Peak Growth Hormone Levels Research Articles

Postoperative growth hormone dynamics in clinically nonfunctioning pituitary adenoma.

Growth hormone deficiency (GHD) is an endocrine disorder characterized by insufficient production of growth hormone (GH). Non-functioning pituitary adenoma (NFPA) is one of common causes of GHD. Although most patients with NFPA have transsphenoidal surgery, the time-dependent changes in GH after operation have yet to be investigated. In this study, we analyzed patients with NFPAs that underwent transsphenoidal surgery. Postoperatively, GH secretion was evaluated in response to GH-releasing peptide-2 (GHRP2) infusion. We also investigated how several factors affected GH dynamics. Of 119 patients analyzed, 94 (79.0%) had peak GH levels less than 9.0 ng/mL and were diagnosed with severe GHD (sGHD) immediately after surgery. Of those patients, 27 (28.7%) recovered from sGHD within 1-2 years after surgery. Univariate analyses confirmed that sGHD recovery improved significantly in patients that were younger, had only undergone a single primary surgery, had not had anterior hormone deficiency except GH, and had cystic adenoma or normal insulin-like growth factor-1 (IGF1) standard deviation score (SD-S) levels immediately after surgery. Multivariate analyses confirmed that younger age and absence of hormone replacement therapy significantly predicted sGHD recovery within 1-2 years after surgery. Taken together, our results indicated that postoperative sGHD should be assessed by GHRP2 infusion, regardless of IGF1 SD-S levels. Furthermore, recovery from sGHD occurs more frequently at 1-2 years after surgery especially in younger patients and/or those with GH deficiency alone. These patients, therefore, should be reassessed for GHD by appropriate tests including GHRP2 test at 1-2 years after surgery.

A surprising treatment response in a patient with rare isolated growth hormone deficiency, type IB.

Isolated Growth Hormone Deficiency (IGHD) is a rare cause of short stature, treated with the standard regimen of subcutaneous synthetic growth hormone (GH). Patients typically achieve a maximum height velocity in the first year of treatment, which then tapers shortly after treatment is stopped. We report a case of a 9-year-old male who presented with short stature (<3rd percentile for age and race). Basal hormone levels showed undetectable serum IGF1. Skeletal wrist age was consistent with chronologic age. Cranial MRI revealed no masses or lesions. Provocative arginine-GH stimulation testing demonstrated a peak GH level of 1.4 ng/mL. Confirmatory genetic testing revealed a rare autosomal recessive single-nucleotide polymorphism (SNP) with mutational frequency of 2%. GH supplementation was started and pursued for 2 years, producing dramatically increased height velocity. This velocity persisted linearly through adolescence, several years after treatment had been discontinued. Final adult height was >95th percentile for age and race. In conclusion, this is a case of primary hypopituitarism with differential diagnosis of IGHD vs Idiopathic Short Stature vs Constitutional Growth Delay. This case supports two objectives: Firstly, it highlights the importance of confirmatory genetic testing in patients with suspected, though diagnostically uncertain, IGHD. Secondly, it demonstrates a novel secondary growth pattern with implications for better understanding the tremendous variability of GH treatment response.Learning points:GHD is a common cause of growth retardation, and IGHD is a specific subtype of GHD in which patients present solely with short stature.The standard treatment for IGHD is subcutaneous synthetic GH until mid-parental height is reached, with peak height velocity attained in the 1st year of treatment in the vast majority of patients.Genetic testing should be strongly considered in cases of diagnostic uncertainty prior to initiating treatment.Future investigations of GH treatment response that stratify by gene and specific mutation will help guide treatment decisions.Response to treatment in patients with IGHD is variable, with some patients demonstrating little to no response, while others are ‘super-responders.’

Rare Frequency of Mutations in Pituitary Transcription Factor Genes in Combined Pituitary Hormone or Isolated Growth Hormone Deficiencies in Korea.

PurposeCongenital hypopituitarism is caused by mutations in pituitary transcription factors involved in the development of the hypothalamic-pituitary axis. Mutation frequencies of genes involved in congenital hypopituitarism are extremely low and vary substantially between ethnicities. This study was undertaken to compare the clinical, endocrinological, and radiological features of patients with an isolated growth hormone deficiency (IGHD) or combined pituitary hormone deficiency (CPHD).Materials and MethodsThis study included 27 patients with sporadic IGHD and CPHD. A mutation analysis of the POU1F1, PROP1, LHX3, LHX4, and HESX1 genes was performed using genomic DNA from peripheral blood leukocytes.ResultsIGHD and CPHD were observed in 4 and 23 patients, respectively. Mean age at diagnosis was 8.28±7.25 years for IGHD and 13.48±10.46 years for CPHD (p=0.37). Serum insulin-like growth factor-1 and peak growth hormone (GH) levels following GH stimulation tests were significantly lower in patients with CPHD than in those with IGHD (p<0.05). Sellar MRI findings revealed structural abnormalities in 3 patients with IGHD (75%) and 21 patients with CPHD (91.3%) (p=0.62). A mutation analysis identified homozygous p.R109Q mutations in HESX1 in a patient with CPHD. Patients with CPHD had more severe GHD than those with IGHD.ConclusionThe frequency of defects in the genes encoding pituitary transcription factors was extremely low in Korean patients with congenital hypopituitarism. Environmental factors and the impact of other causative genes may contribute to this clinical phenotype.

Anthropometric factors have significant influence on the outcome of the GHRH-arginine test: establishment of normative data for an automated immunoassay specifically measuring 22 kDa human growth hormone.

Adult growth hormone (GH) deficiency (GHD) is diagnosed by provocative testing of GH secretion. To improve the diagnostic accuracy of GH-releasing hormone (GHRH) plus arginine (GARG) testing, we evaluated the influence of age, BMI and sex and established normative data for an automatic immunoassay specifically measuring 22 kDa human GH. Prospective multicenter study. Eighty-seven patients with hypothalamic-pituitary disease and 200 healthy controls. Patients were classified according to the number of pituitary hormone deficiencies (PHD). GHD was assumed when ≥2 PHD (in addition to GH) were present (n = 51); 36 patients with <2 PHD were considered GH sufficient (GHS). ROC analysis identified cutoffs with ≥95% specificity for GHD. Controls were prospectively stratified for sex, age and BMI. All participants received GHRH and l-arginine. GH was measured by immunoassay (iSYS, IDS). In controls, multiple stepwise regression analysis showed that BMI (21%, P < 0.0001), sex (20%, P < 0.0001) and age (5%, P < 0.001), accounted for 46% of GH peak level variability during GARG. Comparison of peak GH during GARG (GHD vs GHS + controls) revealed an overall cutoff of 3.9 ng/mL (sensitivity 86%, specificity 95%). After adjustment for BMI and sex, optimal cutoffs (male vs female) were 6.5 vs 9.7 ng/mL in lean, 3.5 vs 8.5 ng/mL in overweight and 2.2 vs 4.4 ng/mL in obese subjects respectively. BMI and sex account for most of the variability of peak GH levels during GARG. Consequently, diagnostic accuracy of the GARG test is significantly improved by use of adjusted cutoffs.

Growth hormone receptor polymorphisms and growth hormone response to stimulation test: a pilot study.

No gold standard pharmacological stimulation test exists for the diagnosis of growth hormone deficiency (GHD). In addition, the genetic factors that influence growth hormone (GH) responses remain unclear. This study aimed to determine whether polymorphisms in exon 6 of the GH receptor gene influence responses to the L-arginine GH stimulation test. This study included 27 prepubertal patients with confirmed GHD. GHD was defined as a peak GH level <8 ng/mL in response to pharmacological stimulation. The mean GH peak after L-arginine stimulation was 2.9±2.9 ng/mL. The included patients had the following genotypes at the third position of codon 168: AA (N.=1), AG (N.=15) and GG (N.=11). Patients carrying the AA and AG genotypes exhibited stronger responses to arginine than patients with the GG genotype (3.1±2.7 vs. 1.5±1.3 ng/mL, P=0.01). The approach employed in this study could elucidate GH profiles under physiological and pathological conditions, facilitating improved interpretation of pharmacological stimulation tests.

Clonidine Stimulation Test For Gh Deficiency: A New Look At Sample Timing

In the glucagon stimulation test (GST), the occurrence of peak growth hormone (GH) levels at typical times is an indication of normal secretion. This has not been studied for the clonidine stimulation test (CST). The 120-minute time is rarely the peak, and previous reports suggest it can be omitted. This study aimed to evaluate the meaning and utility of peak time in the CST and the significance of shortening the test. CSTs performed on 250 consecutive subjects in a single center were evaluated for results (GH sufficient or deficient) and result of confirmatory GST with respect to the peak time of the CST. Peak GH occurred typically at 30, 60, and 90 minutes (91.6% of tests, versus 60% expected) (P<.001). A total of 132 of 155 (85.15%) sufficient tests occurred at typical times, versus 66 of 97 (68%) deficient tests (P<.05). Typicality of timing did not follow in the confirmatory GST and did not predict the final result of testing. Removal of the 120-minute sample affected the final result in 0.4% of evaluations. The timing of the GH peak is not useful when interpreting the CST. The CST is equally effective when terminated at 90 minutes from stimulation.

Short Children with CHARGE Syndrome: Do They Benefit from Growth Hormone Therapy?

Aim: The aim of this study was to evaluate the response to recombinant growth hormone (GH) treatment in short children with CHARGE syndrome. Patients: We identified 51 children (28 boys and 23 girls) in KIGS (Pfizer International Growth Database). The median chronological age was 7.6 years at the start of GH therapy and 13.2 years at the latest visit. Evaluation for GH deficiency (n = 33) was based on the following: peak GH level 7.3 μg/l and IGF-I level -2.01 standard deviation score (SDS). Sixteen subjects (9 boys) were followed longitudinally for 2 years. Results: Birth length (median SDS, -0.47) and weight (-0.97) were slightly reduced. At the start of GH therapy, height was -3.6 SDS, BMI -0.7 SDS, and the GH dose was 0.26 mg/kg/week. At the latest visit after 2.7 years of GH therapy, height had increased to -2.2 SDS and BMI to -0.5 SDS. In the longitudinal group, height increased from -3.72 SDS at the start of GH therapy to -2.92 SDS after 1 year to -2.37 SDS after 2 years of therapy (start - 2 years: p < 0.05), height velocity increased from -1.69 to 2.98 to 0.95 SDS, and BMI and GH dose (mg/kg/week) remained almost unchanged. Conclusions: Our data show a positive effect of conventional doses of GH on short-term growth velocity for the longitudinal as well as for the total group, without any safety issues.

EPHA4 haploinsufficiency is responsible for the short stature of a patient with 2q35-q36.2 deletion and Waardenburg syndrome

BackgroundWaardenburg syndrome type I (WS1), an auditory-pigmentary genetic disorder, is caused by heterozygous loss-of-function mutations in PAX3. Abnormal physical signs such as dystopia canthorum, patchy hypopigmentation and sensorineural hearing loss are common, but short stature is not associated with WS1.Case presentationWe reported a 4-year and 6 month-old boy with a rare combination of WS1 and severe short stature (83.5 cm (−5.8SD)). His facial features include dystopia canthorum, mild synophrys, slightly up-slanted palpebral fissure, posteriorly rotated ears, alae nasi hypoplasia and micrognathia. No heterochromia was noticed. He had a normal intelligence quotient and hearing. Insulin-like growth factor-1 (IGF-1) was 52.7 ng/ml, lower than the normal range (55 ~ 452 ng/ml) and the peak growth hormone level was 7.57 ng/ml at 90 minutes after taking moderate levodopa and pyridostigmine bromide. The patient exhibited a good response to human growth hormone (rhGH) replacement therapy, showing a 9.2 cm/year growth rate and an improvement of 1 standard deviation (SD) of height after one year treatment. CMA test of patient’s DNA revealed a 4.46 Mb de novo deletion at 2q35-q36.2 (hg19; chr2:221,234,146-225,697,363).ConclusionsPAX3 haploinsufficiency is known to cause Waardenburg syndrome. Examining overlapping deletions in patients led to the conclusion that EPHA4 is a novel short stature gene. The finding is supported by the splotch-retarded and epha4 knockout mouse models which both showed growth retardation. We believe this rare condition is caused by the haploinsufficiency of both PAX3 and EPH4 genes. We further reported a growth response to recombinant human growth hormone treatment in this patient.

The Relationship between Subnormal Peak-Stimulated Growth Hormone Levels and Auxological Characteristics in Obese Children.

Context: The hypothesis that obese children are overdiagnosed with growth hormone deficiency (GHD) has not been adequately investigated in the context of adiposity-related differences in auxology.Aim: To investigate the differences in auxological parameters between short, prepubertal, obese children, and normal-weight peers who underwent growth hormone stimulation testing (GHST).Hypothesis: Over-weight/obese children with GHD [peak growth hormone (GH) < 10 μg/L] will have higher values for growth velocity (GV) standard deviation score (SDS), bone age minus chronological age (BA − CA), and child height SDS minus mid-parental height (MPTH) SDS when compared to normal-weight GHD peers.Subjects and Methods: A retrospective review of anthropometric and provocative GHST data of 67 prepubertal, GH-naïve children of age 10.21 ± 2.56 years (male n = 45, age 10.8 ± 2.60 years; female n = 22, age 8.94 ± 2.10). Inclusion criteria: GHST using arginine and clonidine. Exclusion criteria: hypopituitarism, abnormal pituitary magnetic resonance imaging scan, syndromic obesity, or syndromic short stature. Data were expressed as mean ± SD.Results: The over-weight/obese children with peak GH of <10 μg/L had significantly lower value for natural log (ln) peak GH (1.45 ± 0.09 vs. 1.83 ± 0.35, p = 0.022), but similar values for GV SDS, insulin-like growth factor-I, insulin-like growth factor binding protein-3, bone age, BA − CA, MPTH, and child height SDS minus MPTH SDS compared to normal-weight peers with GHD. After adjusting for covariates, the over-weight/obese children (BMI ≥ 85th percentile) were >7 times more likely than normal-weight subjects (BMI < 85th percentile) to have a peak GH of <10 μg/L, and 23 times more likely to have a peak GH of <7 μg/L (OR = 23.3, p = 0.021). There was a significant inverse relationships between BMI SDS and the ln of peak GH (β = −0.40, r2 = 0.26, p = 0.001), but not for BMI SDS vs. GV SDS, ln peak GH vs. BA, or ln peak GH vs. GV SDS.Conclusion: Subnormal peak GH levels in obese prepubertal children are not associated with unique pre-GHST auxological characteristics.

Dose‐sparing and safety‐enhancing effects of an IGF‐I‐based dosing regimen in short children treated with growth hormone in a 2‐year randomized controlled trial: therapeutic and pharmacoeconomic considerations

Context and objectiveTitrating the dosage of growth hormone (GH) to serum levels of insulin-like growth factor-I (IGF-I) is a feasible treatment strategy in children with GH deficiency (GHD) and idiopathic short stature (ISS). The objective was to assess the dose-sparing effect and theoretical safety of IGF-I-based GH therapy.Design, setting and patientsThis was a post hoc analysis of a previously described 2-year, multicenter, open-label, randomized, outpatient, controlled clinical trial in 172 prepubertal short children [age 7·5 ± 2·4 years; height standard deviation score (HSDS) −2·64 ± 0·61] classified by baseline peak GH levels as GHD (<7 ng/ml) or ISS (≥7 ng/ml).InterventionConventional weight-based dosing of GH (0·04 mg/kg/day) (n = 34) or GH dosing titrated to an IGF-I target of 0 SDS (IGF0T; n = 70) or an IGF-I target of +2 SDS (IGF2T; n = 68).Main Outcome MeasuresChange in HSDS per GH mg/kg/day dose (ΔHSDS/GH dose ratio) and proportion of IGF-I levels above +2 SDS at the end of 2 years.ResultsGH dosing titrated to an IGF-I target of 0 SDS was the most dose-sparing treatment regimen for GHD or ISS children (mean±SE ΔHSDS/GH dose ratios 48·1 ± 4·4 and 32·5 ± 2·8, respectively) compared with conventional dosing (30·3 ± 6·6 and 21·3 ± 3·5, respectively; P = 0·02, P = 0·005) and IGF2T (32·7 ± 4·8 and 16·3 ± 2·8, respectively; P = 0·02, P < 0·0001). IGF0T also resulted in the fewest IGF-I excursions above +2 SDS (6·8% vs 30·0% for conventional dosing; P < 0·01).ConclusionsIGF-I-based GH dosing, targeted to age- and gender-adjusted means, may offer a more dose-sparing and potentially safer mode of therapy than traditional weight-based dosing.

GH secretion reserve in subclinical hypercortisolism

In overt hypercortisolism, growth hormone (GH) secretion is decreased and normalizes after surgery. In subclinical hypercortisolism (SH), GH secretion has been scarcely investigated. We assessed GH reserve in patients with and without SH and, in the former, also after recovery. We enrolled 24 patients with adrenal adenomas, 12 with SH (SH+, 8 females, 58.3 ± 6.5 years) and 12 without SH (SH-; 11 females, 61.8 ± 10.6 years). SH was diagnosed in the presence of ≥ 2 out of: 1 mg overnight dexamethasone suppression test >83 nmol/L, urinary free cortisol (UFC) >193 nmol/day and ACTH levels <2.2 pmol/L. GH secretion was assessed by GHRH + Arginine test (GHRH-ARG) and age-adjusted serum IGF-I levels, expressed as SDS (IGF-I SDS). Eight SH+ patients were re-evaluated after the recovery from SH. Age, gender, body mass index (BMI) and IGF-I SDS were comparable between SH+ and SH- patients. After GHRH-ARG the mean GH peak levels (GH-P) and GH response (as Area Under Curve, GH-AUC) were lower in SH+ than in SH- patients (15.2 ± 8.1 vs 44.5 ± 30.9 μg/L, P = 0.004 and 1,418 ± 803 vs 4,028 ± 2,476 μg/L/120 min, P = 0.002, respectively), after adjusting for age and BMI. The GH-AUC and GH-P levels were negatively associated with UFC after adjusting for age and BMI (β = -0.39, P = 0.02 and β = -0.4, P = 0.020 respectively). After recovery, GH-P levels and GH-AUC increased as compared to baseline (23.7 ± 16.3 vs 15.8 ± 10.2 μg/L, P = 0.036 and 2,549 ± 1,982 vs 1,618 ± 911 μg/L/120 min, P = 0.012, respectively). GH secretion reserve is decreased in SH patients and increases after the recovery.

Macimorelin (AEZS-130)-Stimulated Growth Hormone (GH) Test: Validation of a Novel Oral Stimulation Test for the Diagnosis of Adult GH Deficiency

Context:In the absence of panhypopituitarism and low serum IGF-I levels, the diagnosis of adult GH deficiency (AGHD) requires confirmation with a GH stimulation test. Macimorelin is a novel, orally active ghrelin mimetic that stimulates GH secretion.Objective:The objective of the study was to determine the diagnostic efficacy and safety of macimorelin in AGHD.Design:This was a multicenter open-label study comparing the diagnostic accuracy of oral macimorelin with that of arginine+GHRH in AGHD patients and healthy, matched controls. After 43 AGHD patients and 10 controls were tested, the GHRH analog Geref Diagnostic [GHRH(1–29)NH2] became unavailable in the United States. The study was completed by testing 10 additional AGHD patients and 38 controls with macimorelin alone.Main Outcome Measure:Peak GH area under the receiver operating characteristic curve after macimorelin was measured.Results:Fifty AGHD subjects and 48 controls were evaluated. Peak GH levels in AGHD patients and controls after macimorelin were 2.36 ± 5.69 and 17.71 ± 19.11 ng/mL, respectively (P < .0001). With macimorelin, the receiver operating characteristic analysis yielded an optimal GH cut point of 2.7 ng/mL, with 82% sensitivity, 92% specificity, and 13% misclassification rate. For subjects receiving both tests, macimorelin showed discrimination comparable with arginine+GHRH (area under the receiver operating characteristic curve 0.99 vs 0.94, respectively, P = .29). Obesity (body mass index > 30 kg/m2) was present in 58% of subjects, and peak GH levels were inversely associated with body mass index in controls (r = −0.37, P = .01). Using the separate cut points of 6.8 ng/mL for nonobese and 2.7 for obese subjects reduced the misclassification rate to 11%. Only 1 drug-related serious adverse event, an asymptomatic QT interval prolongation on the electrocardiogram, was reported.Conclusion:Oral macimorelin is safe, convenient, and effective in diagnosing AGHD with accuracy comparable with the arginine+GHRH test.

Influence of Body Mass Index on the Growth Hormone Response to Provocative Testing in Short Children without Growth Hormone Deficiency

Obesity and its related factors are known to suppress the secretion of growth hormone (GH). We aimed to evaluate the influence of body mass index (BMI) on the peak GH response to provocative testing in short children without GH deficiency. We conducted a retrospective review of medical records of 88 children (2-15 yr old) whose height was less than 3 percentile for one's age and sex, with normal results (peak GH level > 10 ng/mL) of GH provocative testing with clonidine and dopamine. Peak stimulated GH level, height, weight, pubertal status and serum IGF-1 level were measured. Univariate analysis showed that the BMI standard deviation score (SDS) correlated negatively with the natural log (ln) of the peak stimulated GH level (ln peak GH). BMI SDS did not correlate significantly with sex, age, pubertal status, or ln IGF-1 level. BMI SDS correlated negatively with ln peak GH level induced by clonidine but not by dopamine. In stepwise multivariate regression analysis, BMI SDS was the only significant predictor of ln peak GH level in the combination of tests and the clonidine test, but not in the dopamine test. In children without GH deficiency, BMI SDS correlates negatively with the peak GH level. BMI SDS should be included in the analysis of the results of GH provocation tests, especially tests with clonidine.

Hormonal response during physical exercise of different intensities in adolescents with type 1 diabetes and healthy controls

Physical activity is a critical component in the care of diabetes. Although it offers health benefits it presents challenges. To investigate differences between adolescent boys and girls with type 1 diabetes and healthy controls in terms of maximal work capacity (VO(2) max) and hormonal response to physical exercise of different intensities. Twelve individuals (six boys and six girls; age 14-19 yr, pubertal stage 4-5) with type 1 diabetes (duration, 6.3 ± 4.4 yr; hemoglobin A1c, 63 ± 10 mmol/mol) were compared with 12 healthy controls matched for age, sex, pubertal stage, body mass index standard deviation score, and amount of regular physical activity. During consecutive days, three different workloads; maximal, endurance, and interval, were performed on an Ergometer cycle. During the tests, levels of lactate, glucose, insulin, and regulatory hormones [glucagon, cortisol, growth hormone (GH), adrenaline, and noradrenaline] were measured in blood. Subcutaneous glucose was measured continuously. VO(2) max did not differ between the groups, diabetes 49.8 ± 9.9 vs. control 50.7 ± 12.0 mL/min/kg. Hormonal responses did not differ between the groups except for mean peak GH level during the interval test, diabetes 63.2 ± 27.0 vs. control 33.8 ± 20.9 mU/L, p < 0.05. Physical capacity and hormonal regulation of blood glucose in connection with physical exercise of different intensities did not differ between adolescents with diabetes and healthy controls. Thus, adolescents with type 1 diabetes can participate in physical activity on the same terms as healthy peers.

Blunted response to a growth hormone stimulation test is associated with unfavorable cardiovascular risk factor profile in childhood cancer survivors

Childhood cancer survivors (CCS) are at risk for growth hormone (GH) deficiency. CCS are also at increased risk for early mortality from cardiovascular (CV) disease, but the association between GH levels and CV risk remains poorly understood. The goal of this study was to examine the cross-sectional association between stimulated GH levels and CV risk factors in CCS younger than 18 years. A total of 276 CCS (147 males, 14.4 ± 2.6 years) ≥5 years after cancer diagnosis, and 208 sibling controls (112 males, 13.6 ± 2.4 years) participated in this cross-sectional study, which included anthropometry, body composition, and metabolic studies. Blunted response (BR) was defined as peak GH level <7 µg/L after clonidine and arginine. Insulin sensitivity (M(lbm) ) was measured by euglycemic hyperinsulinemic clamp. Statistical analyses used linear and logistic regression accounting for sibling clustering, adjusted for age, sex, Tanner stage, and adiposity. Thirty-four (12%) CCS showed BR to GH stimulation. BR CCS were shorter and had a lower IGF-1 than controls; only 6 of 34 received cranial radiation therapy. CCS with normal stimulated GH response were similar to controls for CV risk factors. Conversely, BR CCS had greater adiposity, higher lipids, and lower M(lbm) than controls. Differences in lipids and M(lbm) between BR CCS and controls remained significant after adjustment for BMI or visceral fat. BR to GH stimulation is prevalent in CCS youth and is associated with an unfavorable CV risk factor profile. Further studies are needed to establish the mechanisms of these associations.

Growth hormone secretion and its effect on height in pediatric patients with different genotypes of Prader–Willi syndrome

There have been multiple reports regarding the growth hormone (GH) secretion in patients with Prader-Willi syndrome (PWS). However, none have compared GH secretion in children with deletion group to those with maternal uniparental disomy (UPD). We evaluated the GH secretion in pediatric patients with PWS. Seventy-six patients with a deletion (n = 55) or UPD (n = 21) were studied. The secretion of GH by insulin stimulation in the patients with UPD (3.6 ± 2.2 ng/ml) was significantly lower than those with deletions (peak GH level: 11.1 ± 8.6 ng/ml; P = 0.0013). We also compared the response to GH replacement therapy. Yearly improvements in height standard deviation score (SDS) were similar in the two groups (first year SDS: 0.47 ± 0.47, deletion; 0.68 ± 0.26, UPD; P = 0.14).

Characterisation and growth outcomes of children with Insulin-like Growth Factor-1 deficiency in idiopathic short stature

Background/aimsChildren with idiopathic short stature (ISS) constitute a heterogenous group. Recombinant IGF-I (rhIGF-I) have been licensed for the treatment of severe short stature (height <−3 standard deviation scores (SDS)) in...

Predicting the Probability of Abnormal Stimulated Growth Hormone Response in Children After Radiotherapy for Brain Tumors

To develop a mathematical model utilizing more readily available measures than stimulation tests that identifies brain tumor survivors with high likelihood of abnormal growth hormone secretion after radiotherapy (RT), to avoid late recognition and a consequent delay in growth hormone replacement therapy. We analyzed 191 prospectively collected post-RT evaluations of peak growth hormone level (arginine tolerance/levodopa stimulation test), serum insulin-like growth factor 1 (IGF-1), IGF-binding protein 3, height, weight, growth velocity, and body mass index in 106 children and adolescents treated for ependymoma (n=72), low-grade glioma (n=28) or craniopharyngioma (n=6), who had normal growth hormone levels before RT. Normal level in this study was defined as the peak growth hormone response to the stimulation test≥7 ng/mL. Independent predictor variables identified by multivariate logistic regression with high statistical significance (p<0.0001) included IGF-1 z score, weight z score, and hypothalamic dose. The developed predictive model demonstrated a strong discriminatory power with an area under the receiver operating characteristic curve of 0.883. At a potential cutoff point of probability of 0.3 the sensitivity was 80% and specificity 78%. Without unpleasant and expensive frequent stimulation tests, our model provides a quantitative approach to closely follow the growth hormone secretory capacity of brain tumor survivors. It allows identification of high-risk children for subsequent confirmatory tests and in-depth workup for diagnosis of growth hormone deficiency.

Reduced growth hormone secretion after cranial irradiation contributes to neurocognitive dysfunction

The objective of this study was to investigate the relation between growth hormone (GH) and attentional electro-cortical responses to task-relevant stimuli (N2b), target detections, speed of responding, P300 latencies, and performance on neuropsychological tests in 19 patients who received external beam radiation therapy for brain tumors in adulthood. In addition, we studied the association between IGF-I and activation of the motor cortex responses (lateralized readiness potential, LRP).Brain function was assessed using event-related potentials (ERPs) during a go/no go selective-attention task, including N2b, P300 and selective motor preparation as reflected in the LRP. Correlations were calculated between peak GH levels after a standardized growth hormone-releasing hormone (GHRH)–arginine test, plasma IGF-I, and cognitive functions. We separately studied four patients who were diagnosed with GHD according to the GHRH–arginine test.Performance on WAIS digit span backward and the Rey–Osterrieth complex figure test correlated positively with GH peak. GHD patients performed worse than non-GHD patients on Stroop interference, trail making B/A attentional shifting and Rey–Osterrieth complex figure test. At trend-level significance, trails A performance was better in patients with lower GH levels and higher radiation doses, and GHD participants detected fewer targets in the go/no go selective attention task. N2b was not significantly altered by GH status. Furthermore, plasma IGF-I was positively correlated with the sum of digit span forward and backward. No relations with P300 were observed.In this study only 21% (4/19) of the patients who received fractionated radiotherapy for a non-endocrine brain tumor were diagnosed with GHD. GHD in these patients was associated with impaired interference control, attentional shifting, and visual long-term memory. The results for interference control and attentional shifting suggest an additional effect of the radiation history.

Irradiation-Induced Growth Hormone Neurosecretory Disfunction In ALL Patients

AbstractAbstract 4329With the recent developments in the treatment of ALL life expectancy is prolonged and complications due to therapy are increased. Combined chemotherapy may be applied in combination with distinct doses and schema of cranial radiotherapy according to the risk groups of patients. CRT damages the hypothalamus-hypophysis axis and affects the secretion of growth hormone (GH) at first and the other anterior hypophysis hormones also. At high doses of CRT, GH deficiency might occur in the long term follow-up, at lower doses the secretion pattern of GH may change. In this study, GH axis of the ALL patients treated with prophylactic CRT were evaluated.Thirty-two children (14 girls and 18 boys), diagnosed as ALL and applied prophylactic cranial therapy were enrolled to the study. Physical findings, weight and height measurements, Tanner stagings and bone age evaluations were performed to all patients. In order to interpret the functions of anterior and posterior hypophysis morning basal IGF-1, IGFBP-3, thyroid hormones, cortisol, prolactin and dansity of urine were measured. Gonodotrophins were not tested because none of our patients had the signs of early or late puberty. In order to evaluate the growth rate, weights and heights of the patients were measured after the first year. Even though the growth rate of some patients were normal, GH stimulation tests with clonidine were done to all cases, due to the fact that GH deficiency and neurosecretory dysfunction might be present pharmacologically. Second GH stimulation test with L-dopa were applied to patients with peak GH levels of <10 ng/ml. If the level was low in the second test, patients were accepted as GH deficient. For patients with low growth rate, low IGF-1/IGFBP-3 according to age and sex, but normal GH levels, night GH secretion pattern were tested. Patients with inadequate response to night secretion test were accepted as neurosecretory dysfunction.In our study, 25% of the patients were found to have complete and 21,7% incomplete GH deficiency. In 9.3% of cases there was GH-neurosecretory dysfunction (GH_NSD). There was no statistically significant relationship between the time passed after radiotherapy and GH axis dysfunction degree. IGF-BP3 was found to be more reliable than IGF-1 in estimating GH deficiency/GH-NSD.As a result, it is clear that prophylactic CRT affects the GH axis negatively in ALL patients, so their close follow-up is precious and mandatory. Disclosures:No relevant conflicts of interest to declare.