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Background and aims: Fostering patient's self-managing of basal insulin therapy could improve glucose control, by removing patient's and physician's barriers to basal insulin initiation, titration and glucose monitoring. The Italian Titration Approaches Study (ITAS) aims at demonstrating non-inferiority (

Aims The Italian Titration Approach Study (ITAS) demonstrated comparable HbA1c reductions and similarly low hypoglycaemia risk at 6 months in poorly controlled, insulin-naïve adults with T2DM who initiated self- or physician-titrated insulin glargine 300 U/mL (Gla-300) in the absence of sulphonylurea/glinide. The association of patient characteristics with glycaemic and hypoglycaemic outcomes was assessed. Methods This post hoc analysis investigated whether baseline patient characteristics and previous antihyperglycaemic drugs were associated with HbA1c change and hypoglycaemia risk in patient- versus physician-managed Gla-300 titration. Results HbA1c change, incidence of hypoglycaemia (any type) and nocturnal rates were comparable between patient- and physician-managed arms in all subgroups. Hypoglycaemia rates across subgroups (0.03 to 3.52 events per patient-year) were generally as low as observed in the full ITAS population. Small increases in rates of 00:00–pre-breakfast and anytime hypoglycaemia were observed in the ≤ 10-year diabetes duration subgroup in the patient- versus physician-managed arm (heterogeneity of effect; p Conclusions Comparably fair glycaemic control and similarly low hypoglycaemia risk were achieved in almost all patient subgroups with patient- versus physician-led Gla-300 titration. These results reinforce efficacy and safety of Gla-300 self-titration across a range of phenotypes of insulin-naïve people with T2DM. Clinical trial registration EudraCT 2015-001167-39

Objective Isolated hypogonadotropic hypogonadism (IHH) is a rare disorder with pubertal delay, normal (normoosmic-IHH, nIHH) or defective sense of smell (Kallmann syndrome, KS). Other reproductive and non-reproductive anomalies might be present although information on their frequency are scanty, particularly according to the age of presentation. Design Observational cohort study carried out between January 2008 and June 2016 within a national network of academic or general hospitals. Methods We performed a detailed phenotyping of 503 IHH patients with: (1) manifestations of hypogonadism with low sex steroid hormone and low/normal gonadotropins; (2) absence of expansive hypothalamic/pituitary lesions or multiple pituitary hormone defects. Cohort was divided on IHH onset (PPO, pre-pubertal onset or AO, adult onset) and olfactory function: PPO-nIHH (n = 275), KS (n = 184), AO-nIHH (n = 36) and AO-doIHH (AO-IHH with defective olfaction, n = 8). Results 90% of patients were classified as PPO and 10% as AO. Typical midline and olfactory defects, bimanual synkinesis and familiarity for pubertal delay were also found among the AO-IHH. Mean age at diagnosis was significantly earlier and more frequently associated with congenital hypogonadism stigmata in patients with Kallmann’s syndrome (KS). Synkinesis, renal and male genital tract anomalies were enriched in KS. Overweight/obesity are significantly associated with AO-IHH rather than PPO-IHH. Conclusions Patients with KS are more prone to develop a severe and complex phenotype than nIHH. The presence of typical extra-gonadal defects and familiarity for PPO-IHH among the AO-IHH patients indicates a common predisposition with variable clinical expression. Overall, these findings improve the understanding of IHH and may have a positive impact on the management of patients and their families.

Background and aim: The objective of this cross-sectional study was to evaluate the degree of glycaemic control and the frequency of diabetic complications in Italian people with diabetes who were treated with continuous subcutaneous insulin infusion (CSII). Methods and results: Questionnaires investigating the organisation of diabetes care centres, individuals’ clinical and metabolic features and pump technology and its management were sent to adult and paediatric diabetes centres that use CSII for treatment in Italy. Information on standard clinical variables, demographic data and acute and chronic diabetic complications was derived from local clinical management systems. The sample consisted of 6623 people with diabetes, which was obtained from 93 centres. Of them, 98.8% had type 1 diabetes mellitus, 57.2% were female, 64% used a conventional insulin pump and 36% used a sensor-augmented insulin pump. The median glycated haemoglobin (HbA1c) level was 60 mmol/mol (7.6%). The HbA1c target (i.e. 18 years) was achieved in 43.4% of paediatric and 23% of adult participants. Factors such as advanced pump functions, higher rate of sensor use, pregnancy in the year before the study and longer duration of diabetes were associated with lower HbA1c levels. The most common chronic complications occurring in diabetes were retinopathy, microalbuminuria and hypertension. In the year before the study, 5% of participants reported ≥1 episode of severe hypoglycaemic (SH) episodes (SH) and 2.6% reported ≥1 episode of ketoacidosis. Conclusions: Advanced personal skills and use of sensor-based pump are associated with better metabolic control outcomes in Italian people with diabetes who were treated with CSII. The reduction in SH episodes confirms the positive effect of CSII on hypoglycaemia. Clinical trial registration number: NCT 02620917 (ClinicalTrials.gov).

Summary Introduction The outcomes of different types of transitions of young people with chronic diseases have been poorly investigated. Objective To evaluate and compare a structured transition from the paediatric diabetes services (PDS) into the adult diabetic services (ADS) with an unstructured one. Design We retrospectively investigated 62 adolescents and young adults with type 1 diabetes discharged from the PDS from 1 January 1994 to 31 December 2004. Thirty-two patients (group A) were transferred to the ADS of the same hospital with an unstructured method (letter) and 30 patients after a structured transfer planned with adult physicians (group B). We analysed the date of the first admission in ADS, the glycated haemoglobin (HbA1c), the clinic attendance rate in PDS and in the first year in ADS, and a phone questionnaire on the transition experience. Results The duration of the transfer was longer in A than in B with a lack of medical assistance during the unstructured transition (P

An increased prevalence of depression, emotional lability, decreased energy levels, and poor quality of life have been reported in adults with GH deficiency (GHD). The impairment of psychological parameters depends on the aetiology of GHD and the presence of other pituitary hormone deficiencies because of hormonal effects on neural cell metabolism. Cognitive dysfunctions appear to be specifically related to GHD itself, whereas the lower emotional well-being and reduced motor performance are attributed to other pituitary hormone deficiencies. Traumatic Brain Injury causes very often hypopituitarism and GHD as well as other many psychological symptoms: cognitive impairment, sleeping disorders, and depression. Many neurobehavioral symptoms of postconcussion syndrome (PCS) are the same suffered by adult GHD and hypopituitaric patients but there are no data about the occurrence of hypopituitarism in PCS. In some studies treatment with rhGH is reported to have a beneficial effect and GHD could contribute itself to the global impairment of psychological dysfunctions. The link between psychosocial impairments and GHD is not fully understood. The effects of long-term rhGH therapy on cognitive functions are largely unknown. Thus, long-term placebo-controlled double-blind studies are required to investigate whether psychological dysfunctions are reversible on GH substitution.

Traumatic brain injury (TBI)-induced hypopituitarism remains a relevant medical problem, because it may affect a significant proportion of the population. In the last decade important studies have been published investigating pituitary dysfunction after TBI. Recently, a group of experts gathered and revisited the topic of TBI-induced hypopituitarism. During the 2-day meeting, the main issues of this topic were presented and discussed, and current understanding and management of TBI-induced hypopituitarism are summarized here.

Ghrelin circulates in blood as acylated (AG) and unacylated (UAG) ghrelin. The physiological role of the two forms is poorly understood, in particular in childhood. Aim of the study was to evaluate the AG and UAG levels in obese and normal weight (NW) children, pre-pubertal and pubertal, and their relationship with insulin, leptin and adiponectin levels.A population based study in which AG, UAG, leptin, adiponectin, glucose, insulin, testosterone or estradiol levels, insulinemic indexes were evaluated in 82 NW and 58 obese (OB) children.Both ghrelin forms in NW were higher (AG, p0.02; UAG, p0.0001) than in OB subjects, with similar ratio AG/UAG . While no differences were observed for gender, puberty AG (p0.01) and UAG (p0.0001) levels were higher in pre-pubertal than pubertal NW and OB subjects. Adiponectin levels in NW subjects were higher (p0.001), while leptin and insulin levels were lower (p0.0001) than in OB subjects. NW children showed homeostasis model assessment (HOMA) and HOMAβ indices lower than OB children (p0.0001) with a higher a quantitative insulin sensitivity check index (p0.0001). AG and UAG levels correlated to each other (p0.0001), each showing a negative correlation to age, height, weight and body mass index. Both forms, but more strongly UAG, correlated with adiponectin, leptin, and insulin.OB children show lower levels of both AG and UAG when compared to NW subjects, with lower levels during puberty. These results demonstrate a peculiar strong relationship between UAG levels and metabolic parameters in the pediatric population, suggesting a role for UAG in metabolic functions.

The percentage of patients with thyroid cancer incidentally diagnosed during a (18) F-fluorodeoxyglucose Positron Emission Tomography with computed tomography (CT) (FDG-PET/CT) for nonthyroid diseases ranges between 26% and 50%.Retrospective assessment of the clinical and pathological features of thyroid incidentalomas at FDG-PET/CT, aiming to identify potential predictors of malignancy.Fifty-two patients with incidental thyroid uptake at FDG-PET/CT were retrospectively included [38 W, age 64·1 ± 12·5 years (mean ± SD)]. An arbitrary cut-off level of 5·0 for the 'maximum standardized uptake value' (SUV max) was chosen to differentiate benign from malignant tumours. Complete thyroid function, neck ultrasonography (US) features, and cyto-histological results were reported for all cases.In our institution, the prevalence of incidental thyroid (18) F-fluorodeoxyglucose ((18) F-FDG) uptake was nearly 1·76%. The prevalence of focal uptake correlated with greater risk of malignancy (P0·01). In particular, the euthyroidism (P0·003) and a SUV max5·0 (P0·0001) were associated with the diagnosis of thyroid cancer. Diffusely increased FDG-PET/CT uptake in the thyroid was related to benign conditions.The presence of focal uptake with high SUV max and euthyroidism correlate with high likelihood of malignancy. Performing a neck US would have to be recommended in all patients with euthyroidism and an incidental FDG-PET/CT focal thyroid uptake. We do not suggest to use FDG-PET/CT as a screening tool for thyroid cancer in the general population, because of both its high cost and low incidence of thyroid incidentaloma at FDG-PET/CT.

Holoprosencephaly (HPE) is a complex brain malformation caused by impaired or incomplete midline division of the prosencephalon. It's characterized by cerebral and facial anomalies of different levels of severity. Both genetic and environmental factors are known to cause HPE, but they cover only few cases. Genetic causes are responsible for about 20% of cases: they are chromosomal abnormalities and gene mutations: up to date, nine genes (SHH, ZIC2, SIX3, TGIF, PATCHED1, TDGF1/CRIPTO, FAST1, GLI2 and DHCR) are definitely associated with HPE, but many others candidate gene are under investigation. The diagnosis of HPE is usually prenatal and is based on systematic ultrasound scan (US) and magnetic resonance imaging (MRI). Children with HPE have many medical problems in agreement with the severity of the brain malformation: craniofacial abnormalities, neurological signs, endocrine disorders, oromotor and dysautonomic dysfunction, thus requiring a multidisciplinary team for symptomatic treatment of manifestations, prevention of complications and parental support. Genetic counselling is an important step, often made difficult by extreme phenotypic variability, genetic heterogeneity, and a high risk of recurrence in apparently sporadic cases. In conclusion it can be concluded that we are far from a complete explanation of the etiopathogenesis. Future researches on genomic rearrangements all over the genome with techniques like the CGH array should lead to the identification of other causal genes and could improve diagnosis and prognosis. A skill multidisciplinary approach is mandatory to offer the better clinical assistance to patients and their parents.

The most updated guidelines for the diagnosis of adult GH deficiency (GHD) come from the GH Research Society Consensus Workshop held in Sydney, Australia, in 2007. Regarding who to test for GHD, advice should be extended from primitive hypothalamic- pituitary diseases and cranial irradiation to include brain injuries (Traumatic Brain Injury in particular). Regarding how to test for GHD, the insulin tolerance test (ITT) remains a provocative test of reference; among classical provocative test, glucagon test has also been validated. Above all, GHRH + arginine and GHRH + GH-secretagogues are now considered, at least, as reliable as ITT for the diagnosis of adult GHD. Interestingly, it is now accepted that very low IGF-I represents definite evidence of severe GHD in congenital forms of GHD and also in patients with acquired multiple hypopituitarism. These patients would skip provocative test; however, as normal IGFI levels do not rule out severe GHD, patients suspected for hypopituitarism showing normal IGF-I levels must undergo a provocative test of GH secretion. Retesting the GH status in the transition age is of major relevance in order to decide about continuing or not recombinant human GH replacement in adult life.

Recent studies have demonstrated that hypopituitarism, in particular GH deficiency, is common among survivors of traumatic brain injury (TBI) years tested several months or following head trauma. In addition, it has been shown that post-traumatic neuroendocrine abnormalities occur early and with high frequency. These findings may have significant implications for the recovery and rehabilitation of patients with TBI. Although data emerging after year 2000 demonstrate the relevance of the problem, in general there is a lack of awareness in the medical community about the incidence and clinical repercussions of the pathology. Most, but not all, head trauma associated with hypopituitarism is the result of motor vechicle accidents. The subjects at risk are those who have suffered moderate-to-severe head trauma, although mild intensity trauma may also precede hypopituitarism. Particular attention should be paid to this problem in children and adolescents; onset of pituitary deficits can evolve over years following injury. Plasma IGF-I concentrations, plus dynamic GH testing, are indicated for the assessment of the GH-IGF axis in TBI patients. Some degree of hypopituitarism is found in 35-40% of TBI patients. Among mulitple pituitary deficits, the most common ones were GH deficiency (GHD) and gonadotrophin deficiency. In most series, 12-15% presented with severe GHD and 14% with partial GHD after stimulating GH secretion, confirming that the most common isolated deficit is GHD. Psychometric evaluation and neurocognitive testing show variability of disability, and these measures are needed and important to support hormonal replacement. Preliminary data, from small pilot, open-label studies show that subjects treated with GH experience significant improvements in concentration, memory, depression, anxiety and fatigue. In conclusion, pituitary failure can occur even in minor head injuries and is poorly recognized.

The activity of the growth hormone (GH)-insulin-like growth factor-I (IGF-I) axis undergoes marked variations across the human life span, mainly reflecting age-related changes in the neural control of somatotroph function. IGF-I secretion generally reflects GH status, except in newborns, who secrete high levels of GH but low levels of IGF-I. Changes in the gonadal steroid milieu, particularly estradiol, play a major role in the enhanced activity of the GH-IGF-I axis at puberty and probably reflect further changes in the neuroendocrine control of somatotroph secretion. The change in responsiveness of somatotrophs to various stimuli, including GHRH, is not as marked as the spontaneous secretion of GH at puberty. However, in childhood, somatotrophs are unusually refractory to the somatostatin-mediated negative GH autofeedback mechanism. Normal children show normal responsiveness to the stimulatory influence of alpha-adrenergic and cholinergic agonists, galanin and arginine, but the activating effect of these stimuli on somatotroph secretion is reduced in elderly individuals, with the notable exception of arginine. Arginine potentiates both spontaneous and GHRH-induced GH secretion to the same extent in normally growing children, adults and elderly individuals, indicating that the releasable pool of GH is generally preserved across the human life span. Thus, the reduction in spontaneous and GHRH-induced GH secretion in the elderly probably reflects age-related changes in neurotransmitter control, leading to GHRH hypoactivity and absolute or relative somatostatin hyperactivity in the aged hypothalamus. Cholinergic impairment in the aging brain probably involves hypothalamic pathways and leads to decreased activity of the GH-IGF-I axis in normal and elderly individuals, as well as in individuals with premature brain aging. However, there is evidence indicating that age-related variations in the activity of the natural GH-secretagogue ligand(s) at the hypothalamic level could also play a role in the age-dependent changes in the GH-IGF-I axis.

The relationship between the hypothalamus-pituitary morphology and the somatotroph responsiveness to maximal provocative tests exploring the GH releasable pool is still unclear. We evaluated the GH-releasing effect of GHRH plus arginine (GHRH plus Arg) in 36 patients with congenital GH deficiency (GHD) according to their pituitary magnetic resonance imaging findings, consisting of anterior pituitary hypoplasia, stalk agenesis (neural and or vascular component), and posterior pituitary ectopia. Seventeen children (12 boys and 5 girls, aged 1--5.2 yr) were evaluated at the time of diagnosis of GHD (mean age, 3.6 +/- 1.4 yr), and 19 adults (13 males and 6 females, aged 15.9-28.6 yr) with childhood-onset GHD were reevaluated after completion of GH treatment (at least 6 months of withdrawal) at a mean age of 20.5 +/- 3.5 yr. Eleven children had isolated GHD, and 6 had multiple pituitary hormone deficiency (MPHD) whereas 7 adults had isolated GHD, and 12 had MPHD. A residual vascular component of the pituitary stalk was visualized in 7 children and 7 adults with isolated GHD, whereas magnetic resonance imaging showed complete pituitary stalk agenesis (both vascular and neural components) in 10 children and 10 adults, including 16 with MPHD (6 children) and 4 children with isolated GHD. In the children, the median peak GH response to GHRH plus Arg (7.6 microg/L; range, 2.4--40.2 microg/L) was significantly higher than that in the adults (1.8 microg/L; range, 0.8--37.4 microg/L; P = 0.0039); it was also significantly higher in the isolated GHD patients (18 microg/L; range, 3.3--40.2 microg/L) than in those with MPHD (1.9 microg/L; range, 0.8--7.6 microg/L; P = 0.00004). In the patients with residual vascular component of the pituitary stalk the median peak GH responses to GHRH plus Arg (19.1 microg/L; range, 1.6--40.2 microg/L) was significantly higher than that in patients with complete pituitary stalk agenesis (2.2 microg/L; range, 0.8--8.8 microg/L; P = 0.00005). There was a trend toward a decrease with age in peak GH response to GHRH plus ARG: Mean serum insulin-like growth factor I (IGF-I) levels were 36 +/- 7.1 microg/L in the children and 63.5 +/- 22.6 microg/L in the adults (P = 0.0001). The mean IGF-I level did not differ between the children with (35.7 +/- 4.8 microg/L) and those without (36.3 +/- 8.7 microg/L) the pituitary stalk; it was much higher in the adults with residual vascular pituitary stalk (81.1 +/- 17.7 microg/L) than in those with complete pituitary stalk agenesis (47.7 +/- 12.5 microg/L; P = 0.0002). The IGF-I level was 36.1 +/- 6.7 microg/L in the isolated GHD children and 36 +/- 8.6 microg/L in those with MPHD; levels were 82.1 +/- 19.4 and 52.7 +/- 16.8 microg/L respectively, in the adults (P = 0.003). In this study we have confirmed that the partial integrity of the hypothalamic pituitary connections is essential for GHRH plus Arg to express its GH-releasing activity and have shown that this provocative test is able to stimulate GH secretion to a greater extent in those patients with GHD, but with a residual vascular component of the pituitary stalk. This test is reliable in the diagnosis of congenital hypopituitarism in both children and adults when associated with complete pituitary stalk agenesis and MPHD. In younger children with congenital GHD but less severe impairment of the pituitary stalk the GH response to GHRH plus Arg may be within the normal range; deterioration of pituitary GH reserve with a GH response of less than 10 microg/L after 20 yr of age makes this test very sensitive in the diagnosis of adult GHD.

Either in children or in adults, arginine (ARG) alone and combined with GHRH (GHRH+ARG) are reliable tests for the diagnosis of GH deficiency. The procedures of these tests generally include GH measurement every 15 min from baseline up to 90-120 min. Aim of our study was to verify if the procedure of these tests could be usefully shortened in clinical practice. To this goal we have studied 173 normally growing children and adolescents (C, 117 M and 56 F, age: 11.3 +/- 0.4 yr.) and 125 young and middle aged normal adults (A, 68 M and 57 F, age: 30.0 +/- 0.6 yr.). ARG alone test was performed by 81 C and 33 A (0.5 g/kg arginine, i.v., from 0 to +30 min, up to a maximum of 30 g) while GHRH (1 microg/kg i.v. bolus at 0 min) + ARG test was performed by 92 C and 92 A. After ARG alone, taking into account data from +15 to +105 min, GH values above the 3rd centile limit of arbitrary cut-off (7 or 10 microg/l in C and 5 microg/l in A) occurred in 85% or 64% and 94% subjects, respectively. After GHRH+ARG test, taking into account only data at +30, +45, +60 min GH values above the 3rd centile limit (20 microg/l in C and 16.5 microg/l in A) occurred in 99% of subjects in both groups. Taking into account only these 3 timing points, the percentage of GH peak above the third centile limits after ARG alone was never higher than 60% in C and 85% in A. In conclusion, this study shows that single GHRH+arginine test can be reliably performed in a shortened procedure which makes easier the clinical practice and further reduces costs.

Within an appropriate clinical context, severe GH deficiency (GHD) in adults has to be defined biochemically by provocative testing of GH secretion. Patients with childhood-onset GHD need retesting in late adolescence or young adulthood to verify whether they have to continue recombinant human GH treatment. GHRH + arginine (GHRH+ARG) is the most reliable alternative to the insulin-induced hypoglycemia test (ITT) as a provocative test for the diagnosis of GHD in adulthood, provided that appropriate cut-off limits are assumed (normal limits, 16.5 microg/L as 3rd and 9.0 microg/L as 1st centile). We studied the GH response to a single GHRH (1 microg/kg iv) + ARG (0.5 g/kg iv) test in 62 young patients who had undergone GH replacement in childhood, based on the following diagnosis: 1) organic hypopituitarism with GHD (oGHD) In = 18: 15 male (M), 3 female (F); age, 26.8+/-2.2 yr; GH peak10 microg/L after two classical tests]; 2) idiopathic isolated GHD (iGHD) [n = 23 (15 M, 8 F); age, 23.0+/-1.5 yr; GH peak10 microg/L after two classical tests]; and 3) GH neurosecretory dysfunction (GHNSD) [n = 21 (10 M, 11 F); age, 25.1+/-1.6 yr; GH peak10 microg/L after classical test but mGHc3 microg/L]. The GH responses to GHRH+ARG in these groups were also compared with that recorded in a group of age-matched normal subjects (NS) [n = 48 (20 M, 28 F); age, 27.7+/-0.8 yr]. Insulin-like growth factor I levels in oGHD subjects (61.5+/-13.7 microg/L) were lower (P0.001) than those in iGHD subjects (117.2+/-13.1 microg/L); the latter were lower than those in GHNSD subjects (210.2+/-12.9 microg/L), which, in turn, were similar to those in NS (220.9+/-7.1 microg/L). The mean GH peak after GHRH+ARG in oGHD (2.8+/-0.8 microg/L) was lower (P0.001) than that in iGHD (18.6+/-4.7 microg/L), which, in turn, was clearly lower (P0.001) than that in GHNSD (31.3+/-1.6 microg/L). The GH response in GHNSD was lower than that in NS (65.9+/-5.5 microg/L), but this difference did not attain statistical significance. With respect to the 3rd centile limit of GH response in young adults (i.e. 16.5 microg/L), retesting confirmed GHD in all oGHD, in 65.2% of iGHD, and in none of the GHNSD subjects. With respect to the 1st centile limit of GH response (i.e. 9.0 microg/L), retesting demonstrated severe GHD in 94% oGHD and in 52.1% of iGHD. All oGHD and iGHD with GH peak after GHRH+ARG lower than 9 microg/L had also GH peak lower than 3 microg/L after ITT. In the patients in whom GHD was confirmed by retesting, the mean GH peak after GHRH+ARG was higher than that after ITT (3.4+/-0.5 vs. 1.9+/-0.4). In conclusion, given appropriate cut-off limits, GHRH+ARG is as reliable as ITT for retesting patients who had undergone GH treatment in childhood. Among these patients, severe GHD in adulthood is generally confirmed in oGHD, is frequent in iGHD, but never occurs in GHNSD.

There is evidence showing that GH and IGF-I have specific receptors in the heart and that these hormones are able to promote cardiac remodelling and inotropism. It has been reported that patients with dilated cardiomyopathy (DCM) benefit from treatment with rhGH showing a striking increase in cardiac contractility. However, until now, the activity of GH/IGF-I axis in DCM has never been clearly assessed.To clarify this point, we enrolled 39 patients with idiopathic or post-ischaemic DCM (36 M/3 F; age (mean +/- S.D.) 55.3 +/- 9.0 years; BMI: 25.3 +/- 3.2 kg/m2; New York Heart Association class (NYHA) I/2, II/19, III/15, IV/3) and 42 age-matched controls (CS, 38 M/4 F; age 56.0 +/- 7.8 years; BMI: 24.9 +/- 1.5 kg/m2). DCM patients were characterized by a left-ventricular diastolic diameter of 73.8 +/- 8.3 mm, a shortening fraction of 15.9 +/- 6.4% and a left ventricular ejection fraction of 25.1 +/- 8.7%. In all subjects clinical and biochemical indices of renal and hepatic function as well as nutritional parameters were in the normal range.In both groups we studied: a) IGF-I levels in basal conditions and after administration of low rhGH doses for 4 days (5.0 or 10.0 mu/kg/day x 4 days); b) the acute GH-response to GHRH (1.0 mu/kg i.v.) or hexarelin (HEX, 2.0 mu/kg i.v.), a peptidyl GH secretagogue (GHRP); c) mean GH concentration (mGHc) over 10 h sampling (every 20 min) from 2200 h to 0800 h.Basal IGF-I levels in DCM were lower (P = 0.000039) than in CS (135.2 +/- 46.8 vs. 193.7 +/- 63.7 mu/l), whereas, basal IGFBP-3 and GHBP2 levels in DCM and CS were similar (2.5 +/- 1.3 vs. 2.6 +/- 0.5 mg/l and 25.3 +/- 3.6 vs. 28.3 +/- 5.0%; P = 0.95 and P = 0.085, respectively). After 4 days of 5.0 mu/kg/day rhGH administration, IGF-I levels in DCM (215.4 +/- 82.0 mu/l; P = 0.0023 vs. baseline) remained lower (P = 0.027) than those in CS (280.0 +/- 80.7 mu/l; P = 0.000080 vs. baseline). After 10.0 mu/kg/day for 4 days, IGF-I levels in DCM (297.2 +/- 109.2 mu/l; P = 0.0033 vs. baseline) were similar (P = 0.76) to those in CS (310.9 +/- 81.7 mu/l; P = 0.000060 vs. baseline). The GH response to GHRH in DCM was lower (P = 0.0022) than that in CS (hAUC0-120: 192.0 +/- 177.3 vs. 345.3 +/- 191.1 mu/l/h) whereas that to HEX in DCM and CS was similar (611.0 +/- 437.5 vs. 535.4 +/- 302.8 mu/l/h; P = 0.95). Within the DCM group, basal and rhGH-stimulated IGF-levels as wel as the GH response to GHRH or HEX were not different among NYHA classes and did not show any correlation with ECHO parameters. The mGHc in DCM (1.0 +/- 0.5 mu/l) was similar (P = 0.57) to that in CS (0.9 = 0.7 mu/l).Our present data demonstrate that in dilated cardiomyopathy patients with severe left ventricular dysfunction basal IGF-I levels are reduced whereas the IGF-I response to low rhGH doses is preserved. These findings suggest a normal peripheral GH sensitivity in dilated cardiomyopathy. On the other hand, though nocturnal mean GH concentration in dilated cardiomyopathy patients is similar to that in normal subjects, the somatotroph responsiveness to GHRH, but not that to hexarelin, is reduced. Thus, subtle alterations in the activity of GH/IGF-I axis are present in dilated cardiomyopathy.

It is widely accepted that IGF-I synthesis and release depend on GH secretion as well as on the nutritional status and vary with age. Based on these premises, after the definition of normal IGF-I levels during lifespan, in a large population of normal subjects of both sexes, our aim was to verify IGF-I levels in large groups of adult patients with GH deficiency or obesity, a condition in which a reduced somatotrope secretion is well known.To this goal, IGF-I levels were assayed after acid-ethanol extraction, in 326 normal subjects (NS, 98 men and 228 women, age 20-80 yrs, BMI 17.9-26.1 kg/m2), 54 patients with GH deficiency (GHD, 24 men and 30 women, age 20-80 yrs, BMI 18.2-27.1 kg/m2), and 195 patients with obesity (OB, 33 men and 162 women, age 17-71 yrs, BMI 27.7-64.9 kg/m2). In NS, IGF-I levels were similar in both sexes and showed a progressive decrease with age. No correlation was present between IGF-I and BMI in NS. Median IGF-I levels and the 3rd centile in NS when considered per decade were: III) 230 and 108.6; IV) 220 and 129.8; V) 150.5 and 72.4; VI) 163.0 and 62.4; VII) 110 and 41.6; VIII) 82 and 24.7 micrograms/l. In GHD, IGF-I levels were independent on sex and did not show reduction during lifespan. Mean IGF-I levels in GHD were lower than that in NS (64.5 +/- 5.9 vs 171.3 +/- 4.8 micrograms/l, p0.01) and did not correlate with age or BMI. Analyzing individual IGF-I levels, in GHD, in the III and IV decade 21/24 patients had IGF-I levels lower than 3rd centile while, up to the VIII decade, only 10/30 had IGF-I levels below normal limits. In OB, IGF-I levels were independent on sex but, like in NS, showed a progressive decrease with age and were independently, negatively correlated with BMI but not with WHR. Analyzing individual IGF-I levels, in OB, IGF-I levels were below 3rd centile in 10/77 patients in the III and IV decade and in only 8/108 patients up to the VIII decade. Mean IGF-I levels in the whole OB population (179.6 +/- 5.9 micrograms/l) were higher (p0.01) than those in GHD (64.5 +/- 5.9 micrograms/l) while only in the IV decade IGF-I levels in OB group were lower (p0.02) than those in NS (184.7 +/- 12.6 micrograms/l vs 224.0 +/- 9.2 micrograms/l).In conclusion, present data confirm that IGF-I levels depends on GH secretion as well as on nutritional status, being negatively and independently correlated with age and BMI. IGF-I assay is not a reliable test for the diagnosis of GH deficiency in adulthood though it gives good discrimination between GHD and normal subjects up to 40 yrs of age. In spite of low GH secretion, IGF-I levels are only slightly reduced in obesity, probably as consequence of hyperinsulinism.

Low somatotrope responsiveness to secretagogues has been reported in patients affected by Prader-Labhard-Willi Syndrome (PLWS). In normal subjects, GH response to GHRH is known to be greatly potentiated to the same extent by pyridostigmine (PD) or arginine (ARG) which probably act via inhibition of hypothalamic somatostatin release. To clarify somatotrope responsiveness in 7 PLWS patients, we studied GH response to GHRH alone and to GHRH combined with PD or ARG. Eight normal short children were studied as controls (NC). GH response to GHRH in PLWS was lower than in NC (AUC: 615 +/- 205 micrograms/l.h, vs 1271 +/- 333 micrograms/l.h, p < 0.02). In NC, the GHRH-induced GH rise was potentiated to the same extent by PD or ARG. In contrast, in PLWS PD failed to increase the GH response to GHRH (AUC: 615 +/- 205 micrograms/l.h vs 621 +/- 176 micrograms/l.h, n.s.) which was enhanced by ARG (AUC: 615 +/- 205 micrograms/l.h vs 1633 +/- 425 micrograms/l.h, p < 0.02). However, the GH response to GHRH + ARG in PLWS was lower than in NC. In conclusion, our results demonstrate that in PLWS the low somatotrope responsiveness to GHRH is not enhanced by cholinergic potentiation while it is increased by arginine.

Objective: The diagnosis of growth hormone (GH) deficiency (GHD) in adults is based on a reduced peak GH response to provocative tests, such as the insulin tolerance test (ITT) and the GH-releasing hormone-arginine (GHRH-ARG) test. However, the cut-off limits of peak GH response in lean subjects are not reliable in obese patients; this is noteworthy since adult GHD is often associated with obesity. Aim of this study was to evaluate the diagnostic cut-off limits of peak GH response to the GHRH-ARG test in overweight and obese as well as in lean population. Design and methods: The GH responses to the GHRH-ARG test were studied in 322 patients with organic hypothalamic-pituitary disease and in 318 control subjects. Patients were subdivided into two groups on the basis of the number of pituitary hormone deficits, except for GH deficiency: (a) patients with total pituitary hormone deficit (TPHD) and (b) patients without or with no more than two pituitary hormone deficits (PHD). Both patients and control subjects were divided into three subgroups according to body mass index (BMI): lean (BMI 2), overweight (BMI ≥25 and 2) and obese (BMI ≥30 kg/m2). TPHD patients were assumed to be GH deficient, whereas PHD patients may include subjects with either normal or impaired GH secretion. The statistical analysis was carried out by the Receiver-Operating Characteristic curve analysis (Medcalc 7.2). The diagnostic cut-off points were calculated for lean, overweight and obese subjects to provide optimal separation of GH-deficient patients and control subjects according to two criteria: (1) a balance between high sensitivity and high specificity; (2) to provide the highest pair of sensitivity/specificity values for GH deficiency. Results: In the lean population the best pair of values, with highest sensitivity as 98.7% and highest specificity as 83.7%, was found using a peak GH cut-off point of 11.5 μg/l. In the overweight population the best pair of values, 96.7 and 75.5%, respectively, was found using a peak GH cut-off point of 8.0 μg/l. In the obese population the best pair of values, 93.5 and 78.3%, respectively, was found using a peak GH cut-off point of 4.2 μg/l. Applying the above mentioned cut-off points, among PHD patients we found that 80 subjects (72%) were GHD whereas 31 (28%) had normal GH secretion. Conclusions: In conclusion the GHRH-ARG test is a reliable tool for the diagnosis of adult GH deficiency in lean, overweight and obese patients, provided that specific BMI-related cut-off limits are assumed.

The aim of the present study was to correlate the degree of the GH response to the combined arginine and GHRH (ARG+GHRH) test with clinical status in 157 adult hypopituitary patients and 35 healthy controls. On the basis of the GH response to ARG+GHRH, the 192 subjects were subdivided into 5 groups: group 1, very severe GH deficiency (GHD; 65 patients with GH peak 16.5 microg/L); and group 5 (35 controls with GH peak >16.5 microg/L). Plasma insulin-like growth factor I (IGF-I) concentrations were lower (P < 0.001) in patients of group 1 (74.4 +/- 6.7 microg/L) and group 2 (81.4 +/- 6.8 microg/L) than in those of group 3, 4, and 5 (163.6 +/- 40.6, 185.9 +/- 21, and 188.8 +/- 11.1 microg/L, respectively). Plasma IGF-binding protein-3 concentrations were lower (P < 0.01) in group 1 (2.1 +/- 0.2 mg/L) and group 2 (2.0 +/- 0.2 mg/L) than in group 3 (3.4 +/- 0.7 mg/L) and group 5 (3.8 +/- 0.2 mg/L). In patients of group 1, total cholesterol (228.3 +/- 5.7 mg/dL) and triglycerides levels (187.4 +/- 15.3 mg/dL) were higher than those in group 3 (196.6 +/- 9.6 and 115.8 +/- 10.1 mg/dL, respectively), group 4 (176.8 +/- 11.3 and 101.4 +/- 12.5 mg/dL, respectively), and group 5 (160 +/- 6.9 and 99.3 +/- 5.4 mg/dL, respectively). High density lipoprotein cholesterol levels were lower in patients of group 1 (45.2 +/- 2.4 mg/dL) than in those of group 4 (54.7 +/- 3.5 mg/dL; P < 0.05) and group 5 (53.6 +/- 2 mg/dL; P < 0.001), whereas low density lipoprotein cholesterol levels were higher in patients of group 1 (127.3 +/- 7.9 mg/dL), group 2 (129.2 +/- 9.5 mg/dL), and 3 (133 +/- 9 mg/dL) than in those of group 5 (102.4 +/- 7.4 mg/dL; P < 0.05). Patients of group 2 had total cholesterol, high density lipoprotein cholesterol, and triglycerides levels at an intermediate level with respect to those in groups 1, 3, and 4. Among the five groups, no difference was found in fasting glucose concentrations, heart rate, or systolic and diastolic blood pressures. A significant increase in fat body mass and a decrease in lean body mass and total body water were found in all patients compared to controls. Disease duration was significantly shorter in patients of group 4 than in those of the remaining three groups (P < 0.001). A significant correlation was found between the GH peak after ARG+GHRH and disease duration (r = -0.401; P < 0.001), plasma IGF-I (r = 0.434; P < 0.001), total cholesterol (r = -0.324; P < 0.001), and triglycerides levels (r = -0.219; P < 0.05). A significant multiple linear regression coefficient was found between the GH peak after ARG+GHRH and plasma IGF-I levels (t = 2.947; P < 0.005), total cholesterol levels (t = -2.746; P < 0.01), and disease duration (t = -2.397; P < 0.05). In conclusion, the results of the present study indicate that the degree of the GH response to ARG+GHRH is correlated with the severity of lipid profile abnormalities and substantiate the reliability of the ARG+GHRH test for the diagnosis of GHD in adults. Because at present GH treatment is recommended only in adult patients with severe GHD, patients with a GH response below 9 microg/L to the ARG+GHRH test should be treated with GH, as should patients with a peak GH response to an insulin tolerance test below 3 microg/L.

Context: Traumatic brain injury (TBI) and subarachnoid hemorrhage (SAH) are conditions at high risk for the development of hypopituitarism. Objective: The objective of the study was to clarify whether pituitary deficiencies and normal pituitary function recorded at 3 months would improve or worsen at 12 months after the brain injury. Design and Patients: Pituitary function was tested at 3 and 12 months in patients who had TBI (n = 70) or SAH (n = 32). Results: In TBI, the 3-month evaluation had shown hypopituitarism (H) in 32.8%. Panhypopituitarism (PH), multiple (MH), and isolated (IH) hypopituitarism had been demonstrated in 5.7, 5.7, and 21.4%, respectively. The retesting demonstrated some degree of H in 22.7%. PH, MH, and IH were present in 5.7, 4.2, and 12.8%, respectively. PH was always confirmed at 12 months, whereas MH and IH were confirmed in 25% only. In 5.5% of TBI with no deficit at 3 months, IH was recorded at retesting. In 13.3% of TBI with IH at 3 months, MH was demonstrated at 12-month retesting. In SAH, the 3-month evaluation had shown H in 46.8%. MH and IH had been demonstrated in 6.2 and 40.6%, respectively. The retesting demonstrated H in 37.5%. MH and IH were present in 6.2 and 31.3%, respectively. Although no MH was confirmed at 12 months, two patients with IH at 3 months showed MH at retesting; 30.7% of SAH with IH at 3 months displayed normal pituitary function at retesting. In SAH, normal pituitary function was always confirmed. In TBI and SAH, the most common deficit was always severe GH deficiency. Conclusion: There is high risk for H in TBI and SAH patients. Early diagnosis of PH is always confirmed in the long term. Pituitary function in brain-injured patients may improve over time but, although rarely, may also worsen. Thus, brain-injured patients must undergo neuroendocrine follow-up over time.

Hypothalamus–pituitary tumours and their treatments (neurosurgery and/or radiotherapy) are major causes of acquired hypopituitarism. Scientific and clinical evidences show the positive effect of GH replacement therapy in severe adult GH deficiency (GHD) pointed toward the need of diagnostic screening of conditions at high risk for GHD. We screened 152 adults (82 males, 70 females; age: 52.3±1.2 years, age-range: 20–80 years, BMI: 26.4±0.8 kg/m 2 ) in order to disclose the presence of GHD after neurosurgery for hypothalamus–pituitary tumours. The whole group (studied at least 3 months after neurosurgery) included: 111 non-functioning pituitary adenomas and 41 peri-pituitary tumours (24 craniopharyngiomas, 7 meningiomas, 5 cysts, 2 chondrosarcomas, 1 colesteatoma, 1 germinoma and 1 hemangiopericitoma). In 14 patients who underwent both neurosurgery and radiotherapy due to a tumour remnant, the somatotroph function was evaluated again 6 months after the end of radiotherapy. GHD was assumed to be shown by GH peak μg/L (severe 3 μg/L ) after Insulin Tolerance Test (ITT) or 16.5 μg/L (severe 9 μg/L ) after GH-releasing hormone + arginine test (GHRH + ARG) (3rd and 1st centile limits of normality, respectively), two widely accepted provocative tests. Before neurosurgery GHD was present in 97/152 (63.8%) and resulted severe in 66/152 (43.4%) patients. After neurosurgery GHD was present in 122/152 (80.2%) and severe in 106/152 (69.7%). While 26 patients developed severe GHD (GHD) as consequence of neurosurgery, only one patient who had been classified as GHD before neurosurgery showed normal GH response after surgery. After neurosurgery, 91.0% (81/89) of the pan-hypopituitaric patients showed severe GHD. Considering the 14 patients who underwent also radiotherapy after neurosurgery, 7/14 had GHD before neurosurgery while 12/14 became severe GHD after radiotherapy in a context of pan-hypopituitarism. IGF-I levels below the 3rd age-related normal limits were present in 39.0% of patients in whom severe GHD was showed by provocative tests. In conclusion, this study shows that the occurrence of acquired severe GHD is extremely common in adult patients bearing non-functioning tumour masses in the hypothalamus–pituitary area and further increases after neurosurgery. All patients bearing non-functioning hypothalamus–pituitary tumours should undergo evaluation of their somatotroph function before and after neurosurgery that represents a condition at obvious more than high risk for hypopituitarism.

Primary empty sella (PES) is generally not associated with overt endocrine abnormalities, although mild hyperprolactinemia and, in children, deficient GH secretion have been reported. The aim of this multi-center collaborative study was to evaluate basal and stimulated GH secretion in a large series of adult PES patients. The study group consisted of 51 patients [41 women and 10 men, age range: 20-78 yr; (mean+/-SD) 47+/-11 yr]; results were compared with those in normal subjects (Ns) (Ns: no.=110, 55 women, age: 20-50 yr, 37+/-14 yr), and in hypopituitaric patients (HYP) with GH deficiency (HYP: no.=44,17 women, age: 20-72, 49+/-16 yr). Baseline IGF-I levels and GH responses to insulin-induced hypoglycemia (insulin tolerance test, ITT) and/or GHRH+arginine (ARG) stimulation tests were evaluated. PES patients were also subdivided according to BMI in lean (BMI 28 kg/m2 no.=29). PES patients had serum total IGF-I concentrations (mean+/-SE: 142.2+/-9.6 ng/ml) higher than HYP patients (77.4+/-6.4 ng/ml, p

Reduced bone mineral density (BMD) has been reported in patients with isolated GH deficiency (GHD) or with multiple pituitary hormone deficiencies (MPHD). To investigate whether the severity of GHD was correlated with the degree of bone mass and turnover impairment, we evaluated BMD at the lumbar spine and femoral neck; circulating insulin-like growth factor I (IGF-I), IGF-binding protein-3 (IGFBP-3), and osteocalcin levels, and urinary cross-linked N-telopeptides of type I collagen (Ntx) levels in 101 adult hypopituitary patients and 35 sex- and age-matched healthy subjects. On the basis of the GH response to arginine plus GHRH (ARG+/-GHRH), patients were subdivided into 4 groups: group 1 included 41 patients with a GH peak below 3 microg/L (0.9 +/- 0.08 microg/L), defined as very severe GHD; group 2 included 25 patients with a GH peak between 3.1-9 microg/L (4.7 +/- 0.4 microg/L), defined as severe GHD; group 3 included 18 patients with a GH peak between 9.1-16.5 microg/L (11.0 +/- 0.3 microg/L), defined as partial GHD; and group 4 included 17 patients with a GH peak above 16.5 microg/L (28.3 +/- 4.3 microg/L), defined as non-GHD. In all 35 controls (group 5), the GH response after ARG+/-GHRH was above 16.5 microg/L (40.7 +/- 2.2 microg/L). In patients in group 1, circulating IGF-I (P < 0.001), IGFBP-3 (P < 0.05), osteocalcin (P < 0.001), and urinary Ntx levels (P < 0.001) were lower than those in group 3-5, which were not different from each other; the t score at the lumbar spine (-1.99 +/- 0.2) and that at the femoral neck (-1.86 +/- 0.3) were lower than those in groups 3 (-0.5 +/- 0.7, P < 0.01 and -0.3 +/- 0.7, P < 0.01, respectively), 4 (-0.5 +/- 0.2, P < 0.01 and -0.3 +/- 0.7, P < 0.01, respectively), and 5 (-0.5 +/- 0.2, P < 0.001 and 0.0 +/- 0.02, P < 0.001, respectively). In patients in group 2, circulating IGF-I and IGFBP-3 levels were not different from those in group 1, whereas the t scores at the lumbar spine (-1.22 +/- 0.3) and femoral neck (-0.9 +/- 0.3) were significantly higher and lower, respectively, than those in groups 1 and 5 (P < 0.05) but not those in groups 3 and 4, and serum osteocalcin and urinary Ntx levels were significant higher than those in group 1 and lower than those in groups 3-5 (P < 0.001). To evaluate the effect of isolated GHD vs. MPHD, patients were subdivided according to the number of their hormonal deficits, such as panhypopituitarism with (10 patients) or without (31 patients) diabetes insipidus, GHD with 1 or more additional pituitary deficit(s) (36 patients), isolated GHD (7 patients), 1-2 pituitary hormone deficit(s) without GHD (10 patients), and normal anterior pituitary function (7 patients). The t score at the lumbar spine and femoral neck and the biochemical parameters of bone turnover were not significantly different among the different subgroups with similar GH secretions. A significant correlation was found between the GH peak after ARG+GHRH and IGF-I, osteocalcin, urinary Ntx levels, and the t score at the lumbar spine, but not that at the femoral neck level. A significant correlation was also found between plasma IGF-I levels and the t score at the lumbar spine and femoral neck, serum osteocalcin, and urinary Ntx. Multiple correlation analysis revealed that the t score at the lumbar spine, but not that at the femoral neck, was more strongly predicted by plasma IGF-I levels (t = 3.376; P < 0.005) than by the GH peak after ARG+GHRH (t = -0.968; P = 0.338). In conclusion, a significant reduction of BMD associated with abnormalities of bone turnover parameters was found only in patients with very severe or severe GHD, whereas normal BMD values were found in non-GHD hypopituitary patients. These abnormalities were consistently present in all patients with GHD regardless of the presence of additional hormone deficits, suggesting that GHD plays a central role in the development of osteopenia in hypopituitary patients.

In 18 patients with hypothalamo-pituitary diseases aged over 60 years and in 18 sex, age- and BMI-matched healthy subjects, the results of plasma IGF-I and IGF-BP3 levels and the GH response to GHRH + arginine test (GHRH + ATT) were correlated to the results of body composition, serum osteocalcin (OC) and urinary cross-linked N-telopeptides of type I collagen (Ntx) and the bone mineral density (BMD). In 10 patients and 10 controls, the GH response to ITT was also evaluated. The GH response to GHRH + ATT and ITT was markedly reduced in patients compared to controls (3.1 +/- 0.7 vs. 23.2 +/- 2.3 micrograms/L, P < 0.001 and 1.1 +/- 0.3 vs. 6.4 +/- 0.8 micrograms/L, P < 0.001), so all patients were classified as GHD, though no significant difference was found in plasma IGF-I and IGF-BP3 levels between the two groups. Body composition analysis revealed a significant increase of fat mass (37.4 +/- 2.2 vs. 28.0 +/- 1.0%, P < 0.001), a significant decrease of lean mass (62.6 +/- 2.2 vs. 72.0 +/- 1.0%, P < 0.001) and total body water (45.7 +/- 1.5 vs. 52.5 +/- 1.1%, P < 0.001) in patients compared to controls. Serum OC levels were lower (1.9 +/- 0.1 vs. 4.6 +/- 0.4 micrograms/L, P < 0.001) in patients than in controls, whereas urinary Ntx levels were similar. BMD values in lumbar spine (0.81 +/- 0.02 vs. 0.90 +/- 0.02 g/cm2, P < 0.001) and femoral neck (0.70 +/- 0.02 vs. 0.82 +/- 0.02 g/cm2, P < 0.001) were significantly lower in patients than in controls. A significant inverse correlation was found between GHD duration and lumbar spine (r = -0.73, P&1t; 0.001) or femoral neck (r = -0.81, P&1t; 0.001) BMD values and a significant direct correlation was found between GH peak after GHRH + ATT and lumbar BMD (r = 0.69, p = 0.001) in GHD patients. In conclusion, GHD in patients over 60 yrs aged with a characteristic history of hypothalamus-pituitary pathology is distinct from the physiological decline in GH secretion associated with aging.

We studied the variability of the GH response to the synthetic hexapeptide hexarelin (Hex) and the effect of sex steroids on the GH-releasing effect of Hex in a group of prepubertal short normal children. Twenty-five children were tested on two occasions 3-7 days apart with 2 micrograms/kg, i.v., Hex. The GH response to Hex was reevaluated after testosterone (T) administration in 10 boys, after ethinyl estradiol (EE) administration in 15 children (5 boys and 10 girls), and after oxandrolone (Ox) administration in 8 boys. In the 25 children tested twice, the mean GH peak and mean area under the curve after the first and second tests were similar. The mean (+/- SD) coefficients of variation of the GH peak and area under the curve responses to Hex was 22.7 +/- 21.0% and 24.0 +/- 20.7%, respectively. Priming with T and EE resulted in an increased GH response to Hex [41.8 +/- 21.0 before vs. 71.1 +/- 28.3 after T (P < 0.001); 43.0 +/- 14.5 before vs. 60.0 +/- 20.0 after EE (P < 0.005)], whereas Ox administration had no effect on the Hex-induced GH release. These data confirm that Hex is a potent stimulus for GH secretion in children with a limited intraindividual variability. In addition, we have shown that both T and EE, but not Ox, significantly augment the GH-releasing effect of Hex. Our data suggest that the sex steroid-induced increase in the GH response to Hex is mediated by estrogens.

Obesity is characterized by abnormal GH secretion, with GH levels reduced up to levels that are comparable to those found in adult patients with organic GH deficiency (GHD). Despite the marked GH insufficiency, obese patients with no evidence of pituitary disease have generally normal levels of total IGF-I but increased levels of free IGF-I. Although the mechanism of the low GH in obesity is not completely understood nor is it clear whether its relationship with visceral adiposity is causal, it is widely accepted that the low GH secretory state in obesity is reversible since it is completely reversed by the normalization of body weight. Since overweight and obesity might affect the GH response to all provocative stimuli, particular attention has been recently paid to the confounding effect of body weight on the interpretation of GH stimulating tests and appropriate cut-offs for lean, overweight, and obese subjects must be used in order to avoid false-positive diagnoses of severe GHD in obese adults. As the definition of appropriate criteria for the correct diagnosis of GHD in obesity is still debated, and the beneficial effects of chronic recombinant human GH replacement on obese individuals have not been definitely proved yet, further studies are therefore mandatory to confirm the real effectiveness of GH supplementation in conditions associated with a blunted GH secretion without organic hypopituitarism and to understand the physiological relevance of "functional" GHD on the pathogenesis of the multiple maladaptative endocrine changes involved in the pathogenesis of obesity.

This study present results of an Italian multicentric study to establish the GH cutoff levels in order to define the diagnosis of GH deficiency in adult patients with different ages.