence level; FDA = Food and Drug Administration; FD-GST = fixed-dose glucagon stimulation test; GeNeSIS = Genetics and Neuroendocrinology of Short Stature International Study; GH = growth hormone; GHD = growth hormone deficiency; GHRH = growth hormone-releasing hormone; GST = glucagon stimulation test; HDL = high-density lipoprotein; HypoCCS = Hypopituitary Control and Complications Study; IGF-1 = insulin-like growth factor-1; IGFBP = insulin-like growth factor-binding protein; IGHD = isolated growth hormone deficiency; ITT = insulin tolerance test; KIMS = Kabi International Metabolic Surveillance; LAGH = long-acting growth hormone; LDL = low-density lipoprotein; LIF = leukemia inhibitory factor; MPHD = multiple pituitary hormone deficiencies; MRI = magnetic resonance imaging; P-III-NP = procollagen type-III amino-terminal pro-peptide; PHD = pituitary hormone deficiencies; QoL = quality of life; rhGH = recombinant human growth hormone; ROC = receiver operating characteristic; RR = relative risk; SAH = subarachnoid hemorrhage; SDS = standard deviation score; SIR = standardized incidence ratio; SN = secondary neoplasms; T3 = triiodothyronine; TBI = traumatic brain injury; VDBP = vitamin D-binding protein; WADA = World Anti-Doping Agency; WB-GST = weight-based glucagon stimulation test.

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.

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.

The impact of real practice inappropriateness and devices' inefficiency to variability in growth hormone consumption

INTRODUCTION

Growth hormone (GH) consumption is the object of a particular attention by regulatory bodies, due to its financial impact; nevertheless, GH treatment has been demonstrated to be cost-effective and is, therefore, usually reimbursed by public health service systems. In Italy, significant differences in GH consumption between regions have been recorded. Different appropriateness in real practice is a possible explanation, but the proportion of drug wasted due to different combinations of therapeutic regimes and types of devices used in drug administration is a complementary explanation. Aim of the study is, therefore, to determine how much of the variability in GH consumption is actually due to differences in clinical practice, and how much to waste.

MATERIALS AND METHODS

A model was settled to estimate the population with indication for GH administration, separately for children, transition subjects and adults, based on both the scientific evidence available and directly collected clinical evaluations. A systematic literature search was conducted using Cochrane Library (HTA and NHSEE) databases, Medline via Ovid, Econlit via Ovid, Embase.

CONCLUSION

The model applied to the Italian population showed that there was apparently unexplainable over-prescription and potential under-prescription in various regions, ranging from 20 to 40 % less than the estimated theoretical consumption to over 200 %. Wastage, at level of single device, could amount to as much as 15 % of the consumption, demonstrating that price per mg is not in general a good proxy of the cost per mg of therapy. Our estimates of the wastage shows a significant potential gap in the model assessment of the HTA bodies, as far as they do not explicitly take into account the issue of wastage and, consequently, the actual variability in local clinical practice.

The Challenge of Growth Hormone Deficiency Diagnosis and Treatment during the Transition from Puberty into Adulthood

In children with childhood-onset growth hormone deficiency, replacement GH therapy is effective in normalizing height during childhood and achieving adult height within the genetic target range. GH has further beneficial effects on body composition and metabolism through adult life. The transition phase, defined as the period from mid to late teens until 6-7 years after the achievement of final height, represents a crucial time for reassessing children's GH secretion and deciding whether GH therapy should be continued throughout life. Evidence-based guidelines for diagnosis and treatment of growth hormone deficient children during transition are lacking. The aim of this review is to critically review the up-to-date evidence on the best management of transition patients in order to ensure the correct definitive diagnosis and establish the appropriate therapeutic regimen.

Characteristics of the short children referred to an academic paediatric endocrine clinic in Greece

AIM

To describe the characteristics of short children in relation to gender and the various diagnoses.

METHODS

All new patients of Greek origin that were referred to our institution in the years 2007 and 2008 for evaluation of short stature were included in the study. Children were categorized according to the severity of their short stature in those with height standard deviation score (HSDS) ≤ -3 and HSDS > -3.

RESULTS

Two hundred ninety-five children (162 boys and 133 girls, ratio 1.2) were referred. HSDS of boys was -2.3 (0.6) and of girls -2.1 (0.5), P= 0.004. Girls had shorter parents, and the predicted adult HSDS was also shorter for girls -1.7 (0.8) than for boys -1.35 (0.76), P= 0.003. Seventy per cent of the children of both sexes had familial short stature (FSS), constitutional delay of growth or a combination of the two conditions. About 10% presented the auxological and biochemical criteria for growth hormone deficiency (GHD). In addition, 11.8% had a HSDS ≤ -3, the most common diagnosis being GHD (36.1%); the less severely short children most commonly presented FSS (41.2%).

CONCLUSIONS

There is no gender bias in referrals for short stature in Greece. About 70% of children of both sexes presented FSS or constitutional delay of growth or a combination of the two conditions, whereas GHD was diagnosed in about 10% of the children. Normal variants of growth were present in about 80% of children with HSDS > -3, but in only 40% when HSDS was ≤ -3.

Early changes in body composition after cessation of growth hormone therapy in childhood-onset growth hormone deficiency

At final height, somatic maturity has not been reached yet. We investigated bone and body composition in patients, who completed pediatric growth hormone (GH) treatment at final height. After a mean period of 0.55 ± 0.17 yr off GH treatment 90 (66 m/24 f) childhood-onset growth hormone deficiency (GHD) patients were reinvestigated for GHD by insulin tolerance testing at a mean age of 17.52 ± 1.50 yr. Thirty-seven (25 m/12 f) patients remained GH deficient (persistent GHD). Bone and body composition were measured using peripheral quantitative computed tomography of the nondominant forearm. Bone mineral density (BMD) was within normal limits. Total cross-sectional bone area Z-score (0.64 ± 1.3) was significantly higher as a result of an enlarged medullary cavity Z-score (1.12 ± 1.2) leading to reduction of cortical thickness Z-score (-1.21 ± 1.0). Patients with persistent GHD had a significantly higher fat mass (13.3 ± 8.7 and 6.8 ± 4.6 cm(2), p<0.05), which was more pronounced in multiple pituitary hormone deficiency patients. Shortly after cessation of GH treatment in patients treated for childhood-onset GHD age adequate normal BMD and enlarged diaphysis was detectable. Patients with persistent GHD status had a significant higher fat mass.

Growth hormone: the expansion of available products and indications

Growth hormone is a widely used hormone. This article describes its historical use, current indications and studies for possible future uses.

Somatotropin in the treatment of growth hormone deficiency and Turner syndrome in pediatric patients: a review

Growth hormone (GH), also known as somatotropin, is a peptide hormone that is synthesized and secreted by the somatotrophs of the anterior pituitary gland. The main action of GH is to stimulate linear growth in children; however, it also fosters a healthy body composition by increasing muscle and reducing fat mass, maintains normal blood glucose levels, and promotes a favorable lipid profile. This article provides an overview of the normal pathophysiology of GH production and action. We discuss the history of GH therapy and the development of the current formulation of recombinant human GH given as daily subcutaneous injections. This paper reviews two of the longest standing FDA-approved indications for GH treatment, GH deficiency and Turner syndrome. We will highlight the pathogenesis of these disorders, including presentations, presumed mechanism(s) for the associated short stature, and diagnostic criteria, with a review of stimulation test benefits and pitfalls. This review also includes current recommendations for GH therapy to help maximize final height in these children, as well as data demonstrating the efficacy and safety of GH treatment in these populations.

Growth hormone: the expansion of available products and indications

Growth hormone is a widely used hormone. This article describes its historical use, current indications and studies for possible future uses.