Endocrine Abstracts

A 42-year-old man with resistance to thyroid hormone (RTH) and a recognised thyroid hormone receptorβ mutation (R383C) mutation, presented with atrial fibrillation (AF) which was resistant to DC cardioversion until initiation of amiodarone therapy.As expected in RTH, his baseline TFTs were abnormal (FT4 34.6 pmol/l, TSH 2.27 mU/l), but rose further (FT4 45 pmol/l, TSH 0.93 mU/l) following commencement of amiodarone. However, sh...

Background: There is uncertainty as to whether glucocorticoid receptor (GCR) polymorphisms play a role in the development of glucocorticoid-related side-effects in individuals receiving hydrocortisone replacement for Addison’s disease.Method: One-hundred-and-forty-seven Addison’s patients were age, gender, ethnicity and body mass index (BMI) matched with 147 control subjects. Genotyping was performed using polymerase chain reaction (PCR) for th...

Introduction: The stress response post-operatively increases glucocorticoid concentration and a higher cortisol response is associated with better recovery. The measurement of cortisol concentrations post-operatively can be unreliable due to altered binding protein concentrations. Free serum cortisol is felt to be the better marker of bio-active glucocorticoid concentrations but is difficult to measure. Salivary cortisol and cortisone have been shown to correlate well with ser...

The accurate measurement of cortisol by immunoassay is compromised by the potential for cross-reactivity of reagent antibodies with structurally-related steroid compounds present in patient serum. This susceptibility is potentiated when normal steroid metabolism is altered pharmacologically by anti-steroidogenic drugs. This class of drug is utilised in the management of Cushing’s syndrome to moderate cortisol production. To investigate the effect of the 11β-hydroxyla...

Metyrapone (MT) is used in the medical management of Cushing’s syndrome as it decreases serum cortisol (CT) levels by inhibiting adrenal β-hydroxylation of 11-deoxycortisol, the final step in CT synthesis. CT precursors, in particular 11-deoxycortisol (DOC), increase following MT therapy. Monitoring glucocorticoid replacement in patients taking MT could therefore be confounded as DOC cross-reacts in commonly used immunoassays (IA) for serum CT. Serum CT results from ...

Background: Magnesium, the second most abundant intracellular cation, plays a key role in cellular and metabolic reactions including protein synthesis, neurotransmission and electrolyte balance. There are no specific signs or symptoms of hypomagnesaemia and it can coexist with other electrolyte abnormalities. According to various surveys the prevalence of low Magnesium varies between 2–10% in hospitalized patients. However, there are no clear guidelines about when to scre...

Objectives: The audit was carried out to inform the development of a local protocol for investigation of patients with suspected sporadic phaeochromocytoma.Method: Details of all UCAT tests performed in 2006 for a catchment area of approximately 500 000 were obtained.Questionnaires were used to obtain further information about all the patients referred from primary care and secondary care patients with UCAT > upper limit of nor...

A 67 year old female presented with hypertension, oedema and cough. A CT scan of her abdomen showed an enlarged left adrenal gland. Urinary free cortisols were grossly elevated and low dose dexamethasone suppression testing confirmed Cushing’s Syndrome. 24 hour catecholamines were also elevated consistent with a diagnosis of phaeochromocytoma. ACTH levels were high (690 pg/ml) but pituitary MRI was normal. She was commenced on alpha and beta blockade in preparation for su...

Resistance to thyroid hormone (RTH) is a rare, autosomal dominant disorder characterised by a reduced sensitivity of peripheral tissues to thyroid hormone. Thyroid function testing shows elevation of free T4 and T3 with non suppressed TSH levels.Vascular function in these patients has not been fully evaluated. We have studied central arterial stiffness in a cohort of RTH patients, comparing them with age and sex matched controls.Me...

Thyroid hormone resistance (THR) is associated with elevated FT4 and FT3 with inappropriately high TSH levels. T3 action is mediated by two types of thyroid hormone receptor, encoded by alpha and beta genes. We evaluated the endothelial function of a THR transgenic mouse model with a targeted mutation in the thyroid hormone beta receptor gene ex vivo.Isometric tension of aortic rings of 10 mice of each genotype (TRbPV/PV, TRbPV/+</...