Multicenter retro-prospective observational study on chronic hypoparathyroidism and rhPTH (1-84) treatment

PURPOSE

The main purpose of this study was to investigate the effects of 12 months of rhPTH (1-84) (Natpar^®) treatment in a cohort of patients selected according to the indications of hypoparathyroidism guidelines. The use of recombinant human PTH (1-84) [rhPTH (1-84)] is approved as hormonal replacement therapy in patients with hypoparathyroidism not adequately controlled with conventional therapy.

METHODS

It is a multicenter, observational, retro-prospective, open label study. Eleven Italian Endocrinological centers, members of Hypoparathyroidism Working Group of the Italian Society of Endocrinology (HypoparaNET) were involved. Main outcome measures were serum and urinary calcium and phosphate concentration, calcium-phosphate product, renal function, oral calcium and vitamin D doses, and clinical manifestations.

RESULTS

Fourteen adult subjects, affected by chronic hypoparathyroidism, were treated with rhPTH (1-84) for 12 months. At 12 months of rhPTH (1-84) treatment, 61.5% of patients discontinued calcium supplement and 69.2% calcitriol. Mean albumin-adjusted total serum calcium levels quickly normalized after initiation of rhPTH (1-84) treatment compared to baseline (p = 0.009), remaining in the normal range until 12 months. Rare hypo-hypercalcemia episodes were reported. Renal function was maintained normal and no renal complications were reported. Serum and urinary phosphate and urinary calcium were maintained in the normal range. Mean phosphatemia levels linearly decreased from 3 months up to 12 months compared to baseline (p = 0.014). No severe adverse events were described.

CONCLUSIONS

Biochemical and clinical results confirm the efficacy and safety of rhPTH (1-84) therapy, which represents an important option for hypoparathyroid patients unresponsive to conventional therapy.

POR polymorphisms are associated with 21 hydroxylase deficiency

PURPOSE

Genotype-phenotype correlation in congenital 21 hydroxylase deficiency is strong but by no means absolute. Indeed, clinical and hormonal features may vary among patients carrying similar CYP21A2 mutations, suggesting that modifier genes may contribute to the phenotype. Aim of the present study was to evaluate whether polymorphisms in the p450  oxidoreductase (POR) gene may affect clinical features in patients with 21 hydroxylase deficiency METHODS: Sequencing of the POR gene was performed in 96 patients with 21 hydroxylase deficiency (49 classic, 47 non-classic) and 43 control subjects.

RESULTS

Prevalence of POR polymorphisms in patients with 21 hydroxylase was comparable to controls and known databases. The rs2228104 polymorphism was more frequently associated with non-classic vs classic 21 hydroxylase deficiency (allelic risk 7.09; 95% C.I. 1.4-29.5, p < 0.05). Classic 21 hydroxylase-deficient carriers of the minor allele in the rs2286822/rs2286823 haplotype presented more frequently the salt-wasting form (allelic risk 1.375; 95% C.I. 1.138-1.137), more severe Prader stage at birth (allelic risk 3.85; 95% C.I. 3.78-3.92), higher ACTH levels, and younger age at diagnosis.

CONCLUSIONS

Polymorphisms in the POR gene are associated with clinical features of 21 hydroxylase deficiency both as regards predisposition to classic vs non-classic forms and severity of classic adrenal hyperplasia.

Functional and structural analysis of four novel mutations of CYP21A2 gene in Italian patients with 21-hydroxylase deficiency

Congenital adrenal hyperplasia (CAH) is an autosomal recessive disorder mainly caused by defects in the 21-hydroxylase gene (CYP21A2), coding for the enzyme 21-hydroxylase (21-OH). About 95% of the mutations arise from gene conversion between CYP21A2 and the inactive pseudogene CYP21A1P: only 5% are novel CYP21A2 mutations, in which functional analysis of mutant enzymes has been helpful to correlate genotype-phenotype. In the present study, we describe 3 novel point mutations (p.L122P, p.Q481X, and p.E161X) in 3 Italian patients with CAH: the fourth mutation (p.M150R) was found in the carrier state. Molecular modeling suggests a major impact on 21-hydroxylase activity, and functional analysis after expression in COS-7 cells confirms reduced enzymatic activity of the mutant enzymes. Only the p.M150R mutation affected the activity to a minor extent, associated with NC CAH. CYP21A2 genotyping and functional characterization of each disease-causing mutation has relevance both for treatment and genetic counseling to the patients.

Tryptophan hydroxylase autoantibodies as markers of a distinct autoimmune gastrointestinal component of autoimmune polyendocrine syndrome type 1

BACKGROUND

Autoantibodies to tryptophan hydroxylase (TPHAbs) directed against serotonin-producing enterochromaffin cells (EC) have been reported in autoimmune-polyendocrine-syndrome type 1 (APS-1) patients with gastrointestinal dysfunction (GID). Serotonin plays a critical role in enteric function and its peripheral blood levels reflect serotonin release from the gastrointestinal tract.

AIMS

We test the hypothesis that TPHAbs mark a distinct autoimmune component of APS-1 characterized by an autoimmune attack toward EC, which results in clinical GID.

METHODS

TPHAbs were measured in 64 APS-1 patients. Endoscopy with gastric (antrum/body) and duodenal biopsy was carried in 16 TPHAbs+ patients (8 with and 8 without GID) and in 2 TPHAbs- patients (without GID). Immunohistochemistry of biopsy specimens was carried out using antibodies to serotonin, chromogranin-A, CD3, CD4, CD8, and CD20. Serotonin serum levels were measured in TPHAbs+ and TPHAbs- patients who had endoscopy.

RESULTS

Thirty-seven of 64 patients were TPHAbs+ (11/12 with GID and 26/52 without GID; P < .001). Gastric and duodenal biopsies in all 8 TPHAb+ patients with GID showed lymphocytic infiltration with increased CD3+CD8+ intraepithelial lymphocytes and absence of EC. Furthermore, mean serotonin serum levels were below the normal range in TPHAb+ patients with GID (P < .01). In 8 TPHAb+ patients without GID gastric and duodenal biopsies showed different grades of inflammatory infiltration and reduced number of EC. Mean serotonin serum levels were near the lower limit of the normal range. In all TPHAbs+ patients the biopsies showed a reduced number of chromogranin-A positive cells consistent with enteroendocrine cells depletion. TPHAbs- patients without GID showed normal gastrointestinal mucosa and serotonin serum levels.

CONCLUSIONS

TPHAbs appear to be markers of a distinct autoimmune component of APS-1. Progressive involvement of the gastrointestinal EC leads to the transition from preclinical to clinical disease, characterized by GID and reduced serotonin serum levels.

Autoimmune-polyendocrinopathy-candidiasis-ectodermal-dystrophy in Calabria: clinical, immunological and genetic patterns

Autoimmune polyendocrinopathy-candidiasis-ectodermal- dystrophy (APECED), also known as autoimmune polyendocrine syndrome type 1 (APS-1), is a very rare disease. Diagnosis requires the presence of at least two of three major clinical features: chronic mucocutaneous candidiasis, chronic hypoparathyroidism, and Addison's disease.

DESIGN

In this study, we analyzed Autoimmune Regulator (AIRE) gene mutations and genotype-phenotype correlation in APECED patients originating from Calabria, a region in the south of Italy.

PATIENTS AND METHODS

Four patients and their first-degree relatives were evaluated for clinical manifestations, autoantibody presence and AIRE gene mutations.

RESULTS

Three patients carried a homozygous W78R mutation on exon 2, typical of patients with APECED from Apulia; the fourth patient had a homozygous R203X mutation on exon 5, typical of APECED patients from Sicily. Clinical disease expression showed wide variability. Analysis of relatives allowed the identification of 6 heterozygotes, none of whom showed major findings of APECED.

CONCLUSIONS

No AIRE gene mutations specific to Calabria were found in patients with APS-1, but mutations similar to those in patients from Apulia and Sicily. Heterozygosity for AIRE gene mutation is not associated with major findings of APECED.

Evidence for epigenetic abnormalities of the androgen receptor gene in foreskin from children with hypospadias

CONTEXT

Hypospadias is a malformation of the penis due to an incomplete development of the male urethra, the exact etiology of which in the majority of cases remains unknown.

OBJECTIVE

The objective of the study was to assess whether defects of the androgen receptor (AR) gene (CAG repeats and methylation pattern) and DNA methyltransferases (DNMT) family are present in hypospadic patients.

DESIGN

CAG repeats length, methylation status, and expression of the AR gene were analyzed. The DNMT family was studied at the protein level and the DNMT3A sequenced.

SETTING

The study was performed at a pediatric endocrinology referral clinic.

PATIENTS OR OTHER PARTICIPANTS

Twenty boys with isolated glandular hypospadias and 20 age-matched control children undergoing a surgical procedure for circumcision were studied.

MAIN OUTCOME MEASURE(S)

CAG repeats length and AR methylation pattern in PBLs and foreskin tissue, DNMT expression and sequencing in patients and controls, and in vitro studies in cultured fibroblasts were measured.

RESULTS

AR gene methylation in foreskin tissues from patients with hypospadias was higher than in normal children. AR expression in foreskin tissue of hypospadic patients was lower than in controls, whereas the DNMT3A protein level was significantly higher in patients than controls. In cultured fibroblasts, both dihydrotestosterone and testosterone significantly reduced AR gene methylation and DNMT3A expression in a dose-dependent fashion and increased AR expression.

CONCLUSION

The AR gene in target tissues from patients with hypospadias is more methylated than in control children, resulting in a decreased expression of the AR. The mechanism underlying the modulation of the AR gene expression seems to be mediated by DNMT3A. This epigenetic alteration of the AR gene might be involved in the pathogenesis of hypospadias.

Long-term auxological and pubertal outcome of patients with hereditary insulin-like growth factor-I deficiency (Laron and growth hormone-gene deletion syndrome) treated with recombinant human insulin-like growth factor-I

BACKGROUND

GH-IGF-I axis is mainly involved in the complex process of somatic growth but emerging evidence suggests that it also influences hypothalamic-pituitary-gonadal (HPG) function.

SUBJECTS

We report some data regarding long-term auxological and pubertal outcome of five female patients with hereditary forms of GH-IGF-I deficiency (Laron and GH-gene deletion syndrome) and a mean age of 23.4±5.3 yr (range 19-32).

METHODS

All the patients received recombinant human IGF-I (rhIGF-I, Pharmacia and Upjohn, Stockholm, Sweden, and rhIGF-I, Genentech, San Francisco, CA, USA) from a mean age of 8.6 yr (range 3.2-14.2) up to the final height.

RESULTS

Final height was very disappointing (≤ -5.0 SD scores) and lower than target height in all the patients. Pubertal onset was delayed in most of them but menarche occurred spontaneously in all the patients. Median age at menarche was 15.1 yr. Menstrual cycles were regular for several years. Median duration of gynecological follow- up was 8.3 yr with the longest span of 17.2 yr.

CONCLUSION

We can assert that GH-IGF-I axis has an essential role in promoting linear growth in humans and its physiological action cannot be replaced by pharmacological treatment in most patients with hereditary forms of IGF-I insufficiency as demonstrated by their subnormal final height. Our clinical observations can also support an essential role of IGF-I in genitalia growth but not in the function of HPG axis as demonstrated by the maintenance of regular menstrual cycles in the presence of subnormal levels of IGF-I after treatment discontinuation.

GH secretion in a cohort of children with pseudohypoparathyroidism type Ia

Pseudohypoparathyroidism type Ia (PHP-Ia) is characterized by Albright's hereditary osteodistrophy (AHO) and resistance to hormones that act via the alpha subunit of the Gs protein (Gsalpha) protein, ie PTH, TSH, FSH/LH, and, as recently described in limited series, GHRH. However, the current lack of data on GHRH secretion, obesity and short stature included in the AHO phenotype hampers interpretation of GH secretory status and its effects on these subjects. We evaluated GH secretion after GHRH plus arginine (Arg) stimulus, IGF-I levels and anthropometric features in an exclusively pediatric population of 10 PHP-Ia subjects. Of our PHP-Ia children, 5 out of 10 (50%) showed impaired GH responsiveness to the provocative test, with a lower prevalence than the 75-100% previously reported. A negative correlation (p=0.024) was found between GH secretion and body mass index (BMI), whereas no correlation emerged between GH and IGF-I values (p=0.948). Height and growth velocity did not significantly differ between GH-deficient and GH-sufficient subjects. In the 5 GH-deficient patients, GHRH resistance could arguably be responsible for hormonal impairment; however, 3 of them were obese, showing normal stature and IGF-I levels: the increased BMI in these subjects could influence GH secretion and its effects. In conclusion, GH deficiency is frequent among PHP-Ia children and its prevalence is variable, two factors indicating that GH secretory testing should be part of the routine management of this patient group. It could be argued that GHRH resistance is the pathogenetic mechanism in most patients, but further studies on GHRH secretion are needed to define which values can be considered as raised. Lastly, because BMI has been indicated as a major determinant of evoked adult GH response to provocative testing, GH levels related to increased BMI also in childhood could be helpful in defining GH assessment in obese or overweight PHP-Ia children.

Aromatase is differentially expressed in peripheral blood leukocytes from children, and adult female and male subjects

OBJECTIVE

Aromatase, the key enzyme involved in estrogen synthesis, is expressed in a variety of cells and tissues including human peripheral blood leukocytes (PBLs). The present study was designed to evaluate PBL aromatase gene expression in male and female subjects of different age groups. In addition, differences in gene expression during the follicular and luteal phase of the menstrual cycle in women, and before and after testosterone administration in men, were estimated.

DESIGN

Aromatase mRNA and protein were measured in PBLs obtained from young (n = 10) and postmenopausal women (n = 10), men (n = 15), and prepubertal children (n = 10). Aromatase mRNA and protein were also measured during the follicular and luteal phases of the menstrual cycle in women, and before and after the intramuscular administration of 250 mg testosterone enanthate in men.

METHODS AND RESULTS

Aromatase mRNA measured by real-time PCR in PBLs from women during the follicular phase was significantly higher than during the luteal phase of the menstrual cycle (P < 0.05). In men, PBL aromatase mRNA values increased significantly following testosterone administration (P < 0.05). PBL mRNA aromatase levels in women during the follicular phase and men after testosterone administration were significantly higher (one-way ANOVA; P < 0.05) than in any other group. Children, postmenopausal women, and women during the luteal phase showed the lowest aromatase mRNA expression. The results of the immunoblot analysis confirmed the data obtained by real-time PCR. A positive correlation between PBL aromatase mRNA values and plasma estradiol and estrone levels during the follicular phase of the menstrual cycle was observed in the group of adult women. No other correlations were found.

CONCLUSIONS

The aromatase gene is differentially expressed in PBLs from women, men, and prepubertal children, indicating a sexual dimorphism in the enzyme expression and an important role of sex steroids in the modulation of aromatase gene expression.

Decreased androgen receptor gene methylation in premature pubarche: a novel pathogenetic mechanism?

CONTEXT

Several studies found links between DNA methylation and gene expression. In patients with idiopathic hirsutism, a preferential methylation of the of shorter androgen receptor (AR) alleles was hypothesized to be responsible for the abnormal hair growth.

OBJECTIVE

The objective of this study was to assess whether abnormalities in the AR function in both peripheral blood leukocytes (PBLs) and androgen target tissues are present in children with premature pubarche (PP).

DESIGN

Human DNA was extracted from PBLs and pubic hair and CAG repeats length and methylation status of the AR gene were analyzed.

SETTING

The study was performed at a Pediatric Endocrinology referral clinic.

PATIENTS

Twenty-five girls with PP, 23 prepubertal children, and 10 girls with Tanner stage II pubertal development were studied.

MAIN OUTCOME MEASURE

The main outcome measures were CAG repeat length and AR methylation pattern in PBLs and pubic hair.

RESULTS

In PBLs from PP patients, AR gene methylation was significantly lower (P < 0.01) than that of prepubertal children and similar to that of girls with Tanner II stage pubertal development. A negative correlation between AR gene methylation in PBLs and the age of normal children was detected. PATIENTS with PP exhibited a hair follicle AR methylation pattern similar to that of Tanner stage II girls. The mean number of CAG repeats was lower in PP patients than in prepubertal and Tanner stage II girls, although it was within the normal range for the general population in both groups.

CONCLUSIONS

The increased AR gene activity observed in PP patients, as indicated by the reduced AR gene methylation pattern, together with the presence of shorter CAG repeats, might lead to hypersensitivity of the hair follicles to steroid hormones and therefore to the premature development of pubic hair.

Evaluation of the circadian profile of peripheral plasma galanin concentrations in normal subjects

Galanin administration can influence pituitary function principally resulting in an increase in GH secretion. However, the role of circulating GAL levels in human endocrine function is still unknown. In the present study we simultaneously measured the circadian profiles of GAL, ACTH and GH in peripheral blood of ten adult subjects. Plasma samples were collected through an intravenous catheter at 0800, 1200, 1600, 2000, 2200, 2400, 0200, 0400 hours. The results were statistically evaluated by the cosinor analysis technique. A significant circadian rhythm of both plasma ACTH (p < 0.001) and GH levels (p < 0.03) was found with acrophases occurring at 0753 hrs and 0131 hrs for ACTH and GH, respectively. On the contrary, no significant rhythm was found in plasma GAL levels, indicating that no correlations exist between GAL and either GH or ACTH circadian profiles. Furthermore, the simultaneous assay of both GAL and GH plasma levels during a nocturnal frequent sampling performed in four volunteers showed the presence of peaks in GAL levels which, however, were not concomitant to the peaks in GH levels. These data demonstrate the lack of rhythmicity in the circadian profile of plasma GAL levels in healthy human subjects. The role of GAL in human endocrine function remains unknown and these results suggest that, in spite of the well documented increase in plasma GH concentrations following the intravenous administration of GAL, physiologically circulating levels of GAL are likely not involved in the regulation of GH secretion.

[Premature pubarche]

Premature adrenarche refers to the appearance of public hair before age 8 years in girls and 9 years in boys, without other signs of puberty or virilization. Growth velocity may be increased and slightly advanced bone maturation is often present and is usually well correlated with the height age. The transient acceleraration of growth and of bone maturation have no negative effects on the onset and progression of puberty, and on final height. The diagnosis is based on the exclusion of the different forms of hyperandrogenism such as precocious puberty, late-onset congenital adrenal hyperplasia, virilizing tumors, glucocorticoid resistance, and Cushing syndrome. Once the diagnosis is made, no treatment is needed. However, a long-term follow-up of these patients is warranted. Recent data, in fact, indicate that girls with premature adrenarche may not have a benign outcome. Postpubertal girls with premature adrenarche during childhood have an increased frequency of functional ovarian hyperandrogenism. Furthermore, hyperinsulinemia is a common feature in adolescent patients with premature adrenarche and functional ovarian hyperandrogenism, and appears to be directly realted to the degree of androgen excess. Although the mechanisms interlinking the triad of premature pubarche, hyperinsulinemia and ovarian hyperandrogenism remain enigmatic, this frequent concurrence may result, at least in part, from a common early origin rather than from a direct interrelationship later in life.

Leptin, cortisol, and GH secretion interactions in short normal prepubertal children

The hormonal regulation of the ob gene and leptin secretion in humans is still unclear. To investigate the interactions among leptin, cortisol, and GH, we analyzed and time-cross-correlated their spontaneous 24-h secretion in 12 short normal prepubertal children of both sexes (6 females and 6 males). Time-cross-correlation analyses demonstrated that leptin and cortisol were correlated in both a negative and positive fashion. The negative correlation, with cortisol leading leptin by 4 and 3 h for boys and girls, respectively, might reflect the stimulatory effect of CRH on the sympathetic system, which inhibits leptin secretion; the positive correlation, with leptin leading cortisol by 6 and 5 h for boys and girls, respectively, might reflect a direct effect of leptin on CRH secretion in the hypophyseal portal system. Time-cross-correlation analyses also showed a strong positive correlation between GH and leptin concentrations, with GH leading leptin by 5 and 2 h for boys and girls, respectively, suggesting a possible direct leptin-releasing effect of GH on adipocytes. We conclude that cross-correlation analyses of 24-h hormone secretions under baseline physiological conditions suggest that the hypothalamic-pituitary-adrenal axis might have a prevailing inhibitory effect on leptin secretion, whereas leptin might exert a positive effect on the hypothalamic-pituitary-adrenal axis. The relation between GH and leptin could be a direct one and characterized prevalently by a positive effect of GH on leptin secretion. Further investigations using different experimental systems are needed to ascertain the validity of these mathematically educed conclusions.

Leptin inhibits steroid biosynthesis by human granulosa-lutein cells

Absence of leptin secretion compromises reproductive function and fertility in the ob/ob mouse which, when given leptin, shows a rise in serum LH levels and becomes fertile. Recently, the long and active isoform of the leptin receptor was detected in the ovary, indicating that leptin may also show direct gonad-related activity. To examine this, we studied the effect of graded doses of human leptin on estradiol (E2) and progesterone (P4) concentrations in the culture media of human granulosa-lutein cells obtained from follicular fluid of women undergoing in vitro fertilization. We also evaluated the mRNA expression of steroidogenic acute regulatory protein (StAR), aromatase, and cytochrome P450 17alpha (CYP17) in these cells at baseline and after exposure to leptin. Estradiol levels were significantly decreased in the media 24 hours after incubation of the cells with increasing hLeptin concentrations (10(-11) - 10(-7) mol/l). The maximal 30% decrease in E2 production was caused by the 10(-9) mol/l hLeptin concentration; however, P4 levels in the media were not influenced by leptin. Exposure of granulosa-lutein cells to 10(-9) mol/l hLeptin did not produce any measurable changes on StAR, aromatase, or CYP17 mRNA expression. When hLeptin (10(-9) mol/l) was co-incubated with increasing concentrations of hCG (1.25 - 10 mlU/ml), IGF-II (15-60 ng/ml) or 1-6 desaminated IGF-II (deslGF-II; 15-60 ng/ml), it did not modify the elevation of E2 concentrations caused by each of the different stimuli. We conclude that leptin suppresses E2 secretion by human granulosa-lutein cells but does not impair the stimulatory effects of hCG and IGFs on these cells. Leptin may play a minor, but direct regulatory role on unstimulated human ovarian steroidogenesis by interfering with either the translational or post-translational steps of the baseline CYP17 and/or aromatase synthesis and/or the activation of the enzymes.

Interactions of leptin and thyrotropin 24-hour secretory profiles in short normal children

Thyroid hormones and leptin have effects on similar aspects of body homeostasis, such as energy expenditure, thermogenesis, and metabolic efficiency. Thus, the cross-talk between the thyrostat and the lipostat might play a crucial role in the maintenance of body homeostasis. To investigate the relationship between the hypothalamic-pituitary-thyroid (HPT) axis and leptin under physiological conditions, we evaluated the pulsatility and circadian rhythmicity and time-cross-correlated the 24-h secretory patterns of leptin and TSH in 12 short normal prepubertal children (6 girls and 6 boys). In both male and female subjects, leptin was secreted in a pulsatile and circadian fashion, with a nocturnal leptin surge that was more pronounced in males than in females. Mean 24-h leptin levels and total area under the curve were significantly higher in girls than in boys. This was mainly due to the nighttime mean leptin levels and total area under the curve, which were higher than those in boys. The cross-correlated 24-h leptin and TSH levels revealed significant positive and negative correlations. The positive one, of leptin over TSH, suggests a positive feedback regulation by leptin on the HPT axis, which might play an important role in triggering the neuroendocrine response to starvation, including decreased thyroid hormone levels. The negative correlation, of TSH over leptin, could explain the compensatory changes in adipocyte metabolism, and indirectly in circulating leptin levels, in response to alterations in thyroid status. In conclusion, we suggest that under baseline physiological conditions, the HPT axis has a prevailing inhibitory effect on leptin secretion, whereas leptin has a prevailing positive effect on the HPT axis. The sexual dimorphism in leptin levels does not seem to influence in a major way the interactions between the HPT axis and leptin.

Final height in isolated GH deficiency type 1A: effects of 5-year treatment with IGF-I

Data concerning final height (FH) in isolated growth hormone deficiency type 1A (IGHD1A) are scanty and controversial. In this paper we report the FH outcome of two girls with IGHD1A who were treated either with GH only (first patient) or with GH during the first 8 years and successively with IGF-I (second patient). In the first patient, FH was only slightly subnormal and slightly taller with respect to target height (TH). Surprisingly, FH was severely subnormal and very far from TH in the patient who underwent IGF-I therapy for >5 years: an auxological outcome similar to the one recently reported in the only two cases in the literature of patients with IGHD1A who have been treated with IGF-I until near FH achievement. We conclude that IGHD1A could have a very heterogeneous phenotypic expression in terms of FH and that IGF-I therapy, even though initiated some years before puberty onset and prolonged for more than 5 years, may not be able to ensure the normalization of height prognosis and the achievement of an FH close to TH.

Long-term results with growth hormone therapy in idiopathic hypopituitarism

More than 30 years after its introduction, growth hormone (GH) treatment is well established in children with GH deficiency. Nevertheless, the long-term results of this therapy, expressed as height, are generally considered unsatisfactory. We report on results obtained in a group of GH-deficient children who were treated with daily injections of recombinant GH within the first 5 years of life and who reached an adult height very close to their target height. The full catch-up growth to the target height demonstrated in these patients suggests that replacement therapy should be started early and continued until adulthood. Height at onset of puberty is an important variable which might significantly influence the adult height. The significant and prolonged influence of birth weight on growth response to GH therapy underlines the important role of fetal growth in planning early treatment of GH-deficient children.

An unusual MR presentation of the neurohypophyseal "bright spot" in pituitary dwarfism

Abnormalities of the hypothalamo-hypophyseal axis are frequently associated with pituitary deficiency. We describe a previously unknown morphological presentation of the ectopic posterior neurohypophyseal "bright spot."

Growth hormone immunoreactivity does not reflect bioactivity

In childhood, the largest secretory burst of GH occurs during nighttime, and consists of a complex mixture of molecular forms of GH that are thought to have different biologic activity. Standard GH assays cannot distinguish between bioactive and biologically inactive GH isoforms. To examine this relationship, overnight GH secretion was assessed by blood sampling every 30 min in 10 short prepubertal children (7 boys and 3 girls) to evaluate both the serum concentration and the biologic activity of GH. Serum GH concentrations were measured by an immunofluorometric assay and its biologic activity by the Nb2 cell bioassay. The 12-h (2000 h to 0800 h) and 6-h (2000 h to 0200 h and 0200 h to 0800 h) GH profiles were analyzed using the Pulsar program. When GH secretory pattern was measured by immunofluorometric assay, the area under the curve above the 0 line, the mean GH concentration, and the mean height of the secretory peaks were significantly higher during the first than during the second part of the night (29.17+/-5.93 versus 16.29+/-1.87 mIU/L, p<0.05; 7.77+/-1.28 versus 4.83+/-0.33 mIU/L, p<0.05; 4.61+/-0.94 versus 2.68+/-0.27 mIU/L, p<0.05, respectively). In contrast, GH biologic activity was not significantly different during the two parts of the night. In conclusion, a dissociation between GH bioactivity and immunoreactivity is present in physiologic conditions, indicating that standard GH measurements do not provide any information on the biologic activity of the hormone. Although GH secretion is regulated by complex neuroendocrine mechanisms, the biologic activity of the hormone seems to be independent of them and is most probably regulated by peripheral mechanisms acting on its clearance or bioavailability to the target tissues.

Insulin pulsatility in obese and normal prepubertal children

OBJECTIVE

To assess whether in prepubertal children insulin secretion is pulsatile as in adults and to study the influence of body weight on the pattern of insulin secretion.

DESIGN AND PATIENTS

Insulin profiles were obtained by 4-min sampling for 2 h, starting at 08.00 a.m. after an overnight fast in 10 prepubertal obese children (BMI-SDS 4.9 +/- 1.6) and in 6 healthy age-matched controls. Five of the obese children were also studied after weight reduction (Delta BMI-SDS 1.6 +/- 0.4). The data have been analyzed by the Pulsar program.

RESULTS

Obese children had higher mean insulin levels, insulin secretory areas under the curve above 0 (AUC0), and AUC above baseline (AUCb), with more frequent peaks of larger amplitude and duration compared to controls. Following weight reduction there was a normalization of AUC0 and mean insulin levels while AUCb, peak frequency, amplitude and duration did not change significantly. Correlation analysis revealed that BMI-SDS was strictly related to the parameters of pulsatile insulin secretion such as AUC0, AUCb, mean insulin level, peak amplitude and peak frequency.

CONCLUSIONS

Insulin secretion in children is pulsatile and its secretory pattern is influenced by body weight.

[A magnetic resonance study of 39 children with different causes of short stature]

PURPOSE

To investigate the relationship between Magnetic Resonance (MR) findings and the presence of isolated growth hormone deficiency (IGHD) or multiple pituitary hormone deficiency (MPHD).

MATERIAL AND METHODS

39 children, 27 boys and 12 girls (mean age 9.6 years) were enrolled. The growth hormone deficiency and MPHD were defined by standard laboratory methods. MR scans of the hypothalamo-hypophyseal tract were carried out on all patients before the therapy. Perinatal histories were reviewed.

RESULTS

The pituitary anterior lobe was considered small in 13/39 (33%). Twenty-six of 39 (66%) patients did not show any abnormalities of the hypothalamohypophyseal tract. An ectopic neurohypophysis was found in 8/39 patients (20%). Only 2 patients among those with an ectopic neurohypophysis showed a small anterior pituitary lobe. Thirty-three of 39 (84.6%) patients showed IGHD while 6/39 (15.4%) patients showed MPHD. Twenty-eight of 39 (71%) patients had a severe deficiency while 11/39 (28%) patients had a moderate deficiency.

CONCLUSION

Our study confirms the usefulness of MRI in the diagnostic and therapeutic approach to short stature in children; in fact 48% of patients in our series showed MR findings reasonably related to hormonal deficiency.

[Hypopituitarism during the first year of life. A collaborative Italian study]

Literature data on statural growth effect of growth hormone (GH) treatment of children with GH deficiency (GHD) appears disappointing when treatment had late onset. It seems therefore that GH treatment should be started as early as possible, thus requiring early diagnosis. This study was undertaken: 1) to define the main characteristics of early onset GHD which may help the clinician for early diagnosis; 2) to evaluate the effect of a GH treatment on the statural growth of early onset GHD, when treatment is started before 1 year of age. Sixteen children with GHD diagnosed before 1 year of age were included in the study; all of them received a GH treatment before 1 year of age and for a minimal duration of 5 years; four had isolated GHD secondary to a GH gene deletion (type 1A GHD). Based on this series, the main anamnestic and clinical characteristics of early onset GHD are: frequent perinatal pathology, short birth height in more than half of the cases, relatively elevated birth weight in all cases, poor statural growth with neonatal onset, associated signs (hypoglycemia, special facies, micropenis, cryptorchidism, liver dysfunction). The effect of GH treatment (> or = 5 years) on statural growth was limited and transient in children with type 1A GHD, and resulted in an incomplete catch-up growth in children with sporadic GHD, their mean height remaining significantly below their target height.

Birth weight influences long-term catch-up growth and height prognosis of GH-deficient children treated before the age of 2 years

OBJECTIVE

To investigate which pretreatment variables most significantly affect long-term growth response to GH therapy in children with apparently idiopathic GH deficiency (GHD) treated from a similar and very young age (less than 2 years), for the same period (7 years) and with the same therapeutic protocol.

DESIGN AND METHODS

Twelve children with either isolated GHD or multiple pituitary hormone deficiency were treated with biosynthetic human GH (0.7IU/kg per week) and were examined every 6 months. Height measurements were performed by Harpenden stadiometers. Bone age was evaluated every 12 months.

RESULTS

The onset of therapy was followed in all patients by an important height gain, which attained its zenith during the first year of treatment and became progressively less evident during the next 4 years. Cumulative height gain was 3.0+/-1.7SDS. Thanks to the therapy, at the end of the 7-year treatment period, average height in the entire series was not significantly far from mean target height (TH) (-0.7+/-1.3 vs -0. 3+/-0.4SDS) and average predicted height (PH) (-0.2+/-1.4SDS) was very close to TH. A stepwise regression analysis showed that both catch-up growth under therapy and PH at the end of the 7-year treatment period were positively influenced by birth weight (BW).

CONCLUSIONS

a) Our 7-year prospective study on GHD infants treated with GH from less than 2 years of age confirmed the importance of early diagnosis and treatment of GHD in childhood. b) The influence of BW on growth response to GH therapy in GHD children persists over time, at least when treatment is begun from less than 2 years of age.

The natural history of premature adrenarche

The growth and pubertal development of patients with premature adrenarche are reported to be normal, but the effects of this condition on pubertal growth are not well documented. In the present study the growth kinetics of a group of 38 female patients with isolated premature adrenarche followed in our institution for a period of 5.77 (SD=1.7) yr were evaluated to assess whether and how premature adrenarche affects pubertal growth and final height. Birth weight and length, height, skeletal maturation, onset of puberty, age at menarche, height prognosis and final height were documented. To examine the shape of growth kinetics, growth profiles of each girl were fitted with Preece-Baines nonlinear function (PB1) and mean constant curves were obtained by a 2-stage linear model. The biokinetic constants of the patients were compared both with those obtained by Preece and Baines in normal British girls participating in the Harpenden study and by Milani et al. in normal Italian girls. Birth weight and length of premature adrenarche patients were within the normal range for a northern Italian population [+0.29 (1.57) and -0.40 (1.49) SDS, respectively]. Analysis of the biokinetic constants showed that in PA girls the prepubertal component of height velocity, ie. the one preceding the diagnosis of PA, was consistently higher than that of both normal Italian and Harpenden girls, accounting for the increased height of the patients at the beginning of puberty. In contrast, the pubertal component of height velocity was reduced with respect to control groups, leading to a final height similar to the one estimated by the PB1 model and to the target height. In conclusion, the transient acceleration of growth and bone maturation observed in girls with premature adrenarche did not negatively influence the onset and progression of puberty but modified the growth pattern of these patients. Prepubertal growth was enhanced with respect to normal controls, and this enhancement was compensated for by a reduction of the pubertal growth component leading to a final height in accordance with the target height. This abnormal growth shape is not due to an altered tempo of growth but it is rather a consequence of premature adrenarche.

McCune-Albright syndrome: a longitudinal clinical study of 32 patients

We report the diagnostic clinical features and their long term evolution in 32 patients with McCune-Albright syndrome. Patient data are made up of two periods: the first, classified as personal history, is from birth until the time when the diagnosis of McCune-Albright syndrome was made; the second, classified as clinical observation, is from the first observation until the end of follow up. The total duration of these two periods was 9.6+/-2.9 yr; mean age at first observation was 5.7 yr (range 0.7-11 yr). The probability of manifesting main clinical signs according to age was calculated: almost all had skin dysplasia at birth, 50% probability of peripheral precocious puberty in females at 4 years and 50% of bone dysplasia at 8 years of age were found. Other clinical signs had diagnostic relevance when preceding the main signs leading to diagnosis of McCune-Albright syndrome even without specific genetic investigation. The most important clinical manifestations have different evolutions: skin lesions increase in dimensions according to body growth; precocious puberty in females evolves rapidly but periods of regression can be seen in some patients; bone dysplasia in most patients evolves with an increase both in the number of affected bones and in the severity of lesions.

Ketoacidosis and hyperosmolarity as first symptoms of type 1 diabetes mellitus following ingestion of high-carbohydrate-containing fluids

The concomitant occurrence of diabetic ketoacidosis and hyperosmolarity is reported in two children, as early symptoms of misdiagnosed type 1 diabetes mellitus. The precipitating factor for both severe metabolic abnormalities was the ingestion of a large amount of high-carbohydrate-containing fluids, a few days before admission. A similar situation has never been reported before in the literature. A successful therapeutic scheme is described.

Androgen receptor-mediated hypersensitivity to androgens in women with nonhyperandrogenic hirsutism: skewing of X-chromosome inactivation

Idiopathic hirsutism may result from an increase in the androgen receptor (AR)-mediated sensitivity of the hair follicle. The AR gene is located on the X-chromosome and contains a highly polymorphic trinucleotide repeat (CAGn) in its first exon, whose length and methylation pattern affect both AR expression and function. We analyzed these CAG repeats in the genomic DNA from 16 nonhyperandrogenic hirsute patients (Ferriman score: 16 +/- 4.7, mean +/- SD) and 10 normal controls (Ferriman score: 3 +/- 1.4), who were similar in their hormonal profiles. We found no difference in the number of CAG repeats between hirsute patients and controls, and no correlation between number of repeats and the Ferriman score or hormonal values. However, after DNA digestion with methylation-sensitive HpaII and measurement of the optical density, we found a marked decrease in the hirsute group (P < 0.0001), which was greater than in the control group (P = 0.0003). In addition, in the hirsute patients, the shorter of the two alleles was preferentially less methylated (P = 0.007), suggesting skewing of X-chromosome inactivation in the patients but not in the controls. When the mean optical density of both alleles was correlated with the Ferriman score, we observed a significant negative correlation (P = 0.02, r = -0.45), which became stronger when the shorter alleles were analyzed separately (P = 0.01; r = 0.48). We conclude that nonhyperandrogenic hirsutism is associated with skewing of X-chromosome inactivation in peripheral blood lymphocytes. This leads to the longer of the two AR alleles being preferentially methylated, allowing for the shorter (and presumably, more functional) allele to be expressed on the active X-chromosome. Further studies need to be performed to investigate whether this phenomenon is present in androgen-sensitive tissues in these patients.

Effectiveness of a prevention program for diabetic ketoacidosis in children. An 8-year study in schools and private practices

OBJECTIVE

To shorten the period of carbohydrate intolerance preceding the diagnosis of IDDM in children.

RESEARCH DESIGN AND METHODS

The incidence of diabetic ketoacidosis (DKA) was studied in newly diagnosed diabetic children aged 6-14 years, in the area of Parma, Italy, 8 years after an information program on DKA was introduced to teachers, students, parents, and pediatricians. Information was provided by displaying a poster with a few practical messages in 177 primary and secondary public schools. The pediatricians working in the same area were given equipment for the measurement of both glycosuria and blood glucose levels, as well as cards listing guidelines for the early diagnosis of diabetes, to be given to patients. A toll-free number was also provided. Clinical and laboratory features of 24 young diabetic patients diagnosed in the Parma area (group 1) were compared with those of 30 patients coming from two nearby areas in which no campaign for the prevention of DKA had been carried out (group 2).

RESULTS

From 1 January 1991 to 31 December 1997, DKA was diagnosed in 3 children from group 1 (12.5%) and in 25 children from group 2 (83.0%) (chi 2 = 26.8; P = 0.0001). The three cases of DKA in group 1 were observed in 1991 (n = 1) and in 1992 (n = 2). No patients from the Parma area who had DKA were admitted to our unit after 1992. The duration of symptoms before diagnosis was 5.0 +/- 6.0 and 28.0 +/- 10.0 days (P < 0.0001), in groups 1 and 2, respectively, Metabolic derangements were less severe in patients of group 1 than in those of group 2. Hospitalization for the treatment of overt diabetes and for the teaching of self-management of the disease lasted 5.4 +/- 1.2 days in group 1 and 13.3 +/- 2.4 days in group 2 (P = 0.002). The total cost of the 8-year campaign was $23,470.

CONCLUSIONS

The prevention program for DKA in diabetic children aged 6-14 years, carried out in the Parma area during the last 8 years, was successful. Thanks to this program, cumulative frequency of DKA in new-onset IDDM decreased from 78% during 1987-1991 to 12.5% during 1991-1997. None of the newly diagnosed diabetic children aged 6-14 years and from the Parma area were ever admitted to the hospital for DKA after 1992.

An improved polymerase chain reaction (PCR) protocol for unambigous detection of growth hormone gene deletions

hGH-1 gene deletions are detected by simultaneous PCR amplification along the two homologous DNA sequences flanking the hGH-1 gene on both sides and are differentiated by SmaI restriction enzyme digestion. We have observed that among the SmaI digested PCR products from normal homozygous subjects, from those heterozygous for the 7.6 kb deletion and from those heterozygous for a 6.7 kb deletion, along with the expected fragments there is an unexpected 1470 bp fragment. This fragment arises from the co-amplification of a third homologous sequence located downstream from the hGH-1 gene and it confuses differentiation between normal homozygous and heterozygous for 7.6 kb subjects from the 6.7 kb heterozygous subjects. To overcome this problem we have improved PCR conditions using a different reverse primer. These changes avoid the interaction of the primers with the third homologous sequence located downstream from the hGH-1 gene and prevent the appearance of this additional band that complicates the interpretation of the results. We conclude that the new reverse primer sequence avoids the amplification of the downstream hGH-1 gene sequence and the production of the 1474 bp band after SmaI endonuclease enzyme digestion and makes it possible to differentiate homozygous normal subjects and those who are heterozygous for a 7.6 kb deletion from those who are heterozygous for a 6.7 kb deletion.

Relationships between neuroradiological and clinical features in apparently idiopathic hypopituitarism

In this study, perinatal history, postnatal auxological and clinical evolution and endocrine features were retrospectively evaluated in 49 children, adolescents and young adults with apparently idiopathic hypopituitarism. They were divided into two groups according to magnetic resonance images: 32 patients with isolated pituitary hypoplasia (group A) and 17 with pituitary stalk interruption syndrome (group B). The aim of the study was to assess whether these neuroradiological pictures are associated with specific endocrine and clinical patterns. No significant difference in terms of gestational age, intrauterine growth and rates of adverse perinatal events was found between the two groups. Clinical signs documenting the existence of pituitary dysfunction in utero or shortly after birth were either slightly (micropenis, cryptorchidism, cholestatic jaundice) or significantly (hypoglycemia) more frequent in patients in group B. Although diagnosis of hypopituitarism was made significantly earlier in patients in group B, height deficiency at diagnosis was similar in both groups. Endocrine investigations revealed a more severe and widespread impairment of pituitary function among those in group B. The main conclusion is that the postnatal clinical course is more severe when growth hormone deficiency is associated with pituitary stalk interruption syndrome than when the pituitary is only reduced in height, probably because of the more severe and widespread impairment of pituitary function in the former cases.

Precocious puberty in girls adopted from developing countries

Nineteen girls adopted from developing countries were referred for signs of idiopathic precocious puberty. After adoption, the catch up in linear and weight growth, together with improved nutritional and psychological conditions, may trigger the onset of puberty. Precocious puberty is a frequent and unnatural event in these girls. Treatment with gonadotrophin releasing analogues is indicated in patients diagnosed early, and when height prediction is poor.

Growth hormone deficient children treated from before two years old fail to catch-up completely within five years of therapy

We retrospectively investigated growth response to therapy of 12 patients with idiopathic growth hormone deficiency (GHD), who received GH (0.6-0.7 IU/kg/week) in daily subcutaneous injections from before 2 years of age and for a period of 60 months, in order to ascertain whether very early treatment can enable GHD children to catch-up quickly and completely their initial height deficiency. The onset of therapy was followed in all patients during the 1st year by a significant growth spurt, which persisted, even though attenuated, during the following 4 years. Height deficiency for chronological age (CA) significantly and progressively decreased during the entire study period (from -3.7 +/- 1.9 to -1.0 +/- 1.0 SDS, p < 0.0025), with a cumulative height gain of 2.7 +/- 1.6 SDS. In spite of this catch-up growth no patient attained the target percentile by the 5th year of therapy and their average height (CA) was still lower with respect to the average target height (TH) at the last check-up. Because of the significant bone age (BA) delay still persisting in most patients, a further and complete catch-up growth is likely to occur during the next years of treatment, as suggested by the finding that average height (BA) at the last examination was higher than average TH. It is concluded that: a) in spite of modern therapeutical schedules with daily GH injections and frequent adjustments of doses, GHD children, even though treated from before two years of age, fail to catch-up completely their initial height deficiency, at least by the 5th year of therapy; b) a more prolonged treatment is probably needed to allow them to attain their target percentile. This emphasizes the importance of both early diagnosis and long-lasting treatment.

Spontaneous thyrotropin and cortisol secretion interactions in patients with nonclassical 21-hydroxylase deficiency and control children

Both exogenous and endogenous hypercortisolism result in reduced TSH secretion and mild hypothyroidism. However, little is known about the relation between endogenous TSH and cortisol secretion under physiological or slightly disturbed conditions. To examine this, we evaluated the pulsatility and circadian rhythmicity and time-cross-correlated the 24-h secretory patterns of cortisol and TSH in eight prepubertal children with nonclassical congenital adrenal hyperplasia (NCCAH) and eight age-matched short normal children. In both groups, TSH and cortisol were secreted in a pulsatile and circadian fashion, with a clear nocturnal TSH surge. Although no difference in mean 24-h TSH levels was observed between the two groups, daytime TSH levels were lower in the NCCAH group than in control children (P < 0.05). The cross-correlation analysis of the 24-h raw data showed that TSH and cortisol were negatively correlated, with a 2.5-h lag time for both groups, with cortisol leading TSH. This correlation might reflect a negative glucocorticoid effect exerted on the hypothalamic-pituitary-thyroid axis under physiological conditions. A significant positive correlation with TSH leading cortisol was observed at 8.5 and 5.5 h lag times for the control and NCCAH groups, respectively. The substantially shorter lag time of this positive correlation in NCCAH children than in controls suggests that in the latter, the nocturnal TSH peak occurs temporally closer to their compromised morning cortisol peak. These data indicate that the hypothalamic-pituitary-adrenal axis has a primarily negative influence on endogenous TSH secretion and that even mild disturbances in cortisol biosynthesis are associated with slight alterations in TSH secretion.

Corticotropin-releasing hormone (CRH) inhibits steroid biosynthesis by cultured human granulosa-lutein cells in a CRH and interleukin-1 receptor-mediated fashion

The presence of immunoreactive CRH was recently demonstrated in human ovaries. CRH immunoreactivity was localized by immunohistochemistry in the cytoplasm of thecal cells surrounding the ovarian follicles, in luteinized cells of the stroma, and in large granulosa-derived luteinized cells of developing corpora lutea. Also, CRH and its receptors were identified in Leydig cells of the testis where CRH was shown to inhibit testosterone biosynthesis. To examine the role of CRH in the ovary, we studied its effect on estradiol (E2) and progesterone (P4) release by human granulosa cells obtained from women undergoing in vitro fertilization for male factor infertility or uni- or bilateral tubal impatency. In all subjects, superovulation was induced by treatment with gonadotropins. The effects of graded doses of ovine CRH (10[-11]-10[-6] mol/liter) were evaluated in the conditioned medium obtained after 24 h incubation of the cells. All CRH concentrations employed except for the lowest one (10[-11] mol/liter) caused a significant decrease of media E2 and P4 levels. Maximal inhibition for both E2 and P4 production was obtained by 10[-6] mol/liter CRH concentration, which decreased hormone production by 39% and 34%, respectively. The alpha-helical CRH9-41 antagonist at 10(-6) and 10(-7) mol/liter blocked the suppressive effect of 10(-9) mol/liter CRH on both E2 and P4 secretion, while it had no effect when added to the culture media without CRH. Since interleukin (IL-1)-1 mediates certain actions of CRH on leukocytes, we examined whether the CRH effect on ovarian steroidogenesis was IL-1-mediated. Interleukin-1 receptor antagonist at 10(-7) and 10(-6) mol/liter blocked the inhibitory effects of CRH on E2 and P4 secretion, while it had no effect in the absence of CRH. In conclusion, CRH exerts a CRH- and IL-1 receptor-mediated inhibitory effect on ovarian steroidogenesis and might be actively involved in the still enigmatic processes of follicular atresia and luteolysis.

Ovarian 17 alpha-hydroxyprogesterone responses to GnRH analog testing in oligomenorrheic insulin-dependent diabetic adolescents

OBJECTIVE

To investigate the pituitary-ovarian function in adolescent girls with insulin-dependent diabetes mellitus (IDDM).

DESIGN

Clinical case-control study.

METHODS

The GnRH analog leuprolide acetate was administered subcutaneously to 16 adolescents with IDDM (seven eumenorrheic and nine oligomenorrheic) and 13 controls between 0800 and 0900 h. Blood samples were collected at baseline and 0.5, 3, 6 and 24 h after leuprolide to measure levels of gonadotropins, 17 alpha-hydroxyprogesterone (17-OHP), androgens and estradiol.

RESULTS

Mean baseline serum LH levels were significantly higher in eumenorrheic compared with oligomenorrheic IDDM patients, while peak LH responses to GnRH analog testing were similar in all subjects. Oligomenorrheic IDDM girls showed, as a group, a distinct 17-OHP response to GnRH analog stimulation, which in five out of nine girls was in the range of functional ovarian hyperandrogenism (> or = 8.6 nmol/l). Androgen and estradiol levels were not significantly altered in any group. No correlation was found between steroid levels and HbA1c levels, although the latter were significantly higher in oligomenorrheic than in eumenorrheic patients.

CONCLUSION

About 50% of the oligomenorrheic IDDM adolescents had an increased ovarian 17-OHP response to GnRH analog stimulation in the range of functional ovarian hyperandrogenism. Factors other than metabolic control, such as stress, may play an etiologic role in IDDM ovarian dysfunction.

Growth hormone treatment in short normal children

The efficacy of growth hormone (GH) therapy in short normal children (i.e. children without classical growth hormone deficiency [GHD]) is still under debate. This paper presents the preliminary data of a retrospective Italian multicenter study on children treated with GH until adult height was reached. Final adult height (FAH), however, is not significantly different from the predicted adult height (PAH) calculated at the beginning of treatment. This result is in agreement with those reported in the majority of other similar international surveys. In conclusion, GH should be administered to short normal children only within the framework of well designed prospective experimental studies, which should consider several auxological, clinical and biochemical parameters capable of influencing the therapeutic results.

Dose-dependent inhibition of growth hormone (GH)-releasing hormone-induced GH release by corticotropin-releasing hormone in prepubertal children

Previous studies have shown that CRH is capable of inhibiting GH release in response to GHRH in adult subjects, and this effect appeared to be sex dependent and more pronounced in women than in men. To assess whether CRH has an inhibitory action on GH release in children also, the effects of graded doses of CRH on the GHRH-induced GH secretion were studied in three groups of prepubertal children. All subjects underwent a GHRH test (1 microgram/kg), followed, on separate occasions, by the combined administration of GHRH (1 microgram/kg) and CRH (1 microgram/kg, group A, n = 6; 1.5 microgram/kg, group B, n = 6; 2 microgram/kg, group C, n = 7). GH concentrations in response to the single GHRH injection were comparable in the three groups. The combined administration of GHRH and CRH resulted in serum GH concentrations similar to those obtained in the same subjects in response to GHRH alone when 1 and 1.5 microgram/kg CRH were given. In contrast, the administration of 2 microgram/kg CRH together with GHRH led to an increase in GH concentrations significantly lower than those after the GHRH injection alone (GH area under the curve, 1022.18 +/- 106.26 vs. 3109.16 +/- 794.29 microgram/Lx24 h; P < 0.05). No differences in the GH response to GHRH alone or to GHRH plus CRH were detected between male and female subjects. The results of the present study indicate that CRH is capable of inhibiting GHRH-induced GH release in children. Moreover, the inhibitory effect by CRH appears to be dose dependent and not sex related.

Spontaneous cortisol and growth hormone secretion interactions in patients with nonclassic 21-hydroxylase deficiency (NCCAH) and control children

Both exogenous and endogenous hypercortisolism result in reduced GH secretion and decreased somatic growth. However, little is known about the relation between endogenous cortisol and GH secretion under physiological or slightly disturbed conditions. To examine this, we measured and evaluated the pulsatility and circadian rhythmicity, and we cross-correlated the secretory patterns of cortisol and GH in six prepubertal patients with nonclassic 21-hydroxylase deficiency (NCCAH) and seven age-matched short-normal children. Cortisol and GH were secreted in a pulsatile fashion in both the NCCAH and control groups. The nocturnal peak cortisol increment and time-integrated area were lower in the NCCAH patients than in controls, whereas there was no difference in the total 24-h cortisol secretion between the two groups. The nocturnal increase of GH in NCCAH children, on the other hand, was associated with a significant augmentation of the pulse amplitude, whereas in control children there was an elevation of the baseline component. The cross-correlation analysis of the 24-h raw data showed that cortisol and GH were negatively correlated at brief lag times of 0-30 min, and positively correlated at long lag times of 12-12.5 h in both groups, with cortisol leading GH. The negative correlation might reflect either the negative effect of glucocorticoids on the adrenergic system, which stimulates GH secretion through GH-releasing hormone (GHRH) elevations and somatostatin (SRIH) decreases, or the absence of an inhibitory effect of CRH on SRIH. The positive correlation may reflect the positive effect of glucocorticoids on the GH gene. In conclusion, NCCAH children have a mild nocturnal cortisol deficiency compared with control children, as previously reported, and a distinct circadian pattern of pulsatile GH secretion. The hypothalamic-pituitary-adrenal (HPA) axis exerts both negative and positive influences on GH secretion, with mild disturbances in cortisol biosynthesis associated with slight alterations of GH secretion.

Pituitary-ovarian responses to leuprolide acetate testing in patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency

To assess whether patients with congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency exhibit a steroidogenic response to GnRH agonist consistent with functional ovarian hyperandrogenism (FOH) and elucidate the relationship between adrenal and ovarian hyperandrogenism, the LH, FSH, estradiol, 17-hydroxyprogesterone (17-OHP), androstenedione, total testosterone, dehydroepiandrosterone, and 17-hydroxypregnenolone responses to a sc dose of leuprolide acetate (500 micrograms) were evaluated in 10 patients with classic CAH (mean age, 18.4 +/- 0.95 yr), 7 of whom had oligomenorrhea, pretreated with dexamethasone (2 mg/day for 5 days, including the day of the test). The results were compared with those obtained in 11 patients with FOH (mean age, 18.7 +/- 0.46 yr) and 17 normal women (mean age, 19.68 +/- 0.59 yr) not pretreated with dexamethasone. Leuprolide acetate stimulation caused a significant augmentation of plasma E2, 17-OHP, androstenedione, testosterone, and 17-hydroxypregnenolone concentrations in all CAH patients. However, in only 6 (60%) of them, all with oligomenorrhea, was the 17-OHP response (posttest minus pretest value) similar to that of FOH patients and significantly higher than that in controls. In this subset of CAH patients, LH plasma levels after stimulation were significantly higher than those of CAH subjects with 17-OHP responses in the normal range, controls, and FOH patients, whereas FSH levels were similar to those of controls. In this latter group, plasma FSH concentrations after stimulation were significantly higher than those in FOH. In conclusion, the results of the present study indicate that LH-dependent functional ovarian hyperandrogenism is frequent in patients with classic CAH. As ovarian hyperandrogenism might be partially responsible for the menstrual irregularities that are common complications in such patients, all classic CAH patients with oligomenorrhea should undergo short term stimulation with GnRH agonists to ascertain the presence of ovarian hyperandrogenism and receive appropriate treatment.

Growth hormone-releasing effect of oral growth hormone-releasing peptide 6 (GHRP-6) administration in children with short stature

Growth hormone-releasing peptide 6 (GHRP-6) is a synthetic hexapeptide with a potent GH-releasing activity after intravenous, subcutaneous, intranasal and oral administration in man. Previous data showed its activity also in some patients with GH deficiency. The aim of our study was to verify the GH-releasing activity of oral GHRP-6 administration on GH secretion in children with normal short stature. The effect of oral GHRP-6 (300 micrograms/kg) was compared with that of the maximally effective dose of intravenous GH-releasing hormone (GHRH-29, 1 microgram/kg). As the GHRH-induced GH rise in children is potentiated by arginine (ARG), even when administered by oral route at low dose (4 g), we studied also the interaction of oral GHRP-6 and ARG administration. We studied 13 children (nine boys and four girls aged 6.2-10.5 years, pubertal stage I) with normal short stature (height less than -2 SD score; height velocity more than -2 SD score; normal bone age; insulin-like growth factor I > 70 micrograms/l). In a first group of children (N = 7), oral GHRP-6 administration induced a GH response (mean +/- SEM; peak at 60 min vs baseline: 18.8 +/- 3.0 vs 1.1 +/- 0.3 micrograms/l, p < 0.0006; area under curve: 1527.3 +/- 263.9 micrograms l-1 h-1) which was similar to that elicited by GHRH (peak at 45 min vs baseline: 20.8 +/- 4.5 vs 2.2 +/- 0.9 micrograms/l, p < 0.007; area under curve: 1429.4 +/- 248.2 micrograms l-1 h-1).(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in dopaminergic control of circulating melanocyte-stimulating hormone-related peptides at puberty

Desacetyl alpha-melanocyte-stimulating hormone (MSH) (ACTH 1-13) is the main form of immunoreactive alpha-MSH circulating in human plasma. This study evaluates the possibility that a dopaminergic inhibitory mechanism could be operative during human development. Thus, alpha-MSH and ACTH 1-13 plasma levels were measured after dopaminergic blockade (domperidone (0.3 mg/kg body weight, maximum 10 mg, p.o.) in 13 prepubertal (aged 4.5-12.3 y) and 12 pubertal (aged 10.2-16.9 y) children. Both peptides were measured by RIA after plasma extraction on Sep-pak C-18 cartridges and reverse phase HPLC. The chromatographic profile of alpha-MSH immunoreactivity falls into two main peaks, corresponding to the retention time of alpha-MSH and ACTH 1-13. Moreover, in prepubertal children domperidone induced a significant increase of alpha-MSH from 1.7 (median) to 5.0 pmol/L, whereas no changes in alpha-MSH plasma levels were found in pubertal subjects (from 5.0 to 4.1 pmol/L). Similarly, ACTH 1-13 plasma levels significantly increased from 3.0 to 19.8 pmol/L in prepubertal children remaining stable in pubertal ones (from 7.8 to 4.6 pmol/L). Moreover, a significant negative correlation was found between basal DHEA-S levels and the plasma alpha-MSH increase after domperidone. These data demonstrate that: 1) ACTH 1-13 is the main form of immunoreactive alpha-MSH in prepubertal life and 2) the dopaminergic inhibition of both ACTH 1-13 and alpha-MSH plasma levels is apparent only in prepubertal subjects.

Growth hormone response to growth hormone-releasing hormone (GHRH), insulin, clonidine and arginine after GHRH pretreatment in obese children: evidence of somatostatin increase?

To clarify the possible neuroendocrine mechanisms underlying the impairment in growth hormone (GH) secretion present in obesity, the GH response to GH-releasing hormone (GHRH, N = 6), insulin hypoglycemia (N = 6), clonidine (N = 7) and arginine (N = 8) after GHRH pretreatment (1 microgram/kg iv 2 h before the tests) was evaluated in 27 obese peripubertal children and in a group of normal-weight short-normal children (N = 26). Growth hormone-releasing hormone pretreatment and all further stimuli elicited a statistically significant GH response in both obese and short-normal children; in the latter group arginine did not induce a significant GH response. No differences were found among the GH responses after the second stimuli in obese children, while in short-normal children the arginine peak and area values were lower than after GHRH and clonidine. Comparison between the two groups showed similar baseline but higher stimulated GH levels in normal-weight children after all tests except arginine, after which no difference was present. In conclusion, the neuroregulation of GH release seems to be similar qualitatively in normal-weight and obese youngsters; the different behavior observed after arginine, which is supposed to act through somatostatin inhibition, might be due to a chronic increase in somatostatinergic tone responsible for the lower stimulated GH levels in obesity.

Catch-up growth and height prognosis in early treated children with congenital hypopituitarism

The aim of this retrospective study was to ascertain, whether an early growth hormone (GH) treatment can normalize height prognosis of children with congenital GH deficiency (GHD). The study covers 23 children with early onset GHD who received GH 0.1 U/kg/day from the beginning of therapy (0.4-4.9 years). This dose was corrected for weight every 3 months during the whole duration of treatment (mean 7.9 +/- 2.4 years). As a consequence of the significant growth acceleration induced by GH treatment, the patients' height deficiency at the last check had changed from a range of between -8.0 and -1.8 SDS to between +0.5 and -4.3 SDS; on the average, it was significantly less severe than before treatment. Satisfactory growth acceleration was achieved in most patients concomitantly with accelerated bone maturation, as was shown by the stable height age/bone age ratio observed during the follow-up period. The predicted ultimate height was significantly greater than the pretreatment height and it did not differ from the target height. It is concluded that catch-up growth to the target percentile in GHD patients is possible, provided that substitutive treatment is begun during the first years of life and that GH doses are adjusted periodically for weight changes.