Anterior pituitary function in Rathke's cleft cysts versus nonfunctioning pituitary adenomas

Although Rathke's cleft cysts (RCCs) are common sellar/parasellar lesions, studies examining pituitary function in patients with nonsurgical RCC are limited. This study aimed to clarify the importance of RCCs, including small nonsurgical ones, as a cause of hypopituitarism by determining the prevalence of pituitary hormone secretion impairment and its relationship to cyst/tumor size in patients with RCC and in those with nonfunctioning pituitary adenoma (NFA). We retrospectively investigated the basal levels of each anterior pituitary hormone, its responses in the stimulation test(s), and cyst/tumor size in patients with RCC (n = 67) and NFA (n = 111) who were consecutively admitted to our hospital for endocrinological evaluation. RCCs were much smaller than NFAs (median height, 12 vs. 26 mm). The prevalence of gonadotropin, PRL, and GH secretion impairment in RCC was lower in comparison to NFA (19% vs. 44%, 34% vs. 61%, and 24% vs. 46%, respectively), whereas the prevalence of TSH and ACTH secretion impairment was comparable (21-27% and 17-24%, respectively). A significant positive relationship between cyst/tumor size and number of impaired hormones was observed in both groups, but smaller cysts could cause hormone secretion impairment in RCC. Stimulation tests suggested that most hormone secretion impairment was attributable to the interrupted hypothalamic-pituitary axis in both groups. Therefore, RCC, even small ones, can cause pituitary dysfunction. Different mechanisms may underlie hypothalamic-pituitary interruption in RCC and NFA.

A retrospective study of pituitary-thyroid interaction in patients with first-episode of bipolar disorder type I in Mania State

ABSTRACT

Bipolar disorder (BD)-mania is related to the dysfunction of anterior pituitary gland, but the pituitary-thyroid interaction on the acute stage of BD has been controversial. In order to rule out the effects of drugs, we aimed to determine the upstream interaction of first-episode of BD type I in mania state, and tried to find the relationship between thyroid-stimulating-hormone (TSH) and Prolactin (PRL)This study included 70 real-world patients diagnosed with first-episode BD-mania recuited and 70 healthy controls (HC) matched for age and sex from 2016 to 2017 in the same district of Shanghai. We compared the levels of thyroid hormones and prolactin between the two groups, and linear regression and curve estimation were used for the correlation analysis of TSH and PRLThere were differences in triiodothyronine (TT3), total thyroxin (TT4), and free thyroxine (FT4) concentrations between the groups (P's < .05). After being grouped by sex, higher PRL in the male and female BD-mania subgroup were observed compared to each isosexual HC [(P's < .01, Cohen's d = 0.82/1.08, 95%CI (0.33, 1.31)/(0.58, 1.58)]. Higher FT4 in the male BD-mania group was observed compared to the HC males [(P's  < .01, Cohen's d = 0.90, 95%CI (0.41, 1.39)] while the female BD-mania group showed lower TT3 and TT4 compared to the HC females [(P's  < .01, Cohen's d = 0.93/0.88, 95%CI (0.43, 1.42)/(0.39, 1.37)]. In the female BD-mania group, correlation analysis established an inverse relationship between PRL and TSH (r2 = 0.25, F = 11.11, P < .01).The findings demonstrate that sex impacts the concentration of hormones secreted by the anterior pituitary of patients with first-episode BD-mania. The increased PRL may be a putative mechanism that underlies the onset in female patients with a moderate inverse relationship between TSH and PRL. Thyroid hormones and prolactin levels may be developed as potential markers for identifying BD-manic.

Disruption of the Pituitary Circadian Clock Induced by Hypothyroidism and Hyperthyroidism: Consequences on Daily Pituitary Hormone Expression Profiles

BACKGROUND

The secretion of pituitary hormones oscillates throughout the 24-hour period, indicating that circadian clock-mediated mechanisms regulate this process in the gland. Additionally, pituitary hormone synthesis has been shown to be altered in hypo- and hyperthyroidism. Although thyroid hormones can modulate the other peripheral clocks, the interaction between thyroid hormone levels and circadian clock gene expression in the anterior pituitary has yet to be elucidated.

METHODS

Male Wistar rats were divided into three groups: control, hypothyroid, and hyperthyroid. Following the experimental procedures, animals were euthanized every three hours over the course of a 24-hour period. The anterior pituitary glands were excised and processed for mRNA expression analysis by quantitative reverse transcriptase polymerase chain reaction. One- and two-way analysis of variance as well as cosinor analysis were used to evaluate the time-of-day-dependent differential expression for each gene in each experimental group and their interactions.

RESULTS

Hyperthyroidism increased the mRNA expression of core clock genes and thyrotrophic embryonic factor (Tef), as well as the mesor and amplitude of brain and muscle Arnt-like protein-1 (Bmal1) and the mesor of nuclear receptor subfamily 1 (Nr1d1) group D member 1, when compared to euthyroid animals. Hypothyroidism disrupted the circadian expression pattern of Bmal1 and period circadian regulator 2 (Per2) and decreased the mesor of Nr1d1 and Tef. Furthermore, it was observed that the pituitary content of Dio2 mRNA was unaltered in hyperthyroidism but substantially elevated in hypothyroidism during the light phase. The upregulated expression was associated with an increased mesor and amplitude, along with an advanced acrophase. The gene expression of all the pituitary hormones was found to be altered in hypo- and hyperthyroidism. Moreover, prolactin (Prl) and luteinizing hormone beta subunit (Lhb) displayed circadian expression patterns in the control group, which were disrupted in both the hypo- and hyperthyroid states.

CONCLUSION

Taken together, the data demonstrate that hypo- and hyperthyroidism alter circadian clock gene expression in the anterior pituitary. This suggests that triiodothyronine plays an important role in the regulation of pituitary gland homeostasis, which could ultimately influence the rhythmic synthesis and/or secretion of all the anterior pituitary hormones.

Evaluation of serum ferritin and thyroid function in the second trimester of pregnancy

Ferritin is a universal intracellular protein that acts as an iron carrier. Several studies have indicated that iron deficiency affects thyroid function in non-pregnant women. Our objective was to assess the relationship between serum ferritin levels and thyroid function in pregnant women during the second trimester. Pregnant women with sufficient iodine intake and normal antithyroid antibodies during the second trimester were recruited from the obstetric outpatient department of the Fifth People's Hospital of Fudan University. Serum ferritin (SF) levels, thyroid function, anti-thyroid antibodies and vitamin B12 were determined by electrochemiluminescence immunoassay kit. Maternal serum iron (Fe), unsaturated iron binding capacity (UIBC), hemoglobin (Hb), creatinine (Cr), fasting blood glucose (FBG), and alanine aminotransferase (ALT) were also evaluated. Stepwise regressions performed to evaluate the associations between SF and other maternal parameters. In the second trimester, 11.4% pregnant women had a SF concentration less than 12 μg/L, and 7.6% pregnant women were anemic. SF levels were negatively correlated with serum TSH levels (r = -0.219, p < 0.05), and positively correlated with FT4 levels (r = 0.203, p < 0.05). Linear regression analysis showed only SF, age, week of gestation were significant predictors of regression with TSH as the dependent variable (β: -0.007, -0.059, and 0.118 respectively; all p < 0.05). However consistent relation between the SF levels and FT4 was not observed in stepwise linear regression. Maternal iron status is a determinant of TSH concentrations during pregnancy in pregnant women during the second trimester.

Relationship between pituitary stalk (PS) visibility and the severity of hormone deficiencies: PS interruption syndrome revisited

CONTEXT

Pituitary stalk interruption syndrome (PSIS) is a rare cause of combined pituitary hormone deficiency characterized by a triad shown in pituitary imaging, yet it has never been evaluated due to the visibility of pituitary stalk (PS) in imaging findings.

OBJECTIVE

The major objective of the study was to systematically describe the disease including clinical presentations, imaging findings and to estimate the severity of anterior pituitary hormone deficiency based on the visibility of the PS.

METHODS

This was a retrospective study including 74 adult patients with PSIS in Shanghai Clinical Center for Endocrine and Metabolic Diseases between January 2010 and June 2014. Sixty had invisible PS according to the findings on MRI, while the rest had a thin or intersected PS. Basic characteristics and hormonal status were compared.

RESULTS

Of the 74 patients with PSIS, age at diagnosis was 25 (22-28) years. Absent pubertal development (97·3%) was the most common presenting symptom, followed by short stature. Insulin tolerance test (ITT) and gonadotrophin-releasing hormone (GnRH) stimulation test were used to evaluate the function of anterior pituitary. The prevalence of isolated deficiency in growth hormone (GH), gonadotrophins, corticotrophin and thyrotrophin were 100%, 97·2%, 88·2% and 70·3%, respectively. Although the ratio of each deficiency did not vary between patients with invisible PS and with visible PS, panhypopituitarism occurred significantly more frequent in patients with invisible PS. Patients with invisible PS had significantly lower levels of luteinizing hormone (LH), follicle stimulation hormone (FSH) and hormones from targeted glands including morning cortisol, 24-h urine free cortisol, free triiodothyronine (FT3), free thyroxine (FT4) and testosterone (T) in male than patients with visible PS. Moreover, patients with invisible PS had lower peak LH and FSH in GnRH stimulation test, and higher peak cortisol in ITT while peak GH remained unchanged between two groups.

CONCLUSIONS

The prevalence of multiple anterior pituitary hormone deficiency was high in adult patients with PSIS. And more importantly, we found the visibility of PS shown on MRI might be an indication of the severity of PSIS.

Rare case of a primary intracranial chondrosarcoma

BACKGROUND

Intracranial chondrosarcomas comprise 6% of all skull base neoplasms and account for 0.15% of all intracranial tumors. They are potentially fatal, invading the brain and elevating intracranial pressure by progressive enlargement. Diplopia and headache are the most common clinical symptoms. Previous data indicate a particularly aggressive behavior of intracranial chondrosarcomas.

CASE REPORT

A 17-year-old female patient presented to the hospital with focal seizures. A magnetic resonance imaging (MRI) scan revealed a brain tumor located in the right meso-temporal region. Total tumor resection, followed by conformal proton therapy was performed. The tumor displayed a chondroid differentiation, and accordingly, a chondrosarcoma was diagnosed. At follow-up investigation two years after the resection of the tumor, the patient was in a good general state of health and no tumor recurrence had occurred.

DISCUSSION AND CONCLUSION

Intracranial chondrosarcoma is a differential diagnosis for intracranial tumors of the skull base. State-of-the-art therapy should comprise of surgical resection and adjuvant radiotherapy. Previously published data about intracranial chondrosarcomas indicate the extreme aggressiveness of this tumor entity.

[Sheehan's syndrome--a forgotten disease with 100 years' history]

Although named after Harold Sheehan, postpartum ischemic pituitary necrosis was reported for the first time 100 years ago in Przeglad Lekarski by Leon Konrad Gliński. In the majority of cases, the syndrome is a consequence of severe postpartum bleeding episode resulting in severe hypotension or hemorrhagic shock. The frequency of Sheehan's syndrome has decreased in developed countries as a result of improved obstetrical care, but this clinical entity remains a common cause of hypopituitarism in developing countries. The syndrome is characterized by varying degrees of anterior pituitary dysfunction resulting from the deficiency of multiple pituitary hormones. The order of frequency of hormone loss has generally been found to be growth hormone and prolactin, gonadotropins, ACTH and thyrotropin. Women with Sheehan's syndrome exhibit a variety of signs and symptoms including failure to lactate or resume menses, loss of genital and axillary hair, and often occurring long after delivery clinical manifestations of central hypothyroidism and secondary adrenal insufficiency. Diagnosis is based on laboratory studies, including hormone levels and hormone stimulation tests. Treatment of Sheehan's syndrome involves hormone replacement therapy. The aim of this study is to review current knowledge on clinically relevant aspects of this clinical entity and to provide the reader with recommendations concerning its diagnosis and treatment.

Modulatory role of D-chiro-inositol (DCI) on LH and insulin secretion in obese PCOS patients

Polycystic ovary syndrome (PCOS) is a common endocrine condition that affects fertility through oligo-ovulation, hyperandrogenism and polycystic morphology of the ovaries. Since it has been demonstrated a high incidence of insulin resistance in PCOS patients, our study aimed to evaluate the efficacy of the integrative treatment with D-chiro-inositol (DCI) (500 mg die, per os, for 12 weeks) on hormonal parameters and insulin sensitivity in a group of overweight/obese PCOS patients (body mass index; BMI > 26). After the treatment, interval several endocrine parameters improved (luteinizing hormone [LH], LH/follicle stimulating hormone [FSH], androstenedione and insulin), insulin response to oral glucose tolerance test reported the significant improvement of insulin sensitivity as well as the gonadotropin-releasing hormone (GnRH)-induced (10 µg, in bolus) LH response. BMI decreased, though no lifestyle modification was requested. When data were analyzed according to the presence or absence of first-grade diabetic relatives, PCOS patients with diabetic relatives showed greater improvement after DCI administration. In conclusion DCI administration is effective in restoring better insulin sensitivity and an improved hormonal pattern in obese hyperinsulinemic PCOS patients, in particular, in hyperinsulinemic PCOS patients who have diabetic relatives.

Gender differences in GH response to GHRH+ARG in lipodystrophic patients with HIV: a key role for body fat distribution

OBJECTIVE

Gender influence on GH secretion in human immunodeficiency virus (HIV)-infected patients is poorly known.

DESIGN AND METHODS

To determine the effect of gender, we compared GH response to GH-releasing hormone plus arginine (GHRH+Arg), and body composition in 103 men and 97 women with HIV and lipodystrophy. The main outcomes were IGF1, basal GH, GH peak and area under the curve (AUC) after GHRH+Arg, body composition, visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT).

RESULTS

Men had lower GH peak and AUC than women (P<0.001). Of the study population, 21% of women and 37% of men had biochemical GH deficiency (GHD; GH peak <7.5 μg/l). VAT-to-SAT ratio was higher in men than in women with GHD (P<0.05). Unlike women, VAT, SAT, and trunk fat were greater in men with GHD than in men without GHD. IGF1 was significantly lower in women with GHD than in women without GHD, but not in men. At univariate analysis, BMI, trunk fat mass, VAT, and total adipose tissue were associated with GH peak and AUC in both sexes (P<0.05). BMI was the most significant predictive factor of GH peak, and AUC at multiregression analysis. Overall, abdominal fat had a less pronounced effect on GH in females than in males.

CONCLUSIONS

These data demonstrate that GH response to GHRH+Arg is significantly lower in HIV-infected males than females, resulting in a higher percentage of GHD in men. Adipose tissue distribution more than fat mass per se seems to account for GH gender differences and for the alteration of GH-IGF1 status in these patients.

Estradiol regulates GH-releasing peptide's interactions with GH-releasing hormone and somatostatin in postmenopausal women

OBJECTIVE

Estrogen stimulates pulsatile secretion of GH, via mechanisms that are largely unknown. An untested hypothesis is that estradiol (E₂) drives GH secretion by amplifying interactions among GH-releasing hormone (GHRH), somatostatin (SS), and GH-releasing peptide (GHRP).

DESIGN

The design comprised double-blind randomized prospective administration of transdermal E₂ vs placebo to healthy postmenopausal women (n=24) followed by pulsatile GHRH or SS infusions for 13 h overnight with or without continuous GHRP2 stimulation.

METHODS

End points were mean concentrations, deconvolved secretion, and approximate entropy (ApEn; a regularity measure) of GH.

RESULTS

By generalized ANOVA models, it was observed that E₂ vs placebo supplementation: i) augmented mean (13-h) GH concentrations (P=0.023), GHRH-induced pulsatile GH secretion over the first 3 h (P=0.0085) and pulsatile GH secretion over the next 10 h (P=0.054); ii) increased GHRP-modulated (P=0.022) and SS-modulated (P<0.001) GH ApEn; and iii) did not amplify GHRH/GHRP synergy during pulsatile GH secretion. By linear regression, E₂ concentrations were found to be positively correlated with GH secretion during GHRP2 infusion (P=0.022), whereas BMI was found to be negatively correlated with GH secretion during GHRH (P=0.006) and combined GHRH/GHRP (P=0.015) stimulation. E₂ and BMI jointly determined triple (combined l-arginine, GHRH, and GHRP2) stimulation of GH secretion after saline (R²=0.44 and P=0.003) and pulsatile GHRH (R²=0.39 and P=0.013) infusions.

CONCLUSION

In summary, in postmenopausal women, E₂ supplementation augments the amount (mass) and alters the pattern (regularity) of GH secretion via interactions among GHRH, SS, GHRP, and BMI. These outcomes introduce a more complex model of E₂ supplementation in coordinating GH secretion in aging women.

A novel hook-shaped enhancement on contrast-enhanced sagittal magnetic resonance image in acute Sheehan's syndrome: a case report

We report characteristic magnetic resonance (MR) image findings in a case of Sheehan's syndrome. A 37-year-old woman experienced complications of retained placenta and massive bleeding (3600 g) during delivery of a full-term baby. A pituitary function test demonstrated panhypopituitarism. MR image of the pituitary gland on postpartum day 10 revealed swelling of the anterior lobe. A hook-shaped enhancement was demonstrated on a sagittal image. The pituitary stalk, majority of the marginal zone of the anterior lobe, the anterior lobe just in front of the posterior lobe, and posterior lobe were well enhanced. In contrast, the central portion and the superior margin, just in front of the stalk insertion of the anterior lobe, were not enhanced. Anatomically, blood supply to these unenhanced portions of the anterior lobe was via the hypophyseal long portal vein and trabecular artery, which are tributaries of the superior hypophyseal artery that originate far from the internal carotid artery. Based on clinical history and MR image findings, the patient was diagnosed with Sheehan's syndrome and treated with hydrocortisone and levothyroxine. Follow-up MR image revealed marked atrophy of the anterior lobe. The characteristic hook-shaped enhancement in Sheehan's syndrome well reflected the vulnerability to massive bleeding based on the complex pituitary vasculature, which has not been reported previously. MR image with contrast enhancement is useful in the diagnosis of the acute phase of Sheehan's syndrome and in evaluating infarction of the anterior lobe.

Acute glucocorticoid deficiency and diabetes insipidus are common after acute traumatic brain injury and predict mortality

CONTEXT

Published data demonstrates that hypopituitarism is common after traumatic brain injury (TBI). Hormone deficiencies are transient in many, but the natural history of the acute changes after TBI has not been documented. In addition, it is not clear whether there are any early parameters that accurately predict the development of permanent hypopituitarism.

OBJECTIVES

There were 3 main objectives of this study: 1) to describe the natural history of plasma cortisol (PC) changes and sodium balance after TBI; 2) to identify whether acute hypocortisolemia or cranial diabetes insipidus (CDI) predict mortality; and 3) to identify whether the acute pituitary dysfunction predicts the development of chronic anterior hypopituitarism.

DESIGN

Each TBI patient underwent sequential measurement of PC, plasma sodium, urine osmolality, and fluid balance after TBI. All other anterior pituitary hormones were measured on day 10 after TBI. The results from 15 surgical comparisons defined a PC less than 300 nmol/L as inappropriately low for an acutely ill patient. CDI was diagnosed according to standard criteria. Surviving TBI patients underwent dynamic anterior pituitary testing at least 6 months after TBI.

SETTING

The patients were recruited from the Irish National Neurosurgery Centre.

PATIENTS

One hundred sequential TBI patients were recruited. Fifteen patients admitted to Intensive Therapy Unit (ITU) after major surgery were recruited as comparison patients.

MAIN OUTCOME MEASURES

PC in TBI patients was compared with that of comparison patients. The mortality rate was compared between TBI patients with and without acute hypocortisolemia. Results of follow-up dynamic pituitary testing were compared between those with and without acute hypocortisolemia.

RESULTS

Most of the TBI patients (78%) developed inappropriately low PC after TBI. Low PC and CDI were predictive of mortality. Thirty-nine percent of the patients who had follow-up testing had at least 1 pituitary hormone deficit, all of whom had had previous acute hypocortisolemia or CDI.

CONCLUSIONS

Acute hypocortisolemia and CDI are predictive of mortality and long-term pituitary deficits in TBI.

Pituitary function in patients with hereditary haemochromatosis

Haemochromatosis may impair the function of endocrine organs, amongst others the pituitary gland. It was the aim of this study to determine pituitary function in adult patients with genetically defined hereditary haemochromatosis in a prospective diagnostic study using a standardised stimulation test. Therefore, 22 patients (7 females, 15 males; age at diagnosis of haemochromatosis 48.1 ± 7.9 years; age at study inclusion 50.7 ± 7.7 years) with genetically defined hereditary haemochromatosis were investigated by a combined pituitary stimulation test (CRH, GHRH/arginine, GnRH, TRH). In 11 patients (50% of the study population; 2 females, 9 males), pituitary insufficiencies were detected [isolated corticotrophic insufficiency (peak cortisol < 181.25 μg/l/500 nmol/l) n=10 (2 females, 8 males); combined corticotrophic and borderline gonadotrophic insufficiency (basal testosterone 2.4-3.0 μg/l without basal LH-elevation) in 1 male]. Somatotrophic pituitary insufficiencies were not found. IFG-1 concentrations below -2 standard deviations in 7 patients (32%) may be attributed to impaired hepatic IGF-1 synthesis. Hypopituitarism, particularly corticotrophic insufficiency, seems to be prevalent in a considerable number of middle-aged patients with hereditary haemochromatosis. Despite normal somatotrophic function, low IGF-1 serum concentrations may be found in a subgroup of haemochromatosis patients.

ACTH-secreting pituitary microadenomas are associated with a higher prevalence of central hypothyroidism compared to other microadenoma types

CONTEXT

Unlike pituitary macroadenomas, microadenomas (micros) are not commonly associated with hypopituitarism. In clinical practice, we have observed that patients with ACTH-secreting micros have a higher than expected prevalence of central hypothyroidism (HT), and we speculated that this effect might be because of glucocorticoid-induced suppression of the hypothalamic-pituitary-thyroid axis.

OBJECTIVE

To determine whether there is a difference in the prevalence of central HT among ACTH micros compared to other types of microadenoma, and if so, to investigate whether this is directly related to the degree of hypercortisolism.

DESIGN, SETTING AND PATIENTS

Retrospective study of 149 newly diagnosed patients with pituitary micros: 34 ACTH-secreting, 72 prolactin-secreting (PRLomas) and 43 clinically nonfunctioning adenomas (NFAs).

MAIN OUTCOMES MEASURES

Prevalence of central HT, correlation between normalized free T4 or TSH vs normalized urinary free cortisol (UFC) or salivary cortisol.

RESULTS

The prevalence of central HT was significantly higher in the ACTH compared to the non-ACTH adenomas: 18% (ACTH), 1% (PRL) and 0% (NFAs). The mean normalized free T4 was lower in the ACTH micros compared to the non-ACTH micros (1·29 ± 0·06 vs 1·50 ± 0·23, P = 0·0001). There was no correlation between the degree of hypercortisolism, as reflected by 24-h urine free cortisol and salivary cortisol, and free T4 or TSH levels among the ACTH adenomas. Similarly, there were no differences in mean UFC or salivary cortisol between ACTH adenomas with and without central HT. Following transsphenoidal adenomectomy, central HT recovered in three of six patients with ACTH micros.

CONCLUSIONS

These findings suggest that patients with ACTH-secreting microadenomas should always, at a minimum, undergo testing for central HT. However, given the potential for recovery of thyroid function following cure of Cushing disease, we recommend withholding thyroid hormone replacement until after pituitary surgery.

Evaluation of the anterior pituitary function in the acute phase after spontaneous subarachnoid hemorrhage

BACKGROUND

Subarachnoid hemorrhage (SAH) is a potential cause of hypopituitarism. Most of the studies regarding the relationship between SAH and anterior pituitary function were retrospective and hormonal assessment was performed several months after SAH.

AIM

To prospectively evaluate the prevalence of anterior pituitary hormone deficiencies in the acute phase after spontaneous SAH and their possible correlation with clinical and radiological parameters.

METHODS

Pituitary function was tested in 60 patients within 72 h after spontaneous SAH.

RESULTS

56.9% of the patients showed at least one anterior pituitary hormone deficiency: gonadotropin and GH secretion failure represented the most prevalent hormonal deficiencies (33.3 and 22.0%, respectively), whereas ACTH and TSH deficiency was less frequent (7.1 and 1.8%, respectively). With the exception of secondary hypogonadism, the prevalence of other pituitary hormone deficiencies is in agreement with previous studies, which evaluated pituitary function on longterm follow up after SAH. No correlation was found between hypopituitarism and clinical status, as assessed with Hunt-Hess and Glascow Coma Scales. Moreover, no correlation was found between hypopituitarism and bleeding severity evaluated with Fisher's scale.

CONCLUSIONS

We demonstrated a high prevalence of anterior pituitary hormone deficiencies acutely after SAH. Although part of GH and gonadotropin deficiencies might be a consequence of functional alteration due to SAH itself, the finding of low cortisol levels in this stressful condition strongly suggests the presence of true hypocortisolism. Therefore, an evaluation of pituitary function shortly after SAH might be useful to identify a subset of patients who deserve a more accurate follow-up.

GH response to oral glucose tolerance test: a comparison between patients with acromegaly and other pituitary disorders

CONTEXT

The cutoff value of nadir GH after an oral glucose tolerance test (OGTT) used to define disease remission in acromegaly is higher than that observed in healthy subjects. However, it is uncertain whether the impaired GH inhibition might be related to subtle abnormalities of GH secretion or to functional and/or anatomical hypothalamic-pituitary disconnection due to tumor per se or treatments.

OBJECTIVE

The objective of the study was to evaluate the impact of pituitary disorders other than acromegaly on GH response to OGTT. DESIGN, SUBJECTS, AND METHODS: Thirty-three patients (24 females and nine males, aged 50.1 ± 12.3 yr, 13 operated and two irradiated) with various hypothalamic-pituitary disorders (HPDs), 45 healthy subjects (controls), and 42 cured acromegalic patients matched for sex, age. and body mass index were investigated. All subjects were studied for IGF-I levels and GH levels before and during the OGTT.

RESULTS

In HPD patients mean postglucose nadir GH levels were 0.11 ± 0.08 μg/liter without any difference between patients treated with neurosurgery and/or radiotherapy and untreated and between patients with and without pituitary stalk alterations and/or hyperprolactinemia. Mean nadir GH values were similar in HPD patients and controls (0.11 ± 0.08 vs. 0.08 ± 0.08 μg/liter, P = 0.23) and lower than those found in cured acromegalic patients (0.18 ± 0.13 μg/liter, P = 0.02), although there was an overlapping in about half of patients.

CONCLUSIONS

Hypothalamic control of glucose-mediated GH suppression is not perturbed in patients with HPD. These data indicate that defective GH suppression to glucose that is found in acromegaly is unlikely to reflect a lack of integrity of hypothalamic function.

Trauma and the endocrine system

The endocrine system may be the target of different types of trauma with varied consequences. The present article discusses trauma of the hypothalamic-pituitary axes, adrenal glands, gonads, and pancreas. In addition to changes in circulating hormone levels due to direct injury to these structures, there may be an endocrine response in the context of the stress caused by the trauma.

[Selective pituitary resistance to thyroid hormone in a patient treated with amiodarone]

Selective pituitary resistance to thyroid hormones is a syndrome that involves inadequate response of thyroid-stimulating hormone to changes in thyroid hormones. Unlike generalized resistance syndromes, this entity produces central hyperthyroidism and clinical thyrotoxicosis. Sometimes the disease may not be properly diagnosed and is treated with drugs with harmful effects on the thyroid, such as amiodarone, hampering diagnosis and possibly exacerbating the disorder. The treatment of this condition can be symptomatic, based on control of tachycardia and anxiety, or etiological, acting on the pituitary to regulate thyrotropin secretion or on the thyroid gland to control thyroid hormone production. We report the case of a patient with pituitary resistance to thyroid hormone, who was treated with amiodarone to control paroxysmal atrial fibrillation.

The long-term effect of low protein diet on the somatostatin hypothalamic neuronal system and the pituitary growth hormone cells in growing ewe

Three-month old Polish Lowland female lambs were fed isocaloric diets containing 14.2% (standard) or 8.1% of proteins for twenty weeks. Changes in body weight were characteristic for normal growth performance in all animals, but daily body gain calculated for the whole experimental period was significantly lower in lambs fed a low protein diet (87.9 +/- 13.5 and 158 +/- 13.8 g/day, respectively). Two series of blood collections (4 hrs with 15 min interval) were performed at age of 21 and 26 weeks in order to analyze the growth hormone (GH) concentration in the peripheral blood. The results obtained by radioimmunoassay showed that at both ages the mean concentration of GH was significantly higher in the group fed a low protein diet (4.84 +/- 2.23 and 3.68 +/- 1.86 vs 1.46 +/- 0.72 and 1.48 +/- 0.44 ng/ml, respectively) and this difference was associated with significant elevation of the pulse amplitude (3.83 +/- 4.23 and 4.54 +/- 3.06 vs 1.48 +/- 1.11 and 1.31 +/- 0.68 ng/ml, respectively). Using immunocytochemistry, the somatostatin in the hypothalamus and the GH in the pituitary cells were analyzed in all animals slaughtered at age of 8 months. Lowering the content of dietary proteins diminished markedly the content of immunoreactive somatostatin in the median eminence (ME) and augmented the concentrations of the immunoproduct in the somatostatin perikarya. In the pituitary gland, a marked increase of the number of GH-producing cells was observed. The results obtained indicate that chronic restriction of dietary proteins, irrespective of sufficient energy supply, augment the secretion of GH via a decrease in the hypothalamic somatostatin output due to the suppression of its axonal transport.

Alterations in pituitary-thyroid axis function among opioid-dependent subjects after acute and protracted abstinence

The aim of the present study was to investigate the changes in the pituitary-thyroid axis (PTA) and the time course of the hormonal alterations in subjects with opioid dependence after abstinence. Blood samples from in-patients with opioid dependence and age- and sex-matched healthy controls were collected. The severity of opioid abuse and of withdrawal symptoms was assessed. Results were compared between patients with opioid dependence (n = 30) and healthy controls (n = 30). We found that free triiodothyronine and free thyroxine levels were comparable with healthy controls while thyroid-stimulating hormone (TSH) was lower in patients in acute opioid abstinence period. Also, TSH levels in patients remained lower than controls after 30 days of abstinence. These results indicate that PTA function is altered in opioid-dependent subjects. These data highlight the importance of screening the thyroid function for individuals with chronic opioid dependence.

Sexual function and pituitary axis in insulin treated diabetic men

The prevalence of sexual dysfunction and the pituitary-gonadal function were studied in 72 consecutive diabetic male patients. Sexual dysfunction was found in 43% and in these patients peripheral neuropathy was significantly more frequent than in patients with normal sexual function. Sexual dysfunction was more frequent in patients at the age of 50--55 years than in young diabetics (age 25--30 years). No significant correlation between sexual dysfunction and the duration of the disease and no difference in the serum concentrations of luteinizing hormone, follicle stimulating hormone, prolactin, testosterone and oestradiol-17beta between patients with normal and reduced sexual function was found. It is concluded, that sexual dysfunction is not accompanied by altered serum concentrations of testosterone, oestradiol 17beta, gonadotrophins or prolactin. Sexual dysfunction correlates with peripheral neuropathy, but the high prevalence of dysfunction in males with short duration of diabetes without neuropathy makes other causes likely.

Pituitary function in patients with enlarged sella turcica and primary empty sella syndrome

The pituitary function in 20 patients with primary empty sella syndrome has been evaluated. The only endocrine symptom was secondary amenorrhoea in four patients. In half of the patients, pituitary function tests showed minor abnormalities, the most common being impaired growth hormone response to glucagon. In addition to the empty sella, other intracranial abnormalities such as pituitary tumour and hydrocephalus were found in four patients. Although commonly a benign condition, the empty sella may occasionally be associated with clinically important endocrine dysfunction, pituitary tumours and other intracranial abnormalities.

Excessive sensitivity to the hyponatremic effect of chlorpropamide in a patient with diabetes mellitus and anterior pituitary insufficiency

A 67-year-old diabetic woman with undiagnosed anterior pituitary insufficiency developed hyponatremic coma within 5 weeks after initiation of chlorpropamide therapy. A provocation test with 500 mg chlorpropamide orally led within five hours to hyponatremia and sopor with high urinary sodium excretion. This rapid development of the hyponatremic syndrome excludes water retention due to ADH as the dominant cause. It is more probable that known defects in renal sodium conservation, brought about by the anterior pituitary failure, have been potentiated by chlorpropamide.

[Morphofunctional changes in the pituitary-adrenal-gonadal system of Wistar rats exposed long to ethanol at free options]

Experiments were carried out on 40 adult male Wistar rats weighing 220-240 g, which used 15% ethanol or drinking water at free options during 2 months. Ten intact males using the drinking water ad libitum served as controls. Morphofunctional activity was morphologically and morphometrically studied in the anterior pituitary, adrenals, and testicles. The spermogram of epididymal sperm was examined. The plasma levels of follicle-stimulating hormone, luteinizing hormone, corticosterone, testosterone, and estradiol were measured by enzyme immunoassay. The rats using 15% ethanol for 2 months were observed to have feebly marked signs of the suppressed pituitary-adrenal-gonadal system depending on the dose of used ethanol. It is suggested that the amount of ethanol ingested by the animals depends on the baseline level of androgens.

Functional and morphological changes in the adenohypophysis of dogs with induced primary hypothyroidism: loss of TSH hypersecretion, hypersomatotropism, hypoprolactinemia, and pituitary enlargement with transdifferentiation

From case studies in humans it is known that primary hypothyroidism (PH) may be associated with morphological and functional changes of the pituitary. There is no insight into the time scale of these changes. In this study, seven beagle dogs were followed up for 3 years after the induction of primary hypothyroidism. Three of these dogs were followed up for another 1.5 years while receiving l-thyroxine. Adenohypophyseal function was investigated at 2-month intervals with the combined intravenous injection of CRH, GHRH, GnRH, and TRH, and measurement of the plasma concentrations of ACTH, GH, LH, PRL, and TSH. In addition, after 2 years of hypothyroidism a single TRH-stimulation test and a somatostatin test were performed, with measurements of the same pituitary hormones. Every 6 months the pituitary gland was visualized by computed tomography (CT). Induction of PH led to high plasma TSH concentrations for a few months, where after concentrations gradually declined to values no longer significantly different from pre-PH values. A blunted response to stimulation of TSH release preceded this decline. Basal plasma GH concentrations increased during PH and there was a paradoxical hyperresponsiveness to TRH stimulation. Basal GH concentrations remained elevated and returned only to low values during l-thyroxine treatment. Basal PRL concentrations decreased significantly during PH and normalized after several months of l-thyroxine treatment. The pituitary gland became enlarged in all dogs. Histomorphology and immunohistochemical studies in 4 dogs, after 3 years of PH, revealed thyrotroph hyperplasia, large vacuolated thyroid deficiency cells, and decreased numbers of mammotrophs. Several cells stained for both GH and TSH. In conclusion, with time PH led to a loss of the TSH response to low T4 concentrations, hypersecretion of GH, and hyposecretion of PRL. The enlarged pituitaries were characterized by thyrotroph hyperplasia, large vacuolated thyroid deficiency cells, and double-staining cells, which are indicative of transdifferentiation.

Three years prospective investigation of anterior pituitary function after traumatic brain injury: a pilot study

OBJECTIVE

It has been recently demonstrated that traumatic brain injury (TBI)-mediated hypopituitarism could be more frequent than previously known. However, most of the previous data were obtained from retrospective studies, and the natural history of the hypopituitarism due to TBI is still unclear. So far no study has been reported in which the pituitary function of the same patients has been investigated more than 1 year after TBI. Therefore, we report the results of 3 years prospective follow-up of anterior pituitary function in patients with mild, moderate and severe TBI.

PATIENTS AND DESIGN

Thirty patients (25 males, 5 females; age 37.2 +/- 2.4 years) with TBI were included in the study. Pituitary function was evaluated at 1 and 3 years after TBI.

RESULTS

After individual evaluation of GH deficiency from 1 year to 3 years after TBI, 7 of 13 (53.8%) GH-deficient patients at 1st year recovered after 3 years of TBI, and GH deficiency detected at 3 years in one patient was new onset. Additionally, five of six (83.3%) ACTH-deficient patients at 1st year recovered after 3 years of TBI, and ACTH deficiency detected at 3 years in one patient was new onset.

CONCLUSIONS

GH deficiency is the most common pituitary deficit 1 and 3 years after TBI. In patients with mild and moderate TBI, pituitary function improves over time in a considerable number of patients, but it may also worsen rarely over the 3-year period. In patients with severe TBI, ACTH and GH deficiencies at 1st year evaluation persist at 3rd year.

Assessment of traumatic brain injury and anterior pituitary dysfunction in adolescents

Data from the Italian Ministry of Health show that approximately 300-500 per 100.000 Italians are admitted to hospital each year for either TBI or subarachnoid haemorrhage with an annual mortality of 20 per 100.000; 90% of these TBI are of medium severity. Traumatic brain injury-induced hypopituitarism in adults are more common than previously thought. The paucity of clinical reports relating to adolescents with past-TBI induced hypothalamic-pituitary-dysfunction suggests that this phenomenon might be less common that that observed in adults. In the last 25 years, in our Unit a pituitary dysfunction was established during childhood and adolescence in 3 patients (one patient had a precocious puberty, one patient had a gonadal dysfunction and one patient had a partial growth hormone deficiency). In all patients the TBI was severe (unpublished data, 2008). The physiopathological basis of hypopituitarism is lacking. Nevertheless, necrotic, hypoxic, ischemic and shearing lesions are at the hypothalamus and/or the pituitary are likely important factors. The subjects at highest risk appear to be those who have suffered a moderate or severe trauma. Clinical signs of anterior hypopituitarism are often subtle and may be masked by sequalae of TBI. Therefore, post-traumatic anterior pituitary dysfunction may remain undiagnosed and, possibly, aggravate symptoms of brain injury. Moreover it may, if undiagnosed, lead to potentially fatal endocrine crisis. Therefore, adolescents with moderate-severe traumatic brain injury should be screened for such endocrine deficiencies so that replacement therapy can be initiated to optimized the rehabilitation and outcome.

Decreased ACTH secretion during prolonged transportation stress is associated with reduced pituitary responsiveness to tropic hormone stimulation in cattle

The present study examined the effect of transportation stress on hypothalamic-pituitary-adrenal axis responsiveness to tropic hormone stimulation and on abundance of corticotropin releasing factor (CRF) receptor R1 (CRFR1) and arginine vasopressin (AVP) receptor V3 (V3) mRNAs in the anterior pituitary (AP) of cattle. Holstein steers were transported for 10 h or used as non-transported controls (NTC). Blood samples were collected at start of transportation and every 1-2h thereafter. To test AP responsiveness to tropic hormones, animals were challenged (i.v.) with CRF (0.5 microg/kg), AVP (1 microg/kg) or CRF plus AVP immediately after end of transportation and blood samples collected every 30 min for 3h. The AP of animals transported for 0, 4 or 10 h were harvested for mRNA analyses. Plasma ACTH in transported animals increased within 1h and remained elevated for 6 and 8h versus NTC and 0 h values, respectively. Plasma concentrations of cortisol increased in response to transportation and remained elevated throughout the transport period. Injection of CRF or AVP to NTC animals increased plasma ACTH, but ACTH secretion in response to CRF or AVP was dramatically reduced in transported animals. ACTH secretion following co-injection of CRF and AVP tended to be less in transported animals, but was almost 100% greater than when secretagogues were administered separately. Despite decreased AP responsiveness to CRF and AVP, AP CRFR1 and V3 mRNAs were increased after 10 h transportation. Results indicate decreased AP responsiveness to CRF and AVP may regulate duration of ACTH secretion in response to transportation stress in cattle.

24-Hour rhythm in gene expression of nitric oxide synthase and heme-peroxidase in anterior pituitary of ethanol-fed rats

Chronic exposure of rats to ethanol results in significant changes in pituitary hormone secretion. However, identification of the site(s) and mechanism of action of ethanol to induce these effects remains elusive. Free radical damage at the adenohypophyseal level may play a role in the decline in serum gonadotropin levels in ethanol-fed rats. Since 24-h changes in redox state occurred, we analyzed the 24-h changes in pituitary gene expression of the prooxidant enzymes nitric oxide synthase (NOS) 1 and 2, and of heme oxygenase-1 (HO-1) enzyme, and in plasma NO(2)(-) and NO(3)(-) (NO(x)) levels, in ethanol and control rats. Male rats, 35-day-old, received a liquid diet for 4 weeks. The ethanol-fed group received a similar diet to controls except for that maltose was isocalorically replaced by ethanol. Animals were killed at six time intervals during a 24-h cycle. Anterior pituitary mRNA levels encoding NOS1, NOS2 and HO-1 were measured by real-time PCR analysis. Plasma NO(x) concentration was determined by the Griess reaction. Ethanol feeding of prepubertal rats changed significantly the 24-h pattern of expression of NOS1, NOS2 and HO-1 in the adenohypophysis and augmented NOS2 and HO-1 mRNA levels. Peak values for the three enzymes in ethanol-fed rats occurred at the beginning of the scotophase (i.e., at 21:00 h). Ethanol feeding augmented mean values plasma NO(x) levels with a maximum at 13:00 h while in controls a biphasic pattern was observed, with peaks at 09:00 h and 17:00-21:00 h. One of the mechanisms by which ethanol augments oxidative damage in the adenohypophysis may include overproduction of nitric oxide and carbon monoxide.

Prevalence and predictive factors of post-traumatic hypopituitarism

OBJECTIVE

To estimate the prevalence and predictive factors of hypopituitarism following traumatic brain injury (TBI).

DESIGN

A cross-sectional cohort study.

PATIENTS

One hundred and four hospitalized TBI patients (26F/78M), median age 41 (range 18-64) years, body mass index (BMI) 25 (17-39) kg/m(2); severity: mild [Glasgow Coma Scale (GCS) score 13-15) n = 44, moderate (GCS 9-12) n = 20, severe (GCS < 9) n = 40].

MEASUREMENTS

Patients were evaluated 13 (10-27) months post-injury, with measurement of baseline (0800-1000 h) and post-stimulatory hormonal levels during an insulin tolerance test (ITT) (86%) or, if contraindicated, an arginine(arg)-GHRH test + Synacthen test (14%). Insufficiencies were confirmed by retesting.

RESULTS

Hypopituitarism was found in 16 (15%) patients, affecting one axis in 10, two axes in four and more than two axes in two patients. The GH axis was most frequently affected (15%), followed by secondary hypoadrenalism (5%), hypogonadism (2%), hypothyroidism (2%) and diabetes insipidus (2%). The risk of pituitary insufficiency was increased in patients with severe TBI as opposed to mild TBI [odds ratio (OR) 10.1, 95% confidence interval (CI) 2.1-48.4, P = 0.004], and in those patients with increased intracerebral pressure [OR 6.5, 95% CI 1.0-42.2, P = 0.03]. Patients with only one affected axis were all GH deficient; 60% (n = 6) of these were overweight or obese.

CONCLUSION

The prevalence of hypopituitarism was estimated at 16%. Although high, this value was lower than previously reported, and may still be overestimated because of well-known confounding factors, such as obesity. Indicators of increased TBI severity were predictive of hypopituitarism, with a high negative predictive value. Neuroendocrine evaluation should therefore be considered in patients with severe TBI, and in particular in those with increased intracerebral pressure (ICP).

Effects of nalbuphine on anterior pituitary and adrenal hormones and subjective responses in male cocaine abusers

Nalbuphine (Nubain) is a mixed action mu-kappa agonist used clinically for the management of pain. Nalbuphine and other mu-kappa agonists decreased cocaine self-administration in preclinical models. Cocaine stimulates the hypothalamic-pituitary-adrenal (HPA) axis, but the effects of nalbuphine on the HPA axis are unknown. Analgesic doses (5 and 10 mg/70 kg) of IV nalbuphine were administered to healthy male cocaine abusers, and plasma levels of PRL, ACTH and cortisol were measured before and at 10, 17, 19, 23, 27, 31, 35, 40, 45, 60, 75, 105, and 135 min after nalbuphine administration. Subjective effects were measured on a Visual Analog Scale (VAS). Prolactin (PRL) increased significantly within 17 min (P=.04) and reached peak levels of 22.1+/-7.1 ng/ml and 54.1+/-11.3 at 60 min after low and high dose nalbuphine administration, respectively. VAS reports of "Sick," "Bad" and "Dizzy" were significantly higher after 10 mg/70 kg than after 5 mg/70 kg nalbuphine (P=.05-.0001), and were significantly correlated with increases in PRL (P=.05-.0003). However, sedation and emesis were observed only after a 10 mg/70 kg dose of nalbuphine. Interestingly, ACTH and cortisol levels did not change significantly after administration of either dose of nalbuphine. Taken together, these data suggest that nalbuphine had both mu- and kappa-like effects on PRL (PRL increase) but did not increase ACTH and cortisol.

Clinically non-functioning pituitary macroadenomas in the elderly

BACKGROUND AND AIMS

The aim of the present study was to evaluate the clinical presentation, characteristics and post-surgical outcome of non-functioning pituitary macroadenomas (NFPM) in elderly patients.

METHODS

27 patients (65-81 years; 13 Males, 14 Females) with NFPM (20-45 mm in diameter) were studied. The symptoms prompting neuroradiological studies were vision alterations in 52%, and dizziness, loss of memory, confusion, headache and depression in 29%; in 19% of patients, the disease was incidentally discovered during computed tomography (CT) or magnetic resonance imaging (MRI) for head trauma or cerebral ischemic attacks.

RESULTS

Endocrinological evaluation on diagnosis showed global anterior hypopituitarism in 33% and partial hypopituitarism in 37% of patients. Immunohistochemistry showed signs of neurosecretion in most NFPM (chromogranin-A in 55%, gonadotropins in 19%, ACTH in 3.7%). Ki-67 antigen expression was indicative of low proliferative activity. Surgery was highly effective in improving alterations in vision and compressive symptoms, but was unable to restore normal pituitary function in established hypopituitarism in most cases. Eight patients (31%) were free of disease on subsequent MRI (follow-up 1-6 years). In 18 (69%) patients, a post-surgical residue was present. Of these, 6 (33%) underwent radiotherapy in the following years, owing to an increase in the volume of the remnants, and six (33%) underwent additional surgical treatment, followed by radiotherapy for further signs of growth in two. In the remaining patients, a small intrasellar remnant was stable on yearly MRI.

CONCLUSIONS

in elderly patients, the development of hypopituitarism is often overlooked and the initial diagnosis of NFPM may be delayed. This can expose patients to the risks of unrecognized hypopituitarism and jeopardize post-surgical outcome.

Pituitary transcription factors: from congenital deficiencies to gene therapy

Despite the existence of interspecies phenotypic variability, animal models have yielded valuable insights into human pituitary diseases. Studies on Snell and Jackson mice known to have growth hormone, prolactin and thyroid-stimulating hormone deficiencies involving the hypoplastic pituitary gland have led to identifying alterations of the pituitary specific POU homeodomain Pit-1 transcription factor gene. The human phenotype associated with rare mutations in this gene was found to be similar to that of these mice mutants. Terminal differentiation of lactotroph cells and direct regulation of the prolactin gene both require interactions between Pit-1 and cell type specific partners, including panpituitary transcriptional regulators such as Pitx1 and Pitx2. Synergistic activation of the prolactin promoter by Pitx factors and Pit-1 is involved not only in basal condition, but also in responsiveness to forskolin, thyrotrophin-releasing-hormone and epidermal growth factor. In corticotroph cells, Pitx1 interacts with Tpit. Tpit mutations have turned out to be the main molecular cause of neonatal isolated adrenocorticotrophin deficiency. This finding supports the idea that Tpit plays an essential role in the differentiation of the pro-opiomelanocortin pituitary lineage. The effects of Pit-1 are not restricted to hormone gene regulation because this factor also contributes to cell division and protects the cell from programmed cell death. Lentiviral vectors expressing a Pit-1 dominant negative mutant induced time- and dose-dependent cell death in somatotroph and lactotroph adenomas in vitro. Gene transfer by lentiviral vectors should provide a promising step towards developing an efficient specific therapeutic approach by which a gene therapy programme for treating human pituitary adenomas could be based.

High risk of hypopituitarism after traumatic brain injury: a prospective investigation of anterior pituitary function in the acute phase and 12 months after trauma

CONTEXT

Recent data have demonstrated that traumatic brain injury (TBI)-mediated hypopituitarism could be more frequent than previously known. However, most previous data were obtained from retrospective studies.

OBJECTIVES

The aim of this study was to determine 1) the prevalence of anterior pituitary hormone deficiencies in the acute phase of TBI and after 12 months, 2) whether severity of trauma correlated with basal hormone levels, and 3) whether initial hormone deficiencies predicted medium-term hormonal status.

DESIGN AND PATIENTS

Fifty-two TBI patients (43 men and nine women) were included in the prospective study. Pituitary function was evaluated within 24 h of admission and after 1 yr.

RESULTS

Some 5.8% of the patients had TSH deficiency, 41.6% had gonadotropin deficiency, 9.8% had ACTH deficiency, and 20.4% had GH deficiency (GHD). Twelve months after TBI, 5.8% had TSH deficiency, 7.7% had gonadotropin deficiency, 19.2% had ACTH deficiency, and 37.7% had GHD. Twenty-six patients (50.9%) had at least one anterior pituitary hormone deficiency, 21 patients (41.2%) had isolated hormone deficiencies, and five patients (9.7%) had combined hormone deficiencies. Overall, the pituitary hormone deficiencies recovered in 30 (57.7%) patients after 1 yr, and new pituitary hormone deficiencies were present in 27 (51.9%) patients after 1 yr.

CONCLUSIONS

GHD is the most common pituitary deficit 12 months after TBI, and 50.9% of the patients had at least one anterior pituitary hormone deficiency. Pituitary function may improve or worsen in a considerable number of patients over 12 months.

Abnormalities of the somatotrophic axis in the obese agouti mouse

OBJECTIVE

Abnormalities of the melanocortin system produce obesity and increased linear growth. While the obesity phenotype is well characterised, the mechanism responsible for increased linear growth is unclear. The somatotrophic axis was studied in the obese agouti (A(y)/a) mouse as a model of a perturbed melanocortin system.

DESIGN

Adult obese A(y)/a mice were compared to age- and sex-matched wild-type (WT) controls. Weight and body length (nose-anus) were recorded. Plasma growth hormone (GH), insulin-like growth factor-I (IGFI), insulin and leptin were measured using radioimmunoassay. Since ghrelin is a potent GH secretagogue, plasma ghrelin, stomach ghrelin peptide and stomach ghrelin mRNA expression were studied. Hypothalamic periventricular (PeVN) somatostatin neurones and arcuate (Arc) neuropeptide Y (NPY) neurones inhibit the growth axis, whereas Arc growth hormone-releasing hormone (GHRH) neurones are stimulatory. Therefore, specific hypothalamic expression of somatostatin, NPY and GHRH was measured using quantitative in situ hybridisation.

RESULTS

Obese A(y)/a mice were significantly heavier and longer than WT controls. Plasma IGFI concentrations were 30% greater in obese A(y)/a mice. Obese A(y) /a mice were hyperinsulinaemic and hyperleptinaemic, yet plasma ghrelin, and stomach ghrelin peptide and mRNA were significantly reduced. In obese A(y)/a mice, PeVN somatostatin and Arc NPY mRNA expression were reduced by 50% compared to WT controls, whereas Arc GHRH mRNA expression was unchanged.

CONCLUSION

Increased body length in adult obese A(y)/a mice may result from reduced Arc NPY and PeVN somatostatin mRNA expression, which in turn, may increase plasma IGFI concentrations and upregulate the somatotrophic axis.

Children with clinical central diabetes insipidus at King Chulalongkorn Memorial Hospital

OBJECTIVES

To determine the etiologies and associated endocrine disorders in children with central diabetes insipidus (DI).

MATERIAL AND METHOD

The authors retrospectively reviewed the medical records of children with central DI, who were admitted at department of Pediatrics, King Chulalongkorn Memorial Hospital, between 2000 and 2004. Aims of this study were to identify the etiology of central DI in children and also described the anterior pituitary hormone insufficiencies which may occur.

RESULTS

Of the total 51 patients, 27 patients were males and 24 were females. Intracranial tumors produced DI in 36 children (70.6%), but 17 of these 36 children (47.22%) had DI before surgical removal of the tumors. Fifteen patients (29.4%) had DI from non-tumor causes, which include idiopathic in 2 patients (13.5%), terminal events in 4 patients (26.8%), central nervous system (CNS) infection in 5 patients (33.3%), CNS anomalies in 2 patients (13.5%), Kabuki syndrome in 1 patient (6.6%), head injury in 1 patient (6.6%). Anterior pituitary function was evaluated in all tumor group and 8 patients of non-tumor group. In intracranial tumor group, growth hormone deficiency (GHD) was documented in 14 from 22 patients (63.6%), secondary adrenal insufficiency in 13 from 20 patients (65%), central hypothyroid in 27 from 36 patients (75%), hyperprolactinemia in 5 from 8 patients (62.5%).

CONCLUSION

The most common etiology of central DI is intracranial tumor, and at least 50% of them have clinical features suggesting central DI before surgery. More than 60% have associated anterior pituitary hormone insufficiency.

Delay in diagnosis of hypopituitarism after traumatic head injury: a case report and review of the literature

Neuroendocrine complications are among important and frequently missed complications of traumatic brain injury. Hypopituitarism, the partial or complete insufficiency of anterior pituitary secretion may be underrecognized due to its subtle clinical manifestations in traumatic patients. We report a case of 14.5-year-old girl who was admitted due to growth failure and had been diagnosed to have multiple hypophyseal hormone deficiency including thyroid-stimulating hormone, gonadotropins, adrenocorticotropin hormone which developed years after traumatic head injury.

Novel mutations within the POU1F1 gene associated with variable combined pituitary hormone deficiency

CONTEXT

Mutations within the gene encoding the pituitary-specific transcription factor POU1F1 are associated with combined pituitary hormone deficiency (CPHD). Most of the affected individuals manifest GH, prolactin, and TSH deficiency.

OBJECTIVE

We have now screened 129 individuals with CPHD and isolated GH deficiency for mutations within POU1F1.

RESULTS

Causative mutations were identified in 10 of 129 individuals (7.8%). Of these, five patients harbored the dominant negative R271W mutation, which is a well-recognized mutational hot spot. We have also identified a second frequently occurring mutation, E230K, which appears to be common in Maltese patients. Additionally, we describe two novel mutations within POU1F1, an insertion of a single base pair (ins778A) and a missense mutation (R172Q). Functional studies have revealed that POU1F1 (E230K) is associated with a reduction in transactivation, although DNA-binding affinity is similar to the wild-type protein. On the other hand, POU1F1 (R172Q) is associated with a reduction in DNA binding and transactivation, whereas POU1F1 (ins778A) is associated with loss of DNA binding and a reduction in transactivation.

CONCLUSIONS

Our data suggest that the phenotype associated with POU1F1 mutations may be more variable, with the occasional preservation of TSH secretion. Additionally, our data revealed POU1F1 mutations in three patients who were diagnosed as having ACTH deficiency but who, on further evaluation, were found to have normal cortisol secretion. Hence, elucidation of the genotype led to further evaluation of the phenotype, with the cessation of cortisol replacement that had been commenced unnecessarily. These data reflect the importance of mutational analysis in patients with CPHD.

Endocrine function and water metabolism in children and adolescents with surgically treated intra/parasellar tumors

Hydroelectrolytic disorders often complicate surgery of intra/parasellar tumors in children and adolescents. Eighteen patients undergoing microneurosurgical procedures for intra-supra-sellar craniopharyngioma (10 patients), hypothalamic germinomas (3 patients), hypothalamic-chiasmatic astrocytomas (3 patients), pituitary adenomas (2 patients) were studied. The hydroelectrolytic balance was assessed from 8 hours before surgery to 1 week after with a specific protocol in which water metabolism alterations were treated with standard procedure. Diabetes insipidus (DI) was observed in 10/18 patients before surgery and in 15/18 patients after surgery; during surgery it was effectively treated with synthetic desmopressin (DDAVP) and hydroelectrolytic solutions. Hyponatremia, isolated or associated (with diuresis contraction or polyuria), seen during surgery and in the following 24 hours, was treated with variation of the infusion rate. We show that close monitoring and treatment of hydroelectrolytic disorders in patients submitted to neurosurgery for intra/ parasellar tumors may significantly reduce their morbidity and mortality rate.

Auxological, clinical and MRI findings in Taiwanese children with growth hormone deficiency

Growth hormone deficiency (GHD) may be classified into partial isolated GHD (partial IGHD), severe IGHD or multiple pituitary hormone deficiency (MPHD) by the severity of GHD or associated with deficiency of one or more other anterior pituitary hormones during provocative tests. Morphological alterations on magnetic resonance imaging (MRI) in patients with GHD include pituitary hypoplasia, absence or interruption of pituitary stalk, and absence or ectopic posterior lobe. This study investigated the auxological, clinical severity, and anatomical characteristics of the pituitary hypothalamic region by MRI and correlated their relationships. We evaluated these parameters in 45 Taiwanese children with GHD (31 males and 14 females), aged from 3.13 to 17.91 years (10.5+/-2.5), who were divided into diagnostic subgroups of partial IGHD (18 patients), severe IGHD (13 patients), and MPHD (14 patients). We found that BA-CA, peak GH, IGF-I, IGF-I SDS, and height SDS were significantly different among these three groups. The partial IGHD group had significantly higher IGF-I than the MPHD group. There was no significant difference in prematurity, cesarean delivery, birth order, neonatal jaundice, and target height among these three groups. On MRI, patients with MPHD had significantly smaller pituitary height (PHt) SDS (p = 0.0012) and higher frequency of pituitary hypoplasia, pituitary stalk interruption, and ectopic posterior lobe (p = 0.026, 0.008, 0.005, respectively) than the other two groups. Furthermore, PHt SDS was correlated not only with peak GH (r = 0.40, p = 0.0058), but also with basal IGF-I SDS (r = 0.49, p = 0.0007) and body height SDS (r = 0.44, p = 0.025). In conclusion, morphological alterations on MRI of the hypothalamic-pituitary area are correlated with the severity of hypopituitarism. Meticulous evaluation of auxological, clinical and MRI findings can help evaluation of the severity of hypopituitarism and facilitate appropriate treatment in children with GHD.

Pituitary function in patients with newly diagnosed untreated systemic lupus erythematosus

OBJECTIVES

To determine whether hormonal dysfunction involving the hypothalamic-pituitary-adrenal (HPA) axis, prolactin (PRL) secretion, and sex hormone status contribute to development of systemic lupus erythematosus (SLE).

METHODS

11 patients with SLE and 9 healthy controls were tested for their total anterior pituitary gland reserve by simultaneous injection of corticotropin-, growth hormone- (GH), thyrotropin-, and gonadotropin-releasing hormone (GnRH). Serum concentrations of adrenocorticotropin (ACTH), cortisol, GH, thyroid stimulating hormone (TSH), PRL, luteinising hormone (LH), and follicle stimulating hormone (FSH) were measured at baseline and after injection. Baseline values of oestradiol, testosterone, and thyroxine were determined.

RESULTS

Basal and stimulated serum concentrations of ACTH, cortisol, GH, and PRL were similar in both groups. In contrast, despite similar basal thyroxine levels the TSH response to TRH was significantly higher in patients than in controls. LH and FSH levels in premenopausal female patients of both groups were identical. In contrast, two of the three male patients were hypogonadal without compensatory increases of basal LH and FSH levels, but they retained excessive stimulatory capacity in response to GnRH.

CONCLUSION

No significant alteration of the HPA axis was found in patients with SLE, which is inadequate in view of the continuing inflammation. GH and PRL secretion were normal. The pituitary-thyroid and pituitary-gonadal axes were affected in patients with newly diagnosed, untreated SLE.

Deficits in reproduction and pro-gonadotropin-releasing hormone processing in male Cpefat mice

Cpe(fat/fat) mice are obese, diabetic, and infertile. These animals have a point mutation in carboxypeptidase E (CPE), an exopeptidase that removes C-terminal basic amino acids from peptide intermediates. The mutation renders the enzyme unstable, and it is rapidly degraded. Although the infertility of Cpe(fat/fat) mice has not been systematically investigated, it is thought to be due to a deficit in GnRH processing. We have evaluated this hypothesis and found hypothalamic GnRH levels to be reduced by 65-78% and concentrations of pro-GnRH and C-terminal-extended intermediates to be high. Basal serum gonadotropin contents are similar among wild-type, heterozygous, and homozygous mice. Testis morphology and function are abnormal in older obese Cpe(fat/fat) mice. Matings between homozygous mutants yield a 5% pregnancy rate. By comparison, when 50-d-old Cpe(fat/fat) males are paired with heterozygous females, rates increase to 43%, and they rapidly decrease to negligible levels by 120 d. As fertility declines without accompanying changes in the hypothalamic-pituitary-gonadal axis and before obesity is evident, reproduction is more complex than originally thought. This suspicion is confirmed in 90-d-old Cpe(fat/fat) males, who readily interact with females, but rarely mount and fail to show intromission or ejaculation behaviors. Together, these findings show that CPE is a key enzyme for pro-GnRH processing in vivo; however, the reproductive deficits in Cpe(fat/fat) males appear to be due primarily to abnormal sexual behavior.

Obese patients with obstructive sleep apnoea syndrome show a peculiar alteration of the corticotroph but not of the thyrotroph and lactotroph function

OBJECTIVE

Obstructive sleep apnoea syndrome (OSAS) is strongly associated with obesity (OB) and is characterized by several changes in endocrine functions, e.g. GH/IGF-I axis, adrenal and thyroid activity. It is still unclear whether these alterations simply reflect overweight or include peculiar hypoxia-induced hormonal alterations. Hormonal evaluations have been generally performed in basal conditions but we have recently reported that OSAS is characterized by a more severe reduction of the GH releasable pool in comparison to simple obesity. We aimed to extend our evaluation of anterior pituitary function to corticotroph, thyrotroph and lactotroph secretion under dynamic testing in OSAS in comparison with simply obese and normal subjects.

SUBJECTS AND METHODS

In 15 male patients with OSAS [age, mean +/- SEM 43.5 +/- 1.6 years; body mass index (BMI) 39.2 +/- 3.1 kg/m2; apnoea/hypopnoea index, (AHI) 53.4 +/- 8.7], 15 male patients with simple obesity (OB, age 39.7 +/- 1.2 years; BMI 41.2 +/- 2.0 kg/m2; AHI 3.1 +/- 1.2 events/h of sleep) and in 15 normal lean male subjects (NS, age 38.2 +/- 1.4 years; BMI 21.2 +/- 0.8 kg/m2; AHI 1.9 +/- 0.8 events/h of sleep) we evaluated: (a) the ACTH and cortisol responses to CRH [2 microg/kg intravenously (i.v.)] and basal 24 h UFC levels; (b) the TSH and PRL responses to TRH (5 microg/kg iv) as well as FT3 and FT4 levels.

RESULTS

Twenty-four-hour UFC levels in OSAS and OB were similar and within the normal range. Basal ACTH and cortisol levels were similar in all groups. However, the ACTH response to CRH in OSAS (Deltapeak: 30.3 +/- 3.8 pmol/l; DeltaAUC: 682.8 +/- 128.4 pmol*h/l) was markedly higher (P < 0.001) than in OB (Deltapeak: 9.3 +/- 1.4 pmol/l; DeltaAUC 471.5 +/- 97.3 pmol*h/l), which, in turn, was higher (P < 0.05) than in NS (Deltapeak: 3.3 +/- 0.9 pmol/l; DeltaAUC 94.7 +/- 76.7 pmol*h/l). On the other hand, the cortisol response to CRH was not significantly different in the three groups. Basal FT3 and FT4 levels as well as the TSH response to TRH were similar in all groups. Similarly, both basal PRL levels and the PRL response to TRH were similar in the three groups.

CONCLUSIONS

With respect to patients with simple abdominal obesity, obese patients with OSAS show a more remarkable enhancement of the ACTH response to CRH but a preserved TSH and PRL responsiveness to TRH. These findings indicate the existence of a peculiarly exaggerated ACTH hyper-responsiveness to CRH that would reflect hypoxia- and/or sleep-induced alterations of the neural control of corticotroph function; this further alteration is coupled to the previously described, peculiar reduction of somatotroph function.

Clinical Characteristics and Molecular Analysis of PIT1, PROP1,LHX3, and HESX1 in Combined Pituitary Hormone Deficiency Patients with Abnormal Pituitary MR Imaging

BACKGROUND/AIMS

Many genes encoding pituitary transcription factors involved in the formation of the pituitary gland are identified. Different mutations in these genes have been reported in patients with familial combined pituitary hormone deficiency (CPHD). This study was undertaken to analyze PIT1, PROP1, LHX3, and HESX1 in 12 CPHD patients with abnormal pituitary magnetic resonance imaging (MRI). Since embryonic development of the pituitary requires the coordinated expression of specific transcription factors, we postulated the presence of mutations in PIT1, PROP1, LHX3, and HESX1 genes.

METHODS

Anterior pituitary function was evaluated. Each gene was PCR amplified exon by exon, and subsequently sequenced.

RESULTS

In all cases, MRI examination showed abnormal pituitary gland development featuring ectopic neurohypophysis, hypoplastic anterior lobe, empty sella, and septo-optic dysplasia. Endocrinologically, all patients revealed multiple pituitary hormone deficiency including growth hormone, thyroid stimulating hormone, luteinizing hormone, follicular stimulating hormone and adrenocorticotropin. They were all sporadic cases without a positive family history. None of disease-causing specific mutations were identified in PIT1, PROP1, LHX3, and HESX1 genes of 12 sporadic CPHD patients with abnormal pituitary imaging. However, 2 novel polymorphisms were found in PROP1 gene: IVS1+3 A-->G and 27 T-->C (Ala9Ala) in exon 1. Their allele frequencies in patients and normal controls were not statistically different. Overall, allele frequencies of these polymorphisms were as follows: for the IVS1+3 A-->G polymorphism, the allele frequency of A was 54%, and 46% for G, with 58% of an A/G heterozygosity. For the 27 T-->C (Ala9Ala) polymorphism, the allele frequency of T was 46%, and 54% for G, with 42% of a T/C heterozygosity.

CONCLUSIONS

Mutations of PIT1, PROP1, LHX3, and HESX1 genes are very rare in sporadic CPHD patients with abnormal pituitary MRI.

Endocrine evaluation of patients with critical illness

Prolonged critical illness has a high morbidity and mortality. The acute and chronic phases of critical illness are associated with distinct endocrine alterations. The acute neuroendocrine response to critical illness involves an activated anterior pituitary function. In prolonged critical illness, however, a reduced pulsatile secretion of anterior pituitary hormones and the so-called "wasting syndrome" occur. The impaired pulsatile secretion of GH, thyrotropin and gonadotropin can be re-amplified by relevant combinations of releasing factors, which also substantially increase circulating levels of IGF-1, GH-dependent IGFBPs, thyroxin, tri-iodothyronine and testosterone. Anabolism is clearly re-initiated at the time GH secretagogues, thyrotropin-releasing hormone and gonadotropin-releasing hormone are coadministered but the effect on survival remains unknown. A lethal outcome of critical illness is predicted by a high serum concentration of IGFBP-1, pointing to impaired insulin effect rather than pituitary function, and survival was recently shown to be dramatically improved by strict normalization of glycemia with exogenous insulin. In addition to the illness-induced endocrine alterations, patients may have pre-existing central or peripheral endocrine diseases, either previously diagnosed or unknown. Hence, endocrine function testing in a critically ill patient represents a major challenge and the issue of treatment remains controversial. The recent progress in knowledge of the neuroendocrine response to critical illness and its interrelation with peripheral hormonal and metabolic alterations during stress, allows for potential new therapeutic perspectives to safely reverse the wasting syndrome and improve survival.

Pituitary apoplexy induced by corticotrophin-releasing hormone in a patient with Cushing's disease

Pituitary apoplexy can occur spontaneously or following anterior pituitary stimulation tests. Apoplexy is a rare complication of Cushing's disease. We report a 19-year-old woman who was admitted to the National Institutes of Health for evaluation of possible Cushing's syndrome. Her symptoms and initial laboratory work were suggestive of Cushing's disease. Magnetic resonance imaging (MRI) revealed a macroadenoma of the pituitary gland. As part of her evaluation she received corticotrophin-releasing hormone (CRH). Two days later she developed severe headache, accompanied by nausea and vomiting, followed by meningismus, ptosis and diplopia. A diagnosis of pituitary apoplexy was made and she was treated conservatively with dexamethasone. Her neurological symptoms resolved shortly afterwards. By the time of discharge her anterior pituitary function was suppressed. All symptoms and signs of Cushing's syndrome resolved thereafter. This is the first case to demonstrate that CRH administration can induce pituitary apoplexy in a patient with Cushing's disease. Therapy with glucocorticoids was effective in our case, suggesting that conservative treatment can be successfully and safely applied in certain cases with pituitary apoplexy.

Corticotropin-releasing factor receptor type 2 messenger ribonucleic acid in rat pituitary: localization and regulation by immune challenge, restraint stress, and glucocorticoids

CRF receptor 2 (CRF R2) has been identified in the rat pituitary. However, the cell types that express the receptor remained to be determined. In the present study, we localized CRF R2 mRNA in gonadotropes of the anterior pituitary. Ribonuclease protection assays of anterior pituitary mRNA further showed that the dominant receptor type is CRF R2alpha. We also demonstrated that the expression of CRF R2 in the pituitary is sensitive to alterations to the hypothalamic-pituitary-adrenal axis as CRF R2 mRNA levels in the anterior pituitary of male rats were significantly decreased 6 h after bacterial endotoxin lipopolysaccharide (LPS) injection or restraint stress. Subcutaneous corticosterone injections also resulted in significant suppression of CRF R2 mRNA levels in the pituitary, suggesting that glucocorticoids are involved in modulating CRF R2 mRNA levels in the pituitary under stress. LPS administration still caused a significant suppression of CRF R2 mRNA levels in the anterior pituitary of adrenalectomized rats. This suggests that one or more additional factors is involved in the regulation of CRF R2 expression in the anterior pituitary. Taken together, these data suggest that CRF R2alpha in the anterior pituitary might be involved in the regulation of gonadal functions under stress.