Abnormal growth hormone dynamics in chronic liver disease do not depend on severe parenchymal disease

From liver to hormones: The endocrine consequences of cirrhosis

Hepatocrinology explores the intricate relationship between liver function and the endocrine system. Chronic liver diseases such as liver cirrhosis can cause endocrine disorders due to toxin accumulation and protein synthesis disruption. Despite its importance, assessing endocrine issues in cirrhotic patients is frequently neglected. This article provides a comprehensive review of the epidemiology, pathophysiology, diagnosis, and treatment of endocrine disturbances in liver cirrhosis. The review was conducted using the PubMed/Medline, EMBASE, and Scielo databases, encompassing 172 articles. Liver cirrhosis is associated with endocrine disturbances, including diabetes, hypoglycemia, sarcopenia, thyroid dysfunction, hypogonadotropic hypogonadism, bone disease, adrenal insufficiency, growth hormone dysfunction, and secondary hyperaldosteronism. The optimal tools for diagnosing diabetes and detecting hypoglycemia are the oral glucose tolerance test and continuous glucose monitoring system, respectively. Sarcopenia can be assessed through imaging and functional tests, while other endocrine disorders are evaluated using hormonal assays and imaging studies. Treatment options include metformin, glucagon-like peptide-1 analogs, sodium-glucose co-transporter-2 inhibitors, and insulin, which are effective and safe for diabetes control. Established standards are followed for managing hypoglycemia, and hormone replacement therapy is often necessary for other endocrine dysfunctions. Liver transplantation can address some of these problems.

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.

Presentation of Congenital Portosystemic Shunts in Children

Background: Congenital portosystemic shunts (CPSS) are rare vascular anomalies resulting in communications between the portal venous system and the systemic venous circulation, affecting an estimated 30,000 to 50,000 live births. CPSS can present at any age as a multi-system disease of variable severity mimicking both common and rare pediatric conditions. Case presentations: Case A: A vascular malformation was identified in the liver of a 10-year-old girl with tall stature, advanced somatic maturation, insulin resistance with hyperinsulinemia, hyperandrogenemia and transient hematuria. Work-up also suggested elevated pulmonary pressures. Case B: A young girl with trisomy 8 mosaicism with a history of neonatal hypoglycemia, transient neonatal cholestasis and tall stature presented newly increased aminotransferase levels at 6 years of age. Case C: A 3-year-old boy with speech delay, tall stature and abdominal pain underwent abdominal ultrasound (US) showing multiple liver nodules, diagnosed as liver hemangiomas by hepatic magnetic resonance imaging (MRI). Management and outcome: After identification of a venous malformation on liver Doppler US, all three patients were referred to a specialized liver center for further work-up within 12 to 18 months from diagnosis. Angio-computed tomography (CT) scan confirmed the presence of either an intrahepatic or extrahepatic CPSS with multiples liver nodules. All three had a hyperintense signal in the globus pallidus on T1 weighted cerebral MRI. Right heart catheterization confirmed pulmonary hypertension in cases A and C. Shunts were closed either using an endovascular or surgical approach. Liver nodules were either surgically removed if there was a risk of malignant degeneration or closely monitored by serial imaging when benign. Conclusion: These cases illustrate most of the common chief complaints and manifestations of CPSS. Liver Doppler US is the key to diagnosis. Considering portosystemic shunts in the diagnostic work-up of a patient with unexplained endocrine, liver, gastro-intestinal, cardiovascular, hematological, renal or neurocognitive disorder is important as prompt referral to a specialized center may significantly impact patient outcome.

Growth impairment in children with extrahepatic portal vein obstruction is improved by mesenterico-left portal vein bypass

BACKGROUND

Extrahepatic portal vein obstruction (EHPVO) has been associated with growth impairment in children. We hypothesized that growth parameters improve after reversal of portal hypertension and restoration of mesenteric venous blood flow to the liver by the mesenterico-left portal vein bypass (MLPVB).

METHODS

A retrospective review of 45 children with idiopathic EHPVO who underwent MLPVB between 1997 and 2007 and had follow-up data for analysis was carried out. Growth was assessed using SD scores (z scores) for height, weight, and body mass index (BMI) at the time of operation and at early (5-12 months) and late (13-24 months) follow-up.

RESULTS

The mean height and weight of children with EHPVO was significantly lower than the general population before surgery. Mean BMI was also lower, although statistically insignificant. All parameters increased significantly after MLPVB as follows: height from -0.42 before surgery to -0.12 (P = .027) at 5 to 12 months and -0.14 (P = .026) at 13 to 24 months; weight from -0.49 before surgery to 0.03 (P < .001) at 5 to 12 months and 0.35 (P < .001) at 13 to 24 months; and BMI from -0.22 before surgery to 0.17 (P = .001) at 5 to 12 months and 0.48 (P < .001) at 13 to 24 months.

CONCLUSION

Restoration of portal blood flow to the liver by MLPVB improves growth in children with EHPVO.

Effects on growth after portal hypertension induced in young rats

BACKGROUND

Physical growth retardation in children with hypertension portal was observed regardless of schistosomiasis. It has been suggested that the shunt of portal blood through portosystemic collateral vessels would result in metabolic consequences that would lead to the physical growth deficit observed.

AIM

Study the effects of hypertension portal in the growth of young rats.

METHODS

The growth of 20 young rats, divided in the groups hypertension portal, n = 10, 103 +/- 3.7 g and sham operation n = 10, 102.6 +/- 3.4 g was evaluated throughout 5 weeks and the following parameters were under observation: quality of diet offered, diet ingestion, weight increase and urinary creatinine within 24 hours. At the end of the experiment, blood was taken for biochemical tests, prothrombin time and hematocrit and hypertension portal was measured.

RESULTS/CONCLUSIONS

Rats with hypertension portal induced at early stages of their lives present growth delay in the first week after surgery recovering their growth rhythm in the next weeks, catching up with the sham animals. Differences related to urinary creatinine excretion, biochemical tests and hematocrit were not observed. Such results are evidence against the hypothesis that the hypertension portal induced in early stages of rats lives would cause delay in their growth.

Dysfunction of the hypothalamic-pituitary-glandular axes and relation to Child-Pugh classification in male patients with alcoholic and virus-related cirrhosis

OBJECTIVE

To investigate anterior pituitary function (adrenal, somatotropic, thyroid and gonadal axes, and prolactin) in relation to the Child-Pugh score in male patients with alcoholic and virus-related liver cirrhosis.

METHOD

Anterior pituitary function was evaluated in 52 male cirrhotics (26 Child-Pugh class A (CPA), 16 Child-Pugh class B (CPB) and 10 Child-Pugh class C (CPC)) by a combined pituitary stimulation test, and was compared with 50 age-matched controls.

RESULTS

A normal cortisol response to corticotropin-releasing hormone (CRH) stimulation was demonstrated in 57.6% of CPA patients, 31.1% of CPB patients and 20% of CPC patients, while basal levels of adrenocorticotropic hormone (ACTH) and cortisol in cirrhotics were comparable to those in controls. Levels of basal growth hormone (P < 0.001) and stimulated growth hormone (P < 0.01) were significantly higher in cirrhotics compared with controls, while levels of insulin-like growth factor 1 (IGF-1) were significantly lower (P < 0.001). Basal prolactin levels were elevated significantly in CPC patients (P < 0.01), while stimulated prolactin as well as basal and stimulated thyroid-stimulating hormone (TSH) levels were comparable. Basal luteinizing hormone levels were significantly higher in CPA (P < 0.001) and CPB (P < 0.001) patients, and stimulated luteinizing hormone levels were significantly lower in CPC patients than in controls (P < 0.005). Basal and stimulated follicle-stimulating hormone (FSH) levels were comparable in all groups. Child-Pugh score was correlated positively to prolactin and was correlated negatively to IGF-1, stimulated luteinizing hormone and free testosterone.

CONCLUSIONS

In cirrhotics, the hypothalamic-pituitary-adrenal and -gonadal axes and prolactin secretion are impaired. Growth hormone response to growth hormone-releasing hormone (GHRH) is accelerated in cirrhotics. Thus, elevated basal and stimulated levels of growth hormone probably reflect compensation for low levels of IGF-1, which are associated with deteriorating liver function. The aetiology of cirrhosis was found to have no influence on the degree of alteration of the hypothalamic-pituitary-glandular axes.

Dysfunction of the hypothalamic-pituitary-glandular axes and relation to Child-Pugh classification in male patients with alcoholic and virus-related cirrhosis

OBJECTIVE

To investigate anterior pituitary function (adrenal, somatotropic, thyroid and gonadal axes, and prolactin) in relation to the Child-Pugh score in male patients with alcoholic and virus-related liver cirrhosis.

METHOD

Anterior pituitary function was evaluated in 52 male cirrhotics (26 Child-Pugh class A (CPA), 16 Child-Pugh class B (CPB) and 10 Child-Pugh class C (CPC)) by a combined pituitary stimulation test, and was compared with 50 age-matched controls.

RESULTS

A normal cortisol response to corticotropin-releasing hormone (CRH) stimulation was demonstrated in 57.6% of CPA patients, 31.1% of CPB patients and 20% of CPC patients, while basal levels of adrenocorticotropic hormone (ACTH) and cortisol in cirrhotics were comparable to those in controls. Levels of basal growth hormone (P < 0.001) and stimulated growth hormone (P < 0.01) were significantly higher in cirrhotics compared with controls, while levels of insulin-like growth factor 1 (IGF-1) were significantly lower (P < 0.001). Basal prolactin levels were elevated significantly in CPC patients (P < 0.01), while stimulated prolactin as well as basal and stimulated thyroid-stimulating hormone (TSH) levels were comparable. Basal luteinizing hormone levels were significantly higher in CPA (P < 0.001) and CPB (P < 0.001) patients, and stimulated luteinizing hormone levels were significantly lower in CPC patients than in controls (P < 0.005). Basal and stimulated follicle-stimulating hormone (FSH) levels were comparable in all groups. Child-Pugh score was correlated positively to prolactin and was correlated negatively to IGF-1, stimulated luteinizing hormone and free testosterone.

CONCLUSIONS

In cirrhotics, the hypothalamic-pituitary-adrenal and -gonadal axes and prolactin secretion are impaired. Growth hormone response to growth hormone-releasing hormone (GHRH) is accelerated in cirrhotics. Thus, elevated basal and stimulated levels of growth hormone probably reflect compensation for low levels of IGF-1, which are associated with deteriorating liver function. The aetiology of cirrhosis was found to have no influence on the degree of alteration of the hypothalamic-pituitary-glandular axes.

GH/IGF-I axis in anorexia nervosa

Patients with anorexia nervosa (AN) may develop multiple endocrine abnormalities, including amenorrhea, hyperactivity of the hypothalamus-pituitary-adrenal axis, hypothyroidism and particular changes in the activity of the growth hormone (GH)/insulin-like growth factor I (IGF-I) axis. Exaggerated GH secretion and reduced IGF-I levels are usually found in AN, as well as in conditions of malnutrition and malabsorption, insulin-dependent diabetes mellitus, liver cirrhosis and catabolic states. In AN, GH hypersecretion at least partially reflects malnutrition-induced peripheral GH resistance, which leads to reduced IGF-I synthesis and release; this implies an impairment of the negative IGF-I feedback action on GH secretion. On the other hand, primary alterations in the neural control of GH secretion cannot be ruled out. The neuroendocrine alterations include enhanced somatotroph responsiveness to growth hormone releasing hormone (GHRH) and impaired GH response to most central nervous system-mediated stimuli. Particular resistance to cholinergic manipulation has also been demonstrated, thus suggesting a somewhat specific alteration in the somatostatin (SS)-mediated cholinergic influence on GH secretion. Moreover, paradoxical GH responses to glucose load, thyrotropin releasing hormone (TRH) and luteinizing hormone releasing hormone (LHRH) have also been reported. The effect of reduced leptin levels on GH hypersecretion in AN is still unclear, but ghrelin (the gastric hormone that is a natural ligand of the GH secretagogue receptor and strongly stimulates somatotroph secretion) is thought to play a major role. Regardless of the supposed central and peripheral alterations, it has to be emphasised that the activity of the GH/IGF-I axis in AN is generally restored by nutritional and stable weight gain. It therefore reflects an impaired nutritional state and cannot be considered a primary hallmark of the disease.

Regulation of the growth hormone receptor/binding protein, insulin-like growth factor ternary complex system in human cirrhosis

BACKGROUND/AIMS

The liver is the central organ of the endocrine growth hormone/insulin-like growth factor I (GH/IGF-I) axis and cirrhosis effects a state of acquired GH resistance. Low IGF-I levels are associated with adverse clinical outcomes in cirrhotic patients and may be pathogenic to the complications of cirrhosis. We examined the impact of cirrhosis on hepatic mRNA and serum protein levels for the GH receptor (GHR)/binding protein (GHBP), IGF-I, IGF binding protein (IGFBP)-3 and the acid-labile subunit (ALS).

METHODS

Fifty patients with cirrhosis were studied and liver tissue was obtained from 18. Gene expression was assessed by Northern analysis and serum protein levels by immunoassay.

RESULTS

In cirrhotic liver GHR mRNA and GH binding to microsomal membranes were decreased by 61 and 56%, respectively. Serum GHBP levels were decreased only in severe disease, not correlating with GHR mRNA or GH binding. Hepatic IGF-I and ALS mRNA were significantly decreased by 84 and 68%, respectively, in parallel with serum protein, suggesting transcriptional regulation. Hepatic IGFBP-3 mRNA was unchanged but low serum IGFBP-3 suggested post-transcriptional regulation.

CONCLUSIONS

The decreased mRNA and serum levels for the GH-dependent, hepatocyte produced proteins IGF-I and ALS confirm the importance of GH receptor loss to the GH resistance of cirrhosis.

The role of nutritional status and insulin-like growth factor in reduced physical growth in hepatosplenic Schistosoma mansoni infection

The influence of nutritional status and hormonal growth activity on the impaired somatic development of adolescents with the hepatosplenic clinical form of Schistosoma mansoni infection (HS), the intestinal form with high (IH) or low (IL) egg output and non-infected (NI) individuals was evaluated (in Comercinho, Minas Gerais State, Brazil, in 1996-97) by measuring body mass index (BMI), insulin-like growth promoting factor (IGF-I) and its carrier protein (IGFBP-3). BMI, IGF-I and IGFBP-3 concentrations were significantly lower in the HS group compared with the IH and the NI groups, irrespective of age. BMI did not remain associated with the clinical form in the bi-variate model that included IGF-I and BMI or IGFBP-3 and BMI, suggesting that in these groups IGF-I and IGFBP-3 levels were related to the clinical form but independent of nutritional status. It is suggested that physical growth impairment in hepatosplenic S. mansoni infection results from the synergistic action of both hepatic damage and nutritional restriction.

Portosystemic shunting in children during the era of endoscopic therapy: improved postoperative growth parameters

BACKGROUND

Surgical portosystemic shunting has been performed less frequently in recent years. In this retrospective study, recent outcomes of portosystemic shunting in children are described, to evaluate its role in the era of endoscopic therapy.

METHODS

Retrospective chart review of children who underwent surgical portosystemic shunt procedures between October 1994 and October 1997.

RESULTS

Twelve children (age range, 1-16 years) underwent shunting procedures. The causes of portal hypertension were extrahepatic portal vein thrombosis (n = 6), congenital hepatic fibrosis (n = 2), hepatic cirrhosis (n = 2), and other (n = 2). None of the patients were immediate candidates for liver transplantation. Types of shunt included: distal splenorenal (n = 10), portocaval (n = 1), and other (n = 1). Median follow-up was 35 months (range, 24-48 months). All patients are currently alive and well with patent shunts. The mean hospital stay was 8 days. Three patients required readmission for further interventions because of shunt stenosis in two and small bowel obstruction in the other. Mild portosystemic encephalopathy was seen in one child with pre-existing neurobehavioral disturbance. Excluding a patient who underwent placement of a portosystemic shunt for a complication of liver transplantation, mean weight-for-age z score in nine prepubertal patients improved from -1.16 SD to +0.15 SD (P = 0.023), and mean height-for-age z score from -1.23 SD to 0.00 SD (P = 0.048) by 2 years after surgery.

CONCLUSIONS

Surgical portosystemic shunting is a safe and effective method for the management of portal hypertension in childhood. Patients show significant improvements in growth parameters after the procedure. Surgical portosystemic shunting should be actively considered in selected children with portal hypertension.

Spontaneous pulsatility and pharmacokinetics of growth hormone in liver cirrhotic patients

BACKGROUND/AIMS

Liver cirrhosis is characterized by high serum growth hormone levels and low serum insulin-like growth factor I and growth hormone-binding protein levels. The present study was designed to characterize the serum profile of growth hormone and growth hormone pharmacokinetics in postnecrotic liver cirrhosis, correlating it with liver function and nutritional states.

METHODS

Fifteen patients were grouped by the Child-Pugh score (group 1, score of 5 to 8; group 2, score of 9 to 12). Five healthy subjects served as controls. Nutritional status was assessed by the creatinine-height index. Baseline growth hormone, insulin-like growth factor, and growth hormone binding protein were measured, and growth hormone pharmacokinetics was followed for 48 h after administration of subcutaneous recombinant human growth hormone (0.06 mg/kg).

RESULTS

Trough serum growth hormone (microg/l) was higher in both patient groups (5.3+/-3.6) than in controls (1.0+/-0.3; p<0.01). More pulses were recorded in cirrhotic patients, and mean pulse amplitude (microg/l) was higher in cirrhotic patients than in controls (p<0.01). After subcutaneous recombinant human growth hormone injection, maximal growth hormone was higher in cirrhotic patients and the area under the curve over 24 h was greater (626+/-120) than in controls (330+/-54; p<0.01). Single regression analysis showed a weak correlation of both the Child-Pugh score and the creatinine-height index with the pharmacokinetic parameters.

CONCLUSIONS

Due to decreased growth hormone clearance, patients with liver cirrhosis have increased trough and peak serum growth hormone levels, as well as lower serum growth hormone binding protein and insulin-like growth factor. Recombinant human growth hormone pharmacokinetics are typical of a high hepatic extraction substance administered to patients with liver disease and portal hypertension, and this may be relevant to the further use of growth hormone therapy.

The altered plasma amino acid pattern is responsible for the paradoxical growth hormone response to the oral glucose tolerance test in liver cirrhosis

OBJECTIVE

An increased basal growth hormone (GH) secretion and a parodoxical GH response to the oral glucose tolerance test (OGTT) have been reported in patients with liver cirrhosis. It has been suggested that the ratio between branched-chain amino acids (BCAAs) and aromatic amino acids (AAAs) (BCAA/ AAA ratio) may determine in part the brain concentration of the AAAs, since the BCAAs compete with the AAAs for entry across the blood-brain barrier, leading to the accumulation of false neurotransmitters such as octopamine and phenylethanolamine, which are able to stimulate GH secretion (via alpha 2-adrenergic stimulation). In this study we investigated the role of amino acids, particularly the BCAA/AAA ratio, in the paradoxical response of GH to the OGTT in patients with liver cirrhosis.

PATIENTS AND DESIGN

Twelve non-diabetic patients with biopsy-proven cirrhosis of the liver underwent an OGTT. Three of the five patients with a paradoxical response of GH to the OGTT underwent a second oral glucose administration associated with an infusion of BCAA solution from -30 min until 180 min.

RESULTS

During the OGTT, glucose and insulin levels increased from 4.8 +/- 0.2 to 9.6 +/- 0.7 mmol/l (P < 0.001) and from 18.8 +/- 2.6 to 104.4 +/- 13.8 mU/l (P < 0.005), respectively. GH levels increased from 8.6 +/- 2.6 to 22.4 +/- 10.8 mU/l although not significantly. Five patients had a paradoxical GH response to the OGTT. A negative correlation between serum GH values and BCAA/AAA ratio in the plasma at every time point of the OGTT was found. After co-administration of glucose and BCAA in three patients the BCAA/AAAs ratio increased, abolishing the paradoxical GH secretion.

CONCLUSIONS

Our data suggest that in liver cirrhosis the altered BCAA/AAA ratio may influence the altered basal GH secretion and the paradoxical GH response to the OGTT, probably by an increase of adrenergic mediators in the brain. Moreover, the increase of BCAA/AAA ratio seems to be able to abolish the GH paradoxical response to the OGTT.

Extrahepatic portal vein obstruction in children: anthropometry, growth hormone, and insulin-like growth factor I

BACKGROUND

Extrahepatic portal vein obstruction has been shown to cause growth retardation in children, though literature is scant. No information is available regarding the cause of growth retardation in these patients.

METHODS

To document the presence of growth retardation in this disease, we studied growth and nutrition in 33 consecutive prepubertal patients. Anthropometry, fasting growth hormone, and insulin-like growth factor I levels were compared in 22 well-nourished patients from this group with 35 age-matched well-nourished controls.

RESULTS

Mean +/- SD height standard deviation score of well-nourished patients (-1.88 +/- 1.33) was significantly below that of the controls (-1.06 +/- 0.64, p < 0.01). Patients also had significantly lower midarm muscle circumference z scores (-2.65 +/- 1.09) than controls (-1.17 +/- 1.09, p < 0.0001), though triceps skinfold thickness z scores were comparable in the two groups (-1.06 +/- 0.68 vs -1.24 +/- 0.79, p = NS). Insulin-like growth factor I z scores were significantly lower in patients (-1.48 +/- 0.88) than in controls (-0.49 +/- 1.09, p < 0.001), whereas basal growth hormone was significantly higher in patients (4.60 +/- 3.70 mIU/L) compared with controls (2.66 +/- 0.82, p < 0.01).

CONCLUSION

Extrahepatic portal vein obstruction in children leads to growth retardation. Anthropometric and preliminary hormonal evaluation suggest resistance to the action of growth hormone as a possible mechanism.

Insulin-like growth factor 1 has beneficial effects, whereas growth hormone has limited effects on postoperative protein metabolism, gut integrity, and splenic weight in rats with chronic mild liver injury

BACKGROUND

Both growth hormone (GH) and insulin-like growth factor 1 (IGF-1) improve protein metabolism after surgical insult in subjects without liver disease. However, these effects in chronic liver injury, in which the GH-IGF-1 axis is impaired, have not been investigated. We examined the anabolic effects of GH and IGF-1 after gastrectomy in rats with chronic mild liver injury.

METHODS

Rats with chronic mild liver injury induced by thioacetamide were used. After gastrectomy, the rats were randomized into vehicle control, GH, and IGF-1 groups. In the latter two groups, 0.8 IU/kg/d of GH or 4 mg/kg/d of IGF-1 was infused for 72 hours. Anabolic effects were assessed by body weight change, 3-methylhistidine (3-MH) excretion, nitrogen excretion, and whole-body protein turnover. Organ weights, plasma levels of glucose, insulin, and IGF-1, tissue IGF-1 levels, hepatic messenger RNA (mRNA) content, and intestinal structure were also determined.

RESULTS

Both GH and IGF-1 decreased nitrogen excretion. IGF-1, but not GH, increased postoperative body weight, whole-body protein turnover, and splenic weight. IGF-1 reduced atrophy of the intestinal mucosa. GH treatment increased hepatic IGF-1-mRNA and the plasma IGF-1 level, whereas IGF-1 treatment increased the plasma IGF-1 level with no change in the hepatic IGF-1-mRNA content. There were no significant differences in plasma glucose or insulin levels among the three groups. Neither GH nor IGF-1 affected the gastrocnemius muscle IGF-1 level.

CONCLUSIONS

IGF-1 has beneficial effects, whereas GH has only limited effects on post-operative protein metabolism, gut integrity, and splenic weight in chronic mild liver injury.

Nutritional and prognostic significance of insulin-like growth factor 1 in patients with liver cirrhosis

Most of the traditional parameters for nutrition assessment have important limitations in patients with chronic liver disease. Insulin-like growth factor 1 (IGF-1) has been found to be regulated by nutrition and proposed as a nutritional marker. Its nutritional significance in patients with liver cirrhosis, however, has not been investigated. Serum IGF-1 as well as traditional anthropometric, visceral, and immunologic parameters were evaluated in 64 hospitalized cirrhotics, followed up clinically for 2 y. IGF-1Z-score averaged -2.16 +/- 1.08 and inversely correlated with Child-Pugh score (P < 0.01), the most reliable composite score reflecting the severity of liver disease. IGF-1Z-score was not different in patients with or without signs of energy malnutrition, as defined by values of midarm muscle circumference (MAMC) and/or triceps skinfold (TSF) < 5th percentile. Moreover, IGF-1Z-score did not correlate with MAMC or TSF. Despite its correlation with all visceral proteins, the reduction of IGF-1 was much greater and more frequent than that of visceral proteins. Patients with IGF-1Z-score < median values (-2.5) showed lower long-term survival rates compared with patients with IGF-1Z-score > -2.5 (P < 0.01). These data indicate that serum IGF-1 is not related to energy malnutrition in cirrhotic patients, while it appears to be a good predictor of survival and an early marker of liver dysfunction. Multiple factors, most of which are related to the severity of the liver disease, may contribute to the reduction of IGF-1. This multifactorial pathogenesis probably accounts for its prognostic significance.

Nephromegaly and elevated hepatocyte growth factor in children with biliary atresia

Nephromegaly, a rarely mentioned but probably common situation, was studied in children with biliary atresia. We evaluated the length and the cross-sectional diameters of the kidney by ultrasound in 21 children with biliary atresia as well as in 50 healthy children. The ages ranged from 1 month to 10 years. Plasma hepatocyte growth factor (HGF) was measured in 18 children with biliary atresia and also in 18 age- and sex-matched normal controls. There was a significant nephromegaly (increase in the renal length and the kidney volume) in children with biliary atresia as compared with normal children (P < 0.001 by analysis of covariance). Plasma HGF levels were elevated in these patients (2.13 +/- 1.06 v 0.76 +/- 0.19 ng/mL in controls, P < 0.001) and had a positive correlation with the renal size after considering the effect of body height by multiple regression analysis (P = 0.0022 for renal length, and P < 0.001 for kidney volume). These results confirm the presence of large kidneys in biliary atresia and implicate the possible pathogenic role of HGF in such a condition. Nephromegaly in biliary atresia may provide a new in vivo model to study the mechanism of renal growth.

Effects of growth hormone and insulin-like growth factor 1 (IGF-1 ) on hepatic IGF-1-mRNA, plasma IGF-1 and nitrogen excretion in gastrectomized rats with liver cirrhosis

The growth hormone (GH)-insulin-like growth factor 1 (IGF-1) axis is impaired in liver cirrhosis. We determined the effects of GH and IGF-1 treatments in gastrectomized rats with thioacetamide-induced cirrhosis. GH did not increase hepatic IGF-1-mRNA, plasma IGF-1 or the tissue, i.e. gastrocnemius muscle IGF-1 level. IGF-1 administration increased plasma IGF-1 without increasing hepatic IGF-1-mRNA. GH and IGF-1 independently decreased postoperative urinary nitrogen excretion. We conclude that both GH and IGF-1 improve postoperative nitrogen metabolism. Furthermore, GH may exert its anabolic effects directly and/or via actions mediated by IGF-1 production, other than in the liver and in the skeletal muscle, in the setting of cirrhosis.

Altered endogenous growth hormone secretory kinetics and diurnal GH-binding protein profiles in adults with chronic liver disease

OBJECTIVE

Increased serum GH concentrations and GH responses to a variety of stimuli have been reported in patients with chronic liver disease (CLD). We investigated the pulsatile pattern of endogenous GH release and GH-binding protein (GHBP) and insulin-like growth factor-I (IGF-I) diurnal profiles in adults with cirrhosis, in comparison with healthy, matched control subjects.

DESIGN

Case-control, cross-sectional.

PATIENTS

Seven patients with biopsy proven cirrhosis, and sex, age, height, weight and oestrogen status matched controls.

MEASUREMENTS

Serum immunoreactive GH concentrations in samples collected at 20-minute intervals for 24 hours were analysed using a multi-parameter deconvolution method to simultaneously resolve endogenous GH secretory and disappearance rates. Diurnal patterns of GHBP (specific immunoprecipitation method) and serum IGF-I (RIA after acid-ethanol extraction) were assessed.

RESULTS

The mean daily GH secretion rate in patients with CLD was increased (210 +/- 93 vs 100 +/- 55 mU/I/day; P = 0.025), and GH disappearance half-time was prolonged (43 +/- 10 vs 24 +/- 9 min; P = 0.006) compared to controls. Detectable GH secretory bursts were more frequent in patients with CLD (10 +/- 1 vs 6 +/- 3/day; P = 0.038), but of similar mean mass (21 +/- 10 vs 17 +/- 8 mU/I) compared to controls. In patients with CLD, mean serum GHBP was slightly lower (63 +/- 36 vs 71 +/- 14% pooled control; P > 0.1). Fasting serum IGF-I concentrations (after size-exclusion HPLC) were lower in the patients with CLD (13 +/- 5 vs 21 +/- 2 nmol/l; P < 0.0001). Multiple regression analysis showed that GH secretion rate was increased in patients with CLD with higher Child's classifications (R2 = 0.86; P = 0.002) and with lower serum IGF-I concentrations measured after HPLC (R2 = 0.11; P = 0.044).

CONCLUSIONS

Adults with chronic liver disease have (1) increased total daily GH secretion rates, which appear to be influenced by disease severity and diminished serum IGF-I-mediated negative feedback; (2) markedly impaired endogenous GH clearance, possibly reflecting changes in hepatic GH-receptor status; and (3) GHBP levels which do not correlate with GH kinetics or serum IGF-I concentrations.

Diminished concentrations of insulin-like growth factor I in cystic fibrosis

Cystic fibrosis is frequently accompanied by a catabolic condition with low body mass index caused by a number of disease complications. Insulin-like growth factor-I (IGF-I) is an anabolic hormone and an important marker of nutritional status, liver function, and linear growth. Available data on IGF-I in cystic fibrosis are sparse and conflicting. From 1990-3, 235 of our 240 patients (114 males, 121 females, median age 16.2 years, ranged 0.1-44.0 years) had IGF-I measured once by radioimmunoassay. IGF-I was significantly reduced compared with a healthy Scandinavian control population: mean (-2 SD to +2 SD) IGF-I SD score was -0.97 (-3.7 to 1.7) in males and -0.67 (-3.2 to 1.9) in females. Height SD score was -0.95 (-3.3 to 1.4) in males and -0.81 (-3.2 to 1.6) in females. In patients who were still in the growth period a significant correlation of IGF-I SD score to height SD score (r = 0.28, p < 0.001) was found. The low IGF-I concentrations may reflect the catabolic state of many patients with cystic fibrosis and play a part in their abnormal growth pattern.

Short-term effect of recombinant human growth hormone in patients with alcoholic cirrhosis

As growth hormone possesses anabolic properties that are active on protein metabolism, and thus of potential benefit to patients with chronic liver disease, we determined the metabolic effects of recombinant human growth hormone on insulin-like growth factor-I (IGF-I) its specific binding proteins, and liver function. Twenty consecutive patients with cirrhosis were randomized to recombinant human growth hormone (Norditropin, 4 I.U. twice daily) subcutaneously for 6 weeks (n = 10) or conventional medical treatment (n = 10). The serum concentrations of insulin-like growth factor-I in the recombinant human growth hormone group increased after 3 (p < 0.01) and 6 weeks (p < 0.02), whereas no significant changes were observed in the control group. The change in insulin-like growth factor-I during the treatment period was expressed as area under the curve (AUC). The AUCIGF-I was significantly larger in the recombinant human growth hormone group (median AUCIGF-I: 12.1, range: 0.0-54.7 weeks.nmol/l) than in the control group (median AUCIGF-I: 0.2, range: -10.6-9.9 weeks.nmol/l) (p < 0.007). Insulin-like growth factor binding protein-3 concentrations increased in the recombinant human growth hormone treated patients as well as in controls, whereas no change in insulin-like growth factor binding protein-1 concentrations was found. No significant changes were seen in the area under the curve for biochemical liver function tests. We conclude that administration of recombinant human growth hormone induces an increase in very low levels of insulin-like growth factor-I, even in patients with cirrhosis with advanced disease, but the clinical benefits remain to be demonstrated.

Urinary growth hormone (U-GH) excretion and serum insulin-like growth factor 1 (IGF-1) in patients with alcoholic cirrhosis

Basal serum growth hormone (GH) levels are elevated and insulin-like growth factor 1 (IGF-1) concentrations in serum are suppressed in patients with chronic liver disease. The aim of this study was to measure the urinary GH (U-GH) excretion and IGF-1 concentrations in patients with cirrhosis and to correlate these both to clinical and biochemical characteristics and survival rate. Urinary GH excretion, IGF-1, and other biochemical parameters were measured in 36 patients with alcoholic cirrhosis, while in the control group of 34 healthy individuals only U-GH excretion was measured. U-GH excretion was significantly higher in patients than in the healthy controls (p < 0.00001), and increased with deteriorating liver function assessed by modified Child-Turcotte score (p < 0.01). The highest U-GH excretions were found in patients with hepatic encephalopathy (p < 0.003). IGF-1 levels were reduced in cirrhosis and correlated with liver function (p < 0.001). Serum IGF-1 concentrations below 3.1 nmol/l were associated with a poor prognosis (p < 0.004). The elevated U-GH in patients with alcoholic cirrhosis may reflect high serum levels of GH due to increased pituitary secretion or decreased hepatic degradation of GH. In addition, the IGF-1 levels reflect the degree of hepatic insufficiency and, thus, seem to provide new prognostic information.