Endocrine Abstracts

The relationship between serum TSH and thyroid autoantibodies is frequently used to classify thyroid disease both overt and subclinical. Further debate has centred on the validity of the cutoff point for serum TSH elevation (generally between 4-5 mU/l) which it has been suggested is inappropriately high. The significance of the presence of thyroid autoantibodies (hereafter termed antibody positivity) in extrathyroidal disease is unclear but an increased prevalence has been rep...

Adipsic diabetes insipidus (ADI) is a rare condition which has been reported following clipping of anterior communicating artery aneurysms, craniopharyngioma and brain trauma, but not with pituitary adenoma. We report a case of ADI following surgery for a pituitary macroprolactinoma. A 14-year-old boy presented with bitemporal hemianopia due to a large macroprolactinoma. Two debulking surgeries were performed without the development of diabetes insipidus. Following a third rad...

Prostanoids have been elucidated as potent adipogenic hormones. Cyclooxygenase (PTGS) is the rate-limiting enzyme of prostanoid biosynthesis and its product, prostaglandin (PG) H2 is a precursor of PGE2, PGF2, PGD2 and PGI2. PGH2 is also metabolised by prostaglandin D-synthase (PTGDS) to PGD2 which spontaneously converts to PGJ2 or can be enzymatically converted to PGF2alpha by AKR1C3. These two metabolites have opposite effect on adipogenesis; PGF2alpha is a PPARgamma antagon...

Seaweed consumption results in high levels of iodine intake in Asian populations and influences the presentation of thyroid and perhaps extrathyroidal disorders. The relationship of seawater to seaweed is analogous to that between the bloodstream and the thyroid. However, seaweed has a dramatically more efficient uptake system than the thyroid, concentrating iodide from seawater by a factor of up to 106 compared to 40-50 for the thyroid. The ability of seaweeds to b...

While it is generally acknowledged that hyperthyroidism and Paget's disease are states of increased bone turnover and that treatment reduces this, whether treatment entirely corrects or reverses abnormalities has not been established. A variety of biomarkers for bone formation which include serum levels of bone alkaline phosphatase (BAP), osteocalcin (OC) and amino terminal procollagen type 1N propeptide (PINP) and resorption biomarkers which include urinary excretion of deoxy...

The syndrome of inappropriate antidiuretic hormone (SIADH) is characterised by euvolamic hyponatraemia. Patients with SIADH continue to drink normal amounts of fluid, despite plasma osmolalities well below the physiological osmotic threshold for the onset of thirst. The regulation of thirst has not been previously studied in SIADH. We studied the characteristics of osmotically-stimulated thirst and vasopressin (AVP) secretion, and the non-osmotic suppression of thirst and AVP ...

The central obese phenotype characteristic of Cushing's syndrome emphasises the role of glucocorticoids (GC) in regulating adipose tissue mass and distribution. We have shown that GCs stimulate adipocyte differentiation, but equally inhibit adipose stromal cell (ASC) proliferation. These effects are regulated at a pre-receptor level through 11beta-hydroxysteroid dehydrogenase type 1, but the 'post-receptor' signalling pathways remain unclear. To define novel GC targets in huma...

Subarachnoid haemorrhage (SAH) is a well reported cause of hypopituitarism but the precise incidence is controversial. We aimed to prospectively determine the incidence of acute and long term hypopituitarism in SAH.We prospectively recruited 100 patients (61% female, median age 53 (range 16–82)) with non-traumatic aneurysmal SAH. Each patient had plasma sodium, urea, osmolality, glucose, and 0900 h cortisol (PC) measured on days 1, 2, 3, 4, 6, 8, 10...

Hyponatraemia is the most common electrolyte abnormality following subarachnoid haemorrhage (SAH). Retrospective data suggests that the Syndrome of Inappropriate Antidiuresis (SIAD) is the most common cause, although glucocorticoid deficiency and rarely cerebral salt wasting may also cause hyponatraemia.We prospectively studied 100 patients (61% female, median age 53 (range 16–82)) with non-traumatic aneurysmal SAH. Each patient had plasma sodium (p...

We aimed to establish the extent of adult cystic fibrosis-related diabetes (CFRD) in Ireland, and examine the differences between patients with CFRD and those with normal glucose handling.We conducted a retrospective analysis of patients with cystic fibrosis (CF) who attend the national referral centre for adult CF. Data including lung spirometry, sputum microbiology, bone mineral density and genotype were collected. Patients were diagnosed as having CFR...