Cardiovascular effects of high-dose growth hormone treatment in growth hormone-deficient children

Growth hormone (GH) hypersecretion is associated with an increased incidence of cardiac hypertrophy and subclinical abnormalities of left ventricular (LV) function. The unlimited availability of biosynthetic GH has led to progressively increased dosage when treating GH-deficient children, raising the question of its cardiovascular effects during long-term therapy. We compared 22 children (8 girls, 14 boys), mean age 12.1 years (range 3–17 years) with GH deficiency who were receiving chronic GH treatment (GH group) with 22 normal controls matched for sex and body size in order to evaluate: (1) LV volume, mass, and systolic function by two-dimensional guided M-mode echocardiography; (2) LV diastolic function by pulsed-wave Doppler sampling of the transmitral flow; and (3) cardiac output and systemic vascular resistance by Doppler echocardiography. All patients had been on chronic GH therapy for 13.8±7.6 months (range 5–30 months) with an average dose of 0.95±0.12 IU/kg per week (range 0.69–1.17 IU/kg per week). Blood pressure did not differ between the two groups. LV volume, mass, ejection fraction, and mean velocity of circumferential shortening did not differ significantly between the GH group and controls; nor did the peak- and end-systolic meridional stress. All patients had a normal contractile state as estimated by the relation between mean velocity of circumferential shortening and end-systolic meridional stress. The LV filling parameters did not differ between the two groups, and there was no difference in cardiac index and systemic vascular resistance. These f9ndings suggest that long-term treatment with high doses of GH in GH-deficient children and adolescents does not lead to adverse cardiac effects. Whether longer-duration therapy could cause morphofunctional alterations of the left ventricle requires further investigation.     

M-mode echocardiographic evaluation of systolic function, LV volume and mass in children on growth hormone therapy

Since abnormal endogenous growth hormone (GH) secretion in adults is associated with cardiac dysfunction, it is important to ensure that GH therapy in children and adolescents does not cause similar effects. Forty-two growth hormone-deficient children (Group 1) (19 girls, 23 boys) were evaluated. Six girls and seven boys were prepubertal with a mean age of 6.65 yr (range 4.37-9.73 yr). Twenty-nine were pubertal (13 girls, 16 boys), mean age 13.57 yr (range 10.08-16.76 yr). The patients had been on long-term GH therapy for 34.97 +/- 18.78 months with an average weekly dose of 17.61 IU/m2/wk. The mean height SDS was -2.85 +/- 1.22 for boys and -2.5 +/- 0.64 for girls at the onset of therapy, and at the time of examination -1.8 +/- 1.32 for the boys and 1.87 +/- 0.94 for the girls. Thirty-four normal control subjects (Group 2) matched for age, sex and body size were also studied. Left ventricular volume (LV), mass and systolic function [shortening fraction (FS)] were evaluated by two-dimensional guided M-mode echocardiography. Blood pressure was also measured. No differences in blood pressure were observed between patients and controls. There was no correlation of GH dose and duration of therapy with LV measurements. No significant differences were found between Group 1 and Group 2. These observations suggest that long term administration of GH does not produce adverse cardiac effects in GH deficient children. Nevertheless, longer follow-up studies are still needed to confirm the safety of long-term rhGH treatment.     

Onset of puberty and near adult height in short children born small for gestational age and treated with GH: Interim analysis of up to 10 years of treatment in Japan

The safety and effectiveness of long-term (10-yr) GH treatment in short Japanese children born small for gestational age (SGA) were evaluated based on interim data analysis from a clinical study, including the findings concerning the influence on the onset of puberty and subjects who achieved near adult height (NAH). Sixty-one subjects were analyzed at baseline in this study. Eleven subjects (6 boys and 5 girls) achieved NAH (mean 157.4 cm and 145.5 cm, respectively), and the Δ height SDS from the start of GH treatment was +1.6 in boys and +1.8 in girls. The median age (yr) at onset of puberty was 11.4 in boys and 9.9 in girls, comparable to healthy children. However, the mean height (cm) at onset of puberty (137.0 in boys; 125.5 in girls) was shorter than that of healthy children. Treatment-related adverse events were generally mild to moderate in severity; however, adenoidal hypertrophy was observed in two subjects as a serious adverse event. One subject had jaw malformation related to GH treatment at a dose of 0.067 mg/kg/d. No notable changes in HbA1c levels were observed, and the levels remained within the reference range. We have confirmed the safety and effectiveness of long-term GH treatment through this ongoing clinical study.     

Unresolved problems concerning optimal therapy of puberty in children with chronic renal diseases

Many children with chronic renal insufficiency (CRI) show growth retardation and severely delayed pubertal development. Successful renal transplantation (RTx) also rarely results in full growth rehabilitation. Pubertal height gain in CRI patients is only 58% and 48% of that observed in late-maturing boys and girls, respectively. Growth retardation in both CRI and RTx patients is not the result of abnormal GH secretion or decreased levels of IGF-I, but rather of elevated levels of IGFBPs inhibiting the bioavailability of the IGFs. In RTx patients prednisone may also inhibit growth directly via inhibition of bone matrix formation. Several studies have convincingly shown that GH therapy at a dose of 4 IU/m2/day results in a sustained improvement of growth in prepubertal and pubertal children with CRI and in growth-retarded prepubertal and pubertal post-transplant patients. The following consensus was reached concerning optimal therapy of puberty in children with chronic renal disease. GH therapy does not lead to an earlier start of puberty. It is safe to give GH to RTx patients if transplant function is stable. GH therapy will not accelerate bone maturation and can improve the final height of children with CRI and after RTx. Increasing the GH dose above 4 IU/m2/day in pubertal RTx patients does not increase height gain or final height and is not advised as it may increase insulin resistance. GH should best be started before the start of the pubertal growth spurt but will still be effective in RTx patients with advanced bone age. GH testing should not be a prerequisite for starting GH therapy. It is important to optimise other therapies during puberty. During GH therapy of RTx patients use minimum daily, not alternate-day, steroid dosing. Further research is still required on the possible long-term effects of GH therapy in children with chronic diseases. Two studies demonstrated improved long-term growth and final height within the target height range, without significant side effects. Renal graft function did not deteriorate more than in matched controls. A GH dose of 4 IU/m2/day proved adequate.     

Favorable Impacts of Growth Hormone (GH) Replacement Therapy on Atherogenic Risks in Japanese Children with GH Deficiency

Growth hormone (GH) affects body composition and atherogenic risk factors. Severe hyperlipidemia may develop in GH-deficient adults as a consequence of continuous GH deficiency. We investigated changes in lipid profiles in 158 Japanese children (103 boys and 55 girls) with GH deficiency who had been enrolled in the Pfizer International Growth Database Japan during 3 yr of GH replacement therapy to evaluate whether GH treatment has beneficial effects on atherogenic risk factors. Total cholesterol (TC), high-density lipoprotein cholesterol (HDLC), low-density lipoprotein cholesterol (LDLC) and atherogenic index were evaluated before treatment and then once a year during treatment. The mean baseline TC was within the normal range in both boys and girls. Seventeen (16.5%) of the 103 boys and 18 (32.7%) of the 55 girls, however, had a TC level over 200 mg/dl before treatment. The mean TC level showed a significant decrease in girls. In a separate analysis, patients of both sexes with a TC level > 200 mg/dl showed significantly decreased TC. LDLC decreased significantly only in girls, while HDLC showed no change in either sex. The atherogenic index decreased significantly in girls. GH replacement therapy in children with GH deficiency had beneficial effects on lipid metabolism and atherogenic risk in both sexes. Early GH treatment would produce lipid metabolism benefits in these patients.     

Height prognosis of children with true precocious puberty and growth hormone deficiency: effect of combination therapy with gonadotropin releasing hormone agonist and growth hormone.

We evaluated height prognosis and therapeutic efficacy of long-term, combination therapy with gonadotropin releasing-hormone agonist and growth hormone (GH) in five children (three girls) with coexistent precocious puberty and GH deficiency. Their clinical characteristics and growth response were compared with those of 12 girls with idiopathic true precocious puberty and eight prepubertal GH-deficient children (one girl). Precocious GH-deficient subjects were older than the precocious GH-sufficient children (9.5 +/- 1.8 years vs 6.5 +/- 1.3 years; mean +/- SD), but bone ages were comparable (12 +/- 3.7 years vs 10 +/- 0.9 years); their chronologic age was similar to that of the prepubertal GH-deficient children (9.6 +/- 2.1 years), but bone age was significantly more advanced (6.9 +/- 2.3 years). The mean height velocity of the prepubertal GH-deficient children (3.8 +/- 1.5 cm/yr) was lower than that of the precocious GH-deficient subjects (6.7 +/- 1.6 cm/yr) and the precocious GH-sufficient children (9.5 +/- 2.9 cm/yr). Baseline adult height prediction z scores were significantly lower in the precocious GH-deficient children (-3.7 +/- 1.0) than in either the precocious GH-sufficient children (-2.2 +/- 1.0) or the prepubertal GH-deficient subjects (-1.5 +/- 0.8). During therapy with gonadotropin releasing-hormone agonist, growth rates slowed to an average of 3.7 cm/yr in the precocious GH-deficient children but increased after the addition of GH to 7.4 cm during the first year of combination therapy. After 2 to 3 years of combination therapy, height predictions increased an average of 10 cm, compared with an increase of 2.8 cm in the precocious GH-sufficient group treated with gonadotropin releasing-hormone agonist alone. We conclude that combination treatment with gonadotropin releasing-hormone agonist and GH improves the height prognosis of children with coexistent true precocious puberty and GH deficiency, but falls short of achieving normal adult height potential.     

Small for gestational age (SGA): endocrine and metabolic consequences and effects of growth hormone treatment

Several studies have demonstrated an association between low birth weight and impaired insulin sensitivity or even type 2 diabetes mellitus (DM2) in later life. Growth hormone (GH) is known to increase fasting and postprandial insulin levels. For that reason concern has been expressed regarding possible detrimental effects of GH therapy in children born SGA. In a Dutch trial the possible side effects of GH therapy on carbohydrate metabolism were assessed in short children born SGA after 6 years and at 6 months after discontinuation of GH therapy. This study included 79 prepubertal short children born SGA, participating in a multicenter double-blind, randomized, dose-response GH trial. Inclusion criteria were: 1) birth length SDS below -1.88, 2) age 3-11 years in boys and 3-9 years in girls, 3) height SDS < -1.88, 4) no spontaneous catch-up growth, and 5) an uncomplicated neonatal period. Mean (SD) value for age was 7.3 (2.1) years, birth length SDS -3.6, height SDS -3.0 (0.7) and BMI SDS -1.2 (1.3). All children were randomly assigned to either group A (n = 41) using 1 mg GH/m2/day or group B (n = 38) using 2 mg/m2/ d/ay (approximately 0.1 or 0.2 IU/kg/d, respectively). Standard oral glucose tolerance tests (OGTTs) were performed before and during 6 years of GH therapy and 6 months after discontinuation of GH therapy. Before GH therapy 8% of the children had impaired glucose tolerance (IGT) according to criteria of the WHO. After 6 years of GH therapy, IGT was found in 4% and after stopping GH in 10%. Mean fasting glucose increased significantly with 0.5 mMol/l after 1 year of GH therapy, without a further increase thereafter. GH therapy induced considerably higher fasting and glucose-stimulated insulin levels. None of the observed changes were different between the GH dosage groups. Children who remained prepubertal had similar glucose and insulin levels compared to children who entered puberty. HbA1c levels were always in the normal range and none of the children developed diabetes mellitus. After discontinuation of GH therapy the mean serum glucose levels remained normal and the mean serum insulin levels decreased significantly, to normal age reference values. Before the start of GH the mean systolic blood pressure was significantly higher compared to age-matched peers, whereas during GH therapy a significant decline in mean systolic blood pressure occurred, which remained similar after discontinuation of GH treatment. In conclusion, continuous, long-term GH therapy in short children born SGA has no adverse effects on glucose levels, even with GH dosages up to 2 mg/m2/day. However, as has been reported in other patient groups, GH induced higher fasting and glucose-stimulated insulin levels, indicating insulin resistance. After discontinuation of GH, serum insulin levels declined to normal age-matched reference levels. Since impaired insulin sensitivity and DM2 have been demonstrated in relatively young patients born SGA, long-term follow-up of children born SGA is advised, also after discontinuation of GH therapy.     

Three-Year Follow-up Study on Serum Leptin Levels in GH Deficient Children with GH Replacement Therapy

Interactions between GH and leptin have been extensively studied. However, results of long-term GH therapy on serum leptin levels in GH-deficient children were not consistent. Moreover, no such reports were available in Japanese children with this disease. We studied 35 Japanese patients with GH deficiency (26 boys and 9 girls, mean age: 9.8 ± 6.2 yr old), of whom 6 patients with complete and 29 with incomplete GH deficiency were identified by GH provocation test. Serum leptin levels, percent of ideal body weight (%IBW) and percent fat (%fat) were determined at 0, 1, 3, 6, 12, 18, 24, and 36 mo after beginning GH therapy. Baseline levels of %fat and leptin were significantly higher in girls than boys (P<0.05), though serum leptin did not change throughout the study period in either group. Further, %IBW did not change significantly, whereas %fat exhibited significant changes after 6 mo in boys and remained virtually constant thereafter for up to 3 yr. In summary, serum leptin levels did not change in GH-deficient boys and girls during the 3-yr period after the start of GH replacement therapy, despite a decrease in %fat after 6 mo of therapy in the boys. Thus, it is conceivable that long-term GH replacement therapy can be employed without an effect on normal leptin secretion.     

Follow-up height after discontinuation of growth hormone treatment in children with intrauterine growth retardation

Growth hormone (GH) treatment has been used in children with intrauterine growth retardation (IUGR) to promote growth with success in several short- and long-term clinical trials. Intermittent GH therapy has also been advocated in children with IUGR. This study was designed to evaluate the growth of children with IUGR after discontinuation of a two-year trial of GH treatment. Sixteen children (12 F, 4 M) who had received GH (Genotropin) at age 5.3 (1.3) years at a dose of 0.2 IU/kg/day for 2 years (Group 1) and 10 (6 F, 4 M) controls of age 4.3 (1.7) years without treatment (Group 2) were followed after completion of the trial over a median period of 4 years. Height SDS of the GH-treated group showed an increase from -3.0 (0.5) to -1.9 (0.7) (p <0.001) over 2 years of therapy. Off therapy, height SDS decreased to -3.5 (0.5) at a mean age of 11.2 (1.6) years. The difference between the initial and recent height SDS in this group was significantly different (p = 0.02). Height SDS of the control group, -2.7 (1.4) initially, did not change over the two-year observation period. At follow-up, seven control children received GH in a similar fashion for one year. In spite of an insignificant increase in height SDS on one year of GH, it decreased to -2.9 (1.6) at age 11.0 (2.1) years at the latest visit. There was no significant difference between the recent heights of the two groups at final examination. One girl in Group 1 developed acanthosis nigricans and type 2 diabetes mellitus at age 13.3 years, after the follow-up period. A second patient developed osteosarcoma in the left tibia at age 9.9 years, for which she received chemotherapy and surgery. In conclusion, height SDS showed a significant increase on GH therapy for 2 years in children with IUGR; however, it decelerated after discontinuation of therapy. At the final visit, GH therapy did not seem to have had any effect on height prognosis. This finding shows that GH should be given continuously to improve final height in children with IUGR.     

Favorable Impact of Growth Hormone Treatment on Cholesterol Levels in Turner Syndrome

Background: Patients with Turner syndrome (TS) are prone to having metabolic abnormalities, such as obesity, dyslipidemia, hypertension, hyperinsulinemia and type 2 diabetes mellitus, resulting in increased risks of developing atherosclerotic diseases. Objective: To determine the effect of growth hormone (GH) therapy on serum cholesterol levels in prepubertal girls with TS enrolled in the Turner syndrome Research Collaboration (TRC) in Japan. Patients and methods: Eighty-one girls with TS were enrolled in the TRC, and their total cholesterol (TC) levels before GH therapy were compared with reported levels of healthy school-aged Japanese girls. TC levels after 1, 2 and 3 yr of GH treatment were available for 28 of the 81 patients with TS. GH was administered by daily subcutaneous injections, 6 or 7 times/wk, with a weekly dose of 0.35 mg/kg body weight. Results: Baseline TC levels revealed an age-related increase in TS that was in contrast to healthy girls showing unchanged levels. During GH therapy, TC decreased significantly after 1 yr of GH treatment and remained low thereafter. Conclusions: Girls with untreated TS showed an age-related increase in TC that was a striking contrast to healthy girls, who showed unchanged levels. GH therapy in girls with TS brought about a favorable change in TC that indicates the beneficial impact of GH on atherogenic risk.     

Effect of recombinant human growth hormone (rhGH) on hemoglobin concentration in children with idiopathic growth hormone deficiency-related anemia

Normocytic-normochromic anemia (NC/NC) has been attributed to impaired bone marrow erythropoiesis in growth hormone (GH)-deficient patients. Moreover, the GH/insulin-like growth factor-1 (IGF-1) axis has been implicated in erythropoiesis regulation. In this retrospective multicenter study, we evaluated the incidence of NC/NC anemia in 279 children (196 boys), median age 10.52 years, with isolated idiopathic GH deficiency, and the effect of recombinant human growth hormone (rhGH) therapy on hemoglobin levels. At 6-month intervals, we recorded the Hb standard deviation score (Hb-SDS), the IGF-1-SDS, weight, height, and pubertal stage. Forty-one boys and 7 girls had NC/NC anemia before starting substitutive therapy (-2.59 SD). The Hb-SDS was significantly increased (P<0.05) after 12 months of rhGH therapy. The effect of rhGH continued up to 48 months (-0.39 SD), at which point all children had normal hemoglobin values. In conclusion, rhGH therapy resulted in normal hemoglobin values in all children enrolled in the study. These data support the concept that the GH/IGF-1 axis promotes erythropoiesis in vivo.     

Body composition and respiratory function in healthy non-obese children

BACKGROUND: The purpose of the present paper was to evaluate the role that body composition plays in lung function, among healthy children and adolescents. METHODS: Cross-sectional study was undertaken using sex- and age-stratified sampling among healthy children and adolescents aged 6-18 years. Spirometry was performed on every child who fulfilled inclusion criteria. Fat mass (FM) and fat-free mass (FFM) were calculated from triceps skinfold thickness and arm circumference. Multiple logistic regression was used to obtain adjusted prevalence odds ratios (OR) and 95% confidence intervals (95%CI) between low pulmonary function (PF) of schoolchildren and body composition expressed in FM and FFM. Calculations of OR imply that the outcome is dichotomous (low PF/normal PF), therefore those children who had parameters of pulmonary function below the 25th percentile were classed as cases and the rest of the subjects were considered as controls. RESULTS: A total of 2408 children were included; 1270 (53%) of them were male and 1138 (47%), female. Among boys the increase of FFM was associated with an increase of forced expiratory volume in 1 s (FEV1). Among girls the increase of FFM was associated with an increase of FEV1, forced vital capacity, and peak expiratory flow. The increase in FM was associated with a decrease of spirometric parameters in both genders, with a stronger effect among boys. CONCLUSIONS: The present study confirms the negative effect of body fat on the PF of children and adolescents, even though obese subjects were excluded. The effect is different between boys and girls.     

Masa ventricular izquierda,espirometría basal forzada y perfil de adipocitocinas en niños obesos con y sin síndrome metabólico

IntroductionRecent reports have shown an increase in changes in cardiac and pulmonary function among obese patients. Furthermore, it has also been demonstrated that obesity is a state of chronic inflammation. We hypothesized that obese children with metabolic syndrome exhibit a higher percentage of left ventricular hypertrophy and altered spirometry values due to higher levels of inflammation.Patients and methodsLeft ventricular mass was studied using echocardiography, baseline forced spirometry by spirometer (FlowScreen) and adipocytokine profiles (adiponectin, IL-6, leptin, MCP-1, PCR-Hs, RBP-4, TNF-( and visfatin) were evaluated in peripubertal obese children with and without metabolic syndrome.ResultsForty-one patients (20 girls and 21 boys) were included in the study, 20 of whom (10 boys and 10 girls) were subjects with metabolic syndrome. Of the adipocytokines studied, only leptin, hs-CRP, MCP-1, and the leptin/adiponectin ratio yielded values that were substantially greater in the group with metabolic syndrome (P<.01). An analysis of left ventricular mass index and baseline spirometry showed no differences between the groups studied. However, of the entire cohort, 9.5% had left ventricular hypertrophy. No significant relationship was found between anthropometric data and adipocytokines and the parameters used to study left ventricular mass and spirometry values on the other.ConclusionAt the time the study was performed, left ventricular mass and baseline forced spirometry did not appear to be influenced by inflammatory mechanisms.     

Growth hormone treatment enhances nutrition and growth in children with cystic fibrosis receiving enteral nutrition

OBJECTIVES: Impaired longitudinal growth and poor weight gain are common and important problems in children with cystic fibrosis. This study evaluates the hypothesis that adjunctive growth hormone (GH) therapy augments the growth response to nutritional supplementation. STUDY DESIGN: We recruited 18 prepubertal children who received enteral nutritional supplementation for at least 2 years before enrollment. Nine were randomly assigned to receive no GH for 1 year, followed by 1 year of GH. Nine were randomly assigned to receive 1 year of GH followed by a second year of GH. Measurements included height, weight, pulmonary function, lean tissue mass, bone mineral content, hospitalizations, outpatient antibiotic use, and caloric intake. RESULTS: Growth hormone resulted in significant improvement in height, weight, bone mineral content, lean tissue mass, and number of hospitalizations. Pulmonary function was similar at baseline. Absolute forced vital capacity and forced expiratory volume in 1 minute significantly increased in GH treatment, but there was no significant change in percent predicted pulmonary function. Caloric intake was similar in both groups during both years. CONCLUSIONS: These results suggest that GH is a useful for enhancing growth in children with cystic fibrosis receiving enteral nutritional supplementation.     

Responses of bone turnover markers and bone mineral density to growth hormone therapy in children with isolated growth hormone deficiency and multiple pituitary hormone deficiencies

Growth hormone deficiency (GHD) is an important cause of decreased bone mass in childhood and adolescence. The role of other pituitary hormone deficiencies on bone mass is still a query in children. Thirty-nine children (28 with isolated GHD [IGHD] and 11 with multiple pituitary hormone deficiency [MPHD]) were investigated to show the effects of IGHD vs MPHD on bone status. Bone turnover markers (calcium, phosphate, alkaline phosphatase [ALP] Bone ALP [BALP], osteocalcin [OSC], carboxyterminal propeptide of type-1 collagen [CPP-I], parathyroid hormone [PTH]) were measured before and every four months during growth hormone (GH) therapy; bone mineral density (BMD) of the lumbar spine was measured before and every six months during therapy. All bone turnover markers except calcium and PTH increased significantly during 1 year of GH therapy. There were no differences in the levels of bone turnover markers between children with IGHD and MPHD at baseline, and after 4, 8 and 12 months of therapy. Lumbar spine BMD SDS of all patients increased significantly during 1 year of therapy (p = 0.035 after 6 months and p <0.001 after 12 months compared with baseline). BMD SDS of both IGHD and MPHD groups were similar at baseline and after 6 and 12 months of therapy (p = 0.235, p = 0.295 and p = 0.384). Height SDS (HtSDS) at baseline was the most important predictor of baseline BMD SDS in children with GHD (t = 4.166, p <0.001). DeltaHtSDS was also positively related to deltaBMD SDS after 1 year of GH therapy. In conclusion, there was no difference in bone status of the patients with IGHD and MPHD at baseline. GH therapy yielded similar increases in bone mass in both groups. Increase in height contributed to increase in BMD during 1 year of GH therapy.     

Therapie mit Wachstumshormon bei Ullrich-Turner-Syndrom

Therapy with recombinant human growth hormone (GH) of short-statured girls with Ullrich Turner syndrome (UTS) has been authorized in Germany since 1991. To date, the daily recommended GH dose has been 50 µg/kg (s.c. injection). By comparing different GH doses, it could be shown in recent years that height gain was much better in those girls who were treated with a higher GH dose than girls treated with the recommended dose. Therefore, upon request of the company Novo Nordisk, the European Medicines Agency (EMEA) recently authorized a GH dose of 46–67 µg/kg/day for the treatment of this patient population. The current report summarizes the results of an expert workshop of pediatric endocrinologists, which was held to review the present position of GH therapy in girls with Turner syndrome in light of the higher GH dose. The workshop addressed issues such as the current status of therapy, the background to the dose increase, whether the dose should be increased in general or only in certain cases, possible risks, dosage adjustments, approaches in puberty, as well as ending therapy and transition to adult medicine.     

Effect of growth hormone therapy on bone metabolism of growth hormone deficient children

The effects of human growth hormone (hGH) therapy on biochemical markers of bone metabolism were studied in 17 children (10 boys and 7girls, aged 3.7–13.1 years old) with idiopathic GH deficiency, before and 1 and 6 months after GH therapy (0.5–0.7 IU/kg weekly, SC). Serum levels of calcium, phosphate, alkaline phosphatase, osteocalcin, parathyroid hormone, 1,25 dihydroxyvitamin D, insulin-like growth factor I (IGF-I) and renal phosphate per 100 ml glomerular filtrate (TPO₄/GFR) were assessed. During therapy with hGH, a significant decrease of serum calcium levels and increases of phosphate, osteocalcin, parathyroid hormone 1,25 dihydroxyvitamin D and IGF-I were observed. TPO₄/GFR was also significantly increased. Growth response (increment in HV) was positively related with changes in alkaline phosphatase and IGF-I levels after 6 months of hGH therapy. There was also a significant positive correlation between increment in HV and increment in TPO₄/GFR after 1 month of GH therapy, whereas no correlation between HV and changes in osteocalcin levels was found. Conclusion GH treatment significantly influences mineral metabolism and the measurement of TPO₄/GFR after 1 month of GH therapy may serve as a useful predictor of growth response to hGH therapy in GH-deficient children. Received: 16 August 1996 / Accepted: 5 February 1997     

Growth hormone secretory patterns in children with short stature

To assess whether growth-retarded children with a stimulated growth hormone (GH) level greater than 10 ng/mL have an abnormality in spontaneous GH secretion, we measured GH levels every half hour for 24 hours in 50 children 2.7 to 17 years of age. Growth rate was subnormal in all. Mean 24-hour GH concentration ranged from 1.2 to 7.7 ng/mL, and was significantly greater in pubertal than in prepubertal children (P less than 0.01). In both groups, GH concentration during sleep was significantly greater than during wakeful hours (P less than 0.0005); 24-hour GH concentration correlated significantly with sleep-induced GH peak. A decrease in 24-hour GH concentration and sleep-induced GH peak were noted in four pubertal children with stimulated GH less than 15 ng/mL. A progressive and significant increase in somatomedin C (SmC) level was noted with increasing age and sexual development. No correlations were found between 24-hour GH concentration and rate of growth, age, or bone age. Serum SmC values correlated significantly with age and bone age (P less than 0.01), and with 24-hour GH concentration only in prepubertal children (P less than 0.05). A strong correlation between SmC and growth rate was noted only in pubertal children (P less than 0.01). Growth velocity increased significantly during GH therapy regardless of the 24-hour GH concentration. Our results indicate that in children with growth retardation there is a wide variation in 24-hour GH concentration and a significant increase in GH concentration during puberty; the GH concentration during nocturnal sleep, rather than an entire 24-hour GH concentration, can be used for evaluation; during puberty the SmC level reflects sexual development more than GH reserve; and GH therapy appears to increase growth velocity in both non-GH-deficient and partially GH-deficient short children.     

Cardiac function in children post-orthotopic liver transplantation: echocardiographic parameters and biochemical markers of subclinical cardiovascular damage

Tacrolimus and cyclosporin A (CsA), the mainstay of preventive therapy for solid organ rejection, may cause various side-effects, such as hypertension and nephrotoxicity. Furthermore, tacrolimus is associated with cardiac hypertrophy. In the immediate post-transplant period, both drugs raise the levels of Endothelin-1 (ET), a potent vasoconstrictor; and of B-type Natriuretic Peptide (BNP), a sensitive marker of left ventricular volume overload, which may precede echocardiographic changes of cardiac dysfunction. The aim of the study was to investigate the presence of cardiac damage, by echocardiography and by the biochemical markers BNP and ET, in post-orthotopic liver transplantation (OLT) children, receiving long-term immunosuppressive therapy. ET (ELISA) and BNP (RIA) were measured in plasma of 18 children, post-OLT and 18 healthy controls. Children post-OLT were echocardiographically assessed for left ventricular mass (interventricular septum and posterior wall dimensions), systolic function (ejection fraction, fractional shortening) and diastolic parameters (mitral valve E and A waves, deceleration time, isovolumic relaxation time). None of the post-transplant recipients had a history or physical examination consistent with cardiac disease and all recipients were normotensive. Echocardiography revealed no systolic or diastolic dysfunction in any of the recipients. The mean ET and BNP levels tended to be higher among children post-liver transplant, compared with healthy controls (ET: 4.22 +/- 5.35 pg/mL vs. 2.1 +/- 2.0 pg/mL; BNP: 7.05 +/- 4.4 pg/mL vs. 5.87 +/- 2.0 pg/mL, respectively, mean +/- s.d.) although differences did not reach statistical significance. Three children (17%) had elevated BNP and/or ET levels. A strong correlation was observed between ET and BNP levels in post-OLT children (r = 0.79, p < or = 0.05). No correlation was found between ET or BNP levels and echocardiographic findings. In children receiving long-term immunosuppressive therapy post-OLT, although cardiac function is grossly preserved, ET and BNP levels tend to be higher than in healthy, age-matched children. Thus, elevated levels of BNP and/or ET may identify patients with early cardiac damage.     

Growth hormone treatment in the United States: demographic and diagnostic features of 2331 children

Demographic, diagnostic, and baseline clinical data were collected for a large cohort (N = 2331) of children who started treatment with biosynthetic human growth hormone (GH) between October 1985 and October 1987. Eighty-one percent met classic criteria for GH deficiency and were classified as having idiopathic GH deficiency (59%), organic GH deficiency (18%), or septo-optic dysplasia (4%). The remaining 19.8% had short stature of varied causes. Height standard deviation score at diagnosis, maximum GH response to stimulation, and heights of parents were examined according to gender, race, age at diagnosis, and previous treatment history. The predominance of boys in all subgroups except septooptic dysplasia, and the observation that girls with idiopathic GH deficiency were comparatively shorter than boys at diagnosis, suggest ascertainment bias. Black children with idiopathic GH deficiency were shorter than white children at diagnosis, and their low overall representation (6.0%) compared with their percentage in the at-risk population (12.9%) also suggest ascertainment bias among races. These data provide a profile of GH deficiency as it is currently defined and expose possible inherent biases in the diagnostic process. Now that GH supply is no longer limited, criteria for its use should be formulated to avoid apparent underascertainment or late diagnosis of GH deficiency in girls and black children.