Safety aspects of pharmacological GH therapy in adults

Covid-19 and Growth Hormone/Insulin-Like Growth Factor 1: Study in Critically and Non-Critically Ill Patients

OBJECTIVE

We aimed to measure insulin-like growth factor 1 (IGF1) and growth hormone (GH) in critically and non-critically ill patients with Covid-19 and assess them vis-a-vis clinical and laboratory parameters and prognostic tools.

SUBJECTS AND METHODS

We included patients who were admitted to the wards or the ICU of the largest Covid-19 referral hospital in Greece; patients with non-Covid-19 pneumonia served as controls. Apart from the routine laboratory work-up for Covid-19 we measured GH and IGF1 (and calculated normalized IGF-1 values as standard deviation scores; SDS), after blood sampling upon admission to the wards or the ICU.

RESULTS

We studied 209 critically and non-critically ill patients with Covid-19 and 39 control patients. Patients with Covid-19 who were ICU non-survivors were older and presented with a worse hematological/biochemical profile (including white blood cell count, troponin, glucose, aminotransferases and lactate dehydrogenase) compared to ICU survivors or Covid-19 survivors in the wards. Overall, IGF-1 SDS was higher in Covid-19 survivors compared to non-survivors (-0.96 ± 1.89 vs -2.05 ± 2.48, respectively, p=0.030). No significant differences were noted in GH between the groups. Nevertheless, in critically ill patients with Covid-19, the prognostic value of IGF-1 (raw data), IGF-1 (SDS) and GH for survival/non-survival was on a par with that of APACHE II and SOFA (with a marginal difference between GH and SOFA).

CONCLUSION

In conclusion, our findings suggest that there might be an association between low IGF1 (and possibly GH) and poor outcome in patients with Covid-19.

Maternal undernutrition results in altered renal pro-inflammatory gene expression concomitant with hypertension in adult male offspring that is ameliorated following pre-weaning growth hormone treatment

An adverse early life environment is associated with increased cardiovascular disease in offspring. Work in animal models has shown that maternal undernutrition (UN) during pregnancy leads to hypertension in adult offspring, with effects thought to be mediated in part via altered renal function. We have previously shown that growth hormone (GH) treatment of UN offspring during the pre-weaning period can prevent the later development of cardiometabolic disorders. However, the mechanistic basis for these observations is not well defined. The present study examined the impact of GH treatment on renal inflammatory markers in adult male offspring as a potential mediator of these reversal effects. Female Sprague-Dawley rats were fed either a chow diet fed ad libitum (CON) or at 50% of CON intake (UN) during pregnancy. All dams were fed the chow diet ad libitum during lactation. CON and UN pups received saline (CON-S/UN-S) or GH (2.5 µg/g/day; CON-GH/UN-GH) from postnatal day 3 until weaning (p21). Post-weaning males were fed a standard chow diet for the remainder of the study (150 days). Histological analysis was performed to examine renal morphological characteristics, and gene expression of inflammatory and vascular markers were assessed. There was evidence of renal hypotrophy and reduced nephron number in the UN-S group. Tumour necrosis factor-α, monocyte chemoattractant protein-1 (MCP-1), intercellular adhesion molecular-1 and vascular cell adhesion molecule-1 gene expression was increased in UN-S offspring and normalized in the UN-GH group. These findings indicate that pre-weaning GH treatment has the potential to normalize some of the adverse renal and cardiovascular sequelae that arise as a consequence of poor maternal nutrition.

Growth hormone: does it have a therapeutic role in fracture healing?

BACKGROUND

The role of growth hormone (GH) in augmenting fracture healing has been postulated for over half a century. GH has been shown to play a role in bone metabolism and this can be mediated directly or indirectly through IGF-I.

OBJECTIVES

The use of GH was evaluated as a possible therapeutic agent in augmenting fracture healing.

METHOD

A literature search was undertaken on GH and its effect on bone fracture healing primarily using MEDLINE/OVID (1950 to January 2009). Key words and phrases including 'growth hormone', 'insulin like growth factor', 'insulin like growth factor binding protein', 'insulin like growth factor receptor', 'fracture repair', 'bone healing', 'bone fracture', 'bone metabolism', 'osteoblast' and 'osteoclast' were used in different combinations. Manual searches of the bibliography of key papers were also undertaken.

RESULTS

Current evidence suggests a positive role of GH on fracture healing as demonstrated by in vitro studies on osteoblasts, osteoclasts and the crosstalk between the two. Animal studies have demonstrated a number of factors influencing the effect of GH in vivo such as dose, timing and method of administration. Application of this knowledge in humans is limited but clearly demonstrates a positive effect on fracture healing. Concern has been raised in the past regarding the safety profile of the pharmacological use of GH when used in critically ill patients.

CONCLUSION

The optimal dose and method of administration is still to be determined, and the safety profile of this novel use of GH needs to be investigated prior to establishing its widespread use as a fracture-healing agent.

Lipopolysaccharide (LPS) directly suppresses growth hormone receptor (GHR) expression through MyD88-dependent and -independent Toll-like receptor-4/MD2 complex signaling pathways

INTRODUCTION

Sepsis is associated with growth hormone (GH) insensitivity and in the intact animal the major surface component of the bacterial cell wall, lipopolysaccharide (LPS), inhibits GH receptor (GHR) gene expression. The prevailing explanation for LPS-induced effects on the GHR promoter is that this effect is indirect via generation of cytokines. Our recent studies demonstrate that saturated free fatty acids (FFAs) inhibit the activity of the murine GHR promoter. Saturated FFAs are an essential component of the lipid A moiety of LPS required for biological activity of LPS.

HYPOTHESIS

LPS directly modulates the activity of the dominant GHR promoter via interaction with Toll-like receptor(s) (TLR)/MD2 complex and activation of cognate signaling pathway(s).

RESULTS

In transient transfection experiments with RAW 264.7 cells which express endogenous TLR4 and MD2, LPS treatment inhibited GHR promoter activity. Co-transfection of dominant negative TLR4 abrogated this effect on GHR promoter activity. In HEK 293T cells, which are devoid of endogenous TLR4 or MD2, ectopic expression of TLR4 and MD2 resulted in LPS-induced inhibition of the GHR promoter activity. The inhibition of GHR promoter activity was demonstrable by 5-6h after exposure to LPS and persisted at 24h. Fatty-acid free LPS failed to elicit a similar effect on the GHR promoter and the effect of LPS was abrogated by Polymyxin B. The essential role of the cofactor MD2 on the effect of LPS on the GHR promoter was established in experiments using ectopic expression of wild type and mutant MD2. Cotransfection of CD14 in these cells failed to alter the effect of LPS on the activity of the GHR promoter. Analysis of cell culture supernatant excluded the possibility that the effect of LPS was secondary to release of cytokines from the transfected cells. The effect of LPS on the endogenous GHR promoter activity and protein expression was confirmed in F442A preadipocyte cells. In HEK 293T cells, ectopic expression of mutant MyD88 or mutant TRIF abrogated the effect of LPS on the GHR promoter, suggesting that the effect of LPS on the GHR promoter was via both MyD88-dependent and -independent pathways.

CONCLUSIONS

LPS acts through both MyD88-dependent and -independent TLR4 signaling pathways to directly inhibit GHR gene expression. Our results establish a novel cytokine-independent mechanism for decrease in GHR expression in bacterial sepsis.

Systemic metabolic effects of combined insulin-like growth factor-I and growth hormone therapy in patients who have sustained acute traumatic brain injury

OBJECT

Hypermetabolism, hypercatabolism, refractory nitrogen wasting, hyperglycemia, and immunosuppression accompany traumatic brain injury (TBI). Pituitary dysfunction occurs, affecting growth hormone (GH) and plasma insulin-like growth factor-I (IGF-I) concentrations. The authors evaluated whether combination IGF-I/GH therapy improved metabolic and nutritional parameters after moderate to severe TBI.

METHODS

The authors conducted a prospective, randomized, double-blind study comparing combination IGF-I/GH therapy and a placebo treatment. Ninety-seven patients with TBI were enrolled in the study within 72 hours of injury and were assigned to receive either combination IGF-I/GH therapy or placebo. All patients received concomitant nutritional support. Insulin-like growth factor-I was administered by continuous intravenous infusion (0.01 mg/kg/hr), and GH (0.05 mg/kg/day) was administered subcutaneously. Placebo control group patients received normal saline solution in place of both agents. Nutritional and metabolic monitoring continued throughout the 14-day treatment period. The two groups did not differ in energy expenditure, nutrient intake, or use of insulin treatment. The mean daily serum glucose concentration was higher in the treatment group (123 +/- 24 mg/dl) than in the control group (104 +/- 11 mg/dl) (p < 0.03). A positive nitrogen balance was achieved within the first 24 hours in the treatment group and remained positive in that group throughout the treatment period (p < 0.05). This pattern was not observed in the control group. Plasma IGF-I concentrations were above 350 ng/ml in the treatment group throughout the study period. Overall, the mean plasma IGF-I concentrations were 1003 +/- 480.6 ng/ml in the treatment group and 192 +/- 46.2 ng/ml in the control group (p < 0.01).

CONCLUSIONS

The combination of IGF-I and GH produced sustained improvement in metabolic and nutritional endpoints after moderate to severe acute TBI.

Changes within the growth hormone/insulin-like growth factor I/IGF binding protein axis during critical illness

Interest in the somatotropic axis,with its complex network of interactions, during critical illness arose only a few decades ago. Te distinguishing neuroendocrine features of prolonged critical illness were not differentiated from those during the acute phase until the early 1990s. This incomplete understanding of the somatotropic axis contributed to some disastrous results, such as the multicenter growth hormone trial. The goal of stimulating the somatotropic axis without a proper preceding neuroendocrine diagnosis should be held obsolete. Moreover, the fascinating link between regulators of carbohydrate metabolism, such as insulin and insulin-like growth factor I, and the somatotropic axis may lead to future therapeutic possibilities.

Recombinant human growth hormone therapy in HIV-associated wasting and visceral adiposity

This article reviews the clinical data on recombinant human growth hormone therapy of body composition abnormalities in HIV-infected patients. Short-term recombinant human growth hormone therapy at pharmacologic doses modestly increases total body weight and lean body mass in patients with HIV wasting, resulting in improvements in physical capacity and quality of life. Short-term recombinant human growth hormone therapy has a clear dose-dependent impact on trunk and visceral fat in HIV-infected patients with central fat accumulation, resulting in improvements in perception of body image and a beneficial effect on lipid parameters. Recombinant human growth hormone therapy is also accompanied by dose-dependent side effects related to fluid retention and increased insulin resistance. The optimal treatment strategy, maintenance dose and duration of treatment have not been identified.

Changes within the GH/IGF-I/IGFBP axis in critical illness

Interest in the somatotropic axis, with its complex network of interactions, during critical illness started only a few decades ago. The distinguished neuroendocrine features of prolonged critically ill patients were not differentiated from those during the acute phase until the 1990s. This incomplete understanding of the somatotropic axis has contributed to some disastrous results. Aiming to stimulate the somatotropic axis without a proper preceding neuroendocrine diagnosis should be held obsolete, because recent data indicate that the patient with the best anabolic parameters may not necessarily be the most favored to survive the ICU stay. Moreover, the fascinating link between regulators of carbohydrate metabolism, such as insulin and insulin-like growth factor 1, and the somatotropic axis may lead to future therapeutic possibilities.

Treatment with GH and IGF-1 in Critical Illness

Trauma, sepsis, and surgery are associated with global hypercatabolism and a negative nitrogen balance. When critical illness is prolonged the relentless loss of lean tissue becomes functionally important. Protein catabolism in the critically ill patient is associated with complex changes in the growth hormone (GH)/insulin-like growth factor-1 (IGF-1) axis. Many small clinical studies indicate that treatment with recombinant human (rh) GH would be a safe and effective means of limiting the deleterious effects of the catabolic response. Unexpectedly, however, two large prospective randomized controlled trials (PRCTs) demonstrated that administration of rhGH to long-stay critically ill adults increases morbidity and mortality. Some progress has been made in understanding the mechanisms underlying this observation.

Protective effects of recombinant human growth hormone on cirrhotic rats

AIM: To investigate the effects and molecular mechanisms of recombinant human growth hormone (rhGH) on protecting liver function and alleviating portal hypertension of liver cirrhotic rats.

METHODS: Liver cirrhosis of male Sprague-Dawley rats was induced by administration of thioacetamide. The rats with or without liver cirrhosis were randomly divided into four groups. Group A consisted of the normal rats was treated with normal saline (NS), group B consisted of the normal rats was treated with rhGH, group C consisted of cirrhotic rats was treated with NS, and group D consisted of cirrhotic rats was treated with rhGH. The rats of different groups were subcutaneously injected with 0.5 mL of NS or 333 ng/kg of rhGH daily for 7 d. After treatments, the following parameters were examined, including GH-binding capacity (R_T) by ¹²⁵I-hGH binding, growth hormone receptor mRNA(GHR mRNA) expression by RT-PCR, relative content of collagen (RCC) by histomorphomertry, and level of malon-dialdehyde (MDA) and superoxide dismutase (SOD) in liver tissue by thiobarbituric acid reaction and pyrogallic acid self-oxidation, respectively. Serum albumin (ALB), alanine transaminase (ALT) and portal vein pressure (PVP) were also examined.

RESULTS: rhGH up-regulated both the GH-binding capacity (R_T) and the expression of GHR mRNA in vivo. R_T in group A (72 ± 12 fmol/mg protein) was significantly higher than that in group C (31 ± 4 fmol/mg protein) (P < 0.05). R_T in group B (80 ± 9 fmol/mg protein) increased markedly compared to group A (P < 0.05). R_T in group D (40 ± 7 fmol/mg protein) raised remarkably compared with group C (P < 0.05), but less than that in group A, and there was no significant GH binding affinity contrast (Kd) change. The GHR mRNA level (iOD, pixel) in group A (29 ± 3) was significantly higher than that in group C (23 ± 3) (P < 0.05). GHR mRNA levels were significantly raised in group B (56 ± 4) and group D (42 ± 8) compared with groups A and C (29 ± 3 and 23 ± 3, respectively) (P < 0.05). Compared with the normal liver, MDA level was higher and SOD level was lower in cirrhotic livers. After rhGH treatment, MDA level was significantly declined to 12.0 ± 2.2 nmol/mg protein and SOD was raised to 1029 ± 76 U/mg protein in group D (P < 0.05). ALB levels in groups B and D (42 ± 7 g/L and 37 ± 7 g/L, respectively) were significantly raised compared with those in groups A and C (35 ± 5 g/L and 29 ± 4 g/L, respectively) (P < 0.05). ALT level was markedly lower in group D (69 ± 7 U/L) compared to group C (89 ± 15 U/L) (P < 0.05), and close to group A (61 ± 10 U/L). RCC in group C (22.30% ± 3.86%) was significantly higher than that in group A (1.14% ± 0.21%) and group D (14.70% ± 2.07%) (P < 0.05). In addition, rhGH markedly alleviated portal hypertension in liver cirrhotic rats (group D vs C, 9.3 ± 1.5 cmH₂O vs 14.4 ± 2.0 cmH₂O) (P < 0.05).

CONCLUSION: Pharmacological doses of rhGH can increase R_T and GHR mRNA expression, ameliorate liver functions, repress fibrosis and decline portal hypertension, suggesting it has potentially clinical usage as a hepatotropic factor.

Ergogenic aids: a review of basic science, performance, side effects, and status in sports

The use of drugs and supplements to enhance performance has become a part of mainstream athletics. Many team physicians and sports medicine practitioners are unfamiliar with the benefits and risks of these products and thus are unable to educate young athletes on this topic. In spite of numerous reports on the health risks of anabolic steroid use, 1 to 3 million Americans have used them. Human growth hormone has been tried by up to 5% of 10th graders, although no scientific study has shown that it is an effective performance-enhancing drug. Amphetamines and similar compounds may be the most widely abused drug in baseball; recently, they have come under increased scrutiny in sport. Erythropoietin is a highly effective aerobic enhancer that has been linked to multiple deaths in cyclists and other endurance athletes. The neutraceutical industry, led by supplements such as creatine, ephedra, and androstenedione, remains unregulated by the Food and Drug Administration and has serious issues with quality and side effects. An understanding of these products is essential for the sports medicine practitioner to provide sound, safe advice to the athlete.

Expression of growth hormone receptor and its mRNA in hepatic cirrhosis

AIM: To investigate the expression of growth hormone receptor (GHR) and mRNA of GHR in cirrhotic livers of rats with the intension to find the basis for application of recombinant human growth hormone (rhGH) to patients with liver cirrhosis.

METHODS: Hepatic cirrhosis was induced in Sprague-Dawley rats by administration of thioacetamide intraperitoneally for 9-12 weeks. Collagenase IV was perfused in situ for isolation of hepatocytes. The expression of GHR and its mRNA in cirrhotic livers was studied with radio-ligand binding assay, RT-PCR and digital image analysis.

RESULTS: One class of specific growth hormone-binding site, GHR, was detected in hepatocytes and hepatic tissue of cirrhotic livers. The binding capacity of GHR (R_T, fmol/mg protein) in rat cirrhotic liver tissue (30.8 ± 1.9) was significantly lower than that in normal control (74.9 ± 3.9) at the time point of the ninth week after initiation of induction of cirrhosis (n = 10, P < 0.05), and it decreased gradually along with the accumulation of collagen in the process of formation and development of liver cirrhosis (P < 0.05). The number of binding sites (× 10⁴/cell) of GHR on rat cirrhotic hepatocytes (0.86 ± 0.16) was significantly lower than that (1.28 ± 0.24) in control (n = 10, P < 0.05). The binding affinity of GHR among liver tissue, hepatocytes of various groups had no significant difference (P > 0.05). The expression of GHR mRNA (riOD, pixel) in rat cirrhotic hepatic tissues (23.3 ± 3.1) was also significantly lower than that (29.3 ± 3.4) in normal control (n = 10, P < 0.05).

CONCLUSION: The growth hormone receptor was expressed in a reduced level in liver tissue of cirrhotic rats, and lesser expression of growth hormone receptors was found in a later stage of cirrhosis. The reduced expression of growth hormone receptor was partly due to its decreased expression on cirrhotic hepatocytes and the reduced expression of its mRNA in cirrhotic liver tissue.