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Background Pseudohypoparathyroidism (PHP) represents a heterogeneous group of rare endocrine disorders caused by (epi) genetic abnormalities affecting the GNAS locus. It is mainly characterized by resistance to PTH and TSH, and by peculiar clinical features such as short stature, obesity, cognitive impairment, subcutaneous ossifications and brachydactyly. Delayed puberty, GHRH and calcitonin resistances have also been described. The healthcare-pathway recently proposed by the Italian Society of Pediatric Endocrinology and Diabetology (ISPED) has provided a standardized clinical approach to these conditions. The purpose of the present study was to evaluate its application in clinical practice, and to collect data for setting future specific studies. Methods Through a semi-structured survey, based on the indications of the care-pathway, data on PHP clinical management were collected. The compilation of each data in the survey was read as an index of the adoption of the healthcare-pathway in clinical practice. Results In addition to the proposing Center, 4 Centers joined the study, thus obtaining a large collection of data on 48 PHP patients. Highest rates in the completion of data were obtained for diagnostic history, auxological measurements and subcutaneous ossifications evaluation. As expected, the availability of data for the other investigated fields was lower, coming from recent research studies. More information has been obtained on hormonal resistance classically involved in PHP (PTH, TSH, GHRH and GnRH) and on cognitive impairment, while a few data has been collected on bone mineral status, calcitonin levels and glucolipid metabolism. Conclusions The presented data show that the ISPED healthcare-pathway could represent a valid tool both to confirm the clinical approach to PHP patients and to allow homogeneous data collection; however, it has not yet been fully adopted. The strengthening of the network among the major Italian Endocrine Centers will contribute to improve its application in clinical practice, optimizing the follow-up of these patients and increasing knowledge on PHP.

Background/Aims: The diagnosis of growth hormone (GH) deficiency (GHD) in infancy and early childhood is not straightforward. GH stimulation tests are unsafe and unreliable in infants, and normative data are lacking. This study aims to investigate whether brain magnetic resonance imaging (MRI) may replace GH stimulation tests in the diagnosis of GHD in children younger than 4 years. Methods: We examined a retrospective cohort, with longitudinal follow-up, of 68 children consecutively diagnosed with GHD before the age of 4 years. The prevalence of hypothalamic-pituitary (HP) alterations at MRI and the associations with age and either isolated GHD (IGHD) or multiple pituitary hormone deficiency (MPHD) were assessed. Results: The prevalences of IGHD and MPHD were 54.4 and 45.6%, respectively. In the first group, brain MRI showed abnormalities in 83.8%: isolated pituitary hypoplasia in 48.7% and complex defects in 35.1%. In patients with MPHD, MRI showed complex alterations in 100%. All children younger than 24 months showed HP MRI abnormalities, regardless of the diagnosis. Complex defects were found in 94% of patients younger than 12 months and in 75% of patients between 13 and 24 months. Conclusion: Our data suggest that brain MRI may represent the first-line investigation for diagnosing GHD in infancy and early childhood.

It is still controversial whether all girls with central precocious puberty (CPP) should undergo brain magnetic resonance imaging (MRI) for unveiling intracranial pathology.The objectives of the study were to determine the prevalence and type of intracranial lesions in otherwise normal girls with central precocious puberty (idiopathic CPP) and to identify the clinical and biochemical predictors of brain abnormalities.This was a retrospective study conducted at the Endocrine Unit of "Bambino Gesù" Children's Hospital (Rome, Italy) from 1990 to 2012.One hundred eighty-two girls were consecutively diagnosed with CPP. All girls underwent a thorough endocrine assessment and brain MRI with a detailed examination of the hypothalamic-pituitary area. None of them had a history of neurological diseases, endocrine disorders, neurofibromatosis or other genetic syndromes, or previous hormonal therapies.Prevalence of brain abnormalities at MRI scan was measured.Brain MRI showed no alteration in 157 (86%), incidentalomas of the hypothalamic-pituitary area unrelated to CPP in 19 (11%), and hamartomas in six girls (3%). Girls with hamartomas were younger than 6 years and had significantly higher mean baseline and stimulated LH values (P.001), LH to FSH ratio (P.001), serum 17β-estradiol levels (P.001), and uterine length (P.05). However, all the parameters overlapped extensively in girls with or without cerebral alterations.Our data cast doubt on the need of routine screening by brain MRI in girls with idiopathic CPP older than 6 years. Evidence-based criteria to drive clinical decision making about the use of MRI are lacking.

Aim The aim of the study was to assess the diagnostic accuracy of pelvic ultrasound (PUS) and magnetic resonance imaging (PMRI) in detecting polycystic ovary syndrome (PCOS) in hyperandrogenic obese adolescent females with menarche age under 2 years compared with healthy females of the same age. Methods We studied 10 patients of mean age 14.63±1.26 years (±SD range: 12.3–16.2 years), of gynaecological age under 2 years, with clinical and biochemical hyperandrogenism. Other causes of hyperandrogenism were excluded. Out of 10 patients, seven had PUS suggestive of PCOS and three were doubtful. All patients had a body mass index over 95th centile and all underwent PUS and PMRI in early follicular phase (1st to 7th day of cycle). Nine healthy, non-obese girls of the same age formed the control group. Results Using PUS in the 10 patients with suspicion of PCOS, ovary volume was found to be 10 ml in all the patients except one in whom the volume was Conclusion In adolescent girls with suspected PCOS, especially if obese, PMRI is a useful and accurate method for analysing ovary volume or structure alterations. Our data showed that PMRI may be a valid alternative for precocious diagnosis of PCOS in adolescents when PUS is negative or doubtful.

Fetal growth restriction is associated with an increased risk of developing insulin resistance and type 2 diabetes in adulthood. In addition, 10-20% of children born small for gestational age (SGA) do not achieve a normal final height. The purpose of this study was to investigate insulin sensitivity and endocrine status in SGA children, compared with that in children born appropriate for gestational age (AGA). Furthermore, within the SGA group, we aimed to relate postnatal growth to anthropometric, biochemical, and endocrine parameters. Eighty-two SGA children (with a mean age of 8.6 +/- 3.5 yr) and 53 short-AGA children (with a mean age of 9.3 +/- 3.3 yr) were studied. A case-control study was carried out in 26 SGA and 26 short-AGA subjects. For each SGA subject, we selected a short-AGA child matched for sex, age (within 1 yr), pubertal status, body mass index (within 0.5 kg/m(2)), and height (within 0.25 z-score). Children's statures were corrected for their midparental height, and SGA children were subdivided into 2 groups: catch-up growth (CG) group (children with corrected height with at least 0 z-score); and non-CG (NCG) group (subjects with corrected height with less than 0 z-score). Comparing SGA with short-AGA subjects, no significant differences in fasting insulin, fasting glucose/insulin ratio, homeostasis assessment model for insulin resistance, and homeostasis assessment model-beta-cell values were observed. SGA children showed significantly reduced levels of glucose (4.4 +/- 0.6 vs. 4.9 +/- 0.6 mM, P < 0.0001), total cholesterol (160.1 +/- 28.8 vs. 171.8 +/- 28.5 mg/dl, P = 0.02), and high-density-lipoprotein cholesterol (53.3 +/- 12.1 vs. 58 +/- 11.4 mg/dl, P = 0.02). The analysis of the subjects selected for the case-control study confirmed that SGA children did not have significant differences in the indices of insulin sensitivity but showed significantly lower glucose levels (4.4 +/- 0.7 vs. 4.9 +/- 0.4 mM, P < 0.005). Subdividing the SGA group into CG (n = 25) and NCG (n = 57) children, we found that NCG children showed significantly higher levels of TSH (2.5 +/- 1.3 vs. 1.9 +/- 0.6 mU/liter, P = 0.002). Our data indicate that SGA children do not have altered insulin sensitivity when compared with auxologically identical AGA subjects but show a significant reduction of glucose concentrations. Whether the lower glucose levels are attributable to an early phase of augmented insulin sensitivity, as previously reported in animal models, has to be established. The finding of higher TSH concentrations in SGA children with blunted CG suggests that intrauterine reprogramming might involve thyroid function, which, in turn, might affect postnatal growth and cholesterol metabolism, eventually increasing the risk of cardiovascular disease.

Summary objective The diagnosis of GH insufficiency (GHI) in childhood is not straightforward. Our aim was to test the sensitivity and specificity of height velocity (HV), IGF-I, IGFBP-3 and GH stimulation tests alone or in combination in the diagnosis of GHI. design A retrospective review of patients with GHI and idiopathic short stature (ISS) diagnosed in our centre and followed up to the completion of linear growth. patients Thirty-three GHI children and 56 children with ISS were evaluated. GHI diagnosis was based on fulfilment of anthropometric, endocrine and neuroradiological criteria: stature ≤ −2 z-score, delayed bone age (at least 1 year), GH peak response to at least two different provocative tests 10 µg/l (20 mU/l) were diagnosed as ISS. measurements All subjects underwent standard anthropometry. GH secretory status was assessed by clonidine, arginine and GHRH plus arginine stimulation tests. IGF-I and IGFBP-3 circulating levels were measured by immunoradiometric assay (IRMA). The following cut-off values were chosen to discriminate between GHI and nonGHI short children: HV

Pallister-Hall syndrome is a disorder of development consisting of hypothalamic hamartoma, pituitary dysfunction, central polydactyly and visceral malformations. This disorder is inherited as an autosomal dominant trait and is caused by mutations of the GLI3 gene encoding a zinc finger transcription factor. We describe a case of Pallister-Hall syndrome with growth hormone neurosecretory dysfunction, successfully treated with growth hormone until attainment of final height. We conclude that children with Pallister-Hall syndrome and short stature be evaluated carefully for spontaneous somatotropic function and, if necessary, treated with growth hormone.

Aims: To investigate (a) the prevalence of insulin resistance in children with intrauterine growth retardation (IUGR); (b) whether catch-up growth is associated with a higher risk of insulin resistance; (c) the insulin-like growth factor (IGF) system status. Methods: 49 children with IUGR aged 9.1 ± 3.3 years underwent anthropometric measurements, and assessment of insulin resistance and IGF system parameters. A fasting glucose/insulin ratio (G/I) Results: 11/49 (22%) children had a G/I Conclusions: (a) Children with IUGR have a high prevalence of reduced insulin sensitivity; (b) postnatal catch-up growth is related to intrauterine growth and actual nutritional status; (c) insulin sensitivity status is not related to postnatal growth but to liver function; (d) IGF system is normal and not related to the insulin resistance parameters during childhood.

Triple A syndrome is an autosomal recessive disorder characterized by the triad of adrenocorticotropic hormone resistant adrenal insufficiency, achalasia, and alacrima. Our aim was to describe the neuropsychological characteristics and the cooccurring psychopathological and neurological disorders in an Italian male child suffering from Triple A syndrome at the time of admission (T0) and after one year of follow-up (T1). Many difficulties were observed in the motor domain, as well as in manual dexterity and static/dynamic balance domains of the motor task over time. In sharp contrast with previous literature reports on frequent mild cognitive dysfunction in patients with Triple A syndrome, our child did not show any mental retardation. By contrast, he showed an average IQ at T0 with a slight improvement at T1. To our knowledge, this report is the first describing neuropsychological profile and co-occurring psychopathological problems in a child with Triple A syndrome. Considering that the Triple A syndrome is a progressive disorder which can take years to develop the full-blown clinical picture, these patients require periodical medical controls. Moreover, assessment of neuropsychological and psychopathological features should be performed in patients with this disease, in order to underline the variability of this syndrome.

In order to study the pathogenesis of short stature in some of the best known and most frequent dysmorphic syndromes, we have reviewed the most significant studies conducted on somatrotropin secretion and on response to replacement treatment with human growth hormone in pediatric patients. In particular, the study examines the results presented in the literature, and in a few of our cases, those obtained with regard to Noonan, Silver-Russell and Prader-Willi syndrome patients, to achondroplasia and hypochondroplasia patients, and to Down syndrome patients. Finally, we shall present a review of a few, less frequent dysmorphic syndromes with short stature, in which a growth hormone deficiency has been diagnosed and replacement treatment attempted.

An infant with a clinical phenotype of early onset hypoaldosteronism has been screened for mutation analysis of the Cyp11b2 gene encoding aldosterone synthase enzyme. We have described a novel nonsense mutation in exon 3 (c.508C>T) that gave rise to a shorter protein (Q170X) and two known concurrent missense mutations (c.594A>C in exon 3 and c.1157T>C in exon 7) that led to substitution of glutamic acid for aspartic acid at amino acid position 198 (E198D) and of valine for alanine at amino acid position 386 (V386A). The father, who carried E198D plus V386A mutations, showed a fractional sodium excretion of 1.25% that was unmodified by dietary salt restriction, suggesting a mild haploinsufficiency. We examined by in silico analysis the effect of the mutations on the secondary and tertiary structures of aldosterone synthase to explain the inefficient enzymatic activity. The Q170X mutation produced a truncated protein, which was consequently associated with a loss of catalytic activity. As predicted by JPred web system and Dock 6.3 software, the concurrent expression of E198D and V386A mutations induced a significant secondary structure rearrangement and a shift of the heme group and the 18-hydroxycorticosterone substrate from their optimal placement.

Objective: Low birth weight is a risk factor for coronary heart disease. Persons who have coronary events as adults tend to have been small at birth and thin at 2 yr of age, after which they tended to increase their body mass index (BMI). Our aim was to determine whether BMI gain is associated to alterations in insulin sensitivity and/or lipid profile in children born small for gestational age (SGA). Design: Retrospective case-control study. Methods: We studied 78 children (mean age 7.8±2.5 yr): 26 SGA children with catch-up growth in BMI (CGB-SGA) (BMI= 10th to 75th centile), 26 SGA without catch-up growth (NCGB-SGA) (BMI

We describe a child treated with high-dose steroid therapy for congenital adrenal hyperplasia who showed marked left ventricular hypertrophy mimicking hypertrophic cardiomyopathy associated with steroid therapy for congenital adrenal hyperplasia. Cardiomyopathy reversed completely when an appropriate steroid therapeutic regimen was established.

Background/Aims: Our aim was to investigate glucose homeostasis, insulin sensitivity and insulin-like growth factor (IGF) system status in children born small for gestational age (SGA). Methods: A case-control study was carried out at birth, infancy and childhood, comparing SGA with children appropriate for gestational age strictly matched for age, gender, pubertal status and body mass index. Ninety newborns, 52 infants, and 68 children were studied. Fasting insulin (IF), fasting glucose (GF) to IF ratio (GF/IF), the homeostasis model assessment of insulin sensitivity, the quantitative insulin sensitivity check index, insulinogenic index and the triglyceride/high-density lipoprotein-cholesterol ratio were measured. IGF-I, IGF-binding protein-3 and the IGF-I/IGF-binding protein-3 molar ratio were assessed. Results: Glucose concentrations were lower in SGA newborns (p < 0.0001), infants (p = 0.01), and children (p = 0.001). Birth weight correlated with glucose levels at birth (r = 0.59, p < 0.0001), 12 months (r = 0.29, p = 0.04) and childhood (r = 0.44, p < 0.0001). Conclusion: Our results provide evidence for a developmental adaptation of glucose metabolism in SGA children leading to reduced glucose concentrations.

Adiponectin is an adipocytokine with insulin-sensitizing and antiatherogenic properties. Reduced concentrations of adiponectin precede the onset of type 2 diabetes and the development of atherosclerosis. Our aim was to quantify adiponectin concentrations in small for gestational age (SGA) children. Fifty-one SGA children, 24 obese, and 17 short-normal children with birth weight appropriate for gestational age (short-AGA) were studied. The statures of the SGA children were corrected for their midparental height and subdivided into two groups according to their corrected height: catch-up growth group, children with corrected height of 0 z-score or greater (n = 17); and noncatch-up growth group, subjects with corrected height less than 0 z-score (n = 34). SGA children showed adiponectin levels significantly lower than short- normal children (35.2 +/- 3.5 vs. 80.4 +/- 26.6 micro g/ml; P < 0.0001) and obese children (77.5 +/- 39.4 micro g/ml; P < 0.0001). Catch-up growth children showed adiponectin levels significantly lower than noncatch-up growth subjects (29.4 +/- 10.3 vs. 38.1 +/- 11.5 micro g/ml; P = 0.01). Adiponectin concentrations were inversely related to height z-score, corrected stature, weight, and body mass index and were positively related to birth weight. Our results suggest that adiponectin levels are reduced in SGA children and are even lower in those with postnatal catch-up growth. Whether this finding implies a higher risk of developing type 2 diabetes and atherosclerosis remains to be established.

Background: Three-dimensional MRI (3D-MRI) is a reliable tool for the evaluation of anatomical volumes. Volumetric measurement of the normal anterior pituitary gland in childhood has been performed in the past by 2D-MRI calculations, but has inherent inaccuracies. Objective: To obtain accurate normal anterior pituitary gland volume in childhood using 3D-MRI coronal sections. Materials and methods: The anterior pituitary gland was measured using coronal T1-weighted 3D-gradient-echo sequences (section thickness 0.75 mm). The study group was composed of 95 prepubertal children (age range 2 months–10 years) with clinically normal pituitary function and no pituitary or brain abnormalities. Results: A measurement error of 0.2–0.4% was assessed by using a phantom study. Volumetric evaluation of the anterior pituitary gland showed progressive growth of the gland from a mean 131±24 mm3 at 2–12 months, to 249±25 mm3 at 1–4 years and 271±29 mm3 at 5–10 years. Conclusions: These data may be useful for paediatricians in the evaluation of patients with neuroendocrine diseases, in particular growth hormone deficiency.

Pseudohypoparathyroidism (PHP) is a heterogeneous disease characterized by PTH resistance and classified as types Ia, Ib, Ic, and II, according to its different pathogenesis and phenotype. PHP-Ia patients show Gsalpha protein deficiency, PTH resistance, and typical Albright hereditary osteodystrophy (AHO). Heterozygous mutations in the GNAS1 gene encoding the Gsalpha protein have been identified both in PHP-Ia and in pseudopseudohypoparathyroidism (PPHP), a disorder with isolated AHO. A single GNAS1 mutation may be responsible for both PHP-Ia and PPHP in the same family when inherited from the maternal and the paternal allele, respectively, suggesting that GNAS1 is an imprinted gene. To evaluate whether molecular diagnosis is a useful tool to characterize AHO and PHP when testing for Gsalpha activity and PTH resistance is not available, we have performed GNAS1 mutational analysis in 43 patients with PTH resistance and/or AHO. Sequencing of the whole coding region of the GNAS1 gene identified 11 mutations in 18 PHP patients, eight of which have not been reported previously. Inheritance was ascertained in 13 cases, all of whom had PHP-Ia: the mutated alleles were inherited from the mothers, who had AHO (PPHP), consistent with the proposed imprinting mechanism. GNAS1 molecular analysis confirmed the diagnosis of PHP-Ia and PPHP in the mutated patients. Our results stress the usefulness of this approach to obtain a complete diagnosis, expand the GNAS1 mutation spectrum, and illustrate the wide mutation heterogeneity of PHP and PHP-Ia.

The diagnosis of GH insufficiency (GHI) in childhood is not straightforward. Our aim was to test the sensitivity and specificity of height velocity (HV), IGF-I, IGFBP-3 and GH stimulation tests alone or in combination in the diagnosis of GHI.A retrospective review of patients with GHI and idiopathic short stature (ISS) diagnosed in our centre and followed up to the completion of linear growth.Thirty-three GHI children and 56 children with ISS were evaluated. GHI diagnosis was based on fulfilment of anthropometric, endocrine and neuroradiological criteria: statureor = -2 z-score, delayed bone age (at least 1 year), GH peak response to at least two different provocative tests10 micro g/l (20 mU/l), brain MRI positive for hypothalamus-pituitary abnormalities, catch-up growth during the first year of GH replacement therapyor = 75th centile, peak GH response to a third provocative test after growth completion10 micro g/l (20 mU/l). Children with anthropometry resembling that of GHI but with peak GH responses10 micro g/l (20 mU/l) were diagnosed as ISS.All subjects underwent standard anthropometry. GH secretory status was assessed by clonidine, arginine and GHRH plus arginine stimulation tests. IGF-I and IGFBP-3 circulating levels were measured by immunoradiometric assay (IRMA). The following cut-off values were chosen to discriminate between GHI and nonGHI short children: HV25th centile over the 6-12 months prior to the initiation of GH therapy, peak GH responses10 or7 micro g/l (20 or14 mU/l) and IGF-I and IGFBP-3-values-1.9 z-score. Sensitivity (true positive ratio) and specificity (true negative ratio) were evaluated.Taking 10 micro g/l (20 mU/l) as the cut-off value, sensitivity was 100% and specificity 57% for GH provocative tests, whereas taking 7 as the cut-off value, sensitivity was 66% and specificity rose to 78%. Sensitivity was 73% for IGF-I and 30% for IGFBP-3 measurement, whilst specificity was 95% for IGF-I and 98% for IGFBP-3 evaluation. HV assessment revealed a sensitivity of 82% and a specificity of 43%. When HV and IGF-I evaluations were used in combination, sensitivity reached 95% and specificity 96%. When both HV and IGF-I are normal (26% of our subjects) GHI may be ruled out, whereas when both the indices are subnormal (23%) GHI is so highly likely that the child may undergo only one GH provocative test and brain MRI and, thereafter, may begin GH therapy without any further test. In case of discrepancy, when IGF-I is normal and HV25th centile (44% of children), due to the relatively low sensitivity of IGF-I assessment and low specificity of HV, the patient should undergo GH tests and brain MRI. Finally, in the rare case of HV25th centile and subnormal IGF-I-values (7%), due to the high specificity of IGF-I measurement, the child should undergo one provocative test and brain MRI for the high suspicion of GHI.Our results suggest that a simple assessment of HV and basal IGF-I may exclude or, in association with only one stimulation test, confirm the diagnosis of GH insufficiency in more than half of patients with short stature.

We report on two adolescents with 22q11 deletion. Their main clinical manifestation was chronic symptomatic hypocalcemia secondary to hypoparathyroidism, together with seizures and cerebral calcifications. Neither congenital cardiac abnormality nor T cell deficiency were detected. The phenotypic manifestations of the observed patients were consistent with velo-cardiofacial syndrome (VCFS). A microdeletion of chromosome region 22q11 has been demonstrated in approximately 90% of DiGeorge syndrome (DGS) patients and in 75% of VCFS patients; the association of the deletion with a wide spectrum of clinical findings suggests the existence of a contiguous gene syndrome. The presence of certain traits of DGS/VCFS should lead to investigations of parathtroid function and molecular analysis of the 22q11 region hybridization studies. 10 refs., 5 figs., 2 tabs.

The response to growth hormone (GH) of cultured lymphocytes from three patients with Laron dwarfism (LD), one subject with growth hormone deficiency and a normal adult volunteer was examined by employing the cytochemical method of selective silver staining that evidentiates the chromosomal sites of those gene clusters (Nucleolus Organizers, NOs) which are actively involved in rRNA transcription. Lymphocytes from the normal donor responded to GH administration with a significant increase of the mean number of silver positive NOs per cell as well as lymphocytes from the growth hormone deficient patient (P less than 0.001). No response to GH administration was observed in lymphocytes from any of the three subjects with LD. These results suggest that the technique of selective silver staining of NOs can be usefully applied to the study of those growth disorders in which a peripheral unresponsiveness to GH is suspected, as demonstrated by data obtained on lymphocytes from patients with LD. This method seems to offer considerable potentialities for studying the cellular response also to other hormones and environmental stimuli.

Background: Retinol-binding protein 4 (RBP4) is an adipocyte-derived ‘signal’ that may contribute to the pathogenesis of insulin resistance and Type 2 diabetes. The relationship of RBP4 with insulin resistance and metabolic risk in human beings has been the subject of several studies. Subjects born small for gestational age (SGA) are at risk of insulin resistance and Type 2 diabetes. Though RBP4 could represent an early marker of insulin resistance, to date, none have determined RBP4 in SGA children. Aim: Our aim was to measure RBP4 concentrations in cord blood of SGA newborns compared with those in children born with a birth weight appropriate for gestational age (AGA) and to determine whether serum RBP4 levels at birth correlate with insulin sensitivity markers. Subjects and methods: Sixty-four newborns, 17 born SGA (mean gestational age: 36.4±2.1 weeks), and 47 born AGA (mean gestational age: 37.0±3.6 weeks) were studied. The main outcome measures included anthropometry, lipid profile, insulin, homeostasis model assessment, quantitative insulin-sensitivity check index, adiponectin, and RBP4. Results: RBP4 concentrations were significantly reduced in SGA newborns (p

Background: Recent studies have linked raised levels of IGF-I and/or reduced levels of its main binding protein, IGF binding protein (IGFBP)-3, with the risk of developing cancer. A GH dose-dependent increase in IGF-I/IGFBP-3 molar ratio has been reported in subjects treated with GH, raising concern about the long-term safety. Objective: The aim of this study was to evaluate changes in serum IGF-I, IGFBP-3, and IGF-I/IGFBP-3 molar ratio over the first 12 months of replacement GH therapy in GH deficient (GHD) children. Methods: The study included 20 GHD children who had not previously received GH treatment, and 40 untreated non-GHD short children closely matched for age, gender, pubertal stage, and body mass index (BMI), as controls. Serum IGF-I, IGFBP-3 levels were measured before and after 12 months of GH treatment. Based on the molecular weight of IGF-I (7500) and IGFBP-3 (40,000, mean of glycosylated variants), we calculated the molar ratio of IGF-I/IGFBP-3. Results: IGF-I/IGFBP-3 molar ratio significantly increased during GH therapy (p=0.01). No significant difference in IGF-I/IGFBP-3 ratio was found between GHD children and controls at the different time points. In the multiple regression analysis, BMI (β=0.33) and age (β=0.33) proved to be the major predictors of the IGF-I/IGFBP-3 molar ratio (adjusted r2=0.53, p