Endocrine Abstracts

Case historyA 23-year-old woman with no significant past medical history and normal renal function was incidentally found to be hypercalcaemic in 2003. Following investigation, she was diagnosed with primary hyperparathyroidism. She underwent three-gland parathyroidectomy; histology demonstrated hyperplasia. Her bone function remained normal, but 4 years later she was found to have normocalcaemic hyperparathyroidism. Sestamibi demonstrated uptake inferio...

Background: Hormones oscillate in circadian and ultradian rhythms. Consequently, single time point measurements are very difficult to interpret. To address this, we developed an automated system of 24-hour ambulatory microdialysis. This allows measurement of free hormone concentrations in subcutaneous interstitial fluid collected while participants continue normal daily activities. To validate the technique for adrenal steroid hormones, we simultaneously sampled interstitial f...

Background: Hormones oscillate in circadian and ultradian rhythms. Single time point samples are difficult to interpret and high frequency measurements are time consuming, expensive and invasive. We developed a minimally invasive technique of ambulatory, automated microdialysis. This allows frequent 24-hour sampling of interstitial fluid while participants continue normal daily activities.Methods: Healthy volunteers (age 18–68, no regular medication...

Ectopic Cushing’s syndrome (CS) is commonly caused by malignancy, often behaves aggressively and may not clinically manifest with features of hypercortisolism due to its rapid course and associated cachexia. This may mislead clinicians into discounting the diagnosis in patients with more indolent features of CS. We present a 41 year old woman with an 8 year history of Cushingoid features with associated hypertension, obesity and Type 2 Diabetes. Investigations confirmed C...

Background: Establishing endocrine diagnoses including pituitary Cushing’s remains challenging with delayed or misdiagnosis being very costly for both patient and the health care system. A key issue is that standard diagnostic tests are typically single time point, single analyte samples, which do not consider dynamic variation intrinsic to endocrine systems. Having previously demonstrated that free tissue hormones correlate strongly with plasma concentrations, we present...

Patients on long term glucocorticoid replacement therapy have higher rates of morbidity and mortality. One causative factor may be non-physiological cortisol replacement. We have developed as part of the ULTRADIAN consortium (https://www.uib.no/en/ultradian) the U-RHYTHM, an ambulatory bio-sampling device that can collect clinical samples using in-vivo microdialysis every 20 minutes over the 24hour day whilst individuals continue with their normal everyday activities....

Background : Patients with primary adrenal insufficiency (PAI) describe significant impairments in quality of life. Current replacement regimes are non-physiological. Animal studies indicate that pulsatile presentation of endogenous glucocorticoids is critical for normal transcriptional and behavioural responses. Healthy volunteer work also shows that pattern of glucocorticoid presentation alters cognitive and emotional processing.Objective: To assess th...

Adrenal hormones possess both circadian and ultradian rhythms, making interpretation of single time point measurements difficult, particularly in the context of suspected endocrine disease. Attempting to capture either normal or pathological rhythms in detail by traditional measurement of blood is impractical and generally unfeasible. However, minimally invasive microdialysis sampling of free tissue hormones coupled with a portable fraction collector (U-RHYTHM), and a targeted...

Background: Recently, we have shown that ambulatory 24-hour dynamic steroid profiling using the newly developed U-RHYTHM system is possible and presented the circadian and ultradian rhythmicity of adrenal hormones in a healthy cohort. With U-RHYTHM, multiple hormones can be sampled simultaneously, and the free active hormones can be measured in local tissue where the effect is exerted. Thus the hormone fingerprint resulting from replacement therapy in individual patients can b...