Endocrine Abstracts

Background: We recently have shown a close association of high concentrations of soluble alpha klotho (sαKL) to disease activity in acromegaly. Small pilot studies suggested that sαKL concentrations might be reduced in GH deficiency (GHD) and increase after recombinant human GH (rhGH) therapy. Our aim was to evaluate the potential of sαKL as a biomarker in GHD.Methods: We evaluated sαKL in comparison to the classical biomarkers GH, IG...

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...

Context: Unilateral adrenalectomy is the therapy of first choice in aldosterone producing adenoma (APA). Improvement of blood pressure (BP) and hypokalemia is achieved in the majority of patients. Because of hypoaldosteronism, hyperkalemia can develop in the postoperative course. Our aim was to analyze the frequency of hyperkalemia, to determine the cause of hypoaldosteronism and to assess the influence of preoperative mineralocorticoid antagonist (MRA) therapy at our center.<...

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...

Although primary aldosteronism (PA) is considered to be the most prevalent cause of secondary hypertension the underlying genetic mechanisms have been elucidated only for the rare familial forms of the disease. In an attempt to define novel genetic loci involved in the pathophysiology of PA a phenotype-driven mutagenesis screening after treatment with the alkylating agent N-ethyl-N-nitrosourea was established for the parameter aldosterone. The aldosterone values ...

According to recent studies, primary aldosteronism is considered to be responsible for almost 10% of all cases of arterial hypertension. The genetic background of this common disease, however, has been elucidated only for the rare familial types whereas in the large majority of sporadic cases it still remains unclear. In an attempt to define novel genetic mechanisms of hyperaldosteronism we utilized a random mutagenesis screen after treatment with the alkylating agent N...

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: 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...