Endocrine Abstracts

Background: Hyponatremia (Na+≤134 mmol/L), the most common electrolyte derangement, is caused by inappropriate vasopressin-mediated water resorption in the kidney. Treating symptomatic hyponatremia is difficult and risky; as difficult as maintaining normal sodium levels. We tested if tolvaptan, an oral vasopressin V2 receptor antagonist, improves hyponatremia and self-reported health outcomes.Methods: Two multicenter, randomized, double-blind, plac...

Introduction: The effect of oestrogens on the male skeleton has been demonstrated in a number of studies and oestradiol (E2) plays an important role in regulating bone mineral density (BMD). The concentration of bioavailable oestradiol (BE), rather than total oestradiol (TE), is associated with bone loss in elderly men.Oestradiol circulates in the bloodstream in one of three forms: bound to SHBG; bound to albumin; and unbound/free. The albumin-bound plus the free fraction comp...

A 64 year old man presented with confusion and agitation following diarrhoea for 48 hours. He had a background history of hypertension, type 2 diabetes, depression and had a normal sodium concentration of 135 mmol/L a year prior to admission. His medications included bendroflumethiazide and sertraline in addition to metformin, diclofenac sodium, aspirin, simvastatin, nifedipine and enalapril. On examination he was conscious but confused. He was afebrile with a blood pressure o...

Aim: To evaluate whether a prospective randomised controlled trial of intensive lifestyle intervention delivered on a monthly out-patient basis can result in reduced cardiovascular risk, and improved quality of life in obese patients with type 2 diabetes.Patients and Methods: Patients were recruited from diabetes out-patient clinics. All subjects underwent a treadmill exercise test to assess eligibility before randomization. Subjects with a negative exer...

Introduction: The beneficial effect of GH replacement on bone in AGHD patients is mediated by improvements in target organ sensitivity to PTH and phosphocalcium metabolism. In aging women with established osteoporosis, GH and IGF-1 concentrations are lower and administration of GH has been shown to increase bone turnover and BMD, but the mechanisms remain unclear.Methods: Fourteen postmenopausal women (63.4±2.1 years; mean BMD T score ± ...

Rhythmic, timed secretion of ghrelin and leptin is integral to the intricate temporal interplay of hormonal signals that maintains energy balance, feeding and body weight. Growth hormone replacement (GHR) in adult growth hormone deficient (AGHD) patients has been shown to alter body composition, energy balance and insulin sensitivity with changes in leptin secretory pattern and concentration. With GHR, single time point ghrelin concentrations have been shown to either increase...

PTH plays an important role in bone metabolism. Active acromegaly is associated with increased bone turnover. Reduction in bone turnover markers occurs following biochemical cure/control of acromegaly. We examined the effect of active acromegaly and its treatment on PTH concentration and PTH target-organ sensitivity.10 patients with active acromegaly (defined as GH nadir greater than 1mU/L following 75g oral glucose load and IGF1 above reference range) a...

Adult Growth Hormone Deficiency (AGHD) is associated with relative phosphate deficiency. Phosphate is an important determinant of serum PTH concentration. PTH target-organ sensitivity is reduced in AGHD and may underlie the pathogenesis of AGHD-related osteopaenia. We examined the effect of phosphate supplementation on change in PTH target-organ sensitivity when given simultaneously with Growth Hormone Replacement (GHR) in AGHD patients.24 AGHD patients ...

Background: Untreated adult growth hormone deficiency (AGHD) is associated with hypertension, obesity and hyperleptinemia. Leptin is linked to obesity related hypertension, is secreted in a circadian rhythm and may contribute to the regulation of BP circadian rhythmicity.Methods: We studied the relationship between plasma leptin (half hourly samples), ambulatory systolic BP (SBP), diastolic BP (DBP) and mean arterial pressure (MAP) over a 24-h period in ...

Leptin stimulates osteoblastic cell proliferation, differentiation and mineralisation and inhibits osteoclast generation; leptin secretion and bone turnover are altered in adult growth hormone deficiency, a condition associated with osteoporosis. The aim of this study was to investigate leptin circadian rhythm and its association with bone turnover in untreated AGHD and following growth hormone replacement (GHR).We sampled peripheral venous blood at half...