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G Bona

Publications and source records attributed to G Bona.

At least 19 recordsLinked to original sources
PubMed2006

Ghrelin secretion in preterm neonates progressively increases and is refractory to the inhibitory effect of food intake.

CONTEXT: Ghrelin, a natural GH secretagogue, is mainly characterized by nonendocrine activities such as orexigenic effect and modulation of the endocrine and metabolic response to variations in energy balance. Ghrelin levels have been reported to be negatively associated with insulin secretion, enhanced in anorexia, and reduced in obesity. Ghrelin levels in newborns were shown to be similar to those found in children and adults without any gender-related difference. OBJECTIVE: The aim of this study was to evaluate ghrelin variations in preterm newborns as a function of fasting and feeding. METHODS: To this end, in 31 preterm neonates (13 males and 18 females) categorized as appropriate for gestational age, total ghrelin levels were measured in cord blood and then on the fourth day of life before and after meals. RESULTS: Ghrelin levels in cord blood [(median 25th-75th centile) 184; 122-275 pg/ml] were higher (P < 0.006) than levels measured in the mothers at delivery (167.0; 89-190 pg/ml). In newborns on the fourth day of life, ghrelin levels in fasting conditions (451; 348-649 pg/ml) were higher (P < 0.0004) than those in cord blood. The meal did not at all modify ghrelin levels (476; 302-775 pg/ml), which were unchanged, compared with those in fasting condition. Total ghrelin levels in cord blood were not associated with weight and length; conversely, on the fourth day of life ghrelin levels in newborns were negatively correlated to birth weight as well as the present weight (P = 0.05, r = -0.4). Ghrelin levels were independent of gender, type of delivery, and the kind of feeding regimen. CONCLUSIONS: The secretion of total ghrelin increases from delivery to the fourth day of life when it is refractory to the inhibitory effect of food intake, but it is negatively correlated to body weight.

Body Height↗
PubMed2006

Incidence and prevalence rate estimation of GH treatment exposure in Piedmont pediatric population in the years 2002-2004: Data from the GH Registry.

OBJECTIVE: The aim of this study is to estimate the annual incidence and prevalence rate of the GH treatment exposure in patients under the age of 18 treated for hypopituitarism or isolated GH deficiency (GHD) in Piedmont, during the period January 1, 2002 to December 31, 2004. METHODS: The selection criteria for recombinant human GH (rhGH) treatment in childhood were approved by the Ministry of Health in Italy in the yr 1998. The present analysis is based on data from the Registry of subjects receiving GH therapy (GH Registry) made up of the 918 pediatric patients (age <18 yr) with a diagnosis of GHD (excluding Prader-Willi and Turner syndromes and other conditions), diagnosed in the period January 1, 2002 - December 31, 2004. The case series has been described as regards the number of cases per year of diagnosis; the prevalence and incidence rates, calculated per 10,000 (per ten thousand) inhabitants, are given for each year of the study period. RESULTS: The prevalence rate increases slightly from 8.62 per thousand in 2002 to 9.44 per thousand in 2004 and the incidence rates estimated were 2.49 per ten thousand, 1.86 per ten thousand and 1.97 per ten thousand in the yr 2002, 2003 and 2004, respectively. CONCLUSION: The Piedmont GH Registry represents the first database available in Italy and could set an example for the other Italian regions as well.

Adolescent↗
PubMed2006

Influence of gender and pubertal stage at diagnosis on growth outcome in childhood thyrotoxicosis: results of a collaborative study.

OBJECTIVE: To evaluate the influence of sex as well as pubertal stage at diagnosis on the growth outcome of childhood thyrotoxicosis. DESIGN: Retrospective, collaborative study. PATIENTS AND METHODS: Longitudinal auxological evaluation in 101 patients (M/F 23/78) for 4.7 +/- 3.1 years subdivided according to pubertal stage at diagnosis into prepubertal (group I) and pubertal (group II). RESULTS: At diagnosis height and bone age (BA) standard deviation score (SDS) were positive both in girls and boys of groups I and II. In boys of group II, height SDS was significantly higher than in girls of the same group (P = 0.007) and in boys of group I (P = 0.026). During the follow-up, in group I, height SDS remained positive without significant differences between boys and girls, and in group II, height SDS remained significantly lower in girls than in boys. The age at onset of puberty and the age at menarche were within the normal range. Final height (FH) was within target height (TH) range in all groups The FH SDS and the height gain (FH-TH) were similar in girls and in boys in group I and significantly higher in boys than in girls (P < 0.05) in group II. The boys of group II showed a mean height gain significantly greater than that found in all the other groups. CONCLUSIONS: Despite the advancement of BA at presentation, there were no adverse effects on subsequent growth and FH; the growth outcome seems to be better in boys than in girls in group II.

Adolescent↗
PubMed2006

Oral glucose load inhibits circulating ghrelin levels to the same extent in normal and obese children.

OBJECTIVE: The presence of both the GH secretagogue (GHS) receptor and ghrelin in the pancreas indicates an involvement of this hormone in glucose metabolism. Ghrelin secretion is increased by fasting and energy restriction, decreased by food intake, glucose load, insulin and somatostatin in normal adults; however, food intake is not able to inhibit circulating ghrelin levels in children, suggesting that the profile of ghrelin secretion in children is different from that in adults. Moreover, how ghrelin secretion is regulated in childhood as a function of fat mass is still unclear. DESIGN AND SUBJECTS: We studied the effect of oral glucose load (75 g solution orally) on circulating total ghrelin levels in 14 obese children (group A, four boys and 10 girls, aged 9.3 +/- 2.3 years) and 10 lean children (group B, five boys and five girls, aged 9.7 +/- 3.8 years). MEASUREMENTS: In all the sessions, blood samples were collected every 30 min from 0 up to +120 min. GH, insulin and glucose levels were assayed at each time point. RESULTS: Glucose peaks following an oral glucose tolerance test (OGTT) in groups A and B were similar; however, both basal and OGTT-stimulated insulin levels in group A were higher than in group B (P < 0.05). Basal total ghrelin levels in group A (281.3 +/- 29.5 pg/ml) were lower (P < 0.0005) than in group B (563.4 +/- 81.5 pg/ml). In both groups A and B, the OGTT inhibited total ghrelin levels (P < 0.005). In terms of absolute values, total ghrelin levels in group A were lower (P < 0.0005) than those in group B at each time point after glucose load. The percentage nadir in total ghrelin levels recorded in group A (-25% at 90 min) was similar to that recorded in group B (-31% at 120 min). Total ghrelin levels were negatively associated with BMI (r = 0.5, P < 0.005) but not with glucose or insulin levels. CONCLUSION: Ghrelin secretion is reduced in obese children. It is, however, equally sensitive in both obese and lean children to the inhibitory effect of oral glucose load.

Administration, Oral↗
PubMed2006

Role of ghrelin in the regulation of appetite in children.

Ghrelin, the new recently discovered hormone, is a 28 amino-acid acylated peptide predominantly produced by the stomach characterized by a strong GH-releasing activity mediated by the hypothalamic-pituitary GH secretagogues (GHSs) receptors. Ghrelin and GHSs, acting on central and peripheral receptors, exert other actions such as stimulation of ACTH and prolactin secretion, influence on insulin secretion and glucose metabolism, orexigenic effect and modulatory activity on the neuroendocrine and metabolic response to starvation, influence on exocrine gastro-entero-pancreatic functions, cardiovascular activities and modulation of cell proliferation and apoptosis. The wide spectrum of ghrelin action requires further studies to provide critical information on the role of ghrelin and the potential perspectives of its analogues in the clinical practice. This point is of particular interest in the field of pediatric endocrinology and metabolism because the ghrelin story started focusing on GH deficiency and is now extending to aspects that once again are of major relevance such as obesity and eating disorders, regulation of the hypothalamus-pituitary-adrenal and gonadal axis. More studies are needed to evaluate the real impact of ghrelin in different non endocrine processes and the possible use of ghrelin analogues in different diseases condition.

Appetite↗
PubMed2006

Menstrual disorders in adolescence.

Altered frequency of the menstrual cycle accompanied by pain are manifestations of functional anomalies of the female reproductive system. These symptoms require prompt and accurate diagnosis and therapy to prevent a chronic condition that can seriously disturb the adolescent's psychic well being. The most common anomalies of the menstrual cycle and the causes of altered cycle frequency are outlined, as are useful criteria for diagnosing premenstrual syndrome dysmenorrhea and for distinguishing the causes and alterations in frequency and amount of menstrual discharge from other disturbances, including amenorrhea and abnormal uterine bleeding. The treatment of dysmenorrhea and quantitative alterations of the menstrual cycle is the focus of this article.

Adolescent↗
PubMed2006

[Iodine status in historically iodine deficiency area].

AIM: The median urinary iodine concentration (UIC) for schoolchildren was 90 microg/L in Biella and 136 microg/L in Novara in survey carried out in 1995-1996. Biella resulted as iodine deficiency area and Novara as iodine sufficient area. Aim of our study was to assess goiter prevalence by ultrasonography in Biella and Novara schoolchildren and to evaluate median UIC in Biella schoolchildren. METHODS: A total of 829 Biella schoolchildren and 310 Novara schoolchildren, aged 7-15 years, were submitted to thyroideal ultrasonography. Biella schoolchildren were submitted to morning-spot urine sample's collection for UIC's determination. RESULTS: The ultrasound goiter prevalence as function of age resulted 15.7% in Biella and 14.8% in Novara (P = 0.7, chi 2 test). The ultrasound goiter prevalence as function of body surface area resulted 17.1% in Biella and 7.1% in Novara (P < 0.0001, chi 2 test). UIC (25-75 degrees ) for Biella schoolchildren who attended third and fifth year of primary school was 159 microg/L (107-228 microg/L) while for Biella schoolchildren who attended second year of secondary school was 150 microg/L (92-218 microg/L). CONCLUSIONS: Based on the results of UIC, Biella is considered as iodine sufficient area. Based on the results of goiter prevalence by ultrasonography, both Biella and Novara resulted as iodine deficiency area. UIC and goiter prevalence, however, provide different informations about iodine status: UIC supplies informations about present iodine status while goiter prevalence assesses past iodine status.

Adolescent↗
PubMed2006

Geometry and bone density.

Bone development is a key process in the growing child. It is, therefore, of paramount importance to survey this process, which is characterized by increasing length and size of the bone together with its progressive mineralization. The bone status can be evaluated by different techniques, each of them having its pros and cons. Furthermore, it should be underlined that the results of bone assessment depend not only from the employed technique but also from the auxological characteristics of the subjects. It is, therefore, the aim of this review to examine the characteristics of the various methods of bone evaluation, such as dual energy X-ray absorptiometry (DEXA), peripheral quantitative computed tomography (pQCT), ultrasound and metacarpal index and to explain how changes in bone structure and geometry may influence the results.

Absorptiometry, Photon↗
PubMed2005

Hypopituitarism induced by traumatic brain injury in the transition phase.

Traumatic brain injury (TBI) has been associated with hypopituitarism in general and GH deficiency (GHD) in particular; the consequences of this on growth and development are likely to be critical in children and adolescents in the so-called "transition phase". In order to verify the consequences of TBI on pituitary function in the transition phase, we studied a population of adolescents and young adults 3 and 12 months after brain injury [no. = 23, 9 females, 14 males; age: 16-25 yr; body mass index (BMI): 21.9 +/- 0.6 kg/m2]. At 3 months, hypopituitarism was present in 34.6%. Total, multiple and isolated deficits were present in 8.6, 4.3 and 21.7%, respectively. Diabetes insipidus (DI) was present in 8.6% patients and mild hyperprolactinemia in 4.3%. At 12 months, hypopituitarism was present in 30.3%. Total, multiple and isolated deficits were present in 8.6, 4.3 and 17.4%, respectively. DI was present in 4.3% of patients and mild hyperprolactinemia in 4.3%. Total hypopituitarism was always confirmed at retesting. Multiple and isolated hypopituitarism were confirmed in 0/1 and 2/5, respectively. Two/23 patients showed isolated hypopituitarism at 12 months only; 1 patient with isolated at 3 months showed multiple hypopituitarism at retesting. GHD and secondary hypogonadism were the most common acquired pituitary deficits. These results show the high risk of TBI-induced hypopituitarism also in the transition age. Thus it is recommended that pediatric endocrinologists follow-up pituitary function of children and adolescents after brain injuries.

Adolescent↗
PubMed2005

The risk of diabetes mellitus in children born small for gestational age and treated with recombinant growth hormone.

Children born small for gestational age (SGA) are known to be at risk for both short stature and type 2 diabetes mellitus in later life. To evaluate the influence of recombinant growth hormone (rhGH) therapy on insulin sensitivity, 24 children born SGA were treated with GH at traditional doses, from 0.23 mg/kg/week (group A) to 0.46 mg/kg/week (group B). We evaluated glycosylated haemoglobin, basal glucose and insulin levels before and 1 and 2 years after GH therapy. The homeostasis model assessment (HOMA) index was used to evaluate insulin sensitivity. After 2 years of GH therapy, glycosylated haemoglobin and basal glucose did not change significantly. Insulin sensitivity fell, but still remained within the normal range. In conclusion, 2-year GH therapy had beneficial effects in SGA children without changes in glucose homeostasis. Moreover, the insulin sensitivity reduction did not correlate to the GH dose used.

Age Factors↗
PubMed2004

The effects of insulin on mesenteric blood flow in anaesthetized pigs.

Infusion of insulin in anaesthetized pigs has been shown to cause an increase in renal blood flow and a decrease in coronary blood flow, which were the net result of a vasoconstriction involving sympathetic alpha-adrenoceptor-mediated mechanisms and of a local vasodilatation involving the endothelial release of nitric oxide. In the present study, the effect of insulin on superior mesenteric blood flow was examined in pentobarbitone-anaesthetized pigs at constant heart rate, aortic blood pressure, left ventricular contractility and blood levels of glucose and potassium. In 10 pigs, infusion of 0.004 IU kg(-1) min(-1) of insulin increased mesenteric flow. In five of these pigs, intravenous phentolamine enhanced the increase in mesenteric flow elicited by insulin, a response which was abolished by the subsequent injection of N(omega)-nitro-L-arginine methyl ester (L-NAME) into the mesenteric artery. In the remaining five pigs, infusion of insulin after intramesenteric injection of L-NAME caused a decrease in mesenteric flow. This response was abolished by the subsequent intravenous administration of phentolamine. The present study showed that infusion of insulin in anaesthetized pigs primarily caused a mesenteric vasodilatation, which was the net result of two opposite effects, namely a predominant vasodilatation mediated by the endothelial release of nitric oxide and a sympathetic vasoconstrictor mechanism mediated by alpha-adrenoceptors.

Anesthesia↗
PubMed2004

Younger age at diagnosis of type 1 diabetes mellitus in children of immigrated families born in Italy.

The aim of this study was to evaluate the age of immigrants' children at diagnosis of Type 1 diabetes (T1DM) according to their country of birth. Immigration from developing countries to a westernised area causes rapid changes in the environmental conditions, and we investigated whether the location of birth, either inside or outside Italy, is associated with age at diagnosis of diabetes. Out of a prevalent hospital-based cohort of 5718 T1DM children cared for in 2002 in 47 Italian Pediatric Diabetes Units, we recruited 195 children (M: 97) of immigrants from developing countries--119 were born in Italy and 76 outside the European Union. Children with only one immigrant parent (no. 42) were also included. Age at diagnosis of T1DM, and other variables were compared with those of Italian children. Children of immigrated families born in Italy developed T1DM at a median age of 4.0 yr (IQR 2.2-6.9), whereas those born in developing countries and that had immigrated to Italy after birth developed T1DM at a median age of 7.9 yr (IQR 5.1-10.7, p < 0.001). Among the children born in Italy, 77 had parents who were both immigrants and the children's median age at diagnosis was 3.8 yr (IQR 2.1-6.3); 42 had only one immigrant parent and, when it was the father (no. = 23), median age was even younger (2.9 yr, IQR 2.0-8.2). Ten children had immigrated in their first yr of life and their median age was 9.1 yr (IQR 5.0-10.6). The median age of the Italian children was 6.6 yr (IQR 3.6-9.5). Results show that the outbreak of T1DM is earlier in immigrants' children born in Italy than in original countries.

Age of Onset↗
PubMed2004

Leptin levels as function of age, gender, auxological and hormonal parameters in 202 healthy neonates at birth and during the first month of life.

Leptin signals to the brain energy stores and balance while integrating neuroendocrine functions. Leptin levels in adults are higher in females than in males, while a gender-related difference in newborns is controversial. To clarify this point, in 202 healthy neonates we measured dynamic changes in leptin levels over the first month of life and looked for correlation between leptin levels and auxological and hormonal parameters. Cord leptin concentration in females was higher (p < 0.001) than in males. IGF-I, IGF-II, insulin, testosterone and 17beta-estradiol levels were similar in both sexes while insulin-like growth factor binding protein 3 (IGF-BP3) levels in females were slightly higher than in males. Leptin levels were positively associated to body weight, gestational age, IGF-BP3 levels, insulin levels and maternal body mass index (BMI) at time of delivery. In a subset of subjects (no. = 65), in comparison with cord levels, serum leptin levels were decreased on the 5th day of life (p < 0.0001) and then increased at 1 month (p < 0.0001). Positive association between leptin and weight was lost on the 5th day of life but present again at 1 month. In conclusion, our findings in a large population of neonates definitely show that leptin levels at birth are functions of gender, body weight and gestational age but not of length, cranial circumference, IGF-I and IGF-II levels. These findings, coupled with weight-independent prompt decrease after birth followed by weight-dependent increase at one month of life, suggest that leptin secretion in neonates as well as in adults mainly signals the nutritional state to the brain.

Adult↗
PubMed2004

Circulating ghrelin levels in the newborn are positively associated with gestational age.

OBJECTIVE: Ghrelin exerts potent GH-releasing activity and stimulates food intake. Circulating ghrelin levels are increased in anorexia and cachexia, reduced in obesity and restored by weight recovery. Newborns are characterized by GH hypersecretion associated with low IGF-I levels reflecting peripheral GH resistance. STUDY DESIGN: The aim of our study was to measure cord ghrelin levels in 117 newborns appropriate for gestational age, born either at term or preterm. RESULTS: Ghrelin levels in cord blood (median; 25th-75th centile: 327.6; 206.0-413.0 pg/ml) were higher (P < 0.0001) than those in maternal blood at delivery (133.0; 89.0-173.7 pg/ml), without gender differences. A positive correlation between ghrelin levels in mothers and newborns (r = 0.26, P < 0.01) was observed. Ghrelin levels in newborns born at term (399.0; 229.0-438.0 pg/ml) were remarkably higher (P < 0.0001) than those in born preterm (208.0; 144.5-278.9 pg/ml). A clear positive association was present between ghrelin levels and gestational age. No association between ghrelin and GH, IGF-I, insulin, glucose and leptin levels were found. CONCLUSIONS: Cord ghrelin levels show clear gestational age-related dependency. The lack of any direct relationship between ghrelin and anthropometric or biochemical parameters in adequate for gestational age newborns does not support the hypothesis that ghrelin has major role in foetal GH secretion and growth.

Adult↗
PubMed2004

Ghrelin gene polymorphisms and ghrelin, insulin, IGF-I, leptin and anthropometric data in children and adolescents.

BACKGROUND: Previous investigations on the ghrelin gene reported three common polymorphisms (Arg51Gln, Leu72Met, and Gln90Leu), but their role in overweight and obese individuals remains to be clarified. OBJECTIVE: To ascertain whether these genetic variants could influence ghrelin secretion and play a part in predisposing to earlier onset of obesity or in modulating the overweight phenotype in childhood. DESIGN AND METHODS: Mutational analysis of the entire ghrelin gene and total and acylated plasma determinations were performed in 81 obese or overweight children and adolescents (46 were obese and 35 overweight: Ob/Ow). We also recruited 168 normal-weight healthy controls (72 young adults and 96 children) for mutational or plasma ghrelin analysis. RESULTS: Median total and acylated plasma ghrelin concentrations were significantly lower in Ob/Ow individuals than in controls (175 pg/ml compared with 345 pg/ml, P<0.0001, and 95 pg/ml compared with 114 pg/ml, P<0.0001, respectively). The ghrelin gene variants showed similar allele frequencies in the Ob/Ow individuals and in controls; in the former, they were not associated with any change in total and acylated circulating ghrelin concentrations or anthropometric data. The Leu72Met status was associated with a positive family history for obesity (75% for Leu72Met compared with 39% for Leu72Leu, P=0.03) and with a greater percentage of newborns born 'large for gestational age' (33% for Leu72Met compared with 5% for Leu72Leu, P=0.03), but in the control group it was related to a lower mean body mass index z-score (-0.03 for Leu72Met and -0.47 for Leu72Leu, P=0.04). CONCLUSION: Our present findings do not support the hypothesis that the ghrelin gene polymorphisms have a relevant impact in the secretion of total and acylated ghrelin.

Adolescent↗