Endocrine Abstracts

GH suppression during OGTT is the gold-standard test in diagnosis and monitoring of acromegaly. However, discrepancies between GH nadir and IGF-I have been described and have triggered search for factors modifying the extent of GH suppression. Cut-offs at 1.0 or 0.4 ng/ml are currently recommended with modern, highly sensitive GH assays. To establish assay specific GH nadir cutoffs for the 22kD GH specific IDS-iSYS assay, we examined 381 subjects (319 females, 62 males) with n...

Background: Recent studies reported high soluble α-klotho concentrations (α-klotho) in active acromegaly, with normalization after successful therapy. We showed that α-klotho correlates to GH and even better to IGF-I. So far, most studies employed an immunoassay from Immuno-Biological Laboratories (IBL) for measurement of α-klotho, but other assays are available. Agreement between assays remains questionable since α-klotho exists in several isoforms: K...

In an attempt to define novel genetic loci involved in the pathophysiology of primary aldosteronism a mutagenesis screen after treatment with the alkylating agent N-ethyl-N-nitrosourea was established for the parameter aldosterone. One of the established mouse lines with hyperaldosteronism was phenotypically and genetically characterized. Affected animals showed an increased aldosterone to renin ratio (males unaffected, 1.1±0.1 pg/ml per ng per ml per hour v...

Background: Soluble alpha klotho (sαKL) is high in active acromegaly, normalizes after disease control, and therefore is suggested as a new biomarker for growth hormone (GH) excess. However, little is known about the impact of biological variables other than GH.Methods: Serum sαKL (pg/ml) was measured by ELISA (IBL, Hamburg, Germany). We first evaluated pre-analytical stability, defined a reference interval for sαKL in healthy subjects (A:...

Background: Serum soluble alpha klotho (sαKL) is a circulating protein which had been shown to be very high in active acromegaly, and significantly reduced after disease control. Therefore, sαKL has been suggested as a new biomarker for growth hormone (GH) excess. In this study, we aimed to evaluate the impact of short-term stimulation and suppression of GH and acute modulation of glucose metabolism on sαKL concentrations.Methods: Serum s&...

Introduction: 11-ketotestosterone (11KT) and 11β-hydroxyandrostenedione (11OHA4) are new biomarkers for hyperandrogenic disorders. Steroids can be measured in saliva, allowing non-invasive sampling by patients. We modified a published LC-MS/MS method1 for quantification of 11-oxygenated androgens in saliva with respect to sample volume, extraction procedure and equipment, and assessed the potential impact of different sampling devices on results.<p class="a...

Background: Symptoms of hyperandrogenism are common in patients with Cushing’s disease (CD), but they cannot be sufficiently explained by measured concentrations of circulating androgens. In this study we analyzed the contribution of 11-oxygenated (11o×C19) androgens to hyperandrogenemia in female patients with CD as well as the influence of treatment with steroidogenesis inhibitors osilodrostat and metyrapone on 11o×C19 and classic androgens.<p class="abste...

Background: Alpha klotho is a transmembrane protein that regulates calcium metabolism. Its soluble portion has been linked to endocrine functions. We have recently shown high concentrations of serum soluble alpha klotho (sαKL) in active acromegaly. There is limited information about regulation of sαKL secretion. We aimed to gain insight about sαKL as a potential biomarker for H-related diseases.Methods: SαKL was measured by ELISA (IBL...

Primary aldosteronism (PA) describes the most frequent cause of secondary arterial hypertension. Aldosterone itself represents a BP-independent cardiovascular risk factor associated with increased rates of morbidity and mortality. Recently a worsening of lipid metabolism after treatment has been described.Objective: Our aim was to analyse changes in lipid parameters according to treatment outcome in PA patients. Data of 215 consecutive PA patients with u...

Aim: To determine diagnostic performance of normetanephrine (NMN) and metanephrine (MN) measured by an enzyme immunoassay (EIA) compared with liquid chromatographic–tandem mass spectrometry (LC-MS/MS).Methods: Subjects included 341 patients (174 males) with a mean age of 52 year (range 13–86) tested for PHEO, which was confirmed in 54 patients. Samples where collected from fasting patients after 30 min of supine rest and analyzed for NMN, MN an...