Evolving growth hormone deficiency: proof of concept.

Introduction: We present the evolution of GHD in adolescent males with persistent growth failure, in whom the diagnosis was established after a second GH stimulation test (GST). Methods: We performed a retrospective chart review of children who presented for short stature (height less < 2SD for mean/mid-parental height) and/or growth failure (sustained growth velocity < 0 SD) to pediatric endocrinology at Mount Sinai Kravis Children's Hospital, New York and who had 2 GSTs. Data collected from electronic medical records were analyzed using SPSS v28.0. Results: Of 53 patients included, 42 were males. Average GH peak on initial GST was 15.48 ± 4.92 ng/ml, at 10.07 ± 2.65 years, mean height -1.68 ± 0.56SD(28% had <2SD), IGF-1 -1.00 ± 0.88SD. After 2.23 ± 1.22 years, at 12.04 ± 2.41years, height SDs decreased to -1.82 ± 0.63SD and IGF-1 was -1.08 ± 0.84SD. At repeat GST, average GH peak was 7.59 ± 2.12 ng/dL, with 36% ≤7 ng/dl and 32% in puberty. 12 males reached adult height of 0.08 ± 0.69 SD with a mean height gain of 1.83 ± 0.56SD(p<0.005), IGF-1 of -1.15 ± 0.81SD after 4.64 ± 1.4 years of GH. Conclusion: We offer evidence for Evolving Growth Hormone Deficiency (EGHD) through repeat GST in children with persistent growth slowdown, even with pubertal progression; emphasizing the need for careful longitudinal follow-up to make accurate diagnosis.

Children With Short Stature Display Reduced ACE2 Expression in Peripheral Blood Mononuclear Cells.

Background: The cause of short stature remains often unknown. The renin-angiotensin system contributes to growth regulation. Several groups reported that angiotensin-converting enzyme 2 (ACE2)-knockout mice weighed less than controls. Our case-control study aimed to investigate if children with short stature had reduced ACE2 expression as compared to controls, and its significance. Materials and Methods: children aged between 2 and 14 years were consecutively recruited in a University Hospital pediatric tertiary care center. Cases were children with short stature defined as height SD ≤ -2 diagnosed with growth hormone deficiency (GHD) or idiopathic short stature (ISS), before any treatment. Exclusion criteria were: acute diseases, kidney disease, endocrine or autoimmune disorders, precocious puberty, genetic syndromes, SGA history. ACE and ACE2 expression were measured in peripheral blood mononuclear cells, angiotensins were measured by ELISA. Results: Children with short stature displayed significantly lower ACE2 expression, being 0.40 fold induction (0.01-2.27) as compared to controls, and higher ACE/ACE2, with no differences between GHD and ISS. ACE2 expression was significantly and inversely associated with the risk of short stature, OR 0.26 (0.07-0.82), and it had a moderate accuracy to predict it, with an AUC of 0.73 (0.61-0.84). The cutoff of 0.45 fold induction of ACE2 expression was the value best predicting short stature, identifying correctly 70% of the children. Conclusions: Our study confirms the association between the reduction of ACE2 expression and growth retardation. Further studies are needed to determine its diagnostic implications.

Gender-specific soluble α-klotho levels as marker of GH deficiency in children: a case-control study.

PURPOSE: To evaluate circulating soluble α-klotho (sαKL) levels in GHD children before and after 12 months of GH treatment (GHT). METHODS: Auxological and basal metabolic parameters, oral glucose tolerance test for glucose and insulin levels, insulin sensitivity indices and klotho levels were evaluated before and after 12 months of follow-up in 58 GHD children and 56 healthy controls. RESULTS: At baseline, GHD children showed significantly lower growth velocity standard deviation score (SDS) (p < 0.001), bone/chronological age ratio (p < 0.001), GH peak and area under the curve (AUC) after arginine test (ARG) (both p < 0.001) and glucagon stimulation test (GST) (p < 0.001 and 0.048, respectively), IGF-1 (p < 0.001), with higher BMI (SDS) (p < 0.001), WC (SDS) (p = 0.003) and sαKL (p < 0.001) than controls. After 12 months of GHT, GHD children showed a significant increase in height (SDS) (p < 0.001), growth velocity (SDS) (p < 0.001), bone/chronological age ratio (p < 0.001) IGF-1 (p < 0.001), fasting insulin (p < 0.001), Homa-IR (p < 0.001) and sαKL (p < 0.001) with a concomitant decrease in BMI (SDS) (p = 0.002) and WC (SDS) (p = 0.038) than baseline. At ROC curve analysis, we identified a sαKL cut-off to discriminate controls and GHD children of 1764.4 pg/mL in females and 1339.4 pg/mL in males. At multivariate analysis, the independent variables significantly associated with sαKL levels after 12 months of GHT were the oral disposition index (p = 0.004, ß = 0.327) and IGF-1 (p = 0.019, ß = 0.313). CONCLUSIONS: Gender-related sαKL may be used as a marker of GHD combined to GH and IGF-1. Insulin and IGF-1 are independently associated with sαKL values after 12 months of GHT.

A Novel Diagnostic Predictive Model for Idiopathic Short Stature in Children.

Objective: Idiopathic short stature (ISS), an endocrine-related disease, is difficult to diagnose. Previous studies have shown that many children with some inflammation-related diseases often have short stature, but whether inflammation is the underlying mechanism of ISS has not been studied. Here, we attempt to explore the role of inflammation in the occurrence and development of ISS and to demonstrate an available clinical diagnostic model of ISS. Methods: Frozen serum samples were collected from ISS patients (n = 4) and control individuals (n = 4). Isobaric tags for relative and absolute quantitation (iTRAQ) combined with LC-MS/MS analysis were applied to quantitative proteomics analysis. To assess clusters of potentially interacting proteins, functional enrichment (GO and KEGG) and protein-protein interaction network analyses were performed, and the crucial proteins were detected by Molecular Complex Detection (MCODE). Furthermore, serum levels of two selected proteins were measured by ELISA between ISS patients (n = 80) and controls (n = 80). In addition, experiments in vitro were used to further explore the effects of crucial proteins on endochondral ossification. Results: A total of 437 proteins were quantified, and 84 DEPs (60 upregulated and 24 downregulated) were identified between patients with ISS and controls. Functional enrichment analysis showed that the DEPs were primarily enriched in blood microparticle, acute inflammatory response, protein activation cascade, collagen-containing extracellular matrix, platelet degranulation, etc. According to the results of top 10 fold change DEPs and MCODE analysis, C1QA and C1QB were selected to further experiment. The expression levels of C1QA and C1QB were validated in serum samples. Based on the logistic regression analysis and ROC curve analysis, we constructed a novel diagnostic model by serum levels of C1QA and C1QB with a specificity of 91.2% and a sensitivity of 75% (AUC = 0.900, p <0.001). Finally, the western blotting analysis confirmed the expression levels of OCN, OPN, RUNX2, and Collagen X were downregulated in chondrocytes, and the outcome of Collagen II was upregulated. Conclusion: Our study is the first to demonstrate the significant role of inflammation in the development of ISS. In addition, we identify C1QA and C1QB as novel serum biomarkers for the diagnosis of ISS.

Development and Internal Validation of a Predictive Model for Adult GH Deficiency Prior to Stimulation Tests.

Background: The diagnosis of adult GH deficiency (GHD) relies on a reduced GH response to provocative tests. Their diagnostic accuracy, however, is not perfect, and a reliable estimation of pre-test GHD probability could be helpful for a better interpretation of their results. Methods: Eighty patients showing concordant GH response to two provocative tests, i.e. the insulin tolerance test and the GHRH + arginine test, were enrolled. Data on IGF-I values and on the presence/absence of other pituitary deficits were collected and integrated for the estimation of GHD probability prior to stimulation tests. Results: An independent statistically significant association with the diagnosis of GHD was found both for IGF-I SDS (OR 0.34, 95%-CI 0.18-0.65, p=0.001) and for the presence of other pituitary deficits (OR 6.55, 95%-CI 2.06-20.83, p=0.001). A low (<25%) pre-test GHD probability could be predicted when IGF-I SDS > +0.91 in the presence of other pituitary deficits or IGF-I SDS > -0.52 in the absence of other pituitary deficits. A high (>75%) pre-test GHD probability could be predicted when IGF-I SDS < -0.82 in the presence of other pituitary deficits or IGF-I SDS < -2.26 in the absence of other pituitary deficits. Conclusion: This is the first study that proposes a quantitative estimation of GHD probability prior to stimulation tests. Our risk class stratification represents a simple tool that could be adopted for a Bayesian interpretation of stimulation test results, selecting patients who may benefit from a second stimulation test and possibly reducing the risk of wrong GHD diagnosis.

The necessity of magnetic resonance imaging in the evaluation of pediatric growth hormone deficiency: Lessons from a large academic center.

BACKGROUND: Current guidelines indiscriminately recommend magnetic resonance imaging (MRI) of the pituitary gland in pediatric growth hormone deficiency (GHD). The relationship between abnormal MRI, most importantly a tumor, and peak GH levels is not well known. METHODS: In this retrospective chart review, pituitary MRI results of children, ages of 3-16 years with GHD were collected and divided into 3 groups according to peak stimulated GH levels; ≤5, 5-7.4 and 7.5-10 ng/mL, Groups A, B & C respectively. Clinical and MRI findings were compared between the groups. RESULTS: A total of 399 children were included. Abnormal MRI was found in 36.9% of group A subjects, compared to group B (16.7%) and group C (17.0%), both p values =0.0002. Children with multiple pituitary hormonal deficiencies (MPHD) had a higher rate of abnormalities than those with isolated GHD. Children with isolated GHD were more likely to have abnormal MRI with peak GH level < 5 ng/mL compared to those with levels, 5-7.4 & 7.5-10 ng/mL. 4 children in group A had a craniopharyngioma. ROC analysis comparing peak GH levels with abnormal MRI findings showed an area under the curve (AUC) of 0.614 and 0.728 for IGHD and MPHD, respectively. CONCLUSION: Although abnormal MRI was found in all 3 study groups, it was more likely at GH level < 5 ng/mL and in children with MPHD. To avoid missing a tumor, the importance of imaging in children with GHD and peak GH levels <5 ng/mL cannot be overemphasized.

Growth response to growth hormone (GH) treatment in children with GH deficiency (GHD) and those with idiopathic short stature (ISS) based on their pretreatment insulin-like growth factor 1 (IGFI) levels and at diagnosis and IGFI increment on treatment.

OBJECTIVES: Some idiopathic short stature (ISS) patients may have varying degrees of insulin-like growth factor 1 (IGFI) deficiency. Others with growth hormone deficiency (GHD) (peak GH < 7 ng/dL after provocation) have normal IGFI levels. Do children with ISS or those with GHD with variable pretreatment IGFI standard deviation score (IGFISDS) have different IGFI and growth responses to recombinant human growth hormone (rhGH) therapy? METHODS: We studied the effect of GH therapy (0.035-0.06 mg/kg/day) on linear growth and weight gain per day (WGPD) in children with ISS (n=13) and those with GHD (n=10) who have low pretreatment IGFISDS (IGF SDS < -1.5) and compared them with age-matched prepubertal children with ISS (n=10) and GHD (n=17) who had normal pretreatment IGFISDS. An untreated group of children with ISS (n=12) served as a control group. RESULTS: At presentation, the height standard deviation score (HtSDS) of children with ISS who had low pretreatment IGFISDS was significantly lower compared to the normal IGFI group. The age, body mass index (BMI), BMISDS, peak GH response to clonidine provocation and bone age did not differ between the two study groups. After 1 year of treatment with rhGH (0.035-0.06 mg/kg/day) IGFISDS increased significantly in both groups (p<0.05). Both had significantly increased HtSDS (catch-up growth). The increase in the HtSDS and WGPD were significantly greater in the lower pretreatment IGFISDS group. The IGFSDS, BMISDS, HtSDS and difference between HtSDS and mid-parental HtSDS were significantly greater in the rhGH treated groups vs. the not treated group. In the GHD groups (normal and low IGFISDS), after 1 year of GH therapy (0.03-0.05 mg/kg/day), the HtSDS increased significantly in both, (p<0.01). The WGPD and increment in BMI were significantly greater in children who had low pretreatment IGFISDS. There was a significant increase in the IGFSDS in the two treated groups (p<0.05), however, the WGPD was greater in the pretreatment low IGFISDS. CONCLUSIONS: IGFI deficiency represents a low anabolic state. Correction of IGFI level (through rhGH and/or improved nutrition) in short children (ISS and GHD) was associated with increased linear growth and WGPD denoting significant effect on bone growth and muscle protein accretion.

Vasculometabolic effects in patients with congenital growth hormone deficiency with and without GH replacement therapy during adulthood.

PURPOSE: To evaluated the metabolic profiles and vascular properties in congenital growth hormone (GH) deficiency (GHD) and its replacement in adults. PATIENTS AND METHODS: Cross-sectional study conducted in a single tertiary center for pituitary diseases. Eighty-one adult subjects were divided into three groups: (1) 29 GHD patients with daily subcutaneous GH replacement therapy (GHRT) during adulthood; (2) 20 GHD patients without GHRT during adulthood and (3) 32 controls. Only patients with adequate adherence to others pituitary hormone deficiencies were included. Anthropometric parameters, body composition by dual-energy X-ray absorptiometry, metabolic profiles and vascular properties (carotid intima media thickness, pulse wave velocity and flow-mediated dilation) were compared among the groups. RESULTS: Waist-to-height ratio (WHR), body fat percentages and fat mass index (FMI) were lower in patients with GHRT than patients without GHRT during adulthood (0.49 ± 0.06 vs. 0.53 ± 0.06 p = 0.026, 30 ± 10 vs. 40 ± 11 p = 0.003 and 7.3 ± 4 vs. 10 ± 3.5 p = 0.041, respectively). In addition, association between longer GHRT and lower body fat percentage was observed (r = - 0.326, p = 0.04). We found higher triglyceride (113.5 ± 62 vs. 78 ± 36, p = 0.025) and lower HDL cholesterol (51 ± 17 vs. 66 ± 23, p = 0.029) levels in patients without GHRT during adulthood in comparison to controls. No statistical differences were observed for vascular properties among the groups. CONCLUSIONS: No differences in vascular properties were observed in congenital GHD adult patients with or without GHRT despite patients without GHRT had an unfavorable body composition. GHRT currently remains an individualized decision in adults with GHD and these findings bring new insight into the treatment and follow-up of these patients.

Diagnostic Value of Serum Acid-Labile Subunit Alone and in combination with IGF-I and IGFBP-3 in the Diagnosis of Growth Hormone Deficiency.

BACKGROUND: The acid-labile subunit (ALS) is a crucial factor in the tertiary complex. IGF-I and IGFBP-3 are routinely measured during the diagnostic work-up for growth hormone deficiency (GHD). The aim of the study is to evaluate the relevance of serum ALS as an additional biomarker in the diagnosis of GHD. METHODS: Ninety-one children undergoing standard diagnostic work-up for GHD were included in this retrospective study. Inclusion criteria were evidence-based auxological cutoffs, IGF-I and IGFBP-3 <-2 SDS at first presentation, at least 1 growth hormone (GH) stimulation test, and IGF-I, IGFBP-3, and ALS measurements on the same day. Statistical analysis was performed by ROC as well as by odds ratio calculations. RESULTS: Forty-seven of 90 participants presented with peak GH values under the cutoff of 7 ng/mL. AUC from a model containing only IGF-I was 0.76 and 0.68 when using only ALS. A model containing IGF-I, IGFBP-3, and ALS (AUC = 0.77) did not improve the result compared to the combination of IGF-I/IGFBP-3 (0.77) or IGF-I/ALS (0.76). Furthermore, the variation in the outcome (GH peak

Bloom's syndrome with growth hormone deficiency: a rare association.

We report a case of a 5-year-old boy presenting to us with short stature. He was born of consanguineous parentage and was small for gestational age. He had severe short stature, with height Z score of -6.2 SD Score, markedly delayed skeletal age, low level of insulin-like growth factor 1, unstimulated growth hormone and hypoplastic anterior pituitary gland on MRI. He was advised growth hormone (GH) replacement at 2 years of age, but he did not receive it . Later on, he developed photosensitive telangiectatic lesions over face and required multiple hospital admissions for recurrent systemic infections. Genetic analysis confirmed the diagnosis of Bloom's syndrome. The present case report illustrates the need for high vigilance for conditions like Bloom's syndrome in growth hormone deficiency (GHD), in whom GH treatment could potentially be harmful. Bloom's syndrome with GHD is an exceedingly rare association.

Comparison of the efficacy and safety of recombinant human growth hormone in treating idiopathic short stature and growth hormone deficiency in children.

PURPOSE: The present study aimed to compare the efficacy and safety of recombinant human growth hormone (rhGH) therapy between children with idiopathic short stature (ISS) and growth hormone deficiency (GHD). METHODS: A total of 150 pediatric patients with ISS and 153 pediatric patients with GHD who received rhGH treatment for more than one year from 2005 to 2016 were enrolled. Growth velocity (GV); height standard deviation (HtSD); insulin-like growth factor-1 standard deviation (IGF-1SD); body mass index (BMI); and the incidence of fasting hyperglycemia, fasting hyperinsulinemia, and hypothyroidism were recorded and compared. RESULTS: At the beginning of treatment, chronological age, bone age, height, and BMI were not statistically significant between the two groups. rhGH dosage in ISS was significantly higher compared with GHD (P = 0). GV from half a year to three years after rhGH therapy was higher in the GHD group compared with the ISS group, but the differences were not statistically significant (P > 0 .05). HtSD increased in the two groups after rhGH therapy. HtSD at the beginning and after three years of therapy was not different between groups except for after half a year of therapy. HtSD in patients with ISS was significantly higher compared with GHD (P < 0 .05). The incidence of hypothyroidism was significantly higher in the GHD group compared with the ISS group (13.72% vs. 6.0%; P < 0.05). Moreover, the incidence of hyperinsulinemia was significantly higher in the ISS group compared with the GHD group (15.33% vs. 7.84%; P < 0 .05). CONCLUSIONS: rhGH increases growth in children with ISS and GHD. Fasting insulin and thyroid function were closely monitored for long-term follow up.

Questioning the Value of Brain Magnetic Resonance Imaging in the Evaluation of Children with Isolated Growth Hormone Deficiency.

BACKGROUND: Isolated growth hormone deficiency (IGHD) is a relatively common disorder. Current diagnostic protocol requires a brain magnetic resonance imaging (MRI) study of the hypothalamus and the hypophysis to determine the cause after establishment of the diagnosis. This study aimed to examine the yield of brain MRI in the evaluation of children with IGHD and to define clinical and laboratory parameters that justify its performance. METHODS: A retrospective chart review of all children (<18 years) diagnosed with IGHD was conducted at 3 pediatric endocrinology units between 2008 and 2018. RESULTS: The study included 192 children (107 boys) with confirmed IGHD. The mean age ± standard deviation (SD) at diagnosis was 8.2 ± 3.7 years (median 8.5 years, range 0.8-15.9). The mean height SD score (SDS) at diagnosis was -2.25 ± 0.73. The mean height deficit SDS (defined as the difference between height SDS at diagnosis and mid-parental height SDS) was -1.7 ± 0.9. Fifteen children (7.8%) had pathological MRI findings. No space-occupying lesion was detected. Children with pathological MRIs had greater height deficit SDS and lower peak growth hormone levels on provocative tests compared to children with normal MRIs: -2.3 ± 1.2 vs. -1.6 ± 0.8 (p = 0.02) and 4.4 ± 1.9 vs. 5.7 ± 1.3 (p = 0.01), respectively. CONCLUSION: Our preliminary data indicate that most brain MRIs performed for routine evaluation of children with IGHD are not essential for determining cause. Further studies with larger cohorts are needed in order to validate this proposed revision of current protocols.

The Optimized Calculation Method for Insulin Dosage in an Insulin Tolerance Test (ITT): A Randomized Parallel Control Study.

Objective: To explore the most suitable calculation method for insulin dosage in an insulin tolerance test (ITT) and to evaluate the clinical application value of the optimization coefficient (γ). Methods: In this study, 140 adult patients with congenital growth hormone deficiency (GHD) or acquired hypopituitarism were randomized into the following two groups: the conventional group (n = 70) and the optimized group (n = 70). Oral glucose tolerance tests (OGTTs), insulin release tests (IRTs), and ITTs were conducted. For ITTs, insulin doses were the product of body weight (kg) and related coefficient (0.15 IU/kg for the control group and γ IU/kg for the optimized group, respectively). Notably, γ was defined as -0.034 + 0.000176 × AUCINS + 0.009846 × BMI, which was based on our previous study. Results: In the ITTs, the rate of achieving adequate hypoglycemia with a single insulin dose was significantly higher for the optimized group compared with the conventional group (92.9 vs. 60.0%, P < 0.001). The optimized group required higher initial doses of insulin (0.23 IU/kg). Meanwhile, the two groups did not differ significantly in their nadir blood glucose (1.9 vs. 1.9 mmol/L, P = 0.828). Conclusion: This study confirmed that the proposed optimized calculation method for insulin dosage in ITTs led to more efficient hypoglycemia achievement, without increasing the incidence of serious adverse events.

Plasmatic lipocalin-2 levels in chronic low-grade inflammation syndromes: Comparison between metabolic syndrome, total and partial adult growth hormone deficiency.

Lipocalin-2 (LCN2) is a secreted glycoprotein involved in several chronic inflammatory processes. Metabolic syndrome (MetS) and adult growth hormone deficiency (GHD) are known as chronic inflammatory conditions. The primary objective of this observational cross-sectional study was to compare LCN2 plasmatic levels in these clinical settings, whereas the secondary objective was to investigate any possible correlation between LCN2 and BMI and/or indexes of insulin sensitivity/resistance. Seventy-four patients were divided as follows: Group A, MetS (18 patients, 13 females and 5 males, mean ± SEM age 45.1 ± 4.11 years, BMI 31.22 ± 1.73 kg/m2 ); Group B, total GHD (18 patients, 8 females and 10 males, age 52.44 ± 2.61 years, BMI 30.49 ± 1.87 kg/m2 ); Group C, Partial GHD (pGHD; 19 patients, 13 females and 6 males, age 48.63 ± 2.19 years, BMI 29.11 ± 1.85 kg/m2 ); Group D, Controls (19 patients, 13 females and 6males, age 40.26 ± 2.87 years, BMI 23.25 ± 0.95 kg/m2 ). They were evaluated for glucose and insulin, HOMA-index, QUICKI-index, Total/low-density lipoprotein/high-density lipoprotein cholesterol, triglycerides, uric acid, IGF-1, and LCN2. LCN2 plasmatic levels were significantly increased in MetS, while no significant differences with controls were found in total and pGHD. LCN2 levels did not correlate with BMI. A significant positive correlation between LCN2 and HOMA-index was found in controls, while a trend-like, yet not significant, a positive correlation was observed in pGHD. Our data show an increase in LCN2 plasmatic levels in MetS. Different inflammatory patterns characterize MetS and GHD. The correlation between HOMA index and LCN2 in normal subjects and possibly in pGHD ones suggests a modulatory action of LCN2 on insulin resistance.

Development and Validation of a Prediction Rule for Growth Hormone Deficiency Without Need for Pharmacological Stimulation Tests in Children With Risk Factors.

Introduction: Practice guidelines cannot recommend establishing a diagnosis of growth hormone deficiency (GHD) without performing growth hormone stimulation tests (GHST) in children with risk factors, due to the lack of sufficient evidence. Objective: Our goal was to generate an evidence-based prediction rule to diagnose GHD in children with growth failure and clinically identifiable risk factors. Methods: We studied a cohort of children with growth failure to build the prediction model, and a second, independent cohort to validate the prediction rule. To this end, we assessed the existence of: pituitary dysgenesis, midline abnormalities, (supra)sellar tumor/surgery, CNS infection, traumatic brain injury, cranial radiotherapy, chemotherapy, genetic GHD, pituitary hormone deficiencies, and neonatal hypoglycemia, cholestasis, or hypogenitalism. Selection of variables for model building was performed using artificial intelligence protocols. Specificity of the prediction rule was the main outcome measure in the validation set. Results: In the first cohort (n=770), the resulting prediction rule stated that a patient would have GHD if (s)he had: pituitary dysgenesis, or two or more anterior pituitary deficiencies, or one anterior pituitary deficiency plus: neonatal hypoglycemia or hypogenitalism, or diabetes insipidus, or midline abnormalities, or (supra)sellar tumor/surgery, or cranial radiotherapy ≥18 Gy. In the validation cohort (n=161), the specificity of the prediction rule was 99.2% (95% CI: 95.6-100%). Conclusions: This clinical rule predicts the existence of GHD with high specificity in children with growth disorders and clinically identifiable risk factors, thus providing compelling evidence to recommend that GHD can be safely diagnosed without recurring to GHST in neonates and children with growth failure and specific comorbidities.

Untreated adult GH deficiency is not associated with the development of metabolic risk factors: a long-term observational study.

PURPOSE: Uncertainties exist about the predictors of the severity of the clinical picture of GH deficiency (GHD) syndrome. Aim of the study was to evaluate, in adult patients with GHD, the predictors of the development of hypercholesterolemia, hypertension, diabetes mellitus, and osteoporosis. METHODS: We retrospectively studied 327 adult patients (age 47.1 ± 17.1 years) with untreated severe GHD (mean follow-up 110.9 ± 56.8 months). GHD was defined by GHRH + arginine test using BMI cut-offs. The possible development of hypercholesterolemia, hypertension, diabetes mellitus, and osteoporosis was investigated by Kaplan-Meier survival analysis. For each clinical outcome, either a univariate or multivariate analysis according to the Cox proportional-hazards model was performed to identify those factors that were associated with the development of the event. RESULTS: GH secretion parameters were not associated with the outcomes. Hypercholesterolemia was positively and negatively predicted by a BMI ≥ 30 kg/m2 (HR 2.50, p 0.00) and the dose of l-thyroxine possibly in place (HR 0.98, p 0.02), respectively. Hypertension was positively predicted by a BMI ≥ 30 kg/m2 (HR 2.64, p 0.00) and IGF-I SDS values (HR 2.26, p 0.00). Diabetes mellitus was positively predicted by hypertension (HR 11.76, p 0.01). Osteoporosis was positively and negatively predicted by hypercholesterolemia (HR 3.25, p 0.01) and hypertension (HR 0.21, p 0.00), respectively. CONCLUSIONS: The severity of the impairment of GH secretion does not predict the development of the clinical picture of GHD syndrome: untreated adult GHD does not increase the development of metabolic risk factors in hypopituitaric patients.

Peak Growth Hormone Response to Combined Stimulation Test in 315 Children and Correlations with Metabolic Parameters.

BACKGROUND/AIMS: Studies are lacking regarding the timing of peak growth hormone (PGH) response. We aim to elucidate the timing of PGH response to arginine and levodopa (A-LD) and evaluate the influence of body mass index (BMI) and other metabolic parameters on PGH. METHODS: During growth hormone (GH) stimulation testing (ST) with A-LD, serum GH was measured at baseline and every 30 min up to 180 min. The PGH cut-off was defined as &#x3c;10 ng/mL. IGF-1, IGF BP3, BMI, and metabolic parameters were obtained in a fasting state at baseline. RESULTS: In the 315 tested children, stimulated PGH levels occurred at or before 120 min in 97.8% and at 180 min in 2.2%. GH area under the curve (AUC) positively correlated with PGH in all patients and with IGF-1 in pubertal males and females. BMI negatively correlated with PGH in all subjects. GH AUC negatively correlated with HOMA-IR and total cholesterol. CONCLUSION: We propose termination of the GH ST with A-LD at 120 min since omission of GH measurement at 180 min did not alter the diagnosis of GH deficiency based on a cut-off of &#x3c; 10 ng/mL. BMI should be considered in the interpretation of GH ST with A-LD. The relationships between GH AUC and metabolic parameters need further study.

Identification of Haptoglobin as a Readout of rhGH Therapy in GH Deficiency.

BACKGROUND: GH deficiency (GHD) is characterized by a cluster of cardiovascular risk factors and subtle inflammation. We aimed to demonstrate, through a proteomic approach, molecules directly modulated by GHD and involved in the inflammatory state. METHODS: Ten children with isolated GHD were studied before and after 1 year of treatment with rhGH and compared with 14 matched controls. A two-dimensional electrophoresis plasma proteomics analysis was performed at baseline and after GH treatment to identify the top molecules modulated by GH. In vitro studies on human hepatoma (HepG2) cells were performed to validate the data. RESULTS: Twelve of 20 proteomic spots were predicted to be isoforms α and ß of haptoglobin (Hp) and confirmed by liquid chromatography tandem mass spectrometry and Western immunoblot analyses. Hp levels were higher in patients with GHD than controls at baseline (P < 0.001) and were reduced following GH treatment (P < 0.01). In HepG2 cells, both GH and IGF-1 were able to downregulate IL-6-induced Hp secretion. Moreover, Hp secretion was restored in pegvisomant-treated HepG2 cells. CONCLUSIONS: Hp is a molecule acting in the inflammatory state of GHD and a possible biomarker for GH treatment. Nevertheless, the contribution of other factors and the molecular pathways involved in the GH downregulation of Hp remain to be clearly defined.

[Growth hormone of dried blood spot for the diagnosis of growth hormone deficiency]. / Hormona de crecimiento en sangre de papel filtro para el diagnóstico de deficiencia de hormona de crecimiento.

INTRODUCTION: The diagnosis of growth hormone deficiency (GHD) is difficult to determine, and could be associated with severe complications, especially in the neonatal period. The stimulation test of growth hormone (GH) secretion is considered the gold standard for diagnosis, but it has methodological complications and is associated with adverse effects. Neonates present physiological increased secretion of GH, representing a diagnostic window. OBJECTIVE: To evaluate if the dried blood spot on filter paper obtained in the neonatal period, as part of a neonatal screening for con genital hypothyroidism and phenylketonuria, allows differentiating patients with GHD from those who do not have it. PATIENTS AND METHOD: Study of cases and controls by measuring the GH concen tration in dried blood spot on filter paper obtained in the neonatal period, comparing controls with GHD with cases with discarded deficiency. The sample was extracted from the filter paper, obtaining two 0.125 inch discs per each patient from the center of the blood spot on the paper, for a highly sen sitive ELISA assay for human GH based on the use of polyclonal antibodies against 22 kDa recom binant human GH. RESULTS: Seven cases of GHD and ten controls were obtained. The median GH concentration of the dried blood spot in the cases is 2.0 ng/ml (Interquartile range 3.6 ng/ml) and 2.05 ng/ml (Interquartile range 2.0 ng/ml) in the controls, Mann-Whitney U test 30.5 (p = 0.68). The two cases with multiple pituitary-hormone deficiency (MPHD) present concentrations lower than 1 ng/ml. CONCLUSION: The dried blood spot sample did not differentiate GHD patients from control cases, although MPHD cases present much lower concentrations compared to isolated growth hor mone deficiency (IGHD).

Prevalence of growth hormone (GH) deficiency in previously GH-treated young adults with Prader-Willi syndrome.

OBJECTIVE: Some features of subjects with Prader-Willi syndrome (PWS) resemble those seen in growth hormone deficiency (GHD). Children with PWS are treated with growth hormone (GH), which has substantially changed their phenotype. Currently, young adults with PWS must discontinue GH after attainment of adult height when they do not fulfil the criteria of adult GHD. Limited information is available about the prevalence of GHD in adults with PWS. This study aimed to investigate the GH/insulin-like growth factor (IGF-I) axis and the prevalence of GHD in previously GH-treated young adults with PWS. DESIGN: Cross-sectional study in 60 young adults with PWS. MEASUREMENTS: Serum IGF-I and IGFBP-3 levels, GH peak during combined growth hormone-releasing hormone (GHRH)-arginine stimulation test. RESULTS: Serum IGF-I was <-2 standard deviation scores (SDS) in 2 (3%) patients, and IGFBP-3 was within the normal range in all but one patient. Median (IQR) GH peak was 17.8 µg/L (12.2; 29.7) [~53.4 mU/L] and below 9 µg/L in 9 (15%) patients. Not one patient fulfilled the criteria for adult GHD (GH peak < 9 µg/L and IGF-I < -2 SDS), also when BMI-dependent criteria were used. A higher BMI and a higher fat mass percentage were significantly associated with a lower GH peak. There was no significant difference in GH peak between patients with a deletion or a maternal uniparental disomy (mUPD). CONCLUSIONS: In a large group of previously GH-treated young adults with PWS, approximately 1 in 7 exhibited a GH peak <9 µg/L during a GHRH-arginine test. However, none of the patients fulfilled the consensus criteria for adult GHD.