The diagnosis of childhood growth hormone insufficiency and growth hormone resistance

Growth hormone insufficiency (GHI) is an uncommon though treatable cause of retarded growth velocity and short stature in childhood, the diagnosis generally requiring the demonstration of a subnormal growth hormone (GH) response to a physiological or pharmacological stimulus. Physiological and pharmacological GH release is a continuous variable and the relationship between spontaneous GH secretion and height velocity is asymptotic. Cut-off points for defining GH insufficiency are largely derived from adult observations, but have been extrapolated to children, for whom normative data are relatively scanty. There is no absolute cut-off that discriminates between normal and abnormal GH response. Moreover, poor reproducibility, sensitivity and specificity of the many dynamic tests available, particularly when performed in the very young child or in early adolescence, together with the confounding effects of assay performance, further weaken the diagnostic efficiency of biochemical investigations. Between 20-40% of children retested at the completion of GH therapy demonstrate a normal GH response to a provocative stimulus. Such limitations mitigate against over-reliance on GH provocation tests in diagnosis, and further emphasize the importance of careful auxology in evaluating the short child.     

Growth in children with acute lymphocytic leukemia: A pediatric oncology group study

We have studied 127 children from 5 participating institutions as to the effect of acute lymphoblastic leukemia (ALL) or the therapy used in the treatment of ALL on growth, growth hormone concentrations, and somatomedin activity. The study (SWOG No. 7581) was initiated in December 1975 and was closed to new entry in September 1979 and to data collection in February 1981. Heights, weights, and blood samples for growth hormone and somatomedin activity were obtained at the time of initial diagnosis and at intervals during the 55 months of observation. The percentage of boys <4 years of age below the 50th percentile is significantly greater than the expected 50% for both initial and final height (P<0.01). Girls <4 years appeared to have significantly different percentile height distribution from the normal for their final height measurement (P<0.05) but not for their initial height measurement. No other significant differences in the percentile height distribution were found. When growth rate, since time of diagnosis of ALL, is compared to the expected growth of normal children of the same age by linear regression analysis, there is a difference in the slope of the lines. Children with ALL are significantly shorter. The mean initial growth hormone and somatomedin concentration, 6.2 ng/ml and 1.3 μg/ml, respectively, vs mean remission growth hormone and somatomedin of 2.5 ng/ml and 1.1 μg/ml, respectively, were different. This was significant at P<0.01. The slope of the computed regression lines for multiple analysis of growth hormone and somatomedin were negative for more than 60% of the patients when compared to the initial concentration. These data suggest that a significant number of the children <4 years of age are short prior to the onset of therapy, and this persists throughout the course of their disease. Second, there is a reduction in growth rate during intensive therapy or the first year of the disease, with a normal growth rate thereafter. Third, growth hormone and somatomedin concentrations appear to be higher at the time of onset of the disease and decrease while on therapy.     

High Resolution CT Scanning of the Pituitary Gland in Growth Disorders

ABSTRACT. We have performed 217 GEC 8800 CT scans of the hypothalamus and pituitary glands of 202 children with disorders of growth and development. Pituitary morphological abnormalities were common. Intrapituitary low density lesions were found in 17 % of the whole series and in 58% of children with tall stature. Seventy-seven children with idiopathic growth hormone deficiency could be divided on the basis of pituitary morphology seen on CT scan into pituitary aplasia (n = 11) and pituitary hypoplasia (n = 53). Patients with pituitary aplasia had an absent adenohypophysis which probably dated from early intrauterine life and therefore could not be related to birth trauma. We have found a high incidence of evolving endocrinopathy in children with pituitary insufficiency: thus, if a short child is investigated the initial endocrine findings need to be repeated as the pattern of pituitary insufficiency changes with time. An evolving endocrinopathy starting in later childhood is suggestive of the presence of a cerebral tumour. Children with subnormal growth velocities and a normal growth hormone response to pharmacological tests have a wide spectrum of pituitary morphological abnormalities which may be associated with growth hormone neurosecretory dysfunction.     

High resolution CT scanning of the pituitary gland in growth disorders

We have performed 217 GEC 8800 CT scans of the hypothalamus and pituitary glands of 202 children with disorders of growth and development. Pituitary morphological abnormalities were common. Intrapituitary low density lesions were found in 17% of the whole series and in 58% of children with tall stature. Seventy-seven children with idiopathic growth hormone deficiency could be divided on the basis of pituitary morphology seen on CT scan into pituitary aplasia (n = 11) and pituitary hypoplasia (n = 53). Patients with pituitary aplasia had an absent adenohypophysis which probably dated from early intrauterine life and therefore could not be related to birth trauma. We have found a high incidence of evolving endocrinopathy in children with pituitary insufficiency: thus, if a short child is investigated the initial endocrine findings need to be repeated as the pattern of pituitary insufficiency changes with time. An evolving endocrinopathy starting in later childhood is suggestive of the presence of a cerebral tumour. Children with subnormal growth velocities and a normal growth hormone response to pharmacological tests have a wide spectrum of pituitary morphological abnormalities which may be associated with growth hormone neurosecretory dysfunction.     

ACTINOMYCIN D AND TRANSVERSE LINES OF GROWING BONES

Actinomycin D in a dose of 15 µg per kilogram body weight per day for 5 days was given at intervals of two months for two years in the treatment of Wilms' tumor. It was observed that each course of actinomycin D therapy resulted in the occurrence of transverse lines of increased density at the terminal segments of growing bones. Linear growth proceeded at the expected rate in all children studied. Evidently, arrest of longitudinal growth is no prerequisite for the development of transverse lines, and even the formation of multiple lines within a relatively short period does not necessarily imply any retardation of linear growth. The formation of transverse lines in response to actinomycin D administration may indicate that interference with growth hormone secretion and/or peripheral action may be involved in the development of these lines.     

Growth hormone therapy in children with short stature: Is bigger better or achievable?

The introduction of recombinant DNA-synthesized human growth hormone in the mid-1980s, and its attendant unlimited supply, have led to wider application of growth hormone therapy in children. Over the past decade, the efficacy of growth hormone treatment in patients with Turner syndrome and chronic renal insufficiency, two conditions in which growth hormone secretion is normal, in improving growth velocity and final height, has also led to the consideration of growth hormone therapy in children with idiopathic short stature. Although thousands of patients with idiopathic short stature are currently being treated with growth hormone, the limited overall results available at this time do not show a significant improvement in final adult height despite an improvement in short-term growth velocity. Potential reasons for this outcome include 1) skeletal age advancing more rapidly than height age, 2) heterogeneity of the patient population comprising idiopathic short stature, 3) inherent inaccuracies of methodological tools, such as measurement of predicted adult height, and 4) a subset of children with idiopathic short stature who may, in fact, have partial growth hormone insensitivity. From a psychological perspective, the consensus of investigations in non-clinic-referred populations of psychosocial function in children with short stature do not indicate a disadvantage compared with children of normal height when socio-economic status is taken into consideration. These results, in conjunction with the minimal gains reported in behavioural measurements in idiopathic short children treated with growth hormone, question the traditional rationale that augmentation of growth velocity results in improvement in psychosocial well-being.     

Evaluation of growth hormone secretion after completion of therapy

BACKGROUND: Growth hormone (GH) reserve in young adults previously diagnosed as having GH insufficiency, who were treated with human (h)GH replacement in childhood needs confirmation in adulthood. METHODS: Nine patients (seven males, two females; two empty cella, one hypoplasia of the hypophysis and six with idiopathic GH deficiency) diagnosed as having GH insufficiency by the insulin tolerance test (ITT) and dopamine stimulation test in childhood (mean age 12.8+/-2.6 years) were retested at completion of linear growth (mean age 21.0+/-3.0 years), 4.6+/-1.6 years after discontinuation of hGH therapy. RESULTS: At the initial diagnosis, seven had complete and two had partial GH deficiency. At diagnosis, the mean peak GH response to ITT and dopamine was 4.8+/-4.08 and 3.4+/-2.9 mU/L, respectively. At retesting, the mean GH response to ITT and dopamine stimulation was 3.5+/-2.5 and 3.3+/-3.1 mU/L, respectively (P=0.91 and 0.96, respectively). During hGH therapy, mean height velocity increased from 3.5+/-1.9 cm/year at diagnosis to 9.9+/-3.64 cm/year during the first year (P=0.002). One of nine children diagnosed as having GH insufficiency who was treated with hGH replacement had normal growth hormone secretion at completion of linear growth. CONCLUSIONS: All GH-insufficient children should be retested after completion of their hGH treatment and linear growth to identify those who are truly GH insufficient and who may benefit from GH therapy in adulthood.     

Are factors at diagnosis of growth hormone deficiency in childhood associated with persistence of growth hormone deficiency into adult life?

A proportion of children with growth hormone deficiency (GHD) have persistence of GHD as young adults. To date, no markers have been shown in childhood to have predictive value in determining persistence of GHD into adult life. We examined the hypothesis in 31 patients that variables present at the time of diagnosis of childhood-onset GHD, or those related to the early response to growth hormone (GH) therapy, are associated with the likelihood of persistence of GHD. The results show that, as previously demonstrated, children with GHD are more likely to have persistent severe GHD in adult life when the diagnosis is associated with other pituitary hormone deficiencies (p = 0.02), abnormal pituitary neuroimaging (p = 0.003), induced puberty (p = 0.001), early age of diagnosis (p = 0.03) and lower peak GH response at the first dynamic GH test in childhood (p = 0.02). However, there are no associations of persistent severe GHD with the pattern of pretreatment growth or growth response to GH treatment in the initial phase.     

Endocrine dysfunction in children with Crohn's disease

A series of 14 children with Crohn's disease and growth retardation was screened for endocrine dysfunction. Four children presented with growth failure. All had normal cortisol responses to insulin-induced hypoglycaemia. Ten children had normal growth hormone responses in the same test, while four had abnormal responses. Gonadotrophin responsiveness to luteinizing hormone releasing hormone (LHRH) paralleled the clinical evidence of puberty, or its lack. Serum total thyroxine was normal in every patient, while serum total triiodothyronine was low in six; in these six patients serum triiodothyronine normalised with treatment. Serum folate was subnormal in 13 patients and the erythrocyte sedimentation rate was elevated in all at the time of diagnosis. Our results demonstrate a spectrum of endocrine changes seen in children with Crohn's disease, particularly prepubertal gonadotrophin responses to LHRH and a relative preservation of growth hormone and cortisol responsiveness to hypoglycaemia, with a defect in thyroxine to triiodothyronine conversion in severely ill children. Serum folate and sedimentation rate may be useful screening tests for Crohn's disease in a child presenting with failure of growth.     

Diagnosis of congenital endocrinological disease in newborns with prolonged jaundice and hypoglycaemia

IntroductionThe association of prolonged neonatal jaundice and hypoglycaemia may be secondary to an endocrinological disease. Pituitary insufficiency and primary adrenal insufficiency are the most likely endocrine diseases that need to be ruled out.Material and methodsWe retrospectively analysed the clinical and laboratory characteristics of thirteen patients referred to the Hospital de Niños Ricardo Gutiérrez between years 2003 and 2008 due to prolonged neonatal jaundice and hypoglycaemia secondary to pituitary insufficiency in twelve patients, and in one secondary to primary adrenal insufficiency.ResultsAll patients had a history of neonatal hypoglycaemia. Ten patients had conjugated hyperbilirubinaemia and six also had elevated transaminases. Combined pituitary hormone deficiency was observed in the twelve hypopituitarism patients. Hormonal replacement normalised liver function and resolved the prolonged jaundice in all the patients. None of them underwent liver biopsy. Hypoglycaemia also remitted after hormonal therapy.ConclusionsProlonged or cholestatic jaundice associated with neonatal hypoglycaemia is highly likely to be due to pituitary hormone deficiency or primary adrenal insufficiency. Early diagnosis and treatment of these children reverts the prolonged jaundice and prevents morbidity and mortality due to recurrent hypoglycaemia and hormone deficiencies.     

Failure of IGF-I and IGFBP-3 to diagnose growth hormone insufficiency.

BACKGROUND: Growth hormone insufficiency (GHI) is diagnosed conventionally by short stature and slow growth, and is confirmed by diminished peak GH response to a provocation test. Insulin-like growth factor I (IGF-I) and IGF binding protein 3 (IGFBP-3) have previously been considered individually OBJECTIVE: To test the hypothesis that the combined analysis of IGF-I and IGFBP-3 could act as a surrogate marker for the diagnosis of GHI. DESIGN: Reference ranges for IGF-I and IGFBP-3 were calculated using 521 normal individuals. A retrospective analysis was performed on 318 children referred for investigation of short stature. RESULTS: No significant difference was found between either the IGF-I or IGFBP-3 standard deviation scores (SDSs) in children with and without GHI. If the requirement were for both tests to be positive (< -2 SDS) for a diagnosis of GHI, then 99% of children without GHI would be correctly identified; however, the sensitivity of the test was only 15%. CONCLUSIONS: Neither IGF-I nor IGFBP-3 alone is a marker for GHI. In addition, they cannot be used as an effective screening test in combination.     

Traumatic brain injury-mediated hypopituitarism. Report of four cases

Hypopituitarism has been increasingly recognised following traumatic brain injury. We report four children involved in motor vehicle accidents who had traumatic brain injury-mediated hypopituitarism. Various hormone defects are described. Growth hormone was the most commonly affected pituitary hormone. The time interval between the injury and diagnosis of pituitary hormone deficiency was between 2.5 weeks to 1.5 years. Hormone replacement therapy permitted normal completion of growth and development. Awareness among physicians treating children with traumatic brain injury of the risk of hypopituitarism is necessary to optimise the outcome.     

HUMAN GROWTH HORMONE AND HYPOPITUITARY GROWTH RETARDATION

Human growth hormone (HGH) has somatotropic, luteotropic and adipotropic/diabetogenic activities. It is a potent antigen, and serum concentrations can be determined immunologically. However, we do not know whether the somatotropic core or another part of the molecule is active antigenically. The secretion of HGH is influenced by humoral agents as well as by psychical and physical stress. HGH stimulation tests are negative in several states beside hypopituitarism. The diagnosis of hypopituitary nanism can be difficult, especially in isolated growth hormone deficiency, which is not uncommon. Clinical and laboratory characteristics in the diagnosis of pituitary nanism are discussed. It is emphasized that growth retardation usually starts in infancy, and that hereditary types are rather frequent. The most important criteria in the diagnosis are: negative HGH stimulation tests, increased nitrogen retention and urinary hydroxyproline excretion during a metabolic study with HGH, and the catch-up growth at a therapeutical trial with HGH. Experiences in HGH-treatment of 20 children with idiopathic hypopituitary nanism are given. They all responded well, and the mean growth velocity increased from 2.8 cm yearly before to 9.7 cm the first year on treatment. Two patients with organic hypopituitarism did not respond to HGH treatment. The principles for hormonal replacement therapy in pituitary nanism are discussed.     

Fecal elastase-1: a useful test in pediatric practice]

AIM: To study fecal elastase-1 (E1F) and chymotrypsin (ChT) in stools for the diagnosis of pancreatic insufficiency in pediatric practice. MATERIALS AND METHODS: E1F and ChT were measured in stools of 198 children divided in 3 groups: 49 children without any digestive disease (group A), 71 children with pancreatic diseases (group B), and 78 children with non-pancreatic digestive diseases (group C). RESULTS: In group B, E1F values were very low in 64 children and normal in 7 children without pancreatic insufficiency (6 children with cystic fibrosis and 1 with chronic pancreatitis). ChT values were normal in children without pancreatic insufficiency but also in half of children treated with pancreatic enzymes. Decreased E1F values were seen in 2 children (4%) in the group A and 22 children (28%) in the group C, especially those with acute gastroenteritis or celiac disease. CONCLUSION: E1F is a simple, non-invasive, useful tool for the diagnosis of pancreatic insufficiency in children with growth failure or chronic diarrhea, and those with cystic fibrosis. Nevertheless, low values may be found in diseases with villous atrophy or very liquid stools.     

Improvement of growth after growth hormone treatment in children who undergo liver transplantation

BACKGROUND: Chronic liver insufficiency in children is frequently associated with growth retardation. Growth resumes after successful orthotopic liver transplantation in the majority of children with previous chronic liver failure. However, a subgroup of children demonstrates stunted growth even after orthotopic liver transplantation. The current study was conducted to determine whether administration of recombinant human growth hormone might benefit these patients. METHODS: Ten children were identified who met the criteria of growth failure despite normal transplant function in a cohort of 60 transplantation patients: height standard deviation score (hSDS) for chronological age less than -2, and growth velocity SDS (gvSDS) for chronological age equaling 0. Seven of these patients were treated with subcutaneous injections of recombinant human growth hormone at 4.0 U/m2 body surface area per day for at least 1 year. Two patients in this group showed insufficient growth hormone response to stimulation (arginine, clonidine) before therapy. Treatment was begun after a median time of 4.6 years after liver transplantation (2.55-8.4 years). Five children were treated with cyclosporin A and prednisolone and two with tacrolimus and prednisolone for maintenance immunosuppression. RESULTS: Within 3 months of treatment, median serum levels of insulin-like growth factor (IGF)-I increased from 0.05 to 0.71 (P < 0.02). Within 1 year, median hSDS improved from -2.7 (range, -5.6 to -2.3) to -2.1 (-4.5 to -1.4; P < 0.03). Median annual growth rate increased from 3.9 cm/year (range, 3-6) in the year before treatment to 8.2 cm/year (range, 6.1-10.4; P < 0.02) after the beginning of recombinant human growth hormone therapy. All patients tolerated treatment without side effects. During the cumulative treatment time of 14 years no rejection episode was observed. CONCLUSIONS: Short-statured prepubertal liver transplant recipients who do not show sufficient compensatory growth after transplantation benefit from treatment with recombinant human growth hormone. Treatment with the hormone was safe without any side effects.     

Physiological Growth Hormone Secretion and Response to Growth Hormone Treatment in Children with Short Stature and Intrauterine Growth Retardation

Stanhope, R., Ackland, F., Hamill, G., Clayton, J., Jones, J. and Preece, M.A. (Department of Growth and Development, Institute of Child Health, London and Serono Laboratories, UK). Physiological growth hormone secretion and response to growth hormone treatment in children with short stature and intrauterine growth retardation. Acta Paediatr Scand [Suppl] 349: 47, 1989.
Physiological growth hormone (GH) secretion was examined in 31 children (8 girls, 23 boys) with short stature secondary to intrauterine growth retardation (IUGR). Seventeen (4 girls, 13 boys) had dysmorphic features of Russell-Silver syndrome. Four of the 31 children had GH insufficiency with peak GH levels of < 20 mU/I during the night. Nine of the patients (8 of whom had Russell-Silver syndrome) had a single nocturnal GH pulse. Twenty-three children (6 girls, 17 boys) were randomized into two groups treated with either 15 or 30 U/m²/week of GH by daily subcutaneous injections. Age, sex distribution, pretreatment height velocity SD score (SDS), and distribution of dysmorphic and non-dysmorphic children were similar in both groups. The group treated with 15 U/m2/week for a mean of 0.82 years showed an increase in mean height velocity SDS from - 0.61 to +1.09, and the group treated with 30 U/m²/week for a mean of 0.92 years showed an increase in mean height velocity SDS from -0.69 to +3.48. The results suggest that physiological GH insufficiency is probably common in children with Russell-Silver syndrome and that both dysmorphic and non-dysmorphic children with short stature secondary to IUGR will respond to GH treatment. Initial evidence suggests that the increase in short-term growth velocity does not result in an improved final height prognosis.     

Endocrine disorders in septo-optic dysplasia (De Morsier syndrome) — evaluation and follow up of 18 patients

Septo-optic dysplasia (SOD) is characterized by hypoplasia of the optic nerve, various types of forebrain defects and hormonal deficiencies. We have studied the clinical and endocrinological characteristics of 18 such patients retrospectively to: (1) better define the endocrine abnormalities in children with SOD; and (2) to find approaches for the interdisciplinary long-term care of children with SOD. The children were seen at the Children's Hospital of the University of Munich from 1976 to 1992 (8 boys, 10 girls; age at initial presentation: 1 day–13 years of age, mean 1.9 years). Unilateral hypoplasia of the optic nerve was found in 7 cases, bilateral hypoplasia in 11. Sonographic, CCT or MRI yielded the following results: 4 of the patients had a cavum septum pellucidum, 3 patients had hypoplasia of the cerebellum, 1 aplasia of the corpus callosum and 1 aplasia of the fornix. An empty sella with or without an ectopic pituitary was seen in 4 cases. Height standard deviation score (SDS) at time of diagnosis was –4.0 to +0.4, mean –2.92. Endocrine deficiencies were present in all 11 patients who had undergone endocrinological investigations. Seven patients suffered from isolated growth hormone (GH) deficiency or multiple hypopituitarism. One had diabetes insipidus centralis, 2 had hypogonadotropic hypogonadism, 1 had hypothyroidism and 2 adrenal insufficiency. Hypothalamic testing was performed only in a subset of patients: in 5 of 11 children tested a thyrotropin releasing hormone (TRH test), in two out of nine a gonadotropin releasing hormone (GnRH) test, and in three out of six GH releasing hormone (GHRH) test yielded abnormal results. High prolactin levels were measured in two out of five patients.Conclusion SOD is characterized by optic nerve hypoplasia and a variety of endocrine deficiencies. In addition, forebrain malformations are present in most SOD patients. Hormonal disorders are present in some SOD patients which may be of hypothalamic origin and need to be investigated systematically.     

Definitions and prevention of cardiorespiratory arrest in children

In cardiopulmonary resuscitation ages are divided in neonates (in the inmediate period after the birth), infant (from birth to 12 months) and child (from 12 months to puberty). Respiratory arrest is defined by the absence of spontaneous respiration (apnea) or a severe respiratory insufficiency (agonal gasping) that require respiratory assistance. Cardiac arrest is defined as the absence of central arterial pulse or signs of circulation (movement, cough or normal breathing) or the presence of a central pulse less than 60 lpm in a child who does not respond, not breath and with poor perfusion. After resuscitation the return of spontaneous circulation is defined as the recuperation of central arterial pulse or signs of circulation in a child with previous cardiorespiratory arrest. It is maintained when the duration is longer than 20 minutes. Injuries, sudden infant death syndrome, and respiratory diseases are the most frequent etiologies of cardiorrespiratory arrest in children. The prevention and the formation of citizens in basic cardiopulmonary resuscitation are the most effective measures to reduce the mortality of cardiorespiratory arrest in children.     

Abnormalities of insulin and growth hormone secretion in children with coeliac disease

The effect of intravenous tolbutamide on plasma levels of glucose, cortisol, growth hormone, and insulin, and the effect of oral Bovril on plasma growth hormone have been studied in 10 children with coeliac disease and 6 children who, though small, had normal jejunal morphology (`controls'').The growth hormone and insulin responses to tolbutamide in the children with coeliac disease were significantly smaller than in the controls. Growth hormone response to Bovril was normal in most of the children but 3 of them with coeliac disease failed to achieve a satisfactory response in growth hormone levels after both tolbutamide and Bovril.These results cannot be explained by malnutrition or by inadequate hypoglycaemia during tolbutamide stimulation, and a convincing hypothesis to explain them has not been formulated. Clinically, though tests of other conventional stimuli of growth hormone and insulin production require study, the diagnosis of coeliac disease should actively be considered in any child with low levels of insulin and growth hormone. These observations may partly explain the association of coeliac disease and diabetes mellitus.     

Growth failure in children with cystic fibrosis

Poor linear growth and inadequate weight gain are very common problems in cystic fibrosis (CF) children. The most important factors involved in growth failure are undernutrition or malnutrition, chronic inflammation, lung disease, and corticosteroid treatment. Nutritional support and pharmacological therapy with recombinant human growth hormone are essential for a good management of children with CF, although these children are shorter and lighter than healthy children, and despite the catch-up growth observed after diagnosis, deficit in length/height and weight continues to be seen until adulthood. Early diagnosis is essential to ensure better nutritional status and growth, potentially associated with better respiratory function and prognosis. The aims of this review are try to explain etiology and pathogenetic mechanisms of growth failure in CF children and clarify their role in the disease morbidity and in clinical outcome, especially in relation to progressive decline of pulmonary function.