Effect of growth hormone on insulin signaling

Growth hormone in pediatric chronic kidney disease: more than just height

Recombinant human growth hormone therapy, which was introduced in the 1980s, is now routine for children with advanced chronic kidney disease (CKD) who are exhibiting growth impairment. Growth hormone usage remains variable across different centers, with some showing low uptake. Much of the focus on growth hormone supplementation has been on increasing height because of social and psychological effects of short stature. There are, however, numerous other changes that occur in CKD that have not received as much attention but are biologically important for pediatric growth and development. This article reviews the current knowledge about the multisystem effects of growth hormone therapy in pediatric patients with CKD and highlights areas where additional clinical research is needed. We also included clinical data on children and adults who had received growth hormone for other indications apart from CKD. Ultimately, having robust clinical studies which examine these effects will allow children and their families to make more informed decisions about this therapy.

Growth hormone augmentation in metabolic dysfunction-associated steatotic liver disease: a systematic review and meta-analysis of randomized controlled trials

Metabolic dysfunction-associated steatotic liver disease (MASLD) is characterized by hepatic steatosis and metabolic dysregulation. Growth hormone (GH) augmentation has emerged as a potential therapeutic intervention for treating MASLD. This systematic review and meta-analysis aimed to evaluate the impact of GH augmentation on different parameters of MASLD. A systematic literature search identified randomized controlled trials investigating GH augmentation in MASLD patients. Search results were screened via Covidence and the Risk of Bias 2 tool was used to assess bias in randomized controlled trials. Statistical analysis utilized RevMan v5.3. We combined dichotomous outcomes employing odds ratios and continuous outcomes utilizing mean difference (MD), each with a 95% confidence interval (CI). Statistical significance was indicated by a P -value less than 0.05. Heterogeneity was evaluated using I2 tests. Our results showed that GH augmentation resulted in a significant reduction in both relative (MD: -46.26; 95% CI: -71.52, -21.00; P  = 0.0003) and absolute (MD: -5.15; 95% CI: -7.93, -2.37; P  = 0.0003) hepatic fat fraction. GH augmentation significantly reduced alanine aminotransferase (MD: -5.97; 95% CI: -10.31, -1.62; P  = 0.007) and gamma-glutamyl transferase (MD: -16.18; 95% CI: -30.76, -1.59; P  = 0.03) levels. No significant changes were observed in hemoglobin A1c, C-reactive protein, fasting serum glucose, BMI, triglycerides, and low-density lipoprotein cholesterol levels. Our meta-analysis highlights GH augmentation as a promising therapy for reducing liver steatosis and improving liver enzyme levels in MASLD patients. Further large-scale trials are warranted to examine the long-term effects, safety profiles, and potential impact on various measures.

Decreased β-cell volume and insulin secretion but preserved glucose tolerance in a growth hormone insensitive pig model

PURPOSE

Growth hormone (GH) is a central regulator of β-cell proliferation, insulin secretion and sensitivity. Aim of this study was to investigate the effect of GH insensitivity on pancreatic β-cell histomorphology and consequences for metabolism in vivo.

METHODS

Pancreata from pigs with growth hormone receptor deficiency (GHR-KO, n = 12) were analyzed by unbiased quantitative stereology in comparison to wild-type controls (WT, n = 12) at 3 and 7-8.5 months of age. In vivo secretion capacity for insulin and glucose tolerance were assessed by intravenous glucose tolerance tests (ivGTTs) in GHR-KO (n = 3) and WT (n = 3) pigs of the respective age groups.

RESULTS

Unbiased quantitative stereological analyses revealed a significant reduction in total β-cell volume (83% and 73% reduction in young and adult GHR-KO vs. age-matched WT pigs; p < 0.0001) and volume density of β-cells in the pancreas of GHR-KO pigs (42% and 39% reduction in young and adult GHR-KO pigs; p = 0.0018). GHR-KO pigs displayed a significant, age-dependent increase in the proportion of isolated β-cells in the pancreas (28% in young and 97% in adult GHR-KO vs. age-matched WT pigs; p = 0.0009). Despite reduced insulin secretion in ivGTTs, GHR-KO pigs maintained normal glucose tolerance.

CONCLUSION

GH insensitivity in GHR-KO pigs leads to decreased β-cell volume and volume proportion of β-cells in the pancreas, causing a reduced insulin secretion capacity. The increased proportion of isolated β-cells in the pancreas of GHR-KO pigs highlights the dependency on GH stimulation for proper β-cell maturation. Preserved glucose tolerance accomplished with decreased insulin secretion indicates enhanced sensitivity for insulin in GH insensitivity.

Transition Period and Young Adulthood in Patients with Childhood Onset Growth Hormone Deficiency (COGHD): Impact of Growth Hormone Replacement on Bone Mass and Body Composition

The aim of this review article is to highlight the consequences of COGHD after the end of linear growth on bone mass and body composition and the opposing beneficial effects of continuing GH replacement in the transition period and young adults. The role of growth hormone in the period of late adolescence and young adulthood is well established, mainly in achieving peak bone mass and a favorable body composition, characterized by muscle mass increase and fat mass reduction. Patients with childhood onset growth hormone deficiency (COGHD), after reaching the adult height, have a reduced bone mineral density and muscle mass with increased fat mass compared to healthy controls. Inadequate body composition is a predictor for cardiovascular risk, while low bone mass in early youth hallmarks the risk of osteoporosis and bone fractures in later life. Cessation of growth hormone replacement (GHr) after completion of growth will lead to delayed peak bone mass and unbalanced body composition with increased abdominal fat deposits. According to numerous clinical studies monitoring the effects of GH treatment on the physical and psychological status of patients with persistent GHD after completion of growth, we suggest continuing this treatment between 16 and 25 years of age. It is advised that GHr in the transition period be administered in intermediate doses between those for the pediatric population and those for the adult population. Usual daily GHr doses are between 0.3 and 0.5 mg but need to be individually optimized, with the aim of maintaining IGF-I in the age-specific normal range.

Study of the Effect of Phosvitin as a Potential Carrier on the Permeation Process of Somatotropin (STH) and Corticotropin (ACTH) from Biodegradable Polymers Used as Vehicles for STH and ACTH in Semi-Solid Formulations for Skin Application

Phosvitin shows chelating abilities, an affinity for ACTH (corticotropin), growth factors, antioxidant properties, and acidic nature. An attempt was made to use this protein in hydrogels as a transporter of other protein substances: somatotropin (STH) and (ACTH). The aim of the study was to evaluate the effect of phosvitin on the permeation of ACTH and STH from semi-solid forms of the drug applied to the skin. Four hydrogel substrates were prepared using natural polymers: sodium alginate, methylcellulose, and starch. Based on the evaluation of physicochemical parameters, the hydrogel with the most favorable properties was selected and loaded with the active substances STH and ACTH, followed by the addition of phosvitin. A study of the permeation of STH and ACTH through the artificial cellulose membrane and through porcine skin was carried out without and with the addition of phosvitin. The effect of protein substances on rheological and textural parameters was studied. The evaluation of physicochemical parameters showed a favorable effect of STH and Phosvitin on the stability of the hydrogel with 4% methylcellulose and no effect of ACTH. All prepared formulations showed a reaction close to the natural pH of human skin. In the porcine skin permeation study, the addition of Phosvitin to the hydrogel with STH caused a slight increase in the amount of STH permeated and an increase in the time for STH to permeate porcine skin by 30 min. Phosvitin caused an increase in the amount of ACTH permeated through porcine skin almost twofold. Phosvitin may prove to be a promising permeation promoter for model protein-peptide substances when applied to the skin surface.

Acromegaly: Overview and associated temporomandibular joint disorders

OBJECTIVE

To provide a review on acromegaly and its orofacial manifestations, with a focus on associated arthropathies and temporomandibular joint disorders (TMD).

METHODS

A review of current literature was performed through an electronic search of three databases: PubMed, ScienceDirect, and Google Scholar. The literature review was focused on the following topics of interest: etiology, diagnosis, and management of acromegaly, orofacial manifestations of acromegaly, acromegalic arthropathies, and acromegaly-associated TMD.

RESULTS

Acromegaly is a chronic multisystem condition in which excessive production of growth hormone in adults, most commonly caused by benign pituitary adenomas, leads to somatic overgrowth. Orofacial changes are considered hallmarks of the disease. It is important for dentists to recognize signs and symptoms of acromegaly, as this may help to achieve early diagnosis and improve overall disease prognosis. Acromegalic arthropathies typically involve large joints, however, the temporomandibular joints (TMJ) can be affected. TMD associated with acromegaly is under-recognized and poorly characterized in current literature.

CONCLUSION

In the appropriate clinical context, acromegaly should be considered as part of the differential diagnosis for patients presenting with TMD. Further studies are needed to better characterize the nature of TMD associated with acromegaly and to define the role of TMJ involvement in early diagnosis.

New findings on brain actions of growth hormone and potential clinical implications

Growth hormone (GH) is secreted by somatotropic cells of the anterior pituitary gland. The classical effects of GH comprise the stimulation of cell proliferation, tissue and body growth, lipolysis, and insulin resistance. The GH receptor (GHR) is expressed in numerous brain regions. Notably, a growing body of evidence indicates that GH-induced GHR signaling in specific neuronal populations regulates multiple physiological functions, including energy balance, glucose homeostasis, stress response, behavior, and several neurological/cognitive aspects. The importance of central GHR signaling is particularly evident when the organism is under metabolic stress, such as pregnancy, chronic food deprivation, hypoglycemia, and prolonged exercise. These particular situations are associated with elevated GH secretion. Thus, central GH action represents an internal signal that coordinates metabolic, neurological, neuroendocrine, and behavioral adaptations that are evolutionarily advantageous to increase the chances of survival. This review summarizes and discusses recent findings indicating that the brain is an important target of GH, and GHR signaling in different neuronal populations regulates essential physiological functions.

Are there bidirectional associations between maternal thyroid function and glucose metabolism in singleton live births? A birth cohort study

(1) Aims: To examine the associations between maternal thyroid function and glucose metabolism during pregnancy. (2) Methods: This study was based on Ma' anshan Birth Cohort in China. Totally 2375 pregnant women were included in data analysis. Maternal thyroid-stimulating hormone (TSH), free thyroxine (FT4), thyroid peroxidase antibody (TPOAb) and fasting plasma glucose (FPG) levels during the first, second and third trimesters of pregnancy were measured retrospectively. Mplus 8.0 was used to construct a cross-lagged panel model to examine the potential bidirectional association between thyroid function and FPG levels throughout pregnancy. (3) Results: FT4 levels were positively correlated with FPG levels in the first trimester and negatively correlated with FPG levels in the second trimester. TSH levels were negatively associated with FPG levels in the second trimester, and in the first trimester, it could positively predict FPG levels in the second trimester. No significant association was found between TPOAb levels and FPG levels during pregnancy. (4) Conclusions: There was a non-bidirectional association between maternal thyroid function and glucose metabolism during pregnancy. FT4 and TSH levels influence FPG concentrations in the first and second trimesters of pregnancy.

The Fascinating Interplay between Growth Hormone, Insulin-Like Growth Factor-1, and Insulin

This review intends to provide the reader with a practical overview of several (patho)physiological conditions in which knowledge of the interplay between growth hormone (GH), insulin-like growth factor-1 (IGF-1), and insulin is important. This might help treating physicians in making the right decisions on how to intervene and improve metabolism for the benefit of patients, and to understand why and how metabolism responds in their specific cases. We will specifically address the interplay between GH, IGF-1, and insulin in type 1 and 2 diabetes mellitus, liver cirrhosis, and acromegaly as examples in which this knowledge is truly necessary.

Ciliopathy due to POC1A deficiency: clinical and metabolic features, and cellular modeling

OBJECTIVE

SOFT syndrome (MIM#614813), denoting Short stature, Onychodysplasia, Facial dysmorphism, and hypoTrichosis, is a rare primordial dwarfism syndrome caused by biallelic variants in POC1A, encoding a centriolar protein. SOFT syndrome, characterized by severe growth failure of prenatal onset and dysmorphic features, was recently associated with insulin resistance. This study aims to further explore its endocrinological features and pathophysiological mechanisms.

DESIGN/METHODS

We present clinical, biochemical, and genetic features of 2 unrelated patients carrying biallelic pathogenic POC1A variants. Cellular models of the disease were generated using patients' fibroblasts and POC1A-deleted human adipose stem cells.

RESULTS

Both patients present with clinical features of SOFT syndrome, along with hyperinsulinemia, diabetes or glucose intolerance, hypertriglyceridemia, liver steatosis, and central fat distribution. They also display resistance to the effects of IGF-1. Cellular studies show that the lack of POC1A protein expression impairs ciliogenesis and adipocyte differentiation, induces cellular senescence, and leads to resistance to insulin and IGF-1. An altered subcellular localization of insulin receptors and, to a lesser extent, IGF1 receptors could also contribute to resistance to insulin and IGF1.

CONCLUSIONS

Severe growth retardation, IGF-1 resistance, and centripetal fat repartition associated with insulin resistance-related metabolic abnormalities should be considered as typical features of SOFT syndrome caused by biallelic POC1A null variants. Adipocyte dysfunction and cellular senescence likely contribute to the metabolic consequences of POC1A deficiency. SOFT syndrome should be included within the group of monogenic ciliopathies with metabolic and adipose tissue involvement, which already encompasses Bardet-Biedl and Alström syndromes.

Single-Cell Transcriptomics Identifies Pituitary Gland Changes in Diet-Induced Obesity in Male Mice

Obesity is a chronic disease with increasing prevalence worldwide. Obesity leads to an increased risk of heart disease, stroke, and diabetes, as well as endocrine alterations, reproductive disorders, changes in basal metabolism, and stress hormone production, all of which are regulated by the pituitary. In this study, we performed single-cell RNA sequencing of pituitary glands from male mice fed control and high-fat diet (HFD) to determine obesity-mediated changes in pituitary cell populations and gene expression. We determined that HFD exposure is associated with dramatic changes in somatotrope and lactotrope populations, by increasing the proportion of somatotropes and decreasing the proportion of lactotropes. Fractions of other hormone-producing cell populations remained unaffected. Gene expression changes demonstrated that in HFD, somatotropes became more metabolically active, with increased expression of genes associated with cellular respiration, and downregulation of genes and pathways associated with cholesterol biosynthesis. Despite a lack of changes in gonadotrope fraction, genes important in the regulation of gonadotropin hormone production were significantly downregulated. Corticotropes and thyrotropes were the least affected in HFD, while melanotropes exhibited reduced proportion. Lastly, we determined that changes in plasticity and gene expression were associated with changes in hormone levels. Serum prolactin was decreased corresponding to reduced lactotrope fraction, while lower luteinizing hormone and follicle-stimulating hormone in the serum corresponded to a decrease in transcription and translation. Taken together, our study highlights diet-mediated changes in pituitary gland populations and gene expression that play a role in altered hormone levels in obesity.

Changes of Signaling Pathways in Hypothalamic Neurons with Aging

The hypothalamus is an important regulator of autonomic and endocrine functions also involved in aging regulation. The aging process in the hypothalamus is accompanied by disturbed intracellular signaling including insulin/insulin-like growth factor-1 (IGF-1)/growth hormone (GH), phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/protein kinase B (AKT)/the mammalian target of rapamycin (mTOR), mitogen activated protein kinase (MAPK), janus kinase (JAK)/signal transducer and activator of transcription (STAT), AMP-activated protein kinase (AMPK), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-ĸB), and nitric oxide (NO). In the current review, I have summarized the current understanding of the changes in the above-mentioned pathways in aging with a focus on hypothalamic alterations.

Neonatal malnutrition impacts fibroblast growth factor 21-induced neuron neurite outgrowth and growth hormone-releasing hormone secretion in neonatal mouse brain

Neonatal malnutrition is one of the most common causes of neurological disorders. However, the mechanism of action of the factors associated with neonatal nutrition in the brain remains unclear. In this study, we focused on fibroblast growth factor (FGF) 21 to elucidate the effects of malnutrition on the neonatal brain. FGF21 is an endocrine factor produced by the liver during lactation which is the main source of nutrition during the neonatal period. In this study, malnourishment during nursing mice induced decreased levels of Fgf21 mRNA in the liver and decreased levels of FGF21 in the serum. RNA-seq analysis of neonatal mouse brain tissue revealed that FGF21 controlled the expression of Kalrn-201 in the neonatal mouse brain. Kalrn-201 is a transcript of Kalirin, a Ras homologous guanine nucleotide exchange factor at the synapse. In mouse neurons, FGF21 induced the expression of Kalirin-7 (a Kalirin isoform) by down-regulating Kalrn-201. FGF21-induced Kalirin-7 stimulated neurite outgrowth in Neuro-2a cells. FGF21 also induced Growth hormone-releasing hormone (GHRH) expression in Neuro-2a cells. Kalirin-7 and GHRH expression induced by FGF21 was altered by inhibiting the activity of SH2-containing tyrosine phosphatase (SHP2) which is located downstream of the FGF receptor (FGFR). Additionally, malnourished nursing induced intron retention of the SHP2 gene (Ptpn11), resulting in the alteration of Kalirin-7 and GHRH expression by FGF21 signaling. Ptpn11 intron retention is suggested to be involved in regulating SHP2 activity. Taken together, these results suggest that FGF21 plays a critical role in the induction of neuronal neurite outgrowth and GHRH secretion in the neonatal brain, and this mechanism is regulated by SHP2. Thus, Ptpn11 intron retention induced by malnourished nursing may be involved in SHP2 activity.

Comparison of hyperoxia or normoxia resolution of intermittent hypoxia and intermittent hyperoxia episodes on liver histopathology, IGF-1, IGFBP-3, and GHBP in neonatal rats

OBJECTIVE

Extremely low gestational age neonates requiring oxygen therapy for chronic lung disease experience repeated fluctuations in arterial oxygen saturation, or intermittent hypoxia (IH), during the first few weeks of life. These events are associated with a high risk for reduced growth, hypertension, and insulin resistance in later life. This study tested the hypothesis that IH, or intermittent hyperoxia have similar negative effects on the liver; somatic growth; and liver insulin-like growth factor (IGF)-I, IGF binding protein (BP)-3, and growth hormone binding protein (GHBP), regardless of resolution in normoxia or hyperoxia between episodes.

DESIGN

Newborn rats on the first day of life (P0) were exposed to two IH paradigms: 1) hyperoxia (50% O2) with brief hypoxia (12% O2); or 2) normoxia (21% O2) with hypoxia (12% O2); intermittent hypoxia (50% O2/21% O2); hyperoxia only (50% O2); or room air (RA, 21% O2). Pups were euthanized on P14 or placed in RA until P21. Controls remained in RA from P0-P21. Growth, liver histopathology, apoptosis, IGFI, IGFBP-3, and GHBP were assessed.

RESULTS

Pathological findings of the liver hepatocytes, including cellular swelling, steatosis, apoptosis, necrosis and focal sinusoid congestion were seen in the IH and intermittent hyperoxia groups, and were particularly severe in the 21-12% O2 group during exposure (P14) with no significant improvements during recovery/reoxygenation (P21). These effects were associated with induction of HIF1α, and reductions in liver IGFI, IGFBP-3, and GHBP.

CONCLUSIONS

Exposure to IH or intermittent hyperoxia during the first few weeks of life regardless of resolution in RA or hyperoxia is detrimental to the immature liver. These findings may suggest that interventions to prevent frequent fluctuations in oxygen saturation during early neonatal life remain a high priority.

Adverse Metabolic Effects on Glucose in Patients Receiving Anamorelin Using a Japanese Claims Database

BACKGROUND

Anamorelin is the first drug approved for the treatment of cancer cachexia, a debilitating condition characterized by weight loss, anorexia, and muscle mass depletion. Cachexia negatively affects a patient's quality of life, survival, and response to chemotherapy. Studies describing anamorelin use are currently limited to a small number of pancreatic cancer cases.

OBJECTIVES

We aimed to examine the incidence and risk factors of adverse metabolic effects on glucose levels in cachexia patients with various carcinomas treated with anamorelin.

METHOD

We used real-world data of patients who received anamorelin between August 2021 and July 2022 and were registered in the JMDC claims database. We investigated the impact of metabolic adverse effects on glucose in patients receiving anamorelin with respect to the following factors: sex (male), age (>75 years), types of carcinoma, history of diabetes mellitus (DM), and concomitant use of steroids.

RESULTS

The incidence of adverse metabolic effects on glucose was 12.3%, and pancreatic cancer and history of DM were associated with adverse metabolic effects on glucose. The median onset of adverse metabolic effects on glucose was 17 days after anamorelin treatment.

CONCLUSIONS

This study highlights the need to monitor and manage hyperglycemia in cachexia patients receiving anamorelin, especially in those with pancreatic cancer and a history of DM.

Hypoglycemia in Children: Major Endocrine-Metabolic Causes and Novel Therapeutic Perspectives

Hypoglycemia is due to defects in the metabolic systems involved in the transition from the fed to the fasting state or in the hormone control of these systems. In children, hypoglycemia is considered a metabolic-endocrine emergency, because it may lead to brain injury, permanent neurological sequelae and, in rare cases, death. Symptoms are nonspecific, particularly in infants and young children. Diagnosis is based on laboratory investigations during a hypoglycemic event, but it may also require biochemical tests between episodes, dynamic endocrine tests and molecular genetics. This narrative review presents the age-related definitions of hypoglycemia, its pathophysiology and main causes, and discusses the current diagnostic and modern therapeutic approaches.

Direct and systemic actions of growth hormone receptor (GHR)-signaling on hepatic glycolysis, de novo lipogenesis and insulin sensitivity, associated with steatosis

BACKGROUND

Evidence is accumulating that growth hormone (GH) protects against the development of steatosis and progression of non-alcoholic fatty liver disease (NAFLD). GH may control steatosis indirectly by altering systemic insulin sensitivity and substrate delivery to the liver and/or by the direct actions of GH on hepatocyte function.

APPROACH

To better define the hepatocyte-specific role of GH receptor (GHR) signaling on regulating steatosis, we used a mouse model with adult-onset, hepatocyte-specific GHR knockdown (aHepGHRkd). To prevent the reduction in circulating insulin-like growth factor 1 (IGF1) and the subsequent increase in GH observed after aHepGHRkd, subsets of aHepGHRkd mice were treated with adeno-associated viral vectors (AAV) driving hepatocyte-specific expression of IGF1 or a constitutively active form of STAT5b (STAT5bCA). The impact of hepatocyte-specific modulation of GHR, IGF1 and STAT5b on carbohydrate and lipid metabolism was studied across multiple nutritional states and in the context of hyperinsulinemic:euglycemic clamps.

RESULTS

Chow-fed male aHepGHRkd mice developed steatosis associated with an increase in hepatic glucokinase (GCK) and ketohexokinase (KHK) expression and de novo lipogenesis (DNL) rate, in the post-absorptive state and in response to refeeding after an overnight fast. The aHepGHRkd-associated increase in hepatic KHK, but not GCK and steatosis, was dependent on hepatocyte expression of carbohydrate response element binding protein (ChREBP), in re-fed mice. Interestingly, under clamp conditions, aHepGHRkd also increased the rate of DNL and expression of GCK and KHK, but impaired insulin-mediated suppression of hepatic glucose production, without altering plasma NEFA levels. These effects were normalized with AAV-mediated hepatocyte expression of IGF1 or STAT5bCA. Comparison of the impact of AAV-mediated hepatocyte IGF1 versus STAT5bCA in aHepGHRkd mice across multiple nutritional states, indicated the restorative actions of IGF1 are indirect, by improving systemic insulin sensitivity, independent of changes in the liver transcriptome. In contrast, the actions of STAT5b are due to the combined effects of raising IGF1 and direct alterations in the hepatocyte gene program that may involve suppression of BCL6 and FOXO1 activity. However, the direct and IGF1-dependent actions of STAT5b cannot fully account for enhanced GCK activity and lipogenic gene expression observed after aHepGHRkd, suggesting other GHR-mediated signals are involved.

CONCLUSION

These studies demonstrate hepatocyte GHR-signaling controls hepatic glycolysis, DNL, steatosis and hepatic insulin sensitivity indirectly (via IGF1) and directly (via STAT5b). The relative contribution of these indirect and direct actions of GH on hepatocytes is modified by insulin and nutrient availability. These results improve our understanding of the physiologic actions of GH on regulating adult metabolism to protect against NAFLD progression.

Weekly Growth Hormone (Lonapegsomatropin) Causes Severe Transient Hyperglycemia in a Child with Obesity

INTRODUCTION

A 12-year-and-9-month-old non-Hispanic black male with a history of growth hormone deficiency, pituitary hypoplasia, prediabetes, obesity, hypertension, and hyperlipidemia was initiated on weekly growth hormone (lonapegsomatropin-tcgd) and then transiently developed symptomatic hyperglycemia to 500 mg/dL. We aimed to describe this medication's effect.

CASE PRESENTATION

He was born full term and appropriate for gestational age. He was referred to endocrinology at 3.5 years of age for short stature with a height SDS of -2.48. IGF-1 51.1 ng/mL and IGFBP-3 1.2 ng/mL were low. GH stimulation test noted baseline and peak GH of 0.1 ng/mL. MRI brain showed hypoplastic adenohypophysis, aplastic pituitary stalk, and ectopic neurohypophysis. There had been difficulty with adherence to daily GH over the following 9 years. BMI trajectory rose above 180% of the 95th percentile. By age 12, A1c was 6.6%. Metformin was started and increased to 1,000 mg twice daily. Subsequent A1c was 6.0%. Due to poor compliance with daily GH, at 12 years and 9 months, he was initiated on 22 mg (0.25 mg/kg/week) of weekly lonapegsomatropin-tcgd to improve compliance. The day after his first injection, he developed non-bloody, non-bilious emesis. He denied headaches and endorsed polyuria. Due to concern for increased intracranial pressure, he was sent to the emergency department; however, ophthalmologic exam was negative. Initial serum glucose was 500 mg/dL, then 336 mg/dL after 1-L normal saline. Hemoglobin A1c was 5.7%, urine glucose 3+ mg/dL, and urine ketones 2+ mg/dL. Venous pH of 7.379 and bicarbonate of 20.6 mmol/L ruled out diabetic ketoacidosis. Metformin was held during the hospitalization. Hyperglycemia rapidly improved with transient insulin administration. He received one dose of glargine 20 units. He was initiated on lispro carb ratio of 1:8 and correction factor 1:15 for target glucose 150 mg/dL. By day four, glucoses were below 100 mg/dL; lispro was discontinued, and he was discharged home. Weekly GH was discontinued with plans to resume daily GH therapy in several months.

CONCLUSION

Lonapegsomatropin-tcgd offers the convenience of weekly rather than daily GH treatment; however, this patient developed a rapid increase in insulin resistance and hyperglycemia requiring insulin. The discrepancy between the glucose of 500 mg/dL and A1c of 5.7%, along with the rapid resolution of hyperglycemia, is further consistent with a medication side effect. Close glucose monitoring of patients initiated on weekly growth hormone is crucial, particularly in those with a history of prediabetes.

Effects of GHR Deficiency and Juvenile Hypoglycemia on Immune Cells of a Porcine Model for Laron Syndrome

Laron syndrome (LS) is a rare genetic disorder characterized by low levels of insulin-like growth factor 1 (IGF1) and high levels of growth hormone (GH) due to mutations in the growth hormone receptor gene (GHR). A GHR-knockout (GHR-KO) pig was developed as a model for LS, which displays many of the same features as humans with LS-like transient juvenile hypoglycemia. This study aimed to investigate the effects of impaired GHR signaling on immune functions and immunometabolism in GHR-KO pigs. GHR are located on various cell types of the immune system. Therefore, we investigated lymphocyte subsets, proliferative and respiratory capacity of peripheral blood mononuclear cells (PBMCs), proteome profiles of CD4− and CD4+ lymphocytes and IFN-α serum levels between wild-type (WT) controls and GHR-KO pigs, which revealed significant differences in the relative proportion of the CD4+CD8α− subpopulation and in IFN-α levels. We detected no significant difference in the respiratory capacity and the capacity for polyclonal stimulation in PBMCs between the two groups. But proteome analysis of CD4+ and CD4− lymphocyte populations revealed multiple significant protein abundance differences between GHR-KO and WT pigs, involving pathways related to amino acid metabolism, beta-oxidation of fatty acids, insulin secretion signaling, and oxidative phosphorylation. This study highlights the potential use of GHR-KO pigs as a model for studying the effects of impaired GHR signaling on immune functions.

Liver impact of growth hormone (GH) intermittent treatment during the growth period in mice

Liver impact of prolonged GH-treatment given to non-GH-deficient growing mice between the third and eighth week of life was evaluated in both sexes. Tissues were collected 6 h after last dose or four weeks later. Somatometric, biochemical, histological, immunohistochemical, RT-qPCR and immunoblotting determinations were performed. Five-week GH intermittent administration induced body weight gain and body and bone length increase, augmented organ weight, higher hepatocellular size and proliferation, and increased liver IGF1 gene expression. Phosphorylation of signaling mediators and expression of GH-induced proliferation-related genes was decreased in GH-treated mice liver 6h after last injection, reflecting active sensitization/desensitization cycles. In females, GH elicited EGFR expression, associated to higher EGF-induced STAT3/5 phosphorylation. Four weeks after treatment, increased organ weight concomitant to body weight gain was still observed, whereas hepatocyte enlargement reverted. However, basal signaling for critical mediators was lower in GH-treated animals and in male controls compared to female ones, suggesting signaling declination.

Polycystic ovary syndrome preceding the diagnosis of acromegaly: a retrospective study in 97 reproductive-aged women

BACKGROUND

Acromegaly is a disease of growth hormone excess that results in enlargement of extremities, abnormal glucose and lipid metabolism, and gonadal disruption. Manifestations of the disease are insidious and typically lead to a diagnostic delay of 7-10 years. Classically the polycystic ovary syndrome (PCOS) phenotype is described in women with irregular menses, clinical or biochemical evidence of androgen excess, and/or multiple ovarian follicles on pelvic ultrasonography. Women with acromegaly may present with some or all of these symptoms. Our objective was to evaluate the prevalence of PCOS in patients with acromegaly and to determine if diagnosis of PCOS results in a delay in diagnosing acromegaly.

METHODS

Using patient databases at two academic health centers, we identified 97 premenopausal women aged 18-49 years old presenting with acromegaly. Data were collected regarding pelvic sonography and reproductive history, including the diagnosis of PCOS. Patients carrying the diagnosis of PCOS before their diagnosis of acromegaly were identified and the remaining patients were screened using the Rotterdam criteria to identify additional patients meeting the criteria for PCOS prior to their diagnosis of acromegaly.

RESULTS

Mean age of the population (n = 97) at the time of diagnosis of acromegaly was 33.4 ± 7.5 years (SD). Thirty-three percent of patients (n = 32) either carried a diagnosis of PCOS or met diagnostic criteria for PCOS before their diagnosis of acromegaly. In the subset of patients in whom data on symptom onset were available, those who met criteria for PCOS were diagnosed with acromegaly a median of 5 years [4, 9] after the onset of symptoms compared to 2 years [0.92, 3] (p =  0.006) in the patients who did not meet criteria for PCOS.

CONCLUSIONS

Our data demonstrate a high prevalence of signs and symptoms of PCOS in reproductive-aged women with acromegaly and a longer time to diagnosis in women who meet the clinical criteria for PCOS. As screening for acromegaly is relatively simple and done with measurement of a random, non-fasting IGF-1 level that can be drawn at any time during the menstrual cycle, screening patients with PCOS for acromegaly may lessen the delay in diagnosis for reproductive-aged women with this disease.

Biomarkers of growth and carbohydrate metabolism in neonatal rats supplemented with fish oil and/or antioxidants during intermittent hypoxia

OBJECTIVE

Extremely low gestational age neonates (ELGANs) experience frequent intermittent hypoxia (IH) episodes during therapeutic oxygen. ELGANs exhibit poor postnatal growth requiring lipid supplementation. Lipids are targets of reactive oxygen species resulting in lipid peroxidation and cell death, particularly in preterm infants with compromised antioxidant systems. We tested the hypothesis that early supplementation with lipids and/or antioxidants promotes growth and influences biomarkers of carbohydrate metabolism in neonatal rats exposed to IH.

DESIGN

Newborn rats (n = 18/group) were exposed to brief hypoxia (12% O₂) during hyperoxia (50% O₂), or room air (RA), from birth (P0) to P14 during which they received daily oral supplementation with: 1) fish oil; 2) Coenzyme Q10 (CoQ10) in olive oil; 3) glutathione nanoparticles (nGSH); 4) fish oil+CoQ10; or 5) olive oil. At P21, plasma samples were assessed for glucose, insulin, glucokinase (GCK), glucagon, glucagon-like peptide (GLP)-1, growth hormone (GH), corticosterone, and ghrelin. Liver was assessed for histopathology, apoptosis (terminal deoxynucleotidyl transferase dUTP nick end labeling, TUNEL stain), and GH, insulin-like growth factor (IGF)-I, GH binding protein (GHBP), and IGF binding protein (IGFBP)-3.

RESULTS

Neonatal IH resulted in decreased liver weight and liver/body weight ratios, as well as hepatocyte swelling, steatosis, and apoptosis, which were attenuated with fish oil, nGSH, and combined fish oil+CoQ10. IH also decreased plasma glucose, insulin, GCK, and ghrelin, but increased GLP-1. All treatments improved plasma glucose in IH, but insulin was higher with CoQ10 and nGSH only. Glucagon was increased with CoQ10, fish oil, and CoQ10 + fish oil, while corticosterone was higher with nGSH and CoQ10 + fish oil. IGF-I and IGFBP-3 were significantly higher in the liver with CoQ10 in IH, while deficits in GH were noted with CoQ10 and fish oil in RA and IH. Treatment with nGSH and combined CoQ10 + fish oil reduced IGF-I in RA and IH but increased IGFBP-3.

CONCLUSIONS

Neonatal IH impairs liver growth with significant hepatocyte damage. Of all supplements in IH, nGSH and combined fish oil+CoQ10 were most effective for preserving liver growth and carbohydrate metabolism. Data suggest that these supplements may improve poor postnatal organ and body growth; and metabolic dysfunction associated with neonatal IH.

Predictors of response to anamorelin in gastrointestinal cancer patients with cachexia: a retrospective study

PURPOSE

Anamorelin, a ghrelin receptor agonist, has recently been approved for gastric, pancreatic, and colorectal cancer patients with cachexia in Japan. However, only few studies have investigated the predictors of response to anamorelin in clinical settings. Thus, our study aimed to investigate the predictors of the response, in addition to its efficacy and safety.

METHODS

The clinical outcomes of 20 patients were evaluated during administration. They were divided into two groups based on lean body mass, responders and non-responders, and their clinical characteristics were compared.

RESULTS

The mean ± standard error (SE) variations at 12 weeks in lean body mass and handgrip strength were 2.63 ± 0.79 kg and - 1.53 ± 1.20 kg, respectively. The mean ± SE variations at 8 weeks in fasting blood glucose and hemoglobin A1c were 32.88 ± 13.77 mg/dL and 0.90 ± 0.18%, respectively. Total protein, albumin, transferrin, and prognostic nutritional index at baseline were significantly higher in responders (n = 8) than in non-responders (n = 12), whereas the neutrophil/lymphocyte and C-reactive protein/albumin ratios at baseline were significantly higher in non-responders than in responders.

CONCLUSION

The study confirmed the efficacy and safety of anamorelin and identified nutritional or systemic inflammatory markers as predictors of anamorelin response in advanced gastrointestinal cancer patients.

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.

Human CIDEC transgene improves lipid metabolism and protects against high-fat diet-induced glucose intolerance in mice

Cell death–inducing DNA fragmentation factor-like effector C (CIDEC) expression in adipose tissue positively correlates with insulin sensitivity in obese humans. Further, E186X, a single-nucleotide CIDEC variant is associated with lipodystrophy, hypertriglyceridemia, and insulin resistance. To establish the unknown mechanistic link between CIDEC and maintenance of systemic glucose homeostasis, we generated transgenic mouse models expressing CIDEC (Ad-CIDECtg) and CIDEC E186X variant (Ad-CIDECmut) transgene specifically in the adipose tissue. We found that Ad-CIDECtg but not Ad-CIDECmut mice were protected against high-fat diet-induced glucose intolerance. Furthermore, we revealed the role of CIDEC in lipid metabolism using transcriptomics and lipidomics. Serum triglycerides, cholesterol, and low-density lipoproteins were lower in high-fat diet-fed Ad-CIDECtg mice compared to their littermate controls. Mechanistically, we demonstrated that CIDEC regulates the enzymatic activity of adipose triglyceride lipase via interacting with its activator, CGI-58, to reduce free fatty acid release and lipotoxicity. In addition, we confirmed that CIDEC is indeed a vital regulator of lipolysis in adipose tissue of obese humans, and treatment with recombinant CIDEC decreased triglyceride breakdown in visceral human adipose tissue. Our study unravels a central pathway whereby adipocyte-specific CIDEC plays a pivotal role in regulating adipose lipid metabolism and whole-body glucose homeostasis. In summary, our findings identify human CIDEC as a potential ‘drug’ or a ‘druggable’ target to reverse obesity-induced lipotoxicity and glucose intolerance.

Identification of Body Size Determination Related Candidate Genes in Domestic Pig Using Genome-Wide Selection Signal Analysis

This study aimed to identify the genes related to the body size of pigs by conducting genome-wide selection analysis (GWSA). We performed a GWSA scan on 50 pigs belonging to four small-bodied pig populations (Diannan small-eared pig, Bama Xiang pig, Wuzhishan pig, and Jeju black pig from South Korea) and 124 large-bodied pigs. We used the genetic parameters of the pairwise fixation index (FST) and π ratio (case/control) to screen candidate genome regions and genes related to body size. The results revealed 47,339,509 high-quality SNPs obtained from 174 individuals, while 280 interacting candidate regions were obtained from the top 1% signal windows of both parameters, along with 187 genes (e.g., ADCK4, AMDHD2, ASPN, ASS1, and ATP6V0C). The results of the candidate gene (CG) annotation showed that a series of CGs (e.g., MSTN, LTBP4, PDPK1, PKMYT1, ASS1, and STAT6) was enriched into the gene ontology terms. Moreover, molecular pathways, such as the PI3K-Akt, HIF-1, and AMPK signaling pathways, were verified to be related to body development. Overall, we identified a series of key genes that may be closely related to the body size of pigs, further elucidating the heredity basis of body shape determination in pigs and providing a theoretical reference for molecular breeding.

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.

An appetite for growth: The role of the hypothalamic - pituitary - growth hormone axis in energy balance

Links between the regulation of growth and energy balance are clear; to fuel growth, there must be consumption of energy. Therefore, it is perhaps intuitive that interactions between the hypothalamic - pituitary - growth hormone axis (growth axis) and pathways that drive metabolic processes exist. Overproduction of growth hormone has been associated with diabetes and metabolic disease for decades and the opposing effects of growth hormone and insulin have been studied since early experiments almost a century ago. The relationship between neuroendocrine axes can be complex and the growth axis is no exception, interacting with energy balance in several organ systems, both in the periphery and centrally in hypothalamic nuclei. Much is known about peripheral interactions between growth axis hormones and processes such as glucose homeostasis and adipogenesis. More is still being learned about the molecular actions of growth axis hormones in adipose and other metabolically active tissues, and recent findings are discussed in this perspective. However, less is known about interactions with central energy balance pathways in the hypothalamus. This perspective aims to summarise what is known about these interactions, taking lessons from human studies and animal genetic and seasonal models, and discusses what this may mean in an evolving landscape of personalised medicine.

Effect of Dietary Betaine on Muscle Protein Deposition, Nucleic Acid and Amino Acid Contents, and Proteomes of Broilers

To investigate the effect of betaine supplementation on growth performance, muscle protein deposition, muscle nucleic acid and amino acid contents, and muscle proteome of broilers, 160 one-day-old male partridge shank broiler chickens were randomly divided into 2 groups with 8 replicates of 10 broilers each. Broilers were fed a basal diet alone, or a basal diet supplemented with 1000 mg/kg betaine. Compared with the control group, the betaine group significantly increased (p < 0.05) the broilers average daily gain, the levels of serum insulin-like growth factor-1 (IGF-1), growth hormone (GH), total protein (TP), the contents of muscle absolute protein deposition, RNA, Ser, Glu, Met, and Phe, and the ratio of RNA/DNA, and decreased (p < 0.05) the feed conversion ratio and serum blood urea nitrogen content. Moreover, proteomic analysis revealed 35 differentially abundant proteins (DAPs) in the betaine group compared with the control group, including 27 upregulated proteins and 8 downregulated proteins (p < 0.05). These DAPs were mainly related to cell differentiation, small molecule metabolic process, and tissue development. In conclusion, diets supplemented with 1000 mg/kg betaine improved growth performance and muscle protein deposition of broilers. Increased serum GH, IGF-1, and TP contents, and alterations in muscle nucleic acids, amino acids, and protein abundance levels were involved in this process.

Metabolic Effects of Growth Hormone Treatment in Short Prepubertal Children: A Double-Blinded Randomized Clinical Trial

INTRODUCTION

Growth hormone (GH) is a central hormone for regulating linear growth during childhood and also highly involved in the metabolism of lipids, carbohydrates, and protein. However, few studies report on how treatment with GH during childhood influences metabolic parameters. Our aim was to investigate metabolic effects of different doses of GH in short children with GH peak levels in the low to normal range.

DESIGN

Thirty-five prepubertal short children (<-2.5 SDS), aged 7-10 years, with peak levels of GH between 7 and 14 μg/L during an arginine-insulin tolerance test, were randomized to 3 different doses (11/33/100 μg/kg/day) of GH treatment for 2 years. Auxological and metabolic investigations were performed. These included metabolites in blood and interstitial microdialysis fluid, dual-energy X-ray absorptiometry, frequently sampled intravenous glucose tolerance test (FSIVGTT), and stable isotope examinations of rates of glucose production and lipolysis.

RESULTS

At 24 months, the high-dose group (HD) had higher fasting insulin compared with the standard-dose (SD) and low-dose (LD) groups (HD: 111.7 vs. SD: 61.2 and LD: 46.0 pmol/L [p < 0.001]) and showed signs of insulin resistance (HOMA-IR, HD: 4.20 vs. SD: 2.17 and LD: 1.71 (LD) [p < 0.001]). The FSIVGTT also demonstrated higher acute insulin response (p < 0.05). Few other metabolic differences were found at 24 months, but a decreased insulin sensitivity index (Si) could already be seen at 12 months for both SD and HD compared with the LD group (p < 0.05).

CONCLUSION

Treatment with GH resulted in a dose-dependent decrease in insulin sensitivity, demonstrated by higher levels of fasting insulin and signs of insulin resistance in both HOMA indices and FSIVGTT examinations.

Gut Microbiota: A Key Regulator in the Effects of Environmental Hazards on Modulates Insulin Resistance

Insulin resistance is a hallmark of Alzheimer’s disease (AD), type II diabetes (T2D), and Parkinson’s disease (PD). Emerging evidence indicates that these disorders are typically characterized by alterations in the gut microbiota composition, diversity, and their metabolites. Currently, it is understood that environmental hazards including ionizing radiation, toxic heavy metals, pesticides, particle matter, and polycyclic aromatic hydrocarbons are capable of interacting with gut microbiota and have a non-beneficial health effect. Based on the current study, we propose the hypothesis of “gut microenvironment baseline drift”. According to this “baseline drift” theory, gut microbiota is a temporarily combined cluster of species sharing the same environmental stresses for a short period, which would change quickly under the influence of different environmental factors. This indicates that the microbial species in the gut do not have a long-term relationship; any split, division, or recombination may occur in different environments. Nonetheless, the “baseline drift” theory considers the critical role of the response of the whole gut microbiome. Undoubtedly, this hypothesis implies that the gut microbiota response is not merely a “cross junction” switch; in contrast, the human health or disease is a result of a rich palette of gut-microbiota-driven multiple-pathway responses. In summary, environmental factors, including hazardous and normal factors, are critical to the biological impact of the gut microbiota responses and the dual effect of the gut microbiota on the regulation of biological functions. Novel appreciation of the role of gut microbiota and environmental hazards in the insulin resistance would shed new light on insulin resistance and also promote the development of new research direction and new overcoming strategies for patients.

Towards Understanding the Direct and Indirect Actions of Growth Hormone in Controlling Hepatocyte Carbohydrate and Lipid Metabolism

Growth hormone (GH) is critical for achieving normal structural growth. In addition, GH plays an important role in regulating metabolic function. GH acts through its GH receptor (GHR) to modulate the production and function of insulin-like growth factor 1 (IGF1) and insulin. GH, IGF1, and insulin act on multiple tissues to coordinate metabolic control in a context-specific manner. This review will specifically focus on our current understanding of the direct and indirect actions of GH to control liver (hepatocyte) carbohydrate and lipid metabolism in the context of normal fasting (sleep) and feeding (wake) cycles and in response to prolonged nutrient deprivation and excess. Caveats and challenges related to the model systems used and areas that require further investigation towards a clearer understanding of the role GH plays in metabolic health and disease are discussed.

Central Regulation of Metabolism by Growth Hormone

Growth hormone (GH) is secreted by the pituitary gland, and in addition to its classical functions of regulating height, protein synthesis, tissue growth, and cell proliferation, GH exerts profound effects on metabolism. In this regard, GH stimulates lipolysis in white adipose tissue and antagonizes insulin's effects on glycemic control. During the last decade, a wide distribution of GH-responsive neurons were identified in numerous brain areas, especially in hypothalamic nuclei, that control metabolism. The specific role of GH action in different neuronal populations is now starting to be uncovered, and so far, it indicates that the brain is an important target of GH for the regulation of food intake, energy expenditure, and glycemia and neuroendocrine changes, particularly in response to different forms of metabolic stress such as glucoprivation, food restriction, and physical exercise. The objective of the present review is to summarize the current knowledge about the potential role of GH action in the brain for the regulation of different metabolic aspects. The findings gathered here allow us to suggest that GH represents a hormonal factor that conveys homeostatic information to the brain to produce metabolic adjustments in order to promote energy homeostasis.