The modulation of platelet function by growth hormone in growth hormone deficient Hypopituitary patients.

BACKGROUND: Growth hormone deficiency (GHD) has been implicated in increased cardiovascular and cerebrovascular disease risk seen in hypopituitarism, however the mechanism remains speculative. We hypothesise that platelet abnormalities may play a contributory role. Herein we examined platelet behaviour in GHD hypopituitary patients, pre- and post-growth hormone (GH) replacement. METHODS: This study utilizes a physiological flow-based assay to quantify platelet function in whole blood from patient cohorts under arterial shear. Thirteen GH Naïve hypopituitary adults with GHD and thirteen healthy matched controls were studied. Patients were assessed before and after GH treatment. All other pituitary replacements were optimised before the study. In addition to a full endocrine profile, whole blood was labelled and perfused over immobilised von Willibrand factor (vWF). Seven parameters of dynamic platelet-vWF interactions were recorded using digital image microscopy and analysed by customised platelet tracking software. RESULTS: We found a significantly altered profile of platelet-vWF interactions in GHD individuals compared to healthy controls. Specifically, we observed a marked increase in platelets shown to form associations such as tethering, rolling and adherence to immobilized vWF, which were reduced post GH treatment. Speed and distance platelets travelled across vWF was similar between controls and pre-therapy GHD patients, however, this was considerably increased post treatment. This may indicate reduced platelet signaling resulting in less stable adhesion of platelets post GH treatment. CONCLUSIONS: Taken together observed differences in platelet behaviour may contribute to an increased risk of thrombosis in GHD which can in part be reversed by GH therapy.

Familial hypocalciuric hypercalcaemia type 1 caused by a novel heterozygous missense variant in the CaSR gene, p(His41Arg): two case reports.

BACKGROUND: Familial hypocalciuric hypercalcaemia (FHH) is a rare, inherited disorder of extracellular calcium sensing. It is clinically characterised by mild to moderate parathyroid hormone dependent hypercalcaemia, an autosomal dominant pattern of inheritance, and a normal to reduced urinary calcium excretion in spite of high serum calcium. CASE PRESENTATION: We report two cases of FHH in a family caused by a novel pathogenic missense variant in the CaSR gene, p. His41Arg. Case 1, describes a 17 year old female with no significant past medical history, admitted with acute appendicitis requiring laparoscopic appendectomy and reporting a six month history of polydipsia. Routine investigations were significant for hypercalcaemia, corrected calcium 3.19 mmol/L (2.21-2.52mmol/L), elevated parathyroid hormone of 84pg/ml (15-65pg/ml) and a low 24-hour urine calcium of 0.75mmol/24 (2.50-7.50mmol/24). She was initially managed with intravenous fluids and Zolendronic acid with temporary normalisation of calcium though ultimately required commencement of Cinacalcet 30 mg daily for persistent symptomatic hypercalcaemia. Genetic analysis was subsequently positive for the above variant. Case 2, a 50-year-old female, was referred to the endocrine outpatient clinic for the management of type 2 diabetes and reported a longstanding history of asymptomatic hypercalcaemia which had not been investigated previously. Investigation revealed hypercalcaemia; corrected calcium of 2.6 mmol/L (reference range: 2.21-2.52 mmol/L); PTH of 53.7ng/L (reference range: 15-65 ng/L) and an elevated 24-hour urine calcium of 10 mmol/24 (2.50-7.50 mmol/24hr) with positive genetic analysis and is managed conservatively. Despite sharing this novel mutation, these cases have different phenotypes and their natural history is yet to be determined. Two further relatives are currently undergoing investigation for hypercalcaemia and the family have been referred for genetic counselling. CONCLUSION: Accurate diagnosis of FHH and differentiation from classic primary hyperparathyroidism can be challenging, however it is essential to avoid unnecessary investigations and parathyroid surgery. Genetic analysis may be helpful in establishing a diagnosis of FHH in light of the biochemical heterogeneity in this population and overlap with other causes of hypercalcaemia.

Is repeat fine needle aspiration required in thyroid nodules with initial benign cytology? Results from a large Irish series.

BACKGROUND : Fine needle aspiration (FNA) cytology is the preferred method for assessing thyroid nodules for malignancy. Concern remains about the rate of false negative results. The primary aim of this study is to investigate the malignancy rate of thyroid nodules initially classified as benign (Thy 2). METHODS: We retrospectively examined 658 nodules in 653 (429 female) patients between January 2013 to December 2017. All FNA biopsies (FNABs) were performed under ultrasound (US) guidance by a radiologist with expertise in thyroid pathology. Nodules were cytologically classified according to the UK Royal College of Pathologists guidelines. Decisions about further management were made at a regular thyroid multidisciplinary meeting. Follow up of the Thy 2 nodules was determined based on clinical and radiological criteria. RESULTS: The mean age (± SD) was 53.2 (14.6) years. Five hundred out of 658 (76.0%) nodules were classified as Thy 2 (benign) after the first FNAB. Of these thyroid nodules initially classified as benign, 208 (41.6%) underwent repeat FNAB and 9 (1.8%) were surgically removed without repeat FNAB. The remainder were followed up clinically and/or radiologically. Seven (1.4%) of nodules initially classified as Thy 2 were later shown to be or to harbor malignancy after a follow-up of 74.5 (± 19.7) months. Papillary thyroid microcarcinomas were found co-incidentally in two thyroid glands of benign nodules, giving a true prevalence of 5/500 (1.0%). CONCLUSIONS: With a well targeted FNAB, the false negative rate of an initial benign thyroid FNA is very low thus routine second FNAB is not required in patients with a thyroid nodule initially deemed benign. Multidisciplinary input is imperative in informing decision making.

Multiple endocrinopathies, hypercalcaemia and pancreatitis following combined immune checkpoint inhibitor use- case report and review of literature.

BACKGROUND: Immune checkpoint inhibitors (ICIs) are a novel class of oncological agents which are used to treat a number of malignancies. To date seven agents have been approved by the Food and Drug Administration (FDA) to treat both solid and haematological malignancies. Despite their efficacy they have been associated with a number of endocrinopathies. We report a unique case of hypophysitis, thyroiditis, severe hypercalcaemia and pancreatitis following combined ICI therapy. CASE PRESENTATION: A 46-year old Caucasian female with a background history of malignant melanoma and lung metastases presented to the emergency department with lethargy, nausea, palpitations and tremors. She had been started on a combination of nivolumab and ipilimumab 24 weeks earlier. Initial investigations revealed thyrotoxicosis with a thyroid stimulating hormone (TSH) of < 0.01 (0.38-5.33) mIU/L, free T4 of 66.9 (7-16) pmol/.L. TSH receptor and thyroperoxidase antibodies were negative. She was diagnosed with thyroiditis and treated with a beta blocker. Six weeks later she represented with polyuria and polydipsia. A corrected calcium of 3.54 (2.2-2.5) mmol/l and parathyroid hormone (PTH) of 9 (10-65) pg/ml confirmed a diagnosis of non-PTH mediated hypercalcaemia. PTH-related peptide and 1, 25-dihydroxycholecalciferol levels were within the normal range. Cross-sectional imaging and a bone scan out ruled bone metastases but did reveal an incidental finding of acute pancreatitis - both glucose and amylase levels were normal. The patient was treated with intravenous hydration and zoledronic acid. Assessment of the hypothalamic-pituitary-adrenal (HPA) axis uncovered adrenocorticotrophic hormone (ACTH) deficiency with a morning cortisol of 17 nmol/L. A pituitary Magnetic Resonance Image (MRI) was unremarkable. Given her excellent response to ICI therapy she remained on ipilimumab and nivolumab. On follow-up this patient's thyrotoxicosis had resolved without anti-thyroid mediations - consistent with a diagnosis of thyroiditis secondary to nivolumab use. Calcium levels normalised rapidly and remained normal. ACTH deficiency persisted, and she is maintained on oral prednisolone. CONCLUSION: This is a remarkable case in which ACTH deficiency due to hypophysitis; thyroiditis; hypercalcaemia and pancreatitis developed in the same patient on ipilimumab and nivolumab combination therapy. We postulate that hypercalcaemia in this case was secondary to a combination of hyperthyroidism and secondary adrenal insufficiency.

Outcomes of endoscopic transsphenoidal surgery for Cushing's disease.

BACKGROUND: Transsphenoidal surgery (TSS) to resect an adrenocorticotropic hormone (ACTH)-secreting pituitary adenoma is the first-line treatment for Cushing's disease (CD), with increasing usage of endoscopic transsphenoidal (ETSS) technique. The aim of this study was to assess remission rates and postoperative complications following ETSS for CD. METHODS: A retrospective analysis of a prospective single-surgeon database of consecutive patients with CD who underwent ETSS between January 2012-February 2020. Post-operative remission was defined, according to Endocrine Society Guidelines, as a morning serum cortisol < 138 nmol/L within 7 days of surgery, with improvement in clinical features of hypercortisolism. A strict cut-off of < 50 nmol/L at day 3 post-op was also applied, to allow early identification of remission. RESULTS: A single surgeon (MJ) performed 43 ETSS in 39 patients. Pre-operative MRI localised an adenoma in 22 (56%) patients; 18 microadenoma and 4 macroadenoma (2 with cavernous sinus invasion). IPSS was carried out in 33 (85%) patients. The remission rates for initial surgery were 87% using standard criteria, 58% using the strict criteria (day 3 cortisol < 50 nmol/L). Three patients had an early repeat ETSS for persistent disease (day 3 cortisol 306-555 nmol/L). When the outcome of repeat early ETSS was included, the remission rate was 92% (36/39) overall. Remission rate was 94% (33/35) when patients with macroadenomas were excluded. There were no cases of CSF leakage, meningitis, vascular injury or visual deterioration. Transient and permanent diabetes insipidus occurred in 33 and 23% following first ETSS, respectively. There was one case of recurrence of CD during the follow-up period of 24 (4-79) months. CONCLUSION: Endoscopic transsphenoidal surgery produces satisfactory remission rates for the primary treatment of CD, with higher remission rates for microadenomas. A longer follow-up period is required to assess recurrence rates. Patients should be counselled regarding risk of postoperative diabetes insipidus.

A remarkable case of thyrotoxicosis initially caused by graves' disease followed by a probable TSHoma - a case report.

BACKGROUND: Graves' disease is the commonest cause of thyrotoxicosis whilst thyrotropin (TSH)-producing pituitary adenomas (thyrotropinomas, TSHomas) are very rare and account for just 1-2% of all pituitary adenomas. Coexistence of a TSHoma and Graves' disease has been very rarely reported. Here, we report a case of a patient whose initial presentation with primary thyrotoxicosis due to Graves' disease, was subsequently followed by a relapse of thyrotoxicosis due to a probable TSHoma. CASE: A sixty-eight year old woman was referred to our department with classical features of thyrotoxicosis. Initial biochemistry confirmed hyperthyroxinaemia [free thyroxine (fT4) 20.4 pmol/L (reference range 7.0-16.0)] and a suppressed TSH [< 0.02mIU/L (0.50-4.20)]. A technetium pertechnetate uptake scan was consistent with Graves' Disease. She was treated with carbimazole for 18 months and remained clinically and biochemically euthyroid. After stopping carbimazole her fT4 started to rise but TSH remained normal. Laboratory assay interference was excluded. A TRH stimulation test demonstrated a flat TSH response and pituitary MRI revealed a microadenoma. Remaining pituitary hormones were in the normal range other than a slightly raised IGF-1. An 11C-methionine PET/CT scan coregistered with volumetric MRI (Met-PET-MRICR) demonstrated high tracer uptake in the left lateral sella region suggestive of a functioning adenoma. The patient declined surgery and was unable to tolerate cabergoline or octreotide. Thereafter, she has elected to pursue a conservative approach with periodic surveillance. CONCLUSION: This is a very unusual case of thyrotoxicosis caused by two different processes occurring in the same patient. It highlights the importance of considering dual pathology when previously concordant thyroid function tests become discordant. It also highlights a potential role of Met-PET-MRICR in the localisation of functioning pituitary tumours.

The contribution of serum cortisone and glucocorticoid metabolites to detrimental bone health in patients receiving hydrocortisone therapy.

BACKGROUND: Glucocorticoid therapy is the most common cause of iatrogenic osteoporosis. Less is known regarding the effect of glucocorticoids when used as replacement therapy on bone remodelling in patients with adrenal insufficiency. Enhanced intracellular conversion of inactive cortisone to active cortisol, by 11 beta-hydroxysteroid dehydrogenase type 1(11ß-HSD1) and other enzymes leading to alterations in glucocorticoid metabolism, may contribute to a deleterious effect on bone health in this patient group. METHODS: Study design: An open crossover prospective study randomizing ten hypopituitary men, with severe ACTH deficiency, to three commonly used hydrocortisone dose regimens. MEASUREMENTS: Following 6 weeks of each regimen, patients underwent 24-h serum cortisol/cortisone sampling, measurement of bone turnover markers, and a 24-h urine collection for measurement of urinary steroid metabolites by gas chromatography-mass spectrometry (GC-MS). Serum cortisone and cortisol were analysed by liquid chromatography-mass spectrometry (LC-MS). RESULTS: Dose-related and circadian variations in serum cortisone were seen to parallel those for cortisol, indicating conversion of ingested hydrocortisone to cortisone. The median area under the curve (AUC) of serum cortisone was significantly higher in patients on dose A (20 mg/10 mg) [670.5 (IQR 621-809.2)] compared to those on dose C (10 mg/5 mg) [562.8 (IQR 520.1-619.6), p = 0.01]. A negative correlation was observed between serum cortisone and bone formation markers, OC [1-49] (r = - 0.42, p = 0.03), and PINP (r = - 0.49, p = 0.01). There was a negative correlation between the AUC of night-time serum cortisone levels with the bone formation marker, OC [1-49] (r = - 0.41, p = 0.03) but there were no significant correlations between day-time serum cortisone or cortisol with bone turnover markers. There was a negative correlation between total urinary cortisol metabolites and the bone formation markers, PINP (r = - 0.39, p = 0.04), and OC [1-49] (r = - 0.35, p = 0.06). CONCLUSION: Serum cortisol and cortisone and total urinary corticosteroid metabolites are negatively associated with bone turnover markers in patients receiving replacement doses of hydrocortisone, with nocturnal glucocorticoid exposure having a potentially greater influence on bone turnover. TRIAL REGISTRATION: Irish Medicines Board Clinical Trial Number - CT900/459/1 and EudraCT Number - 2007-005018-37 . Registration date: 07-09-2007.

IgG4 hypophysitis - a rare and underdiagnosed cause of pituitary gland and stalk mass-like thickening.

Our aim is to present a typical case of IgG4-related hypophysitis, which will offer insight into the aetiology and pathogenesis of this relatively newly described disease. IgG4 Related Disease is a protean systemic condition that mimics inflammatory, infectious, and malignant processes. Biopsy of affected organs will show a typical histopathological pattern.

Metabolic encephalopathy secondary to diabetic ketoacidosis: a case report.

INTRODUCTION: Metabolic encephalopathy is a rare but potentially devastating complication of diabetic ketoacidosis (DKA). This case highlights the dramatic cognitive decline of a young man due to metabolic encephalopathy complicating DKA. The aims of this case report are to highlight metabolic encephalopathy as a complication of DKA and to explore the current research in diabetic related brain injury. The importance of investigation and treatment of reversible causes of encephalopathy is also demonstrated. CASE PRESENTATION: A 35-year-old man with a background of type 1 diabetes mellitus (T1DM) and relapsing remitting multiple sclerosis (RRMS) presented to the emergency department (ED) in a confused and agitated state. Prior to admission he worked as a caretaker in a school, smoked ten cigarettes per day, took excess alcohol and smoked cannabis twice per week. Following initial investigations, he was found to be in DKA. Despite timely and appropriate management his neurological symptoms and behavioural disturbance persisted. Neuroimaging revealed temporal lobe abnormalities consistent with an encephalopathic process. The patient underwent extensive investigation looking for evidence of autoimmune, infective, metabolic, toxic and paraneoplastic encephalopathy, with no obvious cause demonstrated. Due to persistent radiological abnormalities a temporal lobe biopsy was performed which showed marked astrocytic gliosis without evidence of vasculitis, inflammation, infarction or neoplasia. A diagnosis of metabolic encephalopathy secondary to DKA was reached. The patient's cognitive function remained impaired up to 18 months post presentation and he ultimately required residential care. CONCLUSIONS: Metabolic encephalopathy has been associated with acute insults such as DKA, but importantly, the risk of cerebral injury is also related to chronic hyperglycaemia. Mechanisms of cerebral injury in diabetes mellitus continue to be investigated. DKA poses a serious and significant neurological risk to patients with diabetes mellitus. To our knowledge this is the second case report describing this acute complication.

The frequency and the diagnosis of pituitary dysfunction after traumatic brain injury.

PURPOSE: Clinical research studies over the last 15 years have reported a significant burden of hypopituitarism in survivors of traumatic brain injury (TBI). However, debate still exists about the true prevalence of hypopituitarism after head injury. METHODS: We have reviewed the literature describing the frequency of post-traumatic hypopituitarism and discuss the factors which may explain the variable frequency of the reported deficits in clinical studies including research methodology and the natural history of the disease. RESULTS: Pituitary hormone perturbations in the acute phase following injury are frequent but are difficult to attribute to traumatic pituitary damage due to physiological hormonal changes in acute illness, the confounding effect of medications, other co-morbidities and lack of appropriate control subjects. Nevertheless, a small number of studies have emphasised the clinical importance of acute, dynamic disturbance of the hypothalamic-pituitary-adrenal axis. There is a much larger evidence base examining the frequency of hypopituitarism in the chronic, recovery phase following head injury. These studies report a very broad prevalence of long-term pituitary hormone dysfunction in survivors of TBI. However, systematic review suggests the prevalence to be between 27 and 31%. CONCLUSION: Survivors of head injury are at risk of pituitary hormone dysfunction and we suggest an approach to the diagnosis of post-traumatic hypopituitarism in routine clinical practice.

Growth Hormone Deficiency Following Traumatic Brain Injury.

Traumatic brain injury (TBI) is fairly common and annually affects millions of people worldwide. Post traumatic hypopituitarism (PTHP) has been increasingly recognized as an important and prevalent clinical entity. Growth hormone deficiency (GHD) is the most common pituitary hormone deficit in long-term survivors of TBI. The pathophysiology of GHD post TBI is thought to be multifactorial including primary and secondary mechanisms. An interplay of ischemia, cytotoxicity, and inflammation post TBI have been suggested, resulting in pituitary hormone deficits. Signs and symptoms of GHD can overlap with those of TBI and may delay rehabilitation/recovery if not recognized and treated. Screening for GHD is recommended in the chronic phase, at least six months to a year after TBI as GH may recover in those with GHD in the acute phase; conversely, it may manifest in those with a previously intact GH axis. Dynamic testing is the standard method to diagnose GHD in this population. GHD is associated with long-term poor medical outcomes. Treatment with recombinant human growth hormone (rhGH) seems to ameliorate some of these features. This review will discuss the frequency and pathophysiology of GHD post TBI, its clinical consequences, and the outcomes of treatment with GH replacement.

DIFFERENTIAL REGULATION OF 11ß-HYDROXYSTEROID DEHYDROGENASE TYPE 1 ACTIVITY IN PATIENTS WITH DIFFERING ETIOLOGIES OF HYPOPITUITARISM.

OBJECTIVE: Pituitary patients with different etiologies of hypopituitarism exhibit differing phenotypes, despite similar replacement therapy strategies. We hypothesized that differential regulation of the isoenzyme 11ß-hydroxysteroid dehydrogenase 1 (11ß-HSD1), which mediates the net autocrine conversion of cortisone to cortisol in adipose tissues and liver, may play a role. METHODS: We studied 11ß-HSD1 activity (using urine cortisol/cortisone metabolites ratio) in 36 hypopituitary patients with treated craniopharyngiomas, treated remitted Cushing disease, and treated nonfunctioning pituitary adenomas + prolactinomas on and off growth hormone (GH) replacement. RESULTS: 11ß-HSD1 activity was higher in subjects with craniopharyngioma both on and off GH, as evidenced by increased tetrahydrocortisol to tetrahydrocortisone metabolite ratios compared to other diagnostic groups, but there was no difference in body mass index, insulin levels, serum hormone measurements, or hydrocortisone dose between groups. CONCLUSION: Craniopharyngiomas are associated with enhanced 11ß-HSD1 activity compared to other diagnostic hypopituitary groups, and this may contribute to the adverse phenotypic and metabolic features seen in this condition. ABBREVIATIONS: BMI = body mass index; Em = cortisone metabolites; Fm = cortisol metabolites; GH = growth hormone; 11ß-HSD1 = 11ß-hydroxysteroid dehydrogenase type 1; IGF-1 = insulin-like growth factor 1; NFPA = nonfunctioning pituitary adenoma; THE = tetrahydrocortisone; THF = tetrahydrocortisol.

ALTERATIONS IN THYROID HORMONE LEVELS FOLLOWING GROWTH HORMONE REPLACEMENT EXERT COMPLEX BIOLOGICAL EFFECTS.

OBJECTIVE: Alterations in the thyroid axis are frequently observed following growth hormone (GH) replacement, but uncertainty exists regarding their clinical significance. We aimed to compare fluctuations in circulating thyroid hormone levels, induced by GH, to changes in sensitive biological markers of thyroid hormone action. METHODS: This was a prospective observational clinical study. Twenty hypopituitary men were studied before and after GH replacement. Serum thyroid-stimulating hormone (TSH), thyroid hormones, and insulin-like growth factor 1 were measured. Changes in thyroid hormone concentrations were compared to alterations in resting metabolic rate and cardiac time intervals. Health-related quality of life (QOL) was assessed by disease-sensitive and generic questionnaires. RESULTS: Following GH replacement, free thyroxine concentration declined and free triiodothyronine level increased. Resting energy expenditure increased, particularly in subjects with profound hypopituitarism, including TSH deficiency (16.73 ± 1.75 kcal/kg/min vs. 17.96 ± 2.26 kcal/kg/min; P = .01). Alterations in the thyroid axis were more pronounced in subjects with a low/normal baseline respiratory quotient (RQ) who experienced a paradoxical rise in RQ (0.81 vs. 0.86; P = .01). Subjects with a high baseline RQ experienced a slight but nonsignificant fall in RQ without alteration in thyroid axis. The isovolumetric contraction time was shortened during the study; however, this did not reach statistical significance. Improvements in QOL were observed despite alterations in thyroid axis. CONCLUSION: Changes in the thyroid axis following GH replacement are associated with complex tissue-specific effects. These fluctuations may induce a hypothyroid phenotype in some tissues while appearing to improve the biological action of thyroid hormone in other organs. ABBREVIATIONS: AGHDA = Assessment of Growth Hormone Deficiency in Adulthood; CHOox = carbohydrate oxidation; ET = ejection time; fT3 = free triiodothyronine; fT4 = free thyroxine; GH = growth hormone; GHD = growth hormone deficiency; HB-RQ = high baseline respiratory quotient; HPT = hypothalamic-pituitary-thyroid; ICT = isovolumetric contraction time; IGF-1 = insulin-like growth factor 1; IRT = isovolumetric relaxation time; LB-RQ = low baseline respiratory quotient; LV = left ventricular; NHP = Nottingham Health Profile; QOL = quality of life; REE = resting energy expenditure; RQ = respiratory quotient; rT3 = reverse triiodothyronine; SF-36 = Short Form 36; TSH = thyroid-stimulating hormone; T3 = triiodothyronine; T4 = thyroxine; TT3 = total triiodothyronine; TT4 = total thyroxine.

Increased Population Risk of AIP-Related Acromegaly and Gigantism in Ireland.

The aryl hydrocarbon receptor interacting protein (AIP) founder mutation R304* (or p.R304* ; NM_003977.3:c.910C>T, p.Arg304Ter) identified in Northern Ireland (NI) predisposes to acromegaly/gigantism; its population health impact remains unexplored. We measured R304* carrier frequency in 936 Mid Ulster, 1,000 Greater Belfast (both in NI) and 2,094 Republic of Ireland (ROI) volunteers and in 116 NI or ROI acromegaly/gigantism patients. Carrier frequencies were 0.0064 in Mid Ulster (95%CI = 0.0027-0.013; P = 0.0005 vs. ROI), 0.001 in Greater Belfast (0.00011-0.0047) and zero in ROI (0-0.0014). R304* prevalence was elevated in acromegaly/gigantism patients in NI (11/87, 12.6%, P < 0.05), but not in ROI (2/29, 6.8%) versus non-Irish patients (0-2.41%). Haploblock conservation supported a common ancestor for all the 18 identified Irish pedigrees (81 carriers, 30 affected). Time to most recent common ancestor (tMRCA) was 2550 (1,275-5,000) years. tMRCA-based simulations predicted 432 (90-5,175) current carriers, including 86 affected (18-1,035) for 20% penetrance. In conclusion, R304* is frequent in Mid Ulster, resulting in numerous acromegaly/gigantism cases. tMRCA is consistent with historical/folklore accounts of Irish giants. Forward simulations predict many undetected carriers; geographically targeted population screening improves asymptomatic carrier identification, complementing clinical testing of patients/relatives. We generated disease awareness locally, necessary for early diagnosis and improved outcomes of AIP-related disease.

Immediate versus modified release hydrocortisone in mitotane-treated patients with adrenocortical cancer.

OBJECTIVE: Mitotane induces hepatic CYP3A4 activity, resulting in accelerated cortisol inactivation, and also increases cortisol binding globulin (CBG). Therefore, higher hydrocortisone doses are required in patients with adrenocortical cancer (ACC) on mitotane treatment. Modified release hydrocortisone has not been used in mitotane-treated ACC patients yet. AIM: Case series to compare serum cortisol, calculated free serum cortisol and ACTH levels in ACC patients on mitotane treatment with immediate and modified release hydrocortisone. DESIGN: Pharmacokinetics of immediate and modified release hydrocortisone, each administered at a dose of 40-20-0 mg, in nine patients with ACC and adjuvant mitotane treatment. For comparison, ten patients with secondary adrenal insufficiency (SAI) on three different hydrocortisone regimens and ten healthy males were included. METHODS: Serum cortisol and plasma ACTH were measured by chemiluminescent enzyme immunoassay, and CBG by RIA, followed by calculation of free cortisol. RESULTS: Calculated free serum cortisol levels after 40 mg immediate release hydrocortisone in ACC patients (46 ± 14 nmol/l) were similar to those after 10 mg immediate release hydrocortisone intake in men with SAI (64 ± 16 nmol/l) or to the physiological morning free cortisol levels in healthy subjects (31 ± 5 nmol/l). Compared to immediate release hydrocortisone, free cortisol levels after 40 mg modified release hydrocortisone in ACC patients were significantly lower (12 ± 3 nmol/l; P = 0·03) resulting in a generally lower AUC (98 ± 21 vs 149 ± 37 nmol h/l; P = 0·02). CONCLUSIONS: 40-20-0 mg immediate release, but not modified release hydrocortisone, resulted in sufficient glucocorticoid coverage in patients with ACC receiving mitotane treatment. The use of equivalent doses of modified release hydrocortisone preparation should be avoided in patients on mitotane treatment.

The effect of growth hormone replacement on the thyroid axis in patients with hypopituitarism: in vivo and ex vivo studies.

OBJECTIVE: Alterations in the hypothalamic-pituitary-thyroid axis have been reported following growth hormone (GH) replacement. The aim was to examine the relationship between changes in serum concentration of thyroid hormones and deiodinase activity in subcutaneous adipose tissue, before and after GH replacement. DESIGN: A prospective, observational study of patients receiving GH replacement as part of routine clinical care. PATIENTS: Twenty adult hypopituitary men. MEASUREMENTS: Serum TSH, thyroid hormones - free and total thyroxine (T4) and triiodothyronine (T3) and reverse T3, thyroglobulin and thyroid-binding globulin (TBG) levels were measured before and after GH substitution. Changes in serum hormone levels were compared to the activity of deiodinase isoenzymes (DIO1, DIO2 and DIO3) in subcutaneous adipose tissue. RESULTS: The mean daily dose of growth hormone (GH) was 0·34 ± 0·11 mg (range 0·15-0·5 mg). Following GH replacement, mean free T4 levels declined (-1·09 ± 1·99 pmol/l, P = 0·02). Reverse T3 levels also fell (-3·44 ± 1·42 ng/dl, P = 0·03) and free T3 levels increased significantly (+0·34 ± 0·15 pmol/l, P = 0·03). In subcutaneous fat, DIO2 enzyme activity declined; DIO1 and DIO3 activities remained unchanged following GH substitution. Serum TSH, thyroglobulin and TBG levels were unaltered by GH therapy. CONCLUSIONS: In vitro analysis of subcutaneous adipose tissue from hypopituitary human subjects demonstrates that GH replacement is associated with significant changes in deiodinase isoenzyme activity. However, the observed variation in enzyme activity does not explain the changes in the circulating concentration of thyroid hormones induced by GH replacement. It is possible that deiodinase isoenzymes are differentially regulated by GH in other tissues including liver and muscle.

Acute airway compromise due to parathyroid tumour apoplexy: an exceptionally rare and potentially life-threatening presentation.

BACKGROUND: Spontaneous haemorrhage into a parathyroid adenoma is a rare and potentially life-threatening presentation. CASE PRESENTATION: We report the case of a 45 year old female recently diagnosed with primary hyperparathyroidism who presented with chest discomfort and acute airway compromise due to spontaneous extracapsular haemorrhage into a parathyroid adenoma. Computed tomography (CT) imaging showed a hypopharyngeal haematoma extending 10 cm into the superior mediastinum. Surgical decompression of the cyst followed by enbloc resection of the parathyroid tumour was performed after elective intubation. Calcium and parathyroid hormone (PTH) levels had fallen prior to surgery and remain normal post-operatively. CONCLUSION: Spontaneous parathyroid haemorrhage should be considered in any patient with unexplained spontaneous cervical haemorrhage, particularly if there is a history of hyperparathyroidism. Initial evaluation of such patients should include serum calcium and PTH as well as imaging.

Gastrointestinal stromal tumor metastases to the pituitary: a rare entity.

Gastrointestinal stromal tumors (GISTs) are rare, but represent the most common mesenchymal tumor of the gastrointestinal tract. The paucity of intracranial metastasis makes treatment strategies difficult. This manuscript presents the first documented case report of a GIST that presented clinically with pituitary symptoms due to a pituitary metastasis.

Symptoms of gonadal dysfunction are more predictive of hypopituitarism than nonspecific symptoms in screening for pituitary dysfunction following moderate or severe traumatic brain injury.

OBJECTIVE: The economic and logistic burden of screening for hypopituitarism following moderate/severe traumatic brain injury (TBI) is considerable. A key recommendation in published guidelines is to prioritize for screening those patients with symptoms suggestive of pituitary dysfunction. The purpose of this study was to evaluate the utility of targeted screening for hypopituitarism in long-term survivors after moderate/severe TBI using referrals on the basis of symptoms. DESIGN: In group 1 (G1), consecutive, unselected patients were screened from the Irish National Neurosurgery Centre, whereas in group 2 (G2) patients were targeted based on the presence of symptoms suggestive of pituitary dysfunction. PATIENTS: A total of 137 patients (113 male) were systematically screened (G1) and compared to 112 patients (77 male) referred for pituitary evaluation on the basis of suggestive symptoms (G2). MAIN OUTCOME MEASURES: The rate of GH, ACTH, gonadotrophin (GT), TSH and ADH deficiency was compared among groups. RESULTS: Patients referred with menstrual dysfunction had more GH (50% vs 11%, P = 0·001), ACTH (60% vs 14%, P < 0·0001), GT (90% vs 16%, P < 0·0001) deficiency and any pituitary hormone deficit (80% vs 33%, P = 0·003) than G1. Men with symptoms of hypogonadism had more GH (33% vs 11%, P = 0·003), GT (58% vs 16%, P < 0·0001) and TSH (16% vs 1%, P = 0·03) deficiency than G1. Patients with nonspecific symptoms were no more likely to have hypopituitarism than those consecutively screened. CONCLUSIONS: Symptoms of hypogonadism are sufficiently predictive of hypopituitarism to justify screening for hypopituitarism after moderate/severe TBI. Nonspecific symptoms of hypopituitarism are no more predictive than unselected screening.

How should we interrogate the hypothalamic-pituitary-adrenal axis in patients with suspected hypopituitarism?

Hypopituitarism is deficiency of one or more pituitary hormones, of which adrenocorticotrophic hormone (ACTH) deficiency is the most serious and potentially life-threatening. It may occur in isolation or, more commonly as part of more widespread pituitary failure. Diagnosis requires demonstration of subnormal cortisol rise in response to stimulation with hypoglycemia, glucagon, ACTH(1-24) or in the setting of acute illness. The choice of diagnostic test should be individualised for the patient and clinical scenario. A random cortisol and ACTH level may be adequate in making a diagnosis in an acutely ill patient with a suspected adrenal crisis e.g. pituitary apoplexy. Often however, dynamic assessment of cortisol reserve is needed. The cortisol response is both stimulus and assay- dependent and normative values should be derived locally. Results must be interpreted within clinical context and with understanding of potential pitfalls of the test used.