Endocrine Abstracts

Various haemostatic abnormalities have been associated with thyroid dysfunction, especially with hypothyroidism. The underlying mechanisms are not well established.The aim of the study was to evaluate the primary and secondary haemostasis in patients with severe hypothyroidism, to assess the role of thyroid hormone deficiency and to determine whether increased serum TSH level despite normal free thyroid hormone concentrations could influence the coagulat...

In humans the most abundant source of 11 beta-hydroxysteroid dehydrogenase type 2 is the placenta, notably placental trophoblast. This enzyme catalyses the conversion of cortisol (F) to cortisone (E) and is thought to protect the fetus from maternal hypercortisolaemia, thereby impacting on fetal growth and development. During gestation placental trophoblast is exposed to dramatic changes in oxygen tensions ranging from ~2% - 12%, changes thought to be pivotal in stimulating an...

11 beta-hydroxysteroid dehydrogenase type 2 (11 beta-HSD2) is responsible for the conversion of hormonally active cortisol (F) to inactive cortisone (E), and is expressed in mineralocorticoid target tissues (kidney, colon). However, the most abundant source of this enzyme is human placenta, notably placental trophoblast where it is thought to protect the fetus from maternal hypercortisolaemia and play a role in fetal growth and development. During gestation placental trophobla...

AIMS: Postmenopausal oestrogen replacement therapy (ERT) has been shown to lower serum insulin-like growth factor 1 (IGF-1) levels, requiring the use of higher doses of growth hormone (GH) replacement. Soy derived phytoestrogens (PE) are in widespread usage as a natural alternative to ERT. No data exists on the effects of PE on serum IGF-1 levels. The aim of this pilot study was to determine the effects of Phytoestrogen dietary supplementation on the serum IGF-1 level in postm...

Background: Vascular impairment, most commonly due to endothelial dysfunction, is associated with cardiovascular risk in humans with obesity, insulin resistance or Cushing’s syndrome. Similar endocrine disorders in horses, resulting in insulin resistance, are associated with laminitis, a dysfunction of the vasculature supplying the hooves, the mechanism of which is unclear. We hypothesised that horses with insulin resistance have both local and systemic evidence of vascul...

The risk of death with severe hyponatraemia is well known. What is less clear is the mortality risk according to the pattern of the developing hyponatraemia.Methods: From our laboratory database we retrospectively collected data of all adult patients with severe hyponatraemia (<120 mmol/l) over 6 months. Of 49 155 samples, 101 (0.2%) were <120 mmol/l, obtained from n=54 patients. Two paediatric cases were excluded leaving n=52. Norm...

Background and Objective: Thyroid function reference ranges are statistically defined by the 2.5th and 97.5th percentiles, which do not account for potential risk of clinical outcomes. We aimed to define the optimal ranges of thyroid-stimulating hormone (TSH) and free thyroxine (FT4), based on the risk of cardiovascular disease (CVD) and mortality.Methods: We performed an individual-participant data analysis and identified prospecti...

Introduction: Dual energy X-ray absorptiometry (DXA) scans are regarded as the gold standard for assessing bone health. However, an inability to distinguish between cortical and trabecular bone as well as the use of inapproapriate size corrections mean that this technique is of limited clinical use in conditions affecting either bone microarchitecture or patient size. We have trialled the use of high resolution MRI (micro MRI) in the measurement of bone microarchitecture in pa...

The global epidemic of obesity has heightened the need to understand the mechanisms that underpin its pathogenesis. Clinical observations in patients with Cushing's syndrome have highlighted the link between cortisol and central obesity. However, whilst circulating cortisol levels are normal or reduced in obesity, local regeneration of cortisol, from inactive cortisone, by 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) has been postulated as a pathogenic mechanism. W...

Thyroid hormone and TSH levels change during pregnancy yet most laboratories use reference ranges derived from subjects who are not pregnant and male. Does this lead to an underestimation of thyroid disorders in pregnancy?We have derived our own reference range for Free T4 and TSH levels in pregnancy. The hormones were measured in 82 euthyroid mothers at booking and 68 at 28 weeks of pregnancy. Mean (95%CI: reference range of +2SD) FT4 levels were...