Pathogenesis and Diagnosis of Growth Hormone Deficiency in Adults

Hypopituitarism

Partial or complete deficiency of anterior or posterior pituitary hormone production leads to central hypoadrenalism, central hypothyroidism, hypogonadotropic hypogonadism, growth hormone deficiency, or arginine vasopressin deficiency depending on the hormones affected. Hypopituitarism is rare and likely to be underdiagnosed, with an unknown but rising incidence and prevalence. The most common cause is compressive growth or ablation of a pituitary or hypothalamic mass. Less common causes include genetic mutations, hypophysitis (especially in the context of cancer immunotherapy), infiltrative and infectious disease, and traumatic brain injury. Clinical features vary with timing of onset, cause, and number of pituitary axes disrupted. Diagnosis requires measurement of basal circulating hormone concentrations and confirmatory hormone stimulation testing as needed. Treatment is aimed at replacement of deficient hormones. Increased mortality might persist despite treatment, particularly in younger patients, females, and those with arginine vasopressin deficiency. Patients with complex diagnoses, pregnant patients, and adolescent pituitary-deficient patients transitioning to adulthood should ideally be managed at a pituitary tumour centre of excellence.

Exploring the sex difference in cardiovascular risk during growth hormone therapy in adults

OBJECTIVE

Given the previously identified sex differences in cardiovascular (CV) morbidity and mortality in patients with growth hormone deficiency (GHD) receiving GH replacement therapy (GHRT), our aim is to investigate sex-specific differences in the efficacy of (long-term) GHRT on CV risk profile and disease in subjects with GHD. Our hypothesis is that women will experience less beneficial effects than men.

DESIGN

Retrospective nationwide cohort study.

METHODS

We compared all men (n = 1335) and women (n = 1251) with severe GHD registered in the Dutch National Registry of GH Treatment in Adults database with respect to CV risk profile and morbidity at baseline and during follow-up.

RESULTS

Men had a more unfavourable CV risk profile at baseline. During the first years of GHRT, the reduction in waist circumference, waist-to-hip ratio, total cholesterol, and triglyceride levels was greater in men than in women (all P < .05). Between-sex differences in effects during later follow-up were less clear. No sex differences were found in the risk of developing non-fatal cardiovascular or cerebrovascular diseases during GHRT.

CONCLUSIONS

Our results suggest that men with GHD did indeed experience more beneficial effects of GHRT on body composition and lipoprotein metabolism than women, at least in the early years of treatment. Also, the more unfavourable CV risk profile at baseline in men did not translate into a sex difference in the risk of developing CV and cerebrovascular morbidity during GHRT.

Glucagon does not directly stimulate pituitary secretion of ACTH, GH or copeptin

Glucagon is best known for its contribution to glucose regulation through activation of the glucagon receptor (GCGR), primarily located in the liver. However, glucagon's impact on other organs may also contribute to its potent effects in health and disease. Given that glucagon-based medicine is entering the arena of anti-obesity drugs, elucidating extrahepatic actions of glucagon are of increased importance. It has been reported that glucagon may stimulate secretion of arginine-vasopressin (AVP)/copeptin, growth hormone (GH) and adrenocorticotrophic hormone (ACTH) from the pituitary gland. Nevertheless, the mechanisms and whether GCGR is present in human pituitary are unknown. In this study we found that intravenous administration of 0.2 mg glucagon to 14 healthy subjects was not associated with increases in plasma concentrations of copeptin, GH, ACTH or cortisol over a 120-min period. GCGR immunoreactivity was present in the anterior pituitary but not in cells containing GH or ACTH. Collectively, glucagon may not directly stimulate secretion of GH, ACTH or AVP/copeptin in humans but may instead be involved in yet unidentified pituitary functions.

Structure of GPR101-Gs enables identification of ligands with rejuvenating potential

GPR101 is an orphan G protein-coupled receptor actively participating in energy homeostasis. Here we report the cryo-electron microscopy structure of GPR101 constitutively coupled to Gs heterotrimer, which reveals unique features of GPR101, including the interaction of extracellular loop 2 within the 7TM bundle, a hydrophobic chain packing-mediated activation mechanism and the structural basis of disease-related mutants. Importantly, a side pocket is identified in GPR101 that facilitates in silico screening to identify four small-molecule agonists, including AA-14. The structure of AA-14-GPR101-Gs provides direct evidence of the AA-14 binding at the side pocket. Functionally, AA-14 partially restores the functions of GH/IGF-1 axis and exhibits several rejuvenating effects in wild-type mice, which are abrogated in Gpr101-deficient mice. In summary, we provide a structural basis for the constitutive activity of GPR101. The structure-facilitated identification of GPR101 agonists and functional analysis suggest that targeting this orphan receptor has rejuvenating potential.

Effective growth hormone replacement with once-weekly somapacitan in Japanese children with growth hormone deficiency: Results from REAL4, a phase 3 clinical trial

OBJECTIVE

Somapacitan is a long-acting growth hormone (GH) derivative developed for the treatment of GH deficiency (GHD). This study evaluates the efficacy and tolerability of somapacitan in Japanese children with GHD after 104 weeks of treatment and after switch from daily GH.

DESIGN

Subanalysis on Japanese patients from a randomised, open-labelled, controlled parallel-group phase 3 trial (REAL4, NCT03811535).

PATIENTS AND MEASUREMENTS

Thirty treatment-naïve patients were randomised 2:1 to somapacitan (0.16 mg/kg/week) or daily GH (0.034 mg/kg/day) up to Week 52, after which all patients received somapacitan. Height velocity (HV; cm/year) at Weeks 52 and 104 were the primary measurements. Additional assessments included HV SD score (SDS), height SDS, bone age, insulin-like growth factor-I (IGF-I) SDS, and observer-reported outcomes.

RESULTS

At Week 52, observed mean HV was similar between treatment groups (10.3 vs. 9.8 cm/year for somapacitan and daily GH, respectively). Similar HVs between groups were also observed at Week 104: 7.4 cm/year after continuous somapacitan treatment (soma/soma) and 7.9 cm/year after 1-year somapacitan treatment following switch from daily GH (switch). Other height-related endpoints supported continuous growth. IGF-I SDS increased in both groups with mean IGF-I SDS within -2 and +2 during the study. Somapacitan was well tolerated, one mild injection site reaction was reported, with no reports of injection site pain. Patient preference questionnaires showed that most patients and their caregivers (90.9%) who switched treatment at Week 52 preferred once-weekly somapacitan over daily GH treatment.

CONCLUSIONS

Somapacitan showed sustained efficacy in Japanese children with GHD over 104 weeks and for 52 weeks after switching from daily GH. Somapacitan was well tolerated and preferred over daily GH.

Trends of correlations between serum levels of growth hormone and insulin-like growth factor-I in general practice

Serum levels of growth hormone (GH) and insulin-like growth factor (IGF)-I are crucial in the diagnosis and management of GH-related diseases. However, these levels are affected by nutritional and metabolic status. To elucidate the correlations between GH and IGF-I in various conditions, a retrospective analysis was performed for adult patients in which GH levels were examined by general practitioners during the period from January 2019 to December 2021. Of 642 patients, 33 patients were diagnosed with acromegaly, 21 were diagnosed with GH deficiency (GHD), and 588 were diagnosed with non-GH-related diseases (NGRD). In contrast to the positive correlations found between the levels of GH and IGF-I in patients with acromegaly (R=0.50; P<0.001) and patients with GHD (R=0.39; P=0.08), a negative correlation was found in the NGRD group (R=-0.23; P<0.001). In that group, the results of multivariable analysis showed that GH levels were predominantly influenced by gender and body mass index (BMI), whereas IGF-I levels were modulated by albumin in addition to age and GH. Of note, in the NGRD group, there was an enhanced negative correlation between GH and IGF-I under conditions of BMI < 22 and albumin < 4.0 g/dL (R=-0.45; P<0.001), and the negative correlation between GH and IGF-I was reinforced by excluding patients with other pituitary diseases and patients taking oral steroids (R=-0.51; P<0.001 and R=-0.59; P<0.001, respectively). Collectively, the results indicate that attention should be given to the presence of a negative correlation between serum levels of GH and IGF-I, especially in lean and low-nutritious conditions.

Challenges of insulin-like growth factor-1 testing

Insulin-like growth factor 1 (IGF-1), primarily synthesized in the liver, was initially discovered due to its capacity to replicate the metabolic effects of insulin. Subsequently, it emerged as a key regulator of the actions of growth hormone (GH), managing critical processes like cell proliferation, differentiation, and apoptosis. Notably, IGF-1 displays a longer half-life compared to GH, making it less susceptible to factors that may affect GH concentrations. Consequently, the measurement of IGF-1 proves to be more specific and sensitive when diagnosing conditions such as acromegaly or GH deficiency. The recognition of the existence of IGFBPs and their potential to interfere with IGF-1 immunoassays urged the implementation of various techniques to moderate this issue and provide accurate IGF-1 results. Additionally, in response to the limitations associated with IGF-1 immunoassays and the occurrence of discordant IGF-1 results, modern mass spectrometric methods were developed to facilitate the quantification of IGF-1 levels. Taking advantage of their ability to minimize the interference caused by IGF-1 variants, mass spectrometric methods offer the capacity to deliver robust, reliable, and accurate IGF-1 results, relying on the precision of mass measurements. This also enables the potential detection of pathogenic mutations through protein sequence analysis. However, despite the analytical challenges, the discordance in IGF-1 reference intervals can be attributed to a multitude of factors, potentially leading to distinct interpretations of results. The establishment of reference intervals for each assay is a demanding task, and it requires nationwide multicenter collaboration among laboratorians, clinicians, and assay manufacturers to achieve this common goal in a cost-effective and resource-efficient manner. In this comprehensive review, we examine the challenges associated with the standardization of IGF-1 measurement methods, the minimization of pre-analytical factors, and the harmonization of reference intervals. Particular emphasis will be placed on the development of IGF-1 measurement techniques using "top-down" or "bottom-up" mass spectrometric methods.

Serum afamin and its implications in adult growth hormone deficiency: a prospective GH-withdrawal study

Introduction

Adult growth hormone deficiency (AGHD) is associated with a high prevalence of metabolic syndrome (MS), which contributes to the unfavorable cardiovascular risk profile in these patients. Insulin like growth factor-1 (IGF-1) is a widely used biomarker, however it does not always reflect the cardiometabolic risk and has a poor relationship with clinical efficacy endpoints. Consequently, there is an unmet need for biomarkers to monitor responses to GH-replacement. Afamin is a hormone-like glycoprotein, expressed in the liver. Higher afamin levels are strongly associated with MS and insulin resistance (IR). Although both MS and IR are very common in AGHD, afamin has not been investigated in these patients.

Purpose

To investigate afamin as a potential biomarker in patients with AGHD.

Materials and methods

Participants included 20 AGHD patients (11 GH-substituted and 9 GH-unsubstituted) and 37 healthy controls. Subjects underwent routine laboratory examinations, anthropometric measurements, body composition analysis using multi-frequency bioelectrical impedance analysis (InBody720) and measurement of serum afamin concentrations. In GH-substituted subjects, GH-substitution was withdrawn for 2 months. Measurements were carried out right before GH-withdrawal, at the end of the 2-month withdrawal period, and 1 month after reinstituting GH-replacement therapy (GHRT).

Results

GH-unsubstituted patients demonstrated higher afamin levels compared to controls (p=0.03). Afamin positively correlated with skeletal muscle mass, bone mineral content, total body water, extracellular- and intracellular water content, insulin (all, p<0.01), HOMA-IR (p=0.01) and C-peptide (p=0.03) levels in AGHD but not in healthy controls. In GH-substituted patients 2-month of GH-withdrawal caused significant changes in body composition, including decreased fat-free mass, skeletal muscle mass, total body water, and intracellular water content (all, p<0.01); but these changes almost fully recovered 1 month after reinstituting GHRT. Unexpectedly, afamin levels decreased after GH-withdrawal (p=0.03) and increased with reinstitution (p<0.01). Changes of afamin levels during GH-withdrawal positively correlated with changes of HOMA-IR (r=0.80; p<0.01) and changes of insulin (r=0.71; p=0.02).

Conclusion

Higher afamin levels in unsubstituted AGHD patients might indicate severe metabolic dysregulation. Significant changes accompanying GH-withdrawal and reinstitution, along with strong correlations with measures of IR, suggest that afamin could be a promising biomarker to monitor GHRT-associated changes of insulin sensitivity.

Consensus on criteria for acromegaly diagnosis and remission

PURPOSE

The 14th Acromegaly Consensus Conference was convened to consider biochemical criteria for acromegaly diagnosis and evaluation of therapeutic efficacy.

METHODS

Fifty-six acromegaly experts from 16 countries reviewed and discussed current evidence focused on biochemical assays; criteria for diagnosis and the role of imaging, pathology, and clinical assessments; consequences of diagnostic delay; criteria for remission and recommendations for follow up; and the value of assessment and monitoring in defining disease progression, selecting appropriate treatments, and maximizing patient outcomes.

RESULTS

In a patient with typical acromegaly features, insulin-like growth factor (IGF)-I > 1.3 times the upper limit of normal for age confirms the diagnosis. Random growth hormone (GH) measured after overnight fasting may be useful for informing prognosis, but is not required for diagnosis. For patients with equivocal results, IGF-I measurements using the same validated assay can be repeated, and oral glucose tolerance testing might also be useful. Although biochemical remission is the primary assessment of treatment outcome, biochemical findings should be interpreted within the clinical context of acromegaly. Follow up assessments should consider biochemical evaluation of treatment effectiveness, imaging studies evaluating residual/recurrent adenoma mass, and clinical signs and symptoms of acromegaly, its complications, and comorbidities. Referral to a multidisciplinary pituitary center should be considered for patients with equivocal biochemical, pathology, or imaging findings at diagnosis, and for patients insufficiently responsive to standard treatment approaches.

CONCLUSION

Consensus recommendations highlight new understandings of disordered GH and IGF-I in patients with acromegaly and the importance of expert management for this rare disease.

Association between the triglyceride-glucose index and impaired cardiovascular fitness in non-diabetic young population

BACKGROUND

The triglyceride-glucose (TyG) index has been linked to the onset, progression, and prognosis of cardiovascular disease (CVD) in middle-aged and elderly individuals. Nevertheless, the relationship between the TyG index and impaired cardiovascular fitness (CVF) remains unexplored in non-diabetic young population.

METHODS

We used data from the National Health and Nutrition Examination Survey (NHANES) study (1999-2004) to conduct a cross-sectional study of 3364 participants who completed an examination of CVF. Impaired CVF was defined as low and moderate CVF levels determined by estimated maximal oxygen consumption (Vo2max), based on sex- and age-specific criteria. The TyG index was calculated by [Formula: see text].

RESULTS

The age (median with interquartile range) of the study population was 28 (19-37) years, and the TyG index (median ± standard deviation) was 8.36 ± 0.52. A significant association between the TyG index and impaired CVF was found in multivariable logistical regression analysis (per 1-unit increase in the TyG index: OR, 1.46; 95% Cl 1.13-1.90). A dose‒response relationship between the TyG index and impaired CVF was presented by restricted cubic splines (RCS). A significant interaction (p = 0.027) between sex and the TyG index for impaired CVF was found in the population aged < 20 years.

CONCLUSIONS

In non-diabetic young population, individuals with higher TyG index values are at an increased likelihood of encountering impaired CVF. Furthermore, sex may exert an impact on CVF, as males tend to be more susceptible to impaired CVF under comparable TyG index conditions.

Crosstalk Between the Neuroendocrine System and Bone Homeostasis

The homeostasis of bone microenvironment is the foundation of bone health and comprises 2 concerted events: bone formation by osteoblasts and bone resorption by osteoclasts. In the early 21st century, leptin, an adipocytes-derived hormone, was found to affect bone homeostasis through hypothalamic relay and the sympathetic nervous system, involving neurotransmitters like serotonin and norepinephrine. This discovery has provided a new perspective regarding the synergistic effects of endocrine and nervous systems on skeletal homeostasis. Since then, more studies have been conducted, gradually uncovering the complex neuroendocrine regulation underlying bone homeostasis. Intriguingly, bone is also considered as an endocrine organ that can produce regulatory factors that in turn exert effects on neuroendocrine activities. After decades of exploration into bone regulation mechanisms, separate bioactive factors have been extensively investigated, whereas few studies have systematically shown a global view of bone homeostasis regulation. Therefore, we summarized the previously studied regulatory patterns from the nervous system and endocrine system to bone. This review will provide readers with a panoramic view of the intimate relationship between the neuroendocrine system and bone, compensating for the current understanding of the regulation patterns of bone homeostasis, and probably developing new therapeutic strategies for its related disorders.

Growth Hormone, Atherosclerosis and Peripheral Arterial Disease: Exploring the Spectrum from Acromegaly to Growth Hormone Deficiency

Growth hormone (GH) and insulin-like growth factor 1 (IGF-1) are increasingly recognised for their role in cardiovascular (CV) physiology. The GH-IGF-1 axis plays an essential role in the development of the CV system as well as in the complex molecular network that regulates cardiac and endothelial structure and function. A considerable correlation between GH levels and CV mortality exists even among individuals in the general population without a notable deviation in the GHIGF- 1 axis functioning. In addition, over the last decades, evidence has demonstrated that pathologic conditions involving the GH-IGF-1 axis, as seen in GH excess to GH deficiency, are associated with an increased risk for CV morbidity and mortality. A significant part of that risk can be attributed to several accompanying comorbidities. In both conditions, disease control is associated with a consistent improvement of CV risk factors, reduction of CV mortality, and achievement of standardised mortality ratio similar to that of the general population. Data on the prevalence of peripheral arterial disease in patients with acromegaly or growth hormone deficiency and the effects of GH and IGF-1 levels on the disease progression is limited. In this review, we will consider the pivotal role of the GH-IGF-1 axis on CV system function, as well as the far-reaching consequences that arise when disorders within this axis occur, particularly in relation to the atherosclerosis process.

Growth hormone replacement in adults with cured acromegaly: Efficacy and safety

Between 2% and 60% of patients with cured acromegaly may eventually develop growth hormone deficiency. In adults, growth hormone deficiency is associated with abnormal body composition, decreased exercise capacity and quality of life, dyslipidemia, insulin resistance and increased cardiovascular risk. Similar to patients with other sellar lesions, the diagnosis of growth hormone deficiency in adults with cured acromegaly generally requires stimulation testing, with the exception of patients with very low serum insulin-like growth factor I levels and multiple additional pituitary hormone deficiencies. In adults with cured acromegaly, growth hormone replacement may have beneficial effects on body adiposity, muscle endurance, serum lipids and quality of life. Growth hormone replacement is generally well-tolerated. Arthralgias, edema, carpal tunnel syndrome and hyperglycemia may occur in patients with cured acromegaly, as is true of patients with growth hormone deficiency of other etiologies. However, there is evidence of increased cardiovascular risk in some studies of growth hormone replacement in adults with cured acromegaly. More studies are needed to fully establish the beneficial effects and elucidate the risks of growth hormone replacement in adults with cured acromegaly. Until then, growth hormone replacement can be considered in these patients on a case-by-case basis.

Nonalcoholic fatty liver disease and adult growth hormone deficiency: An under-recognized association?

Growth hormone (GH) plays an essential role not only in promoting growth in children, but also in many important metabolic processes in adults. One of the major metabolic functions of GH is its stimulatory effects on the liver in generating approximately 80% of circulating insulin-like growth factor 1 (IGF-1). Adult growth hormone deficiency (GHD) is an established clinical entity defined as a defect in endogenous GH secretion that is frequently associated with central obesity, loss of muscle mass, decreased bone mass, and impaired quality of life. Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) are conditions that are often under-recognized in adults with GHD, and accordingly some studies have shown that GH and IGF-1 levels are decreased in patients with NAFLD. Furthermore, it has been reported that it can progress to end-stage liver cirrhosis in some adults and children with GHD. Due to their underlying mechanisms of action, GH and IGF-1 can act on hepatocytes, macrophages, and hepatic stellate cells to mitigate progression to steatosis and fibrosis. It is, thus, important to recognize NAFLD/NASH as important complications in adult and childhood GHD. Therefore, careful and thorough evaluation of NAFLD/NASH in adults with GHD and the consideration for GH replacement therapy is crucial in these patients, together with management of other metabolic risk factors, such as obesity and dyslipidemia. This review will focus on recent reports on the role of GH and IGF-1 in the liver and its clinical significance in the regulation of hepatic function.

Impact of long-acting growth hormone replacement therapy in adult growth hormone deficiency: Comparison between adolescent, adult, and elderly patients

The predominant features of the adult growth hormone deficiency (GHD) syndrome may vary between patients of different age and age of onset of GHD. Evidence from clinical trials and long-term observational studies has informed our ability to understand the unique considerations regarding risks and benefits of daily growth hormone replacement therapy (GHRT) and specific dosing and monitoring strategies for these patient subgroups. High rates of nonadherence with daily GHRT presents a challenge to achieving optimal treatment outcomes and long-acting growth hormone (LAGH) formulations have been developed with the promise of improving treatment adherence resulting in improved therapeutic outcomes. While existing data from short-term studies have demonstrated noninferiority of efficacy and safety of LAGH compared to daily GHRT, long-term studies are needed to assess the full spectrum of outcomes of interest and long-term safety considerations specific to patients in adolescence, adulthood and the elderly GHD population. Since each LAGH formulation has a unique pharmacodynamic and pharmacokinetic profile optimal dosing and monitoring strategies will need to be developed to allow for the provision of individualized patient treatment.

Meta-analysis of mortality in adults with growth hormone deficiency: Does growth hormone replacement therapy really improve mortality rates?

Growth hormone (GH) deficiency (GHD) is one of the most prevalent deficiencies in patients with hypopituitarism and several cohort studies have demonstrated an increased mortality risk in hypopituitary patients with a presumed GHD. The cause of the excess mortality is most likely multifactorial, including the etiology of the hypopituitarism, non-physiological replacement therapies (mostly glucocorticoid), tumor treatment and its side effects as well as untreated GHD. Several years later, other cohort studies that investigated life expectancy in patients with hypopituitarism on GH replacement therapy (GHRT) that showed a normalized mortality. By comparison of the distribution of characteristics of interest between cohorts, we discuss the existing literature to answer the following question: does growth hormone replacement really improve mortality rates in adult patients with hypopituitarism and GHD? We also conducted a meta-analysis of these studies. Since the literature suffers from selection and time bias (improvement of tumor management and other pituitary hormone replacement therapies), there is no high-quality evidence that replacement therapy for GHD really improves mortality. However, the available data does suggest that GHRT plays a significant part in the normalization of the mortality in patients with hypopituitarism.

Effective GH Replacement With Somapacitan in Children With GHD: REAL4 2-year Results and After Switch From Daily GH

CONTEXT

Somapacitan is a long-acting GH derivative for treatment of GH deficiency (GHD).

OBJECTIVE

Evaluate the efficacy and tolerability of somapacitan in children with GHD after 2 years of treatment and after the switch from daily GH.

DESIGN

A randomized, multinational, open-labelled, controlled parallel group phase 3 trial, comprising a 52-week main phase and 3-year safety extension (NCT03811535).

SETTING

Eighty-five sites across 20 countries.

PATIENTS

A total of 200 treatment-naïve prepubertal patients were randomized and exposed; 194 completed the 2-year period.

INTERVENTIONS

Patients were randomized 2:1 to somapacitan (0.16 mg/kg/wk) or daily GH (0.034 mg/kg/d) during the first year, after which all patients received somapacitan 0.16 mg/kg/wk.

MAIN OUTCOME MEASURES

Height velocity (HV; cm/year) at week 104. Additional assessments included HV SD score (SDS), height SDS, IGF-I SDS, and observer-reported outcomes.

RESULTS

HV was sustained in both groups between 52 and 104 weeks. At week 104, mean (SD) for HV between weeks 52 and 104 was 8.4 (1.5) cm/year after continuous somapacitan treatment and 8.7 (1.8) cm/year after 1 year of somapacitan treatment following switch from daily GH. Secondary height-related endpoints also supported sustained growth. Mean IGF-I SDS during year 2 was similar between groups and within normal range (-2 to +2). Somapacitan was well tolerated, with no safety or tolerability issues identified. GH patient preference questionnaire results show that most patients and their caregivers (90%) who switched treatment at year 2 preferred once-weekly somapacitan over daily GH treatment.

CONCLUSIONS

Somapacitan in children with GHD showed sustained efficacy and tolerability for 2 years, and after switching from daily GH. Patients/caregivers switching from daily GH expressed a preference for somapacitan.

CLINICAL TRIAL REGISTRATION

NCT03811535.

Effect of GH Deficiency Caused by Nonfunctioning Pituitary Masses on Serum C-reactive Protein Levels

Context

GH supplementation for GH deficiency (GHD) has been reported to decrease high-sensitivity C-reactive protein (hs-CRP), an inflammatory marker; however, the association between GHD and hs-CRP remains unclear.

Objective

We aimed to clarify the impact of impaired GH secretion due to pituitary masses on hs-CRP levels.

Methods

We retrospectively examined the association between GH secretion, assessed using GH-releasing peptide-2, and serum hs-CRP levels before and a year after the pituitary surgery in patients with nonfunctioning pituitary neuroendocrine tumor or Rathke cleft cyst.

Results

Among 171 patients, 55 (32%) presented with severe GHD (peak GH response to GH-releasing peptide-2 < 9 ng/mL). Serum hs-CRP levels were significantly higher in patients with severe GHD than in those without (P < .001) and significantly correlated with the peak GH (r = -0.50, P < .001). Multiple regression analyses showed that the peak GH significantly and negatively predicted hs-CRP levels (β = -0.345; 95% CI, -0.533 to -0.158) and the lowest quartile of the peak GH (<5.04 ng/mL) were significantly associated with increase in hs-CRP levels (exp [β] = 1.840; 95% CI, 1.209 to 2.801), after controlling for other anterior hormones and metabolic parameters. Postoperative change in the peak GH (N = 60) significantly predicted change in hs-CRP levels (β = -0.391; 95% CI, -0.675 to -0.108), independent of alterations in other anterior hormones and metabolic parameters.

Conclusion

The inverse association between GH secretion and hs-CRP levels highlights the protective role of GH in the increase in hs-CRP.

[Unfavourable cardiovascular consequences of adult growth hormone deficiency]

The growth hormone-insulin-like growth factor-1 (GH-IGF-1) axis plays a crucial role in maintaining the normal function of the cardiovascular system. Results of the last decades demonstrated that GH-IGF-1 takes part in regulating peripheral resistance and contributes to preserving physiological cardiac mass and left ventricular function. Vasculoprotective functions of the GH-IGF-1 axis are believed to counteract atherosclerosis. Unlike in childhood, when GH-deficiency results in growth retardation, GH deficiency does not cause specific symptoms in adults. Adult growth hormone deficiency (AGHD) is characterized by a clustering of cardiometabolic risk factors resulting in a clinical picture similar to the metabolic syndrome. Besides visceral obesity, dyslipidemia and insulin resistance, novel cardiovascular risk factors, such as chronic low-grade inflammation, oxidative stress and prothrombotic state have also been reported in AGHD and may contribute to the increased cardiometabolic risk. Based on a growing body of evidence, long-term GH-replacement improves lipid profile significantly and has a favorable impact on body composition, endothelial function, left ventricular mass as well as the novel, non-traditional cardiometabolic risk factors. Increased mortality associated with the disease is now considered to be multicausal and as such cannot be solely attributed to the GH-deficiency. The etiology of GH-deficiency, treatment of the underlying pathology as well as the inadequate treatment of coexisting hormonal deficiencies might also be responsible for the increased mortality. Nevertheless, in hypopituitarism, adequate replacement therapy including GH-substitution may result in a mortality that is comparable to the general population. Orv Hetil. 2023; 164(41): 1616-1627.

Uric acid levels correlate with disease activity in growth hormone-secreting pituitary adenoma patients

Objective

Few studies reported the effects of growth hormone-secreting pituitary adenoma (GHPA) on uric acid (UA) metabolism and the relationship between growth hormone (GH)/insulin-like growth factor-1 (IGF-1) levels and UA are controversial. This study aimed to evaluate the relationship between IGF-1 and UA in patients with GHPA and to further clarify whether UA levels are associated with GHPA disease activity by follow-up.

Methods

A longitudinal study of 424 GHPA patients presenting to Beijing Tiantan Hospital, Capital Medical University between January 2015 and January 2023 was conducted. Spearman's correlation tests were performed to examine the relationship between IGF-1 and UA at baseline. Univariate and multivariate linear regression analysis was conducted to investigate the independent association between UA and IGF-1. Changes in postoperative IGF-1 and UA levels were followed prospectively, and the differences in UA levels between the biochemical remission and nonremission groups were compared.

Results

At baseline, male patients, the lower the age, the higher the IGF-1 and body mass index (BMI), and the higher the UA levels. IGF-1 was significantly associated with UA after controlling for sex, age, and BMI (r = 0.122, P = 0.012). In adjusted multiple linear regression analysis, IGF-1 was independently associated with UA, and UA levels increased significantly with increasing IGF-1. During postoperative follow-up, UA decreased gradually as IGF-1 levels decreased. At 12 months postoperatively, UA levels were significantly lower in the biochemical remission group than in the nonremission group (P = 0.038).

Conclusions

In patients with GHPA, UA levels are associated with disease activity. Changes in UA levels should be taken into account in the comprehensive treatment of GHPA, patients presenting with HUA should be given lifestyle guidance and appropriate urate-lowering treatment according to their condition to better improve their prognosis.

Endocrine disorders associated with obesity

Several endocrine disorders, including diabetes, insulinoma, Cushing syndrome, hypothyroidism, polycystic ovarian syndrome, and growth hormone deficiency, are associated with obesity. The mechanisms underlying the development of obesity vary according to the abnormalities of endocrine function. The primary actions of insulin, glucocorticoids (GCs), thyroid hormone, and growth hormone are associated with energy metabolism in the liver, muscle, adipose tissue, and other tissues. This chapter describes the pathogenesis of obesity and metabolic dysfunction associated with excess insulin or GCs and the deficiency of thyroid hormone or growth hormone.

Growth Hormone and Aging

Growth hormone (GH) secretion declines with aging (somatopause). One of the most controversial issues in aging is GH treatment of older adults without evidence of pituitary pathology. Although some clinicians have proposed reversing the GH decline in the older population, most information comes from not placebo-controlled studies. Although most animal studies reported an association between decreased GH levels (or GH resistance) and increased lifespan, human models have shown contradictory reports on the consequences of GH deficiency (GHD) on longevity. Currently, GH treatment in adults is only indicated for individuals with childhood-onset GHD transitioning to adulthood or new-onset GHD due to hypothalamic or pituitary pathologic processes.

Long-Term Safety of Growth Hormone Deficiency Treatment in Cancer and Sellar Tumors Adult Survivors: Is There a Role of GH Therapy on the Neoplastic Risk?

Experimental studies support the hypothesis that GH/IGF-1 status may influence neoplastic tissue growth. Epidemiological studies suggest a link between GH/IGF-1 status and cancer risk. However, several studies regarding GH replacement safety in childhood cancer survivors do not show a prevalence excess of de novo cancers, and several reports on children and adults treated with GH have not shown an increase in observed cancer risk in these patients. The aim of this review is to provide an at-a-glance overview and the state of the art of long-term effects of GH replacement on neoplastic risk in adults with growth hormone deficiency who have survived cancer and sellar tumors.

Childhood-Onset GH Deficiency versus Adult-Onset GH Deficiency: Relevant Differences Regarding Insulin Sensitivity

The results of the studies on the pattern of insulin sensitivity (IS) are contradictory in patients with GH deficiency (GHD); however, the interference of the GHD onset stage, childhood or adulthood in the IS has not been assessed by euglycemic hyperinsulinemic clamp (EHC), a gold-standard method for the assessment of insulin sensitivity. In a prospective cross-sectional study, we assessed IS and body composition in 17 adults with hypopituitarism without GH replacement, ten with childhood-onset (COGHD) and seven with adulthood-onset (AOGHD) and compared them to paired control groups. COGHD presented higher IS (p = 0.0395) and a similar percentage of fat mass (PFM) to AOGHD. COGHD showed higher IS than the control group (0.0235), despite a higher PFM (0.0022). No differences were found between AODGH and the control group. In AOGHD and the control group, IS was negatively correlated with PFM (rs: −0.8214, p = 0.0234 and rs: −0.3639, p < 0.0344), while this correlation was not observed with COGHD (rs: −0.1152, p = 0.7514). Despite the higher PFM, patients with COGHD were more sensitive to insulin than paired healthy individuals, while patients with AOGHD showed similar IS compared to controls. The lack of GH early in life could modify the metabolic characteristics of tissues related to the glucose metabolism, inducing beneficial effects on IS that persist into adulthood. Thus, the glycometabolic findings in patients with COGHD seems to be not applicable to AOGHD.

Metabolic Profile and Echocardiographic Evaluation in Adults with Growth Hormone Deficiency

Adult growth hormone deficiency (AGHD) is associated with increased cardiovascular risks. The primary endpoint of this retrospective cohort study was to compare metabolic profile and echocardiographic parameters in childhood-onset (CO) and adulthood-onset (AO) AGHD patients. 26 patients with CO AGHD (19 males, 26.8±8.5 years) and 41 patients with AO AGHD (23 males, 35.1±6.8 years) were included. The standard deviation score of insulin-like growth factor-1 (IGF-1 SDS), metabolic profile, liver sonography and echocardiographic parameters were compared. The IGF-1 SDS were significantly lower in CO AGHD patients (p<0.05). AO AGHD patients showed much profound glycolipid aberrations, elevated C-reactive protein levels (p=0.012), and proportionally higher prevalence of non-alcoholic fatty liver disease (95.2% vs.8.3%, p<0.001). In all subjects, IGF-1 SDS was negatively related to low-density lipoprotein cholesterol, and positively related to total cholesterol and lipoprotein a (Lpa). There were significant differences between the two group with regard to the correlations between IGF-1 SDS and high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, LPa, uric acid and creatinine (all p for interaction<0.05). CO AGHD patients exhibited smaller heart, but similar ventricular ejection fraction compared to AO AGHD patients. AGHD may be a group of heterogenous entity based on the onset ages of disease. AO patients had prominent metabolic disorders, while CO patients had smaller heart but similar cardiac performance. Whether growth hormone replacement therapy will equally benefit both CO and AO AGHD patients needs further investigations.

Weekly Somapacitan is Effective and Well Tolerated in Children With GH Deficiency: The Randomized Phase 3 REAL4 Trial

CONTEXT

Somapacitan, a once-weekly reversible albumin-binding GH derivative, is evaluated in children with GH deficiency (GHD).

OBJECTIVE

To demonstrate efficacy and safety of somapacitan vs daily GH.

METHODS

REAL4 is a randomised, multinational, open-labeled, active-controlled parallel group phase 3 trial, comprising a 52-week main trial and 3-year extension (NCT03811535).

SETTING

Eighty-six sites across 20 countries.

PATIENTS

200 treatment-naïve patients were randomized and exposed.

INTERVENTIONS

Patients were randomized 2:1 to somapacitan (0.16 mg/kg/wk) or daily GH (Norditropin; 0.034 mg/kg/d), administered subcutaneously.

MAIN OUTCOME MEASURES

The primary endpoint was annualized height velocity (HV; cm/y) at week 52. Additional assessments included HV SD score (SDS), height SDS, bone age, IGF-I SDS, patient-reported outcomes, and safety measures.

RESULTS

Estimated mean HV at week 52 was 11.2 and 11.7 cm/y for somapacitan and daily GH, respectively. Noninferiority was confirmed. Changes in HV SDS, height SDS, bone age, and IGF-I SDS from baseline to week 52 were similar between treatment groups. At week 52, mean IGF-I SDS values were similar between treatment groups and within normal range (-2 to +2). Safety of somapacitan was consistent with the well-known daily GH profile. Low proportions of injection-site reactions were reported for somapacitan (5.3%) and daily GH (5.9%). Both treatments similarly reduced disease burden from baseline to week 52, whereas a greater treatment burden reduction was observed for somapacitan.

CONCLUSIONS

Similar efficacy for somapacitan compared to daily GH was demonstrated over 52 weeks of treatment with comparable safety and mean IGF-I SDS levels in treatment-naïve children with GHD.

Insulin-like growth factor-1 levels are associated with high comorbidity of metabolic disorders in obese subjects; a Japanese single-center, retrospective-study

Insulin like growth factor-1 (IGF-1) plays important roles in metabolic functions, especially in adulthood. Additionally, obese subjects are reportedly predisposed to having low absolute IGF-1 levels. However, the prevalence and clinical characteristics of obese subjects with low IGF-1 levels are unknown. We examined 64 obese subjects with a body mass index (BMI) ≥ 35 kg/m², with no history of endocrinological disorders, receiving inpatient care. IGF-1 levels were interpreted based on the IGF-1 standard deviation score (SDS) clinically used and standardized by age and sex (low IGF-1 group; ≤ - 2.0 SDS and standard IGF-1 group; - 2.0 < and <  + 2.0 SDS). Notably, 26.6% of the subjects had low IGF-1. Body fat mass and percentage, but not BMI, were significantly higher in the low than in the standard IGF-1 group. Furthermore, natural log-transformed high-sensitivity C-reactive protein, and the frequencies of dyslipidemia and hyperuricemia were higher in the low IGF-1 group. Moreover, among the subjects without diabetes, fasting glucose levels were significantly higher in the low IGF-1 group. Stepwise variable selection procedure revealed body fat percentage to be a parameter most strongly associated with low IGF-1. Thus, low IGF-1 levels may be an important marker of adiposity-associated metabolic disorders in obese patients.

Acromegaly: pathogenesis, diagnosis, and management

Growth hormone-secreting pituitary adenomas that cause acromegaly arise as monoclonal expansions of differentiated somatotroph cells and are usually sporadic. They are almost invariably benign, yet they can be locally invasive and show progressive growth despite treatment. Persistent excess of both growth hormone and its target hormone insulin-like growth factor 1 (IGF-1) results in a wide array of cardiovascular, respiratory, metabolic, musculoskeletal, neurological, and neoplastic comorbidities that might not be reversible with disease control. Normalisation of IGF-1 and growth hormone are the primary therapeutic aims; additional treatment goals include tumour shrinkage, relieving symptoms, managing complications, reducing excess morbidity, and improving quality of life. A multimodal approach with surgery, medical therapy, and (more rarely) radiation therapy is required to achieve these goals. In this Review, we examine the epidemiology, pathogenesis, diagnosis, complications, and treatment of acromegaly, with an emphasis on the importance of tailoring management strategies to each patient to optimise outcomes.

Long-term outcomes in patients with adult-onset craniopharyngioma

PURPOSE

Craniopharyngiomas are nonmalignant sellar and parasellar tumors exhibiting a bimodal age distribution. While the outcomes following treatment in patients with childhood-onset craniopharyngiomas are well characterized, similar information in adult-onset craniopharyngiomas is limited. We aimed to describe the long-term outcomes (weight and metabolic parameters, mortality) in patients with adult-onset craniopharyngioma following treatment.

METHODS

Patients with adult-onset craniopharyngioma with initial treatment (1993-2017) and >6 months of follow-up at our institution were retrospectively identified. Body mass index (BMI) categories included obese (BMI ≥ 30 kg/m2), overweight (BMI 25-29.9 kg/m2), and normal weight (BMI < 25 kg/m2).

RESULTS

For the 91 patients with adult-onset craniopharyngioma (44% women, mean diagnosis age 48.2 ± 18 years) over a mean follow-up of 100.3 ± 69.5 months, weight at last follow-up was significantly higher than before surgery (mean difference 9.5 ± 14.8 kg, P < 0.001) with a higher percentage increase in weight seen in those with lower preoperative BMI (normal weight (20.7 ± 18%) vs. overweight (13.3 ± 18.0%) vs. obese (6.4 ± 15%), P = 0.012). At last follow-up, the prevalence of obesity (62 vs. 40.5%, P = 0.0042) and impaired glucose metabolism (17.4% vs. 34%, P = 0.017) increased significantly. All-cause mortality was 12%, with the average age of death 71.9 ± 19.7 years (average U.S. life expectancy 77.7 years, CDC 2020).

CONCLUSION

Patients with adult-onset craniopharyngioma following treatment may experience weight gain, increased prevalence of obesity, impaired glucose metabolism, and early mortality. Lower preoperative BMI is associated with a greater percentage increase in postoperative weight.

Copeptin in Growth Hormone-Treated Patients

Growth hormone (GH) changes body composition, including increasing body water. GH is known to have an anti-natriuretic effect in the kidney, but little is known of its effect on arginine-vasopressin (AVP) release. We studied the effect of GH on AVP release by measurement of copeptin, a fragment from the same precursor protein, in GH-treated patients with GH deficiency. The study was designed as a retrospective cohort study of biobank samples from 34 patients substituted with GH between 1999 and 2004. Copeptin and insulin-like growth factor 1 (IGF-1) results were compared with previously obtained data. An increase in IGF-1 and copeptin was seen at 3 and 6 months’ treatment compared to baseline. Between the 3 and 6 months follow up, copeptin levels were stable. There was a difference in HbA1c between 3 and 6 months (p < 0.01) and between baseline and 6 months (p = 0.042), with higher levels at 6 months. In addition, LDL levels were lower at the 6 months follow up (p = 0.046). The waist circumference at 3 months was lower (p = 0.02). To conclude, three months of GH treatment increased the levels of copeptin and the increase remained at 6 months. This could be a compensatory mechanism balancing the anti-natriuretic effect of GH treatment seen in previous studies.

A Radiomics-Based Model with the Potential to Differentiate Growth Hormone Deficiency and Idiopathic Short Stature on Sella MRI

PURPOSE

We hypothesized that a radiomics approach could be employed to classify children with growth hormone deficiency (GHD) and idiopathic short stature (ISS) on sella magnetic resonance imaging (MRI). Accordingly, we aimed to develop a radiomics prediction model for differentiating GHD from ISS and to evaluate the diagnostic performance thereof.

MATERIALS AND METHODS

Short stature pediatric patients diagnosed with GHD or ISS from March 2011 to July 2020 at our institution were recruited. We enrolled 312 patients (GHD 210, ISS 102) with normal sella MRI and temporally split them into training and test sets (7:3). Pituitary glands were semi-automatically segmented, and 110 radiomic features were extracted from the coronal T2-weighted images. Feature selection and model development were conducted by applying mutual information (MI) and a light gradient boosting machine, respectively. After training, the model's performance was validated in the test set. We calculated mean absolute Shapley values for each of the selected input features using the Shapley additive explanations (SHAP) algorithm. Volumetric comparison was performed for GHD and ISS groups.

RESULTS

Ten radiomic features were selected by MI. The receiver operating characteristics curve of the developed model in the test set was 0.705, with an accuracy of 70.6%. When analyzing SHAP plots, root mean squared values had the highest impact in the model, followed by various texture features. In volumetric analysis, sagittal height showed a significant difference between GHD and ISS groups.

CONCLUSION

Radiomic analysis of sella MRI may be able to differentiate between GHD and ISS in clinical practice for short-statured children.

Attenuation of Human Growth Hormone-Induced Rash With Graded Dose Challenge

Adult growth hormone (GH) deficiency is rare and requires replacement with extrinsic/synthetic injection. GH hypersensitivity has been reported; specifically, atopic patients may develop rashes from somatotropin therapy. Allergic and non-allergic skin reactions to recombinant human GH are uncommon and infrequently reported. We describe a graded-dose challenge with intravenous Norditropin® in a 65-year-old atopic adult woman who developed a severe whole-body rash with Norditropin FlexPro® administration on several occasions but was negative on skin-prick testing to Norditropin® percutaneously and intradermally, but the patch testing was positive for gold and nickel.

The patient was registered as a direct admission to the emergency room at a university hospital for a rapid antigen coronavirus disease 2019 (COVID-19) testing after having received two COVID-19 vaccinations and re-testing four months after vaccination. She was then directly admitted to a non-COVID-19 intensive care unit with direct bedside supervision by a registered nurse and a physician board certified in internal medicine, allergy/immunology, and pulmonary diseases. The patient brought a Norditropin® pen which our pharmacy team attached to a compatible syringe for dilutions. A graded dose challenge at a final dosage of 0.1 mL was performed and the patient was monitored for allergic and other adverse drug reactions, which did not occur. At the time of writing this case report, the patient has been maintained on Norditropin FlexPro® 0.1 mL and has not experienced any adverse reactions, including recurrent skin eruptions.

The case presented is the first to describe a patient who successfully tolerated a graded dose challenge of an adult patient to GH replacement therapy (as Norditropin®) under supervision in an intensive care unit, whereas prior to reporting of this case, a graded dose challenge to GH replacement therapy had only been successfully performed in a child using another formulation of somatotropin (Humatrope®). Hence, this case lends support that graded dose challenge with somatotropin analogs may be considered for patients with isolated GH deficiency such as in the case presented here.

Reduced Bone Mineral Density in Middle-Aged Male Patients with Adult Growth Hormone Deficiency

The aim of the work was to investigate the bone mineral density (BMD) in middle-aged male patients with both childhood-onset (CO) and adulthood-onset (AO) adult growth hormone deficiency (AGHD). In this retrospective cross-sectional study in a major medical center in China, dual X-ray absorptiometry was performed in 50 male AGHD patients (average age was 35.2±9.8 years) and 50 age- and BMI-matched non-athletic healthy men. BMD was compared between AGHD patients and controls. Compared with healthy controls, AGHD group had significantly decreased IGF-1 (p1<0.001) and IGF-1 SDS (p1<0.001). Serum testosterone levels were significantly lower in AGHD patients (p1<0.001), mainly in AO AGHD patients (p3<0.001). The BMD of the femoral neck, trochanter, femoral shaft, total hip, and lumbar spine were significantly lower in all AGHD patients compared with healthy controls (all p1<0.05), especially in CO AGHD patients (all p2<0.05). Multiple stepwise linear regression indicated AGHD was negatively correlated with BMD at each site (β<0, p<0.05). Additionally, serum testosterone level was an independent influencing factor of BMD of the femoral neck (β=0.256, p=0.018) and lumbar spine (β=0.219, p=0.040). BMD was significantly reduced in AGHD patients, especially in CO AGHD patients. Our data suggested that the status of growth hormone deficiency and testosterone level were important for maintaining of bone mineral density in middle-aged male patients with AGHD.

Growth hormone deficiency and NAFLD: An overlooked and underrecognized link

Growth hormone and its mediator insulin‐like growth factor‐1 exert their effect on different organs and control various physiologic metabolic processes. Adult growth hormone deficiency (AGHD) presents with one or more components of metabolic syndrome and can be associated with nonalcoholic fatty liver disease (NAFLD). AGHD is present in spectrum of hypothalamic/pituitary disorders as well as cranial radiation of brain tumors and often remains underdiagnosed or untreated due to its nonspecific symptoms, relatively difficult diagnosis in some clinical scenarios, and various barriers to treatment. NAFLD usually develops soon after diagnosis of AGHD and might progress rapidly to nonalcoholic steatohepatitis (NASH) with advanced fibrosis, eventually requiring liver transplantation. A timely initiation of growth hormone replacement therapy might be important, although studies so far have demonstrated controversial results on NAFLD, primarily due to small sample size and different diagnostic methods of NAFLD. Increased awareness of the association between AGHD and NAFLD would facilitate early diagnosis of NAFLD and NASH if present. Therefore, a multidisciplinary approach involving hepatology and endocrinology should become a standard of care for these patients.

Long-term Safety of Growth Hormone in Adults With Growth Hormone Deficiency: Overview of 15 809 GH-Treated Patients

CONTEXT

Data on long-term safety of growth hormone (GH) replacement in adults with GH deficiency (GHD) are needed.

OBJECTIVE

We aimed to evaluate the safety of GH in the full KIMS (Pfizer International Metabolic Database) cohort.

METHODS

The worldwide, observational KIMS study included adults and adolescents with confirmed GHD. Patients were treated with GH (Genotropin [somatropin]; Pfizer, NY) and followed through routine clinical practice. Adverse events (AEs) and clinical characteristics (eg, lipid profile, glucose) were collected.

RESULTS

A cohort of 15 809 GH-treated patients were analyzed (mean follow-up of 5.3 years). AEs were reported in 51.2% of patients (treatment-related in 18.8%). Crude AE rate was higher in patients who were older, had GHD due to pituitary/hypothalamic tumors, or adult-onset GHD. AE rate analysis adjusted for age, gender, etiology, and follow-up time showed no correlation with GH dose. A total of 606 deaths (3.8%) were reported (146 by neoplasms, 71 by cardiac/vascular disorders, 48 by cerebrovascular disorders). Overall, de novo cancer incidence was comparable to that in the general population (standard incidence ratio 0.92; 95% CI, 0.83-1.01). De novo cancer risk was significantly lower in patients with idiopathic/congenital GHD (0.64; 0.43-0.91), but similar in those with pituitary/hypothalamic tumors or other etiologies versus the general population. Neither adult-onset nor childhood-onset GHD was associated with increased de novo cancer risks. Neutral effects were observed in lipids/fasting blood glucose levels.

CONCLUSION

These final KIMS cohort data support the safety of long-term GH replacement in adults with GHD as prescribed in routine clinical practice.

Biochemical discrepancies in the evaluation of the somatotroph axis: Elevated GH or IGF-1 levels do not always diagnose acromegaly

The most frequent diagnosis underlying the finding of an elevated growth hormone (GH) and insulin-like growth factor-1 (IGF-1) is acromegaly due to a GH-secreting pituitary tumour. However, GH and IGF-1 levels can be discordant in patients with acromegaly due to early or partially treated disease, or there might be another cause of high GH or high IGF-1 unrelated to acromegaly, such as pre-analytical and technical pitfalls, physiological circumstances and pathological conditions. High GH and normal or low serum IGF-1, or alternatively, normal GH with elevated serum IGF-1, should be carefully assessed to avoid misinterpreting the activity of acromegaly or misdiagnosing a patient with acromegaly. We summarise here these biochemical discrepancies in the evaluation of the somatotroph axis.

Dose-exposure-IGF-I response of once-weekly somapacitan in adults with GH deficiency

OBJECTIVE

Growth hormone (GH) replacement therapy in patients with adult growth hormone deficiency (AGHD) is individually titrated due to variable dose-responses among patients. The aim of this study was to provide clinical guidance on dosing and titration of the novel long-acting GH derivative somapacitan based on analyses of somapacitan dose-insulin-like growth factor I (IGF-I) responses in AGHD patients.

DESIGN

Analyses of dosing information, 4364 somapacitan concentration samples and 4880 IGF-I samples from 330 AGHD patients treated with somapacitan in three phase 3 trials.

METHODS

Pharmacokinetic/pharmacodynamic modelling was used to evaluate starting dose groups by age and oral oestrogen therapy, characterise the dose-IGF-I response in the overall AGHD population and patient subgroups, predict the IGF-I response to dose changes and simulate missed dosing.

RESULTS

The analyses supported the clinical recommendations of higher starting doses for younger patients and women on oral oestrogen replacement therapy. For patients switching from daily GH treatment, the mean maintenance dose ratio between somapacitan (mg/week) and somatropin (mg/day) was predicted to be 8.2 (observed interquartile range of 6.7-9.1). Simulations of IGF-I SDS profiles confirmed the appropriate time for IGF-I sampling to be 3-4 days after somapacitan dosing and supported somapacitan administration with up to 3 days delay in case of missed dosing. Subgroup analyses characterised the dose-exposure-IGF-I response in patient subgroups and indicated that dose requirements are mainly influenced by sex and oral oestrogen treatment.

CONCLUSIONS

This study extends the knowledge of the somapacitan dose-IGF-I response and provides information on clinical dosing of once-weekly somapacitan in patients with AGHD.

Quality of Life in Craniopharyngioma: A Systematic Review

BACKGROUND

Craniopharyngiomas are morbid tumors that significantly reduce patients' quality of life (QoL). The lifelong burden of endocrine, visual, hypothalamic, and limbic dysfunction can have disastrous consequences for the physical and psychosocial health of patients. Elucidating the factors that influence QoL could guide therapeutic interventions to improve patient well-being.

METHODS

A systematic review was performed in accordance with the PRISMA (preferred reporting items for systematic reviews and meta-analyses) statement using the PubMed and Medline databases. Studies that had reported patient QoL using validated metrics in both adult and pediatric populations were included. Bias and methodological rigor were assessed using the MINORS (methodological index for nonrandomized studies) criteria.

RESULTS

A total of 25 studies, including 2025 patients, were available for review. Most studies were small, retrospective, cohort studies with a high risk of bias. The QoL of the patients with craniopharyngioma was lower than that of the general population. Hypothalamic involvement was consistently the strongest predictor of QoL. Endocrinopathy contributed to morbidity but could be ameliorated by hormone replacement therapy. Social and emotional dysregulation and a poor memory are common complaints after surgery, and iatrogenic damage to the infundibulum, hypothalamus, limbic system, and frontal lobes might underlie these concerns. Sleep-wake cycle dysfunction and hypothalamic obesity are serious consequences of hypothalamic damage.

CONCLUSIONS

An experienced multidisciplinary team is necessary to optimally manage the complex cases of these patients. The poor QoL of patients with craniopharyngioma is multifactorial. However, the contribution of iatrogenesis is not insubstantial. Improved surgical techniques, focusing on hypothalamic preservation, and adjuvant treatment options are required to improve the well-being of these patients.

Adult growth hormone deficiency: diagnostic and treatment journeys from the patients’ perspective

Adult growth hormone deficiency (AGHD) is a rare and serious condition associated with significant morbidity, including reduced quality of life, and is underdiagnosed and often missed in patients. Although the onset of AGHD can occur in either childhood or adulthood, adult-onset AGHD is more difficult to identify as it lacks the auxologic signs caused by GHD during childhood, includes symptoms that tend to be nonspecific, and lacks reliable, simple biomarker testing options. A panel of 9 patients with AGHD (3 with childhood onset; 6 with adult onset) was assembled to share their first-hand experiences, to help reveal important areas of need, increase health literacy, and to raise awareness about GHD among patients, caregivers, and healthcare practitioners. Interviews with patients yielded valuable insights from the patient perspective to supplement prior knowledge about AGHD symptomatology, biomarker testing, and treatment outcomes. Some patients described a burdensome and ineffective screening process that sometimes included many visits to different specialists, repeated rounds of biomarker testing, and, in some cases, excessive delays in AGHD diagnosis. All patients expressed frustration with insurance companies that often resist and/or delay treatment authorization and reimbursement and frequently require additional testing to verify the diagnosis, often leading to treatment gaps. These findings emphasize the necessity of more efficient identification and screening of patients with possible AGHD, better recognition by clinicians and insurance providers of the importance of sustained GH replacement therapy during adulthood, and better patient support for accessing and maintaining uninterrupted GH replacement therapy for patients with documented AGHD.

State of the Art of Patient-reported Outcomes in Acromegaly or GH Deficiency: A Systematic Review and Meta-analysis

CONTEXT

Insight into the current landscape of patient-reported outcome (PRO) measures (PROM) and differences between PROs and conventional biochemical outcomes is pivotal for future implementation of PROs in research and clinical practice. Therefore, in studies among patients with acromegaly and growth hormone deficiency (GHD), we evaluated (1) used PROMs, (2) their validity, (3) quality of PRO reporting, (4) agreement between PROs and biochemical outcomes, and (5) determinants of discrepancies.

EVIDENCE ACQUISITION

We searched 8 electronic databases for prospective studies describing both PROs and biochemical outcomes in acromegaly and GHD patients. Quality of PRO reporting was assessed using the International Society for Quality of Life Research (ISOQOL) criteria. Logistic regression analysis was used to evaluate determinants.

EVIDENCE SYNTHESIS

Ninety studies were included (acromegaly: n = 53; GHD: n = 37). Besides nonvalidated symptom lists (used in 37% of studies), 36 formal PROMs were used [predominantly Acromegaly Quality of Life Questionnaire in acromegaly (43%) and Quality of Life-Assessment of Growth Hormone Deficiency in Adults in GHD (43%)]. Reporting of PROs was poor, with a median of 37% to 47% of ISOQOL items being reported per study. Eighteen (34%) acromegaly studies and 12 (32%) GHD studies reported discrepancies between PROs and biochemical outcomes, most often improvement in biochemical outcomes without change in PROs.

CONCLUSIONS

Prospective studies among patients with acromegaly and GHD use a multitude of PROMs, often poorly reported. Since a substantial proportion of studies report discrepancies between PROs and biochemical outcomes, PROMs are pivotal in the evaluation of disease activity. Therefore, harmonization of PROs in clinical practice and research by development of core outcome sets is an important unmet need.

Effects of adult growth hormone deficiency and replacement therapy on the cardiometabolic risk profile

Adult growth hormone deficiency (AGHD) is considered a rare endocrine disorder involving patients with childhood-onset and adult-onset growth hormone deficiency (AoGHD) and characterized by adverse cardiometabolic risk profile. Besides traditional cardiovascular risk factors, endothelial dysfunction, low-grade inflammation, impaired adipokine profile, oxidative stress and hypovitaminosis D may also contribute to the development of premature atherosclerosis and higher cardiovascular risk in patients with AGHD. Growth hormone replacement has been proved to exert beneficial effects on several cardiovascular risk factors, but it is also apparent that hormone substitution in itself does not eliminate all cardiometabolic abnormalities associated with the disease. Novel biomarkers and diagnostic techniques discussed in this review may help to evaluate individual cardiovascular risk and identify patients with adverse cardiometabolic risk profile. In the absence of disease-specific guidelines detailing how to assess the cardiovascular status of these patients, we generally recommend close follow-up of the cardiovascular status as well as low threshold for a more detailed evaluation.

Diagnosis and Treatment of Acromegaly: An Update

Acromegaly is typically caused by a growth hormone-secreting pituitary adenoma, driving excess secretion of insulin-like growth factor 1. Acromegaly may result in a variety of cardiovascular, respiratory, endocrine, metabolic, musculoskeletal, and neoplastic comorbidities. Early diagnosis and adequate treatment are essential to mitigate excess mortality associated with acromegaly. PubMed searches were conducted using the keywords growth hormone, acromegaly, pituitary adenoma, diagnosis, treatment, pituitary surgery, medical therapy, and radiation therapy (between 1981 and 2021). The diagnosis of acromegaly is confirmed on biochemical grounds, including elevated serum insulin-like growth factor 1 and lack of growth hormone suppression after glucose administration. Pituitary magnetic resonance imaging is advised in patients with acromegaly to identify an underlying pituitary adenoma. Transsphenoidal pituitary surgery is generally first-line therapy for patients with acromegaly. However, patients with larger and invasive tumors (macroadenomas) are often not in remission postoperatively. Medical therapies, including somatostatin receptor ligands, cabergoline, and pegvisomant, can be recommended to patients with persistent disease after surgery. Select patients may also be candidates for preoperative medical therapy. In addition, primary medical therapy has a role for patients without mass effect on the optic chiasm who are unlikely to be cured by surgery. Clinical, endocrine, imaging, histologic, and molecular markers may help predict the response to medical therapy; however, confirmation in prospective studies is needed. Radiation therapy is usually a third-line option and is increasingly administered by a variety of stereotactic techniques. An improved understanding of the pathogenesis of acromegaly may ultimately lead to the design of novel, efficacious therapies for this serious condition.

GH and Senescence: A New Understanding of Adult GH Action

Replicative senescence occurs due to an inability to repair DNA damage and activation of p53/p21 and p16INK4 pathways. It is considered a preventive mechanism for arresting proliferation of DNA-damaged cells. Stably senescent cells are characterized by a senescence-associated secretory phenotype (SASP), which produces and secretes cytokines, chemokines, and/or matrix metalloproteinases depending on the cell type. SASP proteins may increase cell proliferation, facilitating conversion of premalignant to malignant tumor cells, triggering DNA damage, and altering the tissue microenvironment. Further, senescent cells accumulate with age, thereby aggravating age-related tissue damage. Here, we review a heretofore unappreciated role for growth hormone (GH) as a SASP component, acting in an autocrine and paracrine fashion. In senescent cells, GH is activated by DNA-damage-induced p53 and inhibits phosphorylation of DNA repair proteins ATM, Chk2, p53, and H2AX. Somatotroph adenomas containing abundant intracellular GH exhibit increased somatic copy number alterations, indicative of DNA damage, and are associated with induced p53/p21. As this pathway restrains proliferation of DNA-damaged cells, these mechanisms may underlie the senescent phenotype and benign nature of slowly proliferating pituitary somatotroph adenomas. In highly proliferative cells, such as colon epithelial cells, GH induced in response to DNA damage suppresses p53, thereby triggering senescent cell proliferation. As senescent cells harbor unrepaired DNA damage, GH may enable senescent cells to evade senescence and reenter the cell cycle, resulting in acquisition of harmful mutations. These mechanisms, at least in part, may underlie pro-aging effects of GH observed in animal models and in patients with chronically elevated GH levels.

PEGylated Recombinant Human Growth Hormone Jintrolong® Exhibits Good Long-Term Safety in Cynomolgus Monkeys and Human Pediatric Growth Hormone Deficiency Patients

Jintrolong^® is a long-acting PEGylated recombinant human growth hormone (PEG-rhGH) developed for weekly injection in patients with pediatric growth hormone deficiency (PGHD). Although PEG modification of therapeutic proteins is generally considered safe, concerns persist about the potential for adverse vacuolation in tissues with long-term exposure to PEG-included therapies, particularly in children. We assessed the safety of Jintrolong^® in cynomolgus monkeys with an examination of vacuolation in the brain choroid plexus (CP) and reported long-term clinical safety data obtained from children with PGHD. The toxicity of Jintrolong^® was assessed following the 52-week administration with doses at 0.3, 1, or 3 mg/kg/week. The levels of vacuolation of CP in animals were dose-dependent and at least partially reversible after a 104- or 157-week recovery period. Vacuolation in the CP epithelium did not lead to obvious subcellular structural or cell functional abnormalities. Compared with the clinical dose of 0.2 mg/kg/week Jintrolong^® in PGHD patients, exposure in monkeys under NOAEL 3 mg/kg/week exhibited safety margins greater than 120.5, the predicted minimum dose to induce vacuolation in monkeys is equivalent to 1.29 mg/kg/week in humans, which is 6.45-fold higher than the clinical dose. The safety data acquired in clinical trials for Jintrolong^® were also analyzed, which included phase III (360 patients), phase IV (3,000 patients) of 26-week treatment, and a follow-up study with treatment lasting for 3 years. There was no statistically significant difference in the incidence of adverse reactions between the Jintrolong^® group and the daily rhGH control group (no PEG), and no new adverse effects (AE) were observed in the Jintrolong^® group at the clinical therapeutic dose of 0.2 mg/kg/week.

Local non-pituitary growth hormone is induced with aging and facilitates epithelial damage

Microenvironmental factors modulating age-related DNA damage are unclear. Non-pituitary growth hormone (npGH) is induced in human colon, non-transformed human colon cells, and fibroblasts, and in 3-dimensional intestinal organoids with age-associated DNA damage. Autocrine/paracrine npGH suppresses p53 and attenuates DNA damage response (DDR) by inducing TRIM29 and reducing ATM phosphorylation, leading to reduced DNA repair and DNA damage accumulation. Organoids cultured up to 4 months exhibit aging markers, p16, and SA-β-galactosidase and decreased telomere length, as well as DNA damage accumulation, with increased npGH, suppressed p53, and attenuated DDR. Suppressing GH in aged organoids increases p53 and decreases DNA damage. WT mice exhibit age-dependent colon DNA damage accumulation, while in aged mice devoid of colon GH signaling, DNA damage remains low, with elevated p53. As age-associated npGH induction enables a pro-proliferative microenvironment, abrogating npGH signaling could be targeted as anti-aging therapy by impeding DNA damage and age-related pathologies.

Chesnokova et al. show that non-pituitary growth hormone (npGH) is induced in aging DNA-damaged colon epithelium and suppresses DNA damage response by attenuating the phosphorylation of DNA repair proteins. npGH induction promotes DNA damage accumulation, resulting in age-associated colon microenvironment changes. Accordingly, disrupted GH signaling in aging mice prevents accumulated DNA damage.

High-throughput mediation analysis of human proteome and metabolome identifies mediators of post-bariatric surgical diabetes control

To improve the power of mediation in high-throughput studies, here we introduce High-throughput mediation analysis (Hitman), which accounts for direction of mediation and applies empirical Bayesian linear modeling. We apply Hitman in a retrospective, exploratory analysis of the SLIMM-T2D clinical trial in which participants with type 2 diabetes were randomized to Roux-en-Y gastric bypass (RYGB) or nonsurgical diabetes/weight management, and fasting plasma proteome and metabolome were assayed up to 3 years. RYGB caused greater improvement in HbA1c, which was mediated by growth hormone receptor (GHR). GHR’s mediation is more significant than clinical mediators, including BMI. GHR decreases at 3 months postoperatively alongside increased insulin-like growth factor binding proteins IGFBP1/BP2; plasma GH increased at 1 year. Experimental validation indicates (1) hepatic GHR expression decreases in post-bariatric rats; (2) GHR knockdown in primary hepatocytes decreases gluconeogenic gene expression and glucose production. Thus, RYGB may induce resistance to diabetogenic effects of GH signaling.

Trial Registration: Clinicaltrials.gov NCT01073020.

Factors underlying the effects of gastric bypass surgery on glucose homeostasis are incompletely understood. Here the authors developed and applied high-throughput mediation analysis to identify proteome/metabolome mediators of improved glucose homeostasis after to gastric bypass surgery, and report that improved glycemia was mediated by the growth hormone receptor.

Metabolomics as a potential tool for the diagnosis of growth hormone deficiency (GHD): a review

Metabolomics uses several analytical tools to identify the chemical diversity of metabolites present in organisms. These metabolites are low molecular weight molecules (<1500 Da) classified as a final or intermediary product of metabolic processes. The application of this omics technology has become prominent in inferring physiological conditions through reporting on the phenotypic state; therefore, the introduction of metabolomics into clinical studies has been growing in recent years due to its efficiency in discriminating pathophysiological states. Regarding endocrine diseases, there is a great interest in verifying comprehensive and individualized physiological scenarios, in particular for growth hormone deficiency (GHD). The current GHD diagnostic tests are laborious and invasive and there is no exam with ideal reproducibility and sensitivity for diagnosis neither standard GH cut-off point. Therefore, this review was focussed on articles that applied metabolomics in the search for new biomarkers for GHD. The present work shows that the applications of metabolomics in GHD are still limited, since the little complementarily of analytical techniques, a low number of samples, GHD combined to other deficiencies, and idiopathic diagnosis shows a lack of progress. The results of the research are relevant and similar; however, their results do not provide an application for clinical practice due to the lack of multidisciplinary actions that would be needed to mediate the translation of the knowledge produced in the laboratory, if transferred to the medical setting.

Safety of growth hormone (GH) treatment in GH deficient children and adults treated for cancer and non-malignant intracranial tumors-a review of research and clinical practice

Individuals surviving cancer and brain tumors may experience growth hormone (GH) deficiency as a result of tumor growth, surgical resection and/or radiotherapy involving the hypothalamic-pituitary region. Given the pro-mitogenic and anti-apoptotic properties of GH and insulin-like growth factor-I, the safety of GH replacement in this population has raised hypothetical safety concerns that have been debated for decades. Data from multicenter studies with extended follow-up have generally not found significant associations between GH replacement and cancer recurrence or mortality from cancer among childhood cancer survivors. Potential associations with secondary neoplasms, especially solid tumors, have been reported, although this risk appears to decline with longer follow-up. Data from survivors of pediatric or adult cancers who are treated with GH during adulthood are scarce, and the risk versus benefit profile of GH replacement of this population remains unclear. Studies pertaining to the safety of GH replacement in individuals treated for nonmalignant brain tumors, including craniopharyngioma and non-functioning pituitary adenoma, have generally been reassuring with regards to the risk of tumor recurrence. The present review offers a summary of the most current medical literature regarding GH treatment of patients who have survived cancer and brain tumors, with the emphasis on areas where active research is required and where consensus on clinical practice is lacking.

Safety and effectiveness of replacement with biosimilar growth hormone in adults with growth hormone deficiency: results from an international, post-marketing surveillance study (PATRO Adults)

PURPOSE

To evaluate safety and effectiveness of biosimilar recombinant human growth hormone (rhGH; Omnitrope®) in adults with growth hormone deficiency (GHD), using data from the PATRO Adults study.

METHODS

PATRO Adults was a post-marketing surveillance study conducted in hospitals and specialized endocrinology units across Europe. The primary objective was to assess the safety of rhGH in adults treated in routine clinical practice. All adverse events (AEs) were monitored and recorded for the complete duration of Omnitrope® treatment. Effectiveness was evaluated as a secondary objective.

RESULTS

As of January 2020, 1447 patients (50.9% male) had been enrolled from 82 centers in 9 European countries. Most patients had adult-onset GHD (n = 1179; 81.5%); 721 (49.8%) were rhGH-naïve at study entry. Overall, 1056 patients (73.0%) reported adverse events (AEs; n = 5397 events); the majority were mild-to-moderate in intensity. Treatment-related AEs were reported in 117 patients (8.1%; n = 189 events); the most commonly reported (MedDRA preferred terms) were arthralgia (n = 19), myalgia (n = 16), headache (n = 14), and edema peripheral (n = 10). In total, 495 patients (34.2%) had serious AEs (SAEs; n = 1131 events); these were considered treatment-related in 28 patients (1.9%; n = 35 events). Mean (standard deviation) IGF-I SDS increased from - 2.34 (1.47) at baseline to - 0.23 (1.65) at 12 months, and remained relatively stable thereafter (up to 3 years). Body mass index remained stable between baseline and 3 years.

CONCLUSION

Data from PATRO Adults indicate biosimilar rhGH (Omnitrope^®) is not associated with any unexpected safety signals, and is effective in adults with GHD treated in real-world clinical practice.