Searchable abstracts of presentations at key conferences in endocrinology

ea0022p547 | Neuroendocrinology and Pituitary (<emphasis role="italic">Generously supported by Novartis</emphasis>) | ECE2010

Ghrelin and leptin levels in acromegalic patients treated with pegvisomant

Roemmler Josefine , Otto Baerbel , Ayman Arafat , Martin Bidlingmaier , Jochen Schopohl

Introduction: GH rises dose dependently during treatment with the GH receptor antagonist pegvisomant. Ghrelin stimulates GH secretion. In de novo acromegalic patients with high GH levels, ghrelin levels are lowered and fat mass is reduced. Leptin levels are positively correlated to fat mass. We performed this cross-sectional study to evaluate whether elevated endogenous GH in acromegalic patients on pegvisomant treatment (peg) reduces ghrelin and leptin levels.<p class="ab...

ea0022p142 | Cardiovascular endocrinology and lipid metabolism | ECE2010

Insulin mediates the glucagon-induced decrease in atrial natriuretic peptide: a randomized controlled trial

Arafat Ayman , Rudovich Natalia , Adamidou Aikaterini , Spranger Joachim , Weickert Martin , Mohlig Matthias , Pfeiffer Andreas

Objectives: Atrial natriuretic peptide (ANP) is a cardiac hormone that is known to play an essential role in regulation of blood pressure and vascular endothelial function. However, the metabolic regulation of ANP is not fully understood. In patients suffering from metabolic syndrome hypertension, hyperinsulinemia and postprandial hyperglucagonemia are common features. It was the aim of the present study to evaluate the impact of glucagon on proANP and the possible mechanisms ...

ea0022p687 | Obesity | ECE2010

Glucagon stimulates cholecystokinin secretion in humans

Arafat Ayman , Otto Barbel , Adamidou Aikaterini , Spranger Joachim , Weickert Martin , Mohlig Matthias , Pfeiffer Andreas

Objectives: Gastrointestinal hormones are known to modulate satiety. The mechanisms underlying the impact of glucagon on satiety are so far unknown. However, it can be postulated that the glucagon-induced reduction in hunger feeling is mediated through changes in Cholecystokinin (CCK), which is known to play a role in meal termination. It was the aim of the present study to evaluate the impact of glucagon on CCK and the modulation of these effects in obesity.<p class="abst...

ea0016p215 | Diabetes and cardiovascular diseases | ECE2008

Metabolic changes induced by glucose infusion in persons with Glu23Lys polymorphism

Bobbert Thomas , Mittag Marc , Mai Knut , Fischer Antje , Arafat Ayman , Pfeiffer AFH , Spranger Joachim

The development of diabetes mellitus type 2 (T2DM) is affected by genetic and lifestyle factors. Polymorphisms within the KIR6.2 gene seem to be associated with a higher risk for T2DM. The protein encoded by this gene represents a potassium channel, which plays an essential role in insulin and glucagon secretion by the pancreas.A hyperglycaemic clamp without insulin was performed over 2 h in 10 healthy persons with the Kir6.2 E23K wild type Glu/Glu, 10 a...

ea0016p540 | Obesity | ECE2008

Retinol-binding protein 4 is independently associated with insulin resistance in PCOS women

Mohlig Matthias , Weickert Martin O , Ghadamgahi Elham , Arafat Ayman M , Spranger Joachim , Pfeiffer Andreas FH , Schofl Christof

Objective: Adiposity, insulin resistance, and hyperandrogenism are features of the polycystic ovary syndrome (PCOS). Retinol-binding protein 4 (RBP4) secreted from adipose and liver tissue has been linked to insulin resistance. We here address the impact of RBP4 on insulin resistance in PCOS and its usability to identify women with metabolic syndrome or impaired glucose metabolism (IGT or diabetes).Design: RBP4 was determined in plasma of 115 PCOS...

ea0014p19 | (1) | ECE2007

Insulin decreases IGF-I bioactivity in patients with impaired glucose tolerance and in healthy subjects

Arafat Ayman M , Frystyk Jan , Weickert Martin O , Spranger Joachim , Schöfl Christof , Möhlig Mathias

Objectives: Insulin resistance (IR) is a very common metabolic abnormality in obesity, which is often associated with reduced growth hormone (GH) secretion. GH deficiency is associated with increased in intra-abdominal fat and several parameters of the metabolic syndrome. IGF-I improves IR but the IGF-binding proteins are supposed to regulate its bioactivity although only little information exists. We postulated that the elevated insulin levels due to IR do not only suppress G...

ea0037gp.17.03 | Pituitary–Neuroendocrinology and central salt regulation | ECE2015

Insulin-induced hypoglycaemia decreases IGF1 bioactivity in humans: a missing link to increased mortality in diabetic patients?

Sarem Zeinab , Assefa Biruhalem , Weickert Martin O , Adamidou Aikatarini , Frystyk Jan , Mohlig Matthias , Lieske Stefanie , Birkenfeld Andreas L , Pfeiffer A.F.H , Spranger Joachim , Arafat Ayman M

Background: The mechanisms underlying the association between severe hypoglycaemia and increased cardiovascular mortality among patients with diabetes mellitus are not fully understood. Our aim was to evaluate changes in GH/IGF1 axis during insulin-induced hypoglycaemia, as a possible link.Methods: Twenty-five healthy subjects, 12 obese participants (OP; 6/ 6; 34.4±1.7 kg/m2), and 13 healthy lean participants (LP; 6/ 7; 21.7±0.6 kg/m...

ea0016p439 | Neuroendocrinology | ECE2008

A comparison between three automated chemiluminescence assays for growth hormone: on the use of recombinant hGH as a primary calibrant

Arafat Ayman M , Mohlig Matthias , Weickert Martin O , Perschel Frank H , Purschwitz Johannes , Spranger Joachim , Strasburger Christian J , Schofl Christof , Pfeiffer Andreas FH

Objectives: GH measurements during OGTT have profound effects on therapy and follow-up management of acromegaly. To minimize the discordance between immunoassays, it is recommended to calibrate them using 22 kDa-GH-preparation instead of the use of pituitary-derived calibrants. The aim of our study was to evaluate the between-method discrepancies in GH determinations by assays using different calibrants considering further confounders like age, gender, and BMI.<p class="ab...

ea0016p541 | Obesity | ECE2008

Glucagon suppression of total but not of acylated ghrelin is preserved in obesity: the impact on appetite control

Arafat Ayman M , Adamidou Aikaterini , Otto Barbel , Weickert Martin O , Perschel Frank H , Spranger Joachim , Schofl Christof , Mohlig Matthias , Pfeiffer Andreas F H

Objective: The mechanisms underlying the well known glucagon-induced satiety effect are unclear. As we showed recently, the glucagon-induced reduction in total ghrelin, that might be responsible for this effect, is exerted at hypothalamus–pituitary level. The aim of the present study was to further evaluate glucagon’s suppressive effect on both total and acylated-ghrelin in obesity with respect to its role in appetite control.Methods: Prospecti...

ea0014oc8.1 | Neuroendocrinology clinical | ECE2007

Growth hormone response during OGTT: the impact of assay method, gender and BMI on the estimation of reference values in patients with acromegaly and in healthy controls

Arafat Ayman M , Möhlig Mathias , Weickert Martin O , Perschel Frank H , Purschwitz Johannes , Spranger Joachim , Strasburger Christian J , Schöfl Christof , Pfeiffer Andreas FH

Objectives: Besides the measurement of IGF-1, GH suppression during OGTT to assess the biochemical status in acromegaly is recommended. However, as a consequence of the development of highly sensitive and specific GH assays a critical re-evaluation of the criteria for the diagnosis and follow-up management of acromegaly is mandatory. The aim of our study was to evaluate the between-method discrepancies in GH determinations by different immunoassays considering further confound...