Endocrine Abstracts

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...

Cushing’s disease (CD) is a rare condition, associated with significant morbidities.The long-term morbidities in a series of patients with CD who presented in two tertiary referral centres between 01/1967-06/2009 were assessed. All information was collected as documented in the records of the patients.224 patients were identified (174 females) with median age at diagnosis 39 years (range 10–76 (females 38 (12–72) &#1...

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....

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...