Basal Growth Hormone Levels Research Articles

Epidemiology of acromegaly in Ecuador

Abstract Objectives To assess the epidemiology of acromegaly in the city of Guayaquil, Ecuador, and to compare our results to those reported in the literature. Patients, material and methods An analysis was made of retrospective and prospective data from all patients with acromegaly attending endocrinology clinics at the 4 main hospitals of the public health network of Guayaquil from January 2000 to December 2014. Age at diagnosis, estimated delay in diagnosis, imaging studies of pituitary gland, basal growth hormone (GH) level, GH after an oral glucose tolerance test (OGTT-GH), and serum levels of insulin-like growth factor 1 (IGF-1) were recorded. Incidence and prevalence of the disease were estimated using information from the 2010 census of population and housing. Results Forty-eight cases were recorded in the study period in 17 males (35.4%) and 31 females (64.5%); M/F ratio = 1.8:1. Mean age at diagnosis was 47.3 ± 16.8 years (range 18–86). Delay in diagnosis was 7.3 ± 6.3 years (range 1–30). Mean age at diagnosis was 47.9 ± 18.2 years in males and 46.3 ± 15.8 years in females. Delay in diagnosis was 10.2 ± 7.9 and 5.7 ± 3.9 years in males and females, respectively. Prevalence of acromegaly is 18.7 cases per million inhabitants, and incidence of acromegaly 1.3 cases per million people per year. Conclusions Acromegaly predominates in females, and is diagnosed in the fourth decade with a delay of approximately 8 years, usually even longer in males. Incidence and prevalence are lower than reported in international series. The disease is underdiagnosed and underreported in Ecuador.

Epidemiología de la acromegalia en Ecuador

ObjectivesTo assess the epidemiology of acromegaly in the city of Guayaquil, Ecuador, and to compare our results to those reported in the literature. Patients, material and methodsAn analysis was made of retrospective and prospective data from all patients with acromegaly attending endocrinology clinics at the 4 main hospitals of the public health network of Guayaquil from January 2000 to December 2014. Age at diagnosis, estimated delay in diagnosis, imaging studies of pituitary gland, basal growth hormone (GH) level, GH after an oral glucose tolerance test (OGTT-GH), and serum levels of insulin-like growth factor 1 (IGF-1) were recorded. Incidence and prevalence of the disease were estimated using information from the 2010 census of population and housing. ResultsForty-eight cases were recorded in the study period in 17 males (35.4%) and 31 females (64.5%); M/F ratio=1.8:1. Mean age at diagnosis was 47.3±16.8 years (range 18-86). Delay in diagnosis was 7.3±6.3 years (range 1-30). Mean age at diagnosis was 47.9±18.2 years in males and 46.3±15.8 years in females. Delay in diagnosis was 10.2±7.9 and 5.7±3.9 years in males and females, respectively. Prevalence of acromegaly is 18.7 cases per million inhabitants, and incidence of acromegaly 1.3 cases per million people per year. ConclusionsAcromegaly predominates in females, and is diagnosed in the fourth decade with a delay of approximately 8 years, usually even longer in males. Incidence and prevalence are lower than reported in international series. The disease is underdiagnosed and underreported in Ecuador.

Prevalence of Simple Renal Cysts in Acromegaly.

Objective Various organs are known to be affected by the comorbidities of acromegaly. However, the involvement of renal structural comorbidities, such as cysts, has so far remained largely unknown. In this single-center study, we aimed to determine the prevalence and factors associated with simple renal cysts in Japanese patients with acromegaly. Methods A total of 71 consecutive patients with acromegaly were analyzed, who all underwent abdominal ultrasonography at diagnosis between 1986 and 2012 at Kobe University Hospital. Results Of these 71 patients, 23 (32.4%) exhibited simple renal cysts. Acromegalic patients with renal cysts tended to be significantly older, had a higher prevalence of smoking- and higher nadir growth hormone (GH) levels during the oral glucose tolerance test (OGTT) than did those without renal cysts. A multivariate logistic regression analysis showed age, smoking, and nadir GH to be independent factors associated with renal cysts. Interestingly, the number of renal cysts positively correlated with both the basal GH levels and nadir GH levels during OGTT (r=0.66, p<0.05 and r=0.70, p<0.05, respectively). In addition, the mean diameter of renal cysts positively correlated with the systolic blood pressure (r=0.84, p<0.005). Conclusion This is the first report to show the prevalence of simple renal cysts in patients with acromegaly. Elevated nadir GH levels during OGTT were found to be associated with an increased risk of simple renal cysts. Therefore, an excessive secretion of GH may be related to the development of renal cysts.

Prevalence of colonic polyp and its predictors in patients with acromegaly.

Background:There are conflicting data regarding the prevalence of colorectal polyp in patients with acromegaly.Subjects and Methods:Consecutive forty-seven acromegalic patients (21 men, 26 women), with a mean age of (40 ± 12 years) attending endocrinology outpatient department underwent full colonoscopy. All the patients underwent clinical and biochemical evaluation (glucose suppressed growth hormone (GH), Insulin-like growth factor-1 [IGF-1], fasting insulin, and glucose). The control group (n = 120) for colonoscopy was adult subjects undergoing evaluation for symptoms of irritable bowel syndrome. Clinical and biochemical parameters in acromegalic patients with colonic polyp were compared to those without a polyp.Results:Patients with acromegaly had significantly higher prevalence of colonic polyp as compared to control subjects (10.6% vs. 0.8%). None of the patients with polyp had skin tags. There was no significant difference between subjects with and without colonic polyp in duration of illness, basal, and glucose-suppressed GH and most recent IGF-1. Fasting blood sugar was significantly higher (P < 0.05) in adenoma group after adjusting for age, body mass index (BMI), and insulin levels. Patients in adenoma group showed a trend toward male gender and younger age as compared to those without adenoma.Conclusions:Subjects with acromegaly as compared to control have a higher prevalence of colonic polyps. There was no association of polyps seen with age, BMI, skin tags, homeostasis model assessment of insulin resistance index, duration of disease, and basal and glucose-suppressed GH and IGF-1 levels. There were no specific predictive factors detected. Screening full colonoscopy is recommended in all cases with acromegaly.

Growth hormone insensitivity: diagnostic and therapeutic approaches.

Growth hormone resistance defines several genetic (primary) and acquired (secondary) pathologies that result in completely or partially interrupted activity of growth hormone. An archetypal disease of this group is the Laron-type dwarfism caused by mutations in growth hormone receptors. The diagnosis is based on high basal levels of growth hormone, low insulin like growth factor-I (IGF-1) level, unresponsiveness to IGF generation test and genetic testing. Recombinant IGF-1 preparations are used in the treatment In this article, clinical characteristics, diagnosis and therapeutic approaches of the genetic and other diseases leading to growth hormone insensitivity are reviewed.

Thyroid hormone and estrogen regulate exercise-induced growth hormone release.

Growth hormone (GH) regulates whole body metabolism, and physical exercise is the most potent stimulus to induce its secretion in humans. The mechanisms underlying GH secretion after exercise remain to be defined. The aim of this study was to elucidate the role of estrogen and pituitary type 1 deiodinase (D1) activation on exercise-induced GH secretion. Ten days after bilateral ovariectomy, animals were submitted to 20 min of treadmill exercise at 75% of maximum aerobic capacity and tissues were harvested immediately or 30 min after exercise. Non-exercised animals were used as controls. A significant increase in D1 activity occurred immediately after exercise (~60%) in sham-operated animals and GH was higher (~6-fold) 30 min after exercise. Estrogen deficient rats exhibited basal levels of GH and D1 activity comparable to those found in control rats. However, after exercise both D1 activity and serum GH levels were blunted compared to sedentary rats. To understand the potential cause-effect of D1 activation in exercise-induced GH release, we pharmacologically blocked D1 activity by propylthiouracil (PTU) injection into intact rats and submitted them to the acute exercise session. D1 inhibition blocked exercise-induced GH secretion, although basal levels were unaltered. In conclusion, estrogen deficiency impairs the induction of thyroid hormone activating enzyme D1 in the pituitary, and GH release by acute exercise. Also, acute D1 activation is essential for exercise-induced GH response.

Effect of regular yogic training on growth hormone and dehydroepiandrosterone sulfate as an endocrine marker of aging.

Growth hormone (GH) and dehydroepiandrosterone sulfate (DHEAS) secretion decline with advancing age and are associated with the symptoms of aging. Yogic texts claimed that regular practice of yoga may restore and maintain general endocrinological properties in the human body. Objective of the Study. To observe the effect of yogic training for twelve weeks on basal level of GH and DHEAS in middle aged group. Method. Forty-five untrained volunteers were divided into two groups, that is, yoga practicing (experimental: male 15, age 42.80 ± 7.43 yrs; female 8, age 44.75 ± 8.40 yrs) and waitlisted control group (male 15, age 41.67 ± 7.87 yrs; female 7, age 45.43 ± 7.00 yrs). The experimental group underwent combined yogic practices daily in the morning for 6 days/week for 12 weeks, whereas control group continued their usual routine activities. Standing height, body weight, body mass index, and basal level of GH and DHEAS were measured before commencement and after six and twelve weeks of yogic training period. The repeated measure ANOVA was used for data analysis. Results. 12 weeks of yogic training produces a significant increase in GH and DHEAS for both male and female groups as compared to their baseline data, whereas no as such changes were observed in the control group. Conclusion. Combined approach of graded yogic training may be beneficial for maintaining the basal level of GH and DHEAS in the human body, thus promoting healthy aging.

Growth hormone/insulin-like growth factor-1 axis: a possible non-nutritional factor for growth retardation in children with cerebral palsy

To assess growth hormone (GH)/insulin like growth factor-1 (IGF-1) axis as a possible non-nutritional factor for growth retardation in children with cerebral palsy (CP). A case-control study was conducted at a tertiary university hospital. Thirty children with CP (seven children with normal growth [CP-N] and 23 with retarded growth [CP-R]), 30 children with protein energy malnutrition (PEM), and 30 healthy children (REF group) underwent an assessment of growth parameters, serum IGF-1, basal GH, and peak GH after stimulation with insulin. PEM patients had higher basal GH levels than CP-N, CP-R and REF groups (p = 0.026, p < 0.001, and p < 0.001 respectively). After insulin stimulation, CP-N, CP-R, and PEM patients had lower GH levels compared to the REF group (p = 0.04, p = 0.007, and p = 0.036 respectively). IGF-1 levels were lower in CP-R group compared to CP-N and REF groups (p = 0.037 and p < 0.001 respectively), and in PEM group compared to CP-N and REF groups (p < 0.001 and p < 0.001 respectively). CP-R patients failed to demonstrate the same high basal GH response as PEM patients, and responded inadequately to the insulin stimulation test, but they had IGF-1 levels comparable to those of PEM patients. On the other hand, CP-N patients behaved as controls regarding their basal GH and IGF-1 levels, but failed to respond adequately to the insulin stimulation test. The PEM group presented high basal GH and low IGF-1 levels. These findings suggest that non-nutritional factors contribute to growth retardation in CP children.

Growth hormone response to the strenuous training in professional skiers has longer recovery time than expected

According to literature, 20–30 minutes recovery period is considered sufficient to normalize growth hormone (GH) levels after exercise stimulation. Aim of our study was to analyze GH response in elite athletes after strenuous training and after 2 hours recovery. We used longitudinal (different years, repeated measures) GH secretion data of 15 skiers (altogether 78 measurements) after very intensive training. Training lasted 3.5 hours with following structure: 0…1 h Lactate (La) &lt;2.5; 1…2h La &lt;3; 2&amp;#8230;2:45 La&lt;4; 2:45…3:30 La&lt;8. Exercise induced very high increase in GH level. Mean basal level of GH was 0.9 mU/L (range 11.2 ), after exercise GH level was 22.1 mU/L (range 103.7). After 2 h recovery, GH level was 3.1 mU/L (range 18.7, p &lt; 005 compared to the basal level). Our results show that depending on intensity and individual variability, GH responses to exercise in elite athletes can be much higher than described in the literature.ConclusionGH level after strenuous training in professional skiers remain still significantly higher after 2‐hour recovery period compared to the pre‐exercise level. The European Regional Development Fund together with the Archimedes Foundation supported this study.

Epidermal Growth Factor‐Activated Extracellular Signal‐Regulated Kinase Suppresses Growth Hormone Expression and Stimulates Proliferation in MtT/ E Cells

The mechanism for the inhibition of growth hormone (GH) expression by the epidermal growth factor (EGF) was examined in two clonal cell lines, MtT/E and MtT/S. The former has a negligible basal level of GH, whereas the latter has a high basal GH. The treatment of MtT/E cells with retinoic acid resulted in a significant increase in GH mRNA and subsequently GH. This stimulatory response to retinoic acid was strongly suppressed by EGF. This suppression was associated with an increase in the phosphorylation of extracellular signal-regulated kinase 1 and 2 (Erk1/2). The MEK [mitogen-activated protein kinase (MAPK) kinases that activate ERK1 and ERK2] inhibitor, PD98059, clearly inhibited the phosphorylation of Erk1/2 and restored the stimulatory effects of retinoic acid. These results suggest that the inhibitory effects of EGF on GH expression are mediated by MAPK activation in these cells. By contrast to the GH-producing clones examined previously, EGF showed a marked stimulation of proliferation of the MtT/E cells through a mechanism dependent on MAPK activation. On the other hand, the inhibitory effect of EGF on GH expression was less pronounced and the stimulation of cellular proliferation was not seen in MtT/S cells, even though it induced Erk-phosphorylation similar to that seen in MtT/E. The distinct difference in the response to EGF between these two GH cell lines appears to be attributed to differences in the function of MAPK cascade in each cell line. This may reflect the developmental stage of the cells from which MtT/E and MtT/S are derived.

Basal growth hormone concentration increased following a weight loss focused dietary intervention in older overweight and obese women.

Growth and sex steroid hormones decrease with aging and obesity. The effect of dietary weight loss and exercise training lifestyle interventions was examined on hormones as well as determining their relationships with physical function in older obese and overweight adults. Individuals were randomized into one of four 18 month interventions: Healthy Lifestyle (HL), Exercise, Diet, and Exercise-Diet. Clinical research setting with facility based exercise and nutrition education and behavior classrooms. Older (≥60 yrs) overweight and obese (BMI≥28 kg/m(2)) adults with knee osteoarthritis (n=309) were recruited for the study. Weight loss goal for Diet groups was ≥5%. Exercise groups trained (mostly walking and resistance training) 3 days/week for 60 min/session. Body weight, growth hormone (GH), corticosterone, sex-hormone binding globulin (SHBG), testosterone, and dehydroepiandrosterone (DHEA) were measured at baseline, 6, and 18 months. Physical function was determined through performance task (6-min walking distance) and self-reported questionnaires (Western Ontario McMaster University Osteoarthritis Index-WOMAC) at similar time points. Diet, Exercise, and Exercise-Diet groups lost 4.9%, 3.5%, and 6.2% of their weight at 18 months, respectively. There was a significant diet treatment effect on GH levels in women as higher concentrations of this hormone were apparent following dietary weight loss intervention (p=0.01). No other hormones were affected by either diet or exercise treatments in men or women. A significant inverse correlation between baseline 6-minute walking distance and SHBG (r=-0.33) was found in men. The increase in basal GH levels from the diet treatment in women suggests that this lifestyle behavior intervention may mitigate the age- and obesity-related decreases in growth hormone levels, to help preserve muscle mass, strength, and physical function in older adults.

Comparison of Growth Hormone Pulsatile Secretion and Serum Metabolites in Growing Taihu and Landrace Pigs

In this paper we compared growth performance, growth hormone (GH) pulsatile secretion and serum metabolites in growing Taihu and Landrace gilts at the same age. The results showed that compared with Landrace gilts, Taihu gilts decreased by 45.48% (P&lt;0.05), 25.25% (P&lt;0.05) in average daily gain and carcass muscle percentage, and increased by 52.44% (P&lt;0.05), 69.50% (P&lt;0.05) in feed/gain ratio and carcass fat percentage, respectively. While, average daily feed intake was not affected by breeds. Serum basal GH level, mean GH level and GH pulse amplitude were decreased by 26.67% (P&lt;0.05), 20.00% (P&lt;0.05) and 18.81% (P&lt;0.05), respectively, but GH pulse frequency and pulse duration remained unchanged (P&gt;0.05). Serum urea nitrogen concentration in Taihu gilts was 32.04% (P&lt;0.05) higher, whereas, total protein level was 17.73% (P&lt;0.05) lower than that of Landrace gilts.

Pattern of adrenal morphology and function in patients with acromegaly

Acromegaly is well known to induce hypertrophic and hyperplastic changes in various organs and is commonly accompanied by arterial hypertension. In our study, we assess the adrenal morphology and function in a series of patients with acromegaly and possible associations with the activity of the disease and arterial hypertension. Sixty patients with acromegaly, admitted to two endocrinology departments in the time period 2005-2010, were studied prospectively. Basal IGF-1 and growth hormone levels after oral glucose tolerance test were used to assess the disease activity. All subjects underwent adrenal CT scan, basal adrenal hormonal investigation and evaluation with 24-h urinary free cortisol and cortisol levels following low-dose dexamethasone suppression test. In 33 acromegalics, the 'modified' saline infusion test (MSI), i.e. saline infusion after dexamethasone administration, was performed to identify autonomous aldosterone (ALD) secretion. Abnormal adrenal morphology was present in 48% of our patients, and a significant association was found between the presence of arterial hypertension and adrenal morphology. Among patients with adrenal morphological changes, 55% exhibited no adrenal secretory hyperactivity, 34% autonomous cortisol, 7% ALD and 4% combined autonomous cortisol and ALD secretion, when applying recently proposed modified cut-off levels compared to widely used criteria. An increased prevalence of autonomous ALD secretion was shown among the subgroup of patients with acromegaly tested with MSI. This study provides evidence of an increased prevalence of anatomic and functional adrenal alterations in patients with acromegaly; further studies will clarify the importance of evaluating these subjects with baseline hormonal investigation along with dynamic testing and modified cut-offs.

Ultrasound therapy of diabetes mellitus type 2

maryWe studied the possibility of low-frequency UST in the correction of carbohydrate metabolism by assessing levels of fasting glucose and Cpeptide, as well as the content of the contrinsuline hormones (cortisol, samatotropin) in groups of diabetic patients.Ultrasonic treatment was carried out at 44 kHz and amplitude of oscillations 2 microns using the therapeutic device MIT-11 on theprojection area of the pancreas stable technique, 5 times per week, exposure to the session for 3 minutes. As the contact material used liquid paraffin.To enhance the effect further impacted on the segmental zone Th7-Th12 labile technique for 2 min. for each area to the left and right. The treatmentcourse consisted of 8-10 sessions. Patients were followed for 12 months. Ultrasonic treatment was carried out against lowering drug therapy, 91patients aged 18-78 years, including type 1 diabetes was observed in 23 individuals (control group), and type 2 - 68 people. First identified diabeteswas diagnosed in 47 patients, the remaining 44 suffered from more than 5 years. Before and after treatment were studied basal levels of C-peptide,cortisol and growth hormone (GH) in serum of venous blood radio immunoassay, we determined the glycemic profile and blood sugar levels in dailyurine.Analysis of results showed that 82% surveyed, under the influence of treatment was recorded reduction of hyperglycemia with newlydiagnosed diabetes type 1 diabetes and type 2, as well as a long ill patients. Blood glucose levels prior to treatment during the day ranged from 10-15mmol / l after the treatment - 6.10 mg / dL.The resulting dynamics parameters after UST during observation showed an improvement insulinoproductive function of the pancreasunder the influence of ultrasound exposure, which contributed to a more rapid onset of diabetes compensation and reduce the dose glucose-loweringdrugs.UST is combined with many kinds of physiotherapy effects: electrotherapy, massage, balneotherapy, laser-and SWT-therapy and otheroptions for therapy with electromagnetic waves, enhancing their effect. This kind of treatment so far has not found wide application in the treatment ofdiabetes and its complications, however, is a promising method of physiotherapy treatment, given its mechanism of action and different ways ofapplication.

Up-regulation of lymphocytic growth hormone secretion during the luteal phase of cycle and early pregnancy

Growth hormone (GH) has been shown to be produced and secreted by priphereal immune cells. Therefore, we studied the release of GH by lymphocytes, during various stages of pregnancy and estrous cycle in the cow. The effect of leptin on the lymphocytic GH release was also investigated. Estradiol-17β and progesterone concentrations in plasma were measured in all animals to confirm their reproductive status. Growth hormone levels measured in cell cultures during early pregnancy (days 60–80) and during the luteal phase were greater (p≤0.01) than levels during follicular phase or mid (days 100–160) and late (days 240–245) pregnancy. Leptin treatment stimulated (p≤0.05) lymphocytic GH release during mid-pregnancy when the basal GH levels were low. Changes in lymphocytic GH release and elevation of lymphocytic GH secretion by leptin during pregnancy and the absence of such effects in estrous cycle may indicate that leptin modulation of lymphocytic GH plays a role in the regulation of immune response during pregnancy.

The vagus nerve as a regulator of growth hormone secretion

The growth hormone (GH) axis is mainly regulated by the growth hormone releasing hormone (GHRH) and somatostatin (SS) hypothalamic peptides. Nevertheless, since ghrelin peptide was discovered as the natural ligand for growth hormone secretagogue receptor (GHS-R), the mechanism of GH regulation has acquired a new dimension. It was described that ghrelin possesses a relevant effect inducing GH secretion when it is administered peripherally. A role of the vagus nerve mediating ghrelin action has been described although this effect is not understood. Under this context the main objective of this work was to determine the possible involvement of the vagus in the somatotroph axis regulation. The results in this manuscript show that animals with a disruption of the vagus connection presented lower basal IGF-1 and GH levels, a decreased GH response to peripheral GHRH administration and a marked diminution in the GH response to peripheral and central ghrelin treatments. In addition, vagotomized animals showed a down-regulation of GHRH mRNA in the arcuate nucleus of the hypothalamus and a down-regulation in both GHRH and GHS receptors' mRNA at the pituitary level. In conclusion, the present work reveals that the vagus nerve is crucial in growth hormone regulation and essential for the full GH-releasing effect of ghrelin.

A case of fugitive acromegaly, initially presented as invasive prolactinoma

Fugitive acromegaly is most commonly caused by pituitary acidophil stem cell adenomas, and is characterized by a relatively short clinical history, a large and locally invasive tumor, and relatively low hormonal activity. Here, we report an unusual case of fugitive acromegaly that initially presented as invasive prolactinoma. A 48-year-old man with a huge pituitary mass extending to the suprasellar area was referred to our hospital in December 2007. He had undergone transsphenoidal surgery in November 1999 because of a large invasive prolactinoma. The tumor had grown progressively, despite therapy with dopamine agonists. Subtle features of acromegaly were noted and serum IGF-1 levels were high (733 ng/ml). An oral glucose tolerance test revealed that basal and nadir levels of growth hormone (GH) were 1.56 and 1 ng/ml, respectively. As a therapeutic trial, long-acting octreotide (20 mg IM, monthly) was added, and the tumor size markedly reduced within 6 months on magnetic resonance imaging examination. Immunohistochemical staining of the tumor tissue obtained at the surgery in 1999 showed positive staining for GH and prolactin (PRL). Double immunofluorescence staining showed a mixed positivity for GH and PRL in the majority of tumor cells; however, the two hormones colocalized in a minority of tumor cells, indicating that the tumor was composed of three different cell types (GH, PRL, and GH/PRL). The diagnosis of fugitive acromegaly was initially overlooked in this patient because of normal serum GH levels and a lack of acromegalic features, although histological evidence for GH production was present. IGF-1 determinations would be helpful for the diagnosis of fugitive acromegaly.

Growth hormone levels in children and adolescents with epilepsy

Background Patients with epilepsy often complain of symptoms that may be caused by disturbances in their hormonal balance. Disturbances in physical growth has been previously described. The aim of this study was to evaluate the effect of epilepsy and/or anti-epileptic drugs on the physical growth of patients with idiopathic epilepsy, as well as on the growth hormone (GH) and insulin growth factor-1 (IGF-1) status in those patients. Methods The study comprised 40 children and adolescents with idiopathic epilepsy on either valproate or carbamazepine. Anthropometric measurements [occipitofrontal circumference, weight, height, body mass index, span, and midarm circumference] were taken. Serum levels of GH before and after provocation with L-dopa and of IGF-1 were assessed. Results were compared to a matched control group. Results The height measurements were reduced in patients with epilepsy compared to the controls group. Though weight values were not significantly different, the body mass indices of the patients were significantly higher than controls, especially in patients on valproate therapy. Basal GH levels showed no significantly variation between patients and controls. However, post provocation GH and IGF-1 levels were significantly lower in patients. The type of epilepsy, disease duration, and the degree of seizure control had no significant effect on the studied parameters. In conclusion, physical growth seems to be affected in patients with epilepsy. This may be due to hormonal imbalance as evident by reduced post provocation GH levels and IGF-1 levels in the included group of patients.

The value of an acute octreotide suppression test in predicting response to long-term somatostatin analogue therapy in patients with acromegaly

The usefulness of the acute octreotide test in the selection of patients with acromegaly for chronic somatostatin depot analogues treatment is controversial. To determine the efficacy of acute octreotide suppression test (OST) in predicting response to long-term somatostatin analogue (Octreotide-long-acting repeatable, OCT-LAR) therapy in patients with acromegaly. Prospective study (2006-2007) conducted at a tertiary healthcare centre in western India. Sixteen drug-naive patients with active acromegaly (postoperative+/-post radiotherapy) underwent 50 microg subcutaneous OST. Ten patients were treated with OCT-LAR for one year. Remission was defined as a nadir growth hormone (GH) < 1 ng/ml during 75 g oral glucose tolerance test (OGTT) (0, 10, 30, 60, 120, 180 min) and normal age, sex-matched insulin-like growth factor 1 (IGF1) levels. SPSS Software Version 11 was used for data analysis. Using GH cutoff. Nadir GH < 1 ng/ml following an OST is a useful predictive marker of achieving disease remission with long-term OCT-LAR therapy.

A mouse model of ghrelinoma exhibited activated growth hormone-insulin-like growth factor I axis and glucose intolerance

Ghrelin is a stomach-derived peptide that has growth hormone-stimulating and orexigenic activities. Although there have been several reports of ghrelinoma cases, only a few cases have elevated circulating ghrelin levels, hampering the investigation of pathophysiological features of ghrelinoma and chronic effects of ghrelin excess. Furthermore, standard transgenic technique has resulted in desacyl ghrelin production only because of the limited tissue expression of ghrelin O-acyltransferase, which mediates acylation of ghrelin. Accordingly, we attempted to create ghrelin promoter SV40 T-antigen transgenic (GP-Tag Tg) mice, in which ghrelin-producing cells continued to proliferate and finally developed into ghrelinoma. Adult GP-Tag Tg mice showed elevated plasma ghrelin levels with preserved physiological regulation. Adult GP-Tag Tg mice with increased plasma ghrelin levels exhibited elevated IGF-I levels despite poor nutrition. Although basal growth hormone levels were not changed, those after growth hormone-releasing hormone injection tended to be higher. These results indicate that chronic elevation of ghrelin activates GH-IGF-I axis. In addition, GP-Tag Tg mice demonstrated glucose intolerance. Insulin secretion by glucose tolerance tests was significantly attenuated in GP-Tag Tg, whereas insulin sensitivity determined by insulin tolerance tests was preserved, indicating that chronic elevation of ghrelin suppresses insulin secretion and leads to glucose intorelance. Thus, we successfully generated a Tg model of ghrelinoma, which is a good tool to investigate chronic effects of ghrelin excess. Moreover, their characteristic features could be a hint on ghrelinoma.