Kunihiko Hanew

Effect of acute elevation of IGF-I on circulating GH, TSH, insulin, IGF-II and IGFBP-3 levels in non-endocrine short stature (NESS)

It is not clear whether acute and slight elevation of serum IGF-I, which does not affect blood glucose levels, modulates circulating GH levels. To clarify this, small doses of recombinant human IGF-I (rhIGF-I, 5 μg/kg, iv) were administered as a bolus to 10 children with non-endocrine short stature (NESS) (5 males and 5 females, 11.2±0.7 yr old) after an overnight fast. Physiological saline was administered intravenously to sex- and age-matched NESS controls (5 males and 5 females, 10.9±0.7 yr old). The changes of serum GH, TSH, PRL, IGF-I, IGF-II, IGFBP-3, T4, T3 and plasma glucose levels after the administration were compared to those of the control subjects. Serum IGF-I levels increased significantly from 15 to 150 min after injection compared to those in the control group. The peak value was observed at 15 min (Δ increment, 74.6±11.8 μg/l). At 15 min after the injection, serum insulin was suppressed significantly (p<0.05), although plasma glucose levels were not modified significantly. Serum TSH showed a significant decrease by rhIGF-I at 15 min and 60 min, whereas serum T4 and T3 levels were not modified. Serum GH was also significantly suppressed at 60 min (p<0.02) and showed a rebound increase at 120 min (p<0.05). Serum IGFBP-3 levels after rhIGF-I were higher than controls at 90 min and 150 min. No significant changes of serum PRL, IGF-II, (IGF-I plus IGF-II)/IGFBP-3 ratios were observed after the IGF-I injection compared to controls. These results indicate that circulating IGF-I is a physiological regulator of GH secretion in normal children, since the changes of IGF-I after the small doses of rhIGF-I administration were within physiological ranges and did not affect plasma glucose levels.

Development and Validation of a New Questionnaire Assessing Quality of Life in Adults with Hypopituitarism: Adult Hypopituitarism Questionnaire (AHQ)

Objective To develop and validate the Adult Hypopituitarism Questionnaire (AHQ) as a disease-specific, self-administered questionnaire for evaluation of quality of life (QOL) in adult patients with hypopituitarism. Methods We developed and validated this new questionnaire, using a standardized procedure which included item development, pilot-testing and psychometric validation. Of the patients who participated in psychometric validation, those whose clinical conditions were judged to be stable were asked to answer the survey questionnaire twice, in order to assess test-retest reliability. Results Content validity of the initial questionnaire was evaluated via two pilot tests. After these tests, we made minor revisions and finalized the initial version of the questionnaire. The questionnaire was constructed with two domains, one psycho-social and the other physical. For psychometric assessment, analyses were performed on the responses of 192 adult patients with various types of hypopituitarism. The intraclass correlations of the respective domains were 0.91 and 0.95, and the Cronbach’s alpha coefficients were 0.96 and 0.95, indicating adequate test-retest reliability and internal consistency for each domain. For known-group validity, patients with hypopituitarism due to hypothalamic disorder showed significantly lower scores in 11 out of 13 sub-domains compared to those who had hypopituitarism due to pituitary disorder. Regarding construct validity, the domain structure was found to be almost the same as that initially hypothesized. Exploratory factor analysis (n = 228) demonstrated that each domain consisted of six and seven sub-domains. Conclusion The AHQ showed good reliability and validity for evaluating QOL in adult patients with hypopituitarism.

Plasma growth hormone (GH) responses to corticotropin-releasing hormone in patients with acromegaly — The effect of dexamethasone pretreatment and the comparison with GH responses to thyrotropin-releasing hormone, gonadotropin-releasing hormone and GH-releasing hormone

It has been reported that paradoxical GH responses to corticotropin-releasing hormone (CRH) occur in only few patients with acromegaly. However, we have observed such responses in 7 of 14 active acromegalic patients. Therefore, we have studied the GH responses to thyrotropin-releasing hormone (TRH) (500 μ, iv), gonadotropin-releasing hormone (LHRH) (100 μg, iv) and GH-releasing hormone (GHRH) (100 μg, iv) in these patients to examine the relationships between the GH responses to CRH and the responses to these hypothalamic hormones. Further, these patients received human CRH (1–41) NH2 (100 μg, iv) with or without dexamethasone (Dex) pretreatment (1 mg/100 ml saline, iv, from -30 to + 30 min) to study the mechanism of CRH-induced GH secretion, and a perifusion experiment was performed using adenoma tissue obtained at surgery from one patient (10-7M CRH and TRH were added) to elucidate whether CRH acts directly at the pituitary level. Aberrant GH responses induced by CRH were found in 7 of 14 (50%) acromegalic patients (TRH responded: 10/13,77%; LHRH responders: 2/9,22%; GHRH responders: 10/12,83%). In these patients, percent GH increment induced by CRH ranged from 81 to 144% (Mean ± SE, 118 ± 8%), and the GH peak (19 ± 3 min) appeared as early as after TRH (23 ± 4 min, N = 10). Plasma GH responses to CRH were not affected by Dex pretreatment in 4 acromegalic patients (AUC of GH responses: before, 3730 ± 1339; after Dex, 3867 ± 1616 μg/L min), whereas plasma ACTH responses of 7 patients including CRH nonresponders were significantly suppressed (AUC of ACTH responses: before, 181 ± 1827; after Dex, 1090 ± 384 μg/L-min) (p = 0.0156). In the perifusion experiment, CRH also stimulated GH release as well as TRH. These results indicate that: i) Paradoxical GH responses to CRH in acromegalic patients are not so rare, suggesting multiple abnormalities of the cell membrane of the tumor somatotrophs; ii) The relationship between CRH and glucocorticoids as is present in normal corticotropins is lacking in GH adenoma cells.

The evaluation of hypothalamic somatostatin tone using pyridostigmine and thyrotropin releasing hormone in patients with acromegaly

To indirectly evaluate the hypothalamic somatostatin (SS) tone in patients with acromegaly, the effects of pyridostigmine (PD), a Cholinesterase inhibitor which can inhibit hypothalamic SS secretion, on TRH-induced TSH secretion and the effects of SMS 201–995 on TSH or GH secretion were studied in acromegalic patients (31–69 yr, n=10), normal young (21–24 yr, n=7) and normal old male subjects (62–71 yr, n=7). After pretreatment with PD (60 mg po, -30 min), normal young subjects showed significantly enhanced TSH responses to TRH (500 μg iv, 0 min) compared to single administration of TRH, whereas normal old and acromegalic patients did not show such enhancement. Plasma TSH response to a single administration of TRH in acromegalic patients was significantly lower than that of normal young and old subjects. Although normal young and old subjects showed significantly enhanced GH responses to GHRH (100 μg iv at 0 min) after the pretreatment with PD (60 mg, -30 min), no such enhancement was observed in acromegalic patients. In contrast, the decrement in plasma TSH after SMS 201–995 administration was similar between normal subjects (5 young 5 old) and 7 acromegalic patients. Further, the maximal plasma GH decrement after administration was significantly greater in acromegalic patients than in the 5 normal young and 5 old subjects p<0.01). In conclusion, hypothalamic SS tone does not appear to be elevated in acromegalic patients compared to normal young and probably old subjects.

Women with Turner syndrome are at high risk of lifestyle-related disease -From questionnaire surveys by the Foundation for Growth Science in Japan.

In this study, the prevalence of obesity and complications of lifestyle-related diseases, such as diabetes mellitus, hypertension, dyslipidemia and liver dysfunction, as well as the relationship with karyotypes, were investigated in 492 patients with Turner syndrome (TS) aged 17 years or older. Data were obtained through questionnaire surveys administered by attending physicians throughout Japan. Collected data were compared with data from the National Health and Nutrition Survey. Patient ages ranged from 17.1 to 42.5 years (mean ± standard error, 26.6±0.2). The prevalence of lifestyle-related diseases at age 20 or over was 6.3% for diabetes, 8.7% for hypertension, 20.2% for dyslipidemia and 12.4% for liver dysfunction. These four diseases were clearly associated with severity of obesity. Obesity (BMI ≥25 kg/m(2)) was observed in 106 out of 426 patients with TS aged 15 to 39 years (24.7%) and the prevalence was significantly higher than that of the general female population (9.4%). The mean BMI in age subgroups without any complications ranged from 21.2 to 22.7, which although was within normal ranges was significantly higher than that in the general female population (20.3-21.3). In this study population, patients with TS had more complications related to lifestyle-related diseases that were highly related to obesity. Few associations between complications and karyotypes were found. In the follow-up of patients with TS, the presence of lifestyle-related disease should be considered in the evaluation and treatment of the disease.

Complex X-Chromosomal Rearrangements in Two Women with Ovarian Dysfunction: Implications of Chromothripsis/Chromoanasynthesis-Dependent and -Independent Origins of Complex Genomic Alterations.

Our current understanding of the phenotypic consequences and the molecular basis of germline complex chromosomal rearrangements remains fragmentary. Here, we report the clinical and molecular characteristics of 2 women with germline complex X-chromosomal rearrangements. Patient 1 presented with nonsyndromic ovarian dysfunction and hyperthyroidism; patient 2 exhibited various Turner syndrome- associated symptoms including ovarian dysfunction, short stature, and autoimmune hypothyroidism. The genomic abnormalities of the patients were characterized by array-based comparative genomic hybridization, high-resolution karyotyping, microsatellite genotyping, X-inactivation analysis, and bisulfite sequencing. Patient 1 carried a rearrangement of unknown parental origin with a 46,X,der(X)(pter→ p22.1::p11.23→q24::q21.3→q24::p11.4→pter) karyotype, indicative of a catastrophic chromosomal reconstruction due to chromothripsis/chromoanasynthesis. Patient 2 had a paternally derived isochromosome with a 46,X,der(X)(pter→ p22.31::q22.1→q10::q10→q22.1::p22.31→pter) karyotype, which likely resulted from 2 independent, sequential events. Both patients showed completely skewed X inactivation. CpG sites at Xp22.3 were hypermethylated in patient 2. The results indicate that germline complex X-chromosomal rearrangements underlie nonsyndromic ovarian dysfunction and Turner syndrome. Disease-causative mechanisms of these rearrangements likely include aberrant DNA methylation, in addition to X-chromosomal mispairing and haploinsufficiency of genes escaping X inactivation. Notably, our data imply that germline complex X-chromosomal rearrangements are created through both chromothripsis/chromoanasynthesis-dependent and -independent processes.

Plasma GH responses to GHRH, arginine, L-dopa, pyridostigmine, sequential administrations of GHRH and combined administration of PD and GHRH in Turner’s syndrome

To investigate GH secretory capacities in patients with Turner’s syndrome, GHRH, arginine, L-dopa and pyridostigmine (PD) were administered singly and GHRH was administered sequentially for 3 days. In addition, plasma GH and TSH responses to GHRH and TRH after pretreatment with PD were analyzed to investigate whether the hypothalamic cholinergic somato-statinergic system functioned normally. The maximal GH responses to GHRH, L-dopa and PD were significantly smaller in Turner’s syndrome (no.=14) than in normal short children (NSC, no.=14). However, there was no difference in plasma GH responses to arginine between the two groups. In ten patients with Turner’s syndrome, the plasma GH response to GHRH did not improve even after the sequential 3-day administrations. Although plasma GH and TSH responses to GHRH and TRH were significantly enhanced by the pretreatment of PD in NSC (no.=12), these responses were not enhanced in Turner’s syndrome. Plasma GH response to GHRH in Turner’s syndrome with normal body fat was still significantly lower than in NSC. It is therefore concluded that somatotroph sensitivity to GHRH is decreased in Turner’s syndrome and that this may be due to the primary defects of the somatotrophs rather than to the increased body fat. In addition, the network of cholinergic-somatostatinergic systems seemed to be impaired in these patients, while the activity of hypothalamic somatostatin neurons was thought to be maintained.

MRI of pituitary dwarfism

MR images in 52 patients with pituitary dwarfism were reviewed. Pituitary stalk was normal in 20 patients (38%), hypoplastic in 20 (38%), and absent, socalled transection, in 12 (23%). The size of pituitary stalk correlated well with clinical data and other MRI findings. MRI could disclose the morphological basis in patients with pituitary dwarfism.

Prevalence of diverse complications and its association with karyotypes in Japanese adult women with Turner syndrome—a questionnaire survey by the Foundation for Growth Science—

The reported prevalence of complications in Turner Syndrome (TS) was highly variable because of the rarity and the limited numbers analyzed. Again, possible presence of other complications that are not described as specific for TS, is also speculated. To resolve these issues, a questionnaire survey was conducted in hGH treated 492 patients with adult TS (17-42 years). The possible association with these complications and karyotypes were also analyzed. The complications and their prevalence were as follows: chronic thyroiditis (25.2%), inflammatory bowel disease (1.8%), congenital cardiovascular anomaly (11.8%), urinary tract malformation (11.8%), low bone mineral density (BMD) (42.9%), scoliosis (8.4%), hearing loss (6.2%), epilepsy (2.8%) and schizophrenia (0.9%). The majority of prevalence of these diseases in TS was higher than in the general population. In distribution, the most frequent karyotype was 45,X monosomy (28.9%), followed by 45,X/46,X,Xi (16.9%), 46,X,Xi (9.1%), and 45,X/46,XX (6.3%), while other mosaic 45,X was noted in 29.9%. Regarding the karyotype, cardiovascular anomaly was more frequent in the 45,X group and less in the 46,X,Xi group. Urinary tract malformation and epilepsy were frequently associated with the chromosome 45,X. The prevalence of low BMD was noticed more in the chromosome 46,X,Xi and 45,X/46,X,Xi, and less in other mosaic 45,X. In conclusion, the more exact prevalence of diverse complications was clarified and it exceeded the prevalence of the majority of complications in general population. As novel findings, it was observed that the prevalence of epilepsy was significantly high, and epilepsy and low BMD were frequently associated with the specific karyotypes.

Adult Heights of 258 Girls with Turner Syndrome on Low Dose of Growth Hormone Therapy in Japan

Growth hormone (GH) therapy was approved in 1999 for only GH-deficient Turner syndrome (TS) in Japan. It was subsequently approved for all cases of TS regardless of GH secretory status since 1999. The dose of GH is 1.0 u (0.35 mg)/kg/wk at present, but it was 0.5 u (0.175 mg)/kg/wk before 1999. The adult height in patients with TS on the dose of 0.5 u/kg/wk was studied from the report on of Foundation for Growth Science in 2000. GH therapy was registered for 920 cases, and 258 cases reached adult height. The mean adult height was 145.7 cm. The adult height in patients with TS without GH therapy was reported to be 138 cm in Japan. Thus, the height gain by GH treatment was 7.7 cm. The mean age at the start of GH therapy was 12.0 yr old. The mean duration of GH therapy was 5.6 yr. The mean age at the start of estrogen therapy was 17.0 yr old. Patients in Japan were older at the start of GH and estrogen therapy than in the US and Europe at that time. The adult height and gain of height SD were not correlated with age at the start GH therapy in this study. This may be the result of the older age at the start of GH therapy and the low dose of the GH therapy. Patients are beginning to start GH therapy at a much earlier age and the dose has been doubled in Japan. We expect that the recent data concerning adult height in the patients with TS after GH therapy will improve better than this report.