Searchable abstracts of presentations at key conferences in endocrinology

ea0035s26.1 | Pitfalls in hormone measurement | ECE2014

Guidelines on GH/IGF1 measurement

Frystyk Jan

For decades, measurements of the circulating concentrations of GH and IGF1 have constituted a mainstay in the diagnosis and clinical management of GH disorders. However, it is also well-known that considerable discrepancies exist between different assays, resulting in highly assay dependent results. Therefore, in 2009 an International Expert Committee was established with the aim to produce an international consensus statement on the standardization and evaluation of GH and IG...

ea0032p464 | Diabetes | ECE2013

Effects of human insulin and insulin aspart preparations on levels of IGFI, IGFBPs and IGFI bioactivity in patients with type 1 diabetes

Ma Zhulin , Christiansen Jens Sandahl , Lauritzen Torsten , Parkner Tina , Laursen Torben , Frystyk Jan

Introduction: Type 1 diabetes (T1D) is characterized by primary insulin insufficiency and secondary disruption of GH–IGF–IGFBP axis. S.c. insulin therapy is necessary to normalize this axis. This study aimed to investigate whether the distinct insulin profiles obtained with insulin aspart and human insulin preparations, respectively, affect IGF1 concentration and bioactivity and IGFBP levels differently.Methods: In a randomized, four-period cro...

ea0032p622 | Growth hormome IGF axis – basic | ECE2013

A comparison of the in vitro production of IGFs, IGFBP-4 and PAPP-A in cultures of visceral and subcutaneous adipose tissue fragments from obese subjects

Frystyk Jan , Gude Mette Faurholdt , Hjortebjerg Rikke , Oxvig Claus , Pedersen Steen Bonlokke

Background: Visceral adipose tissue (VAT) is less insulin sensitive and more harmful than subcutaneous adipose tissue (SAT). In adipocytes, IGF1 receptor signaling has been linked to insulin resistance, but it is unknown whether VAT and SAT also differ in production of IGFs. Therefore, we compared IGFs, IGFBP-4 and PAPP-A production in cultured fragments of VAT and SAT from obese subjects.Methods: VAT and SAT was collected perioperatively during elective...

ea0020p462 | Obesity and Metabolism | ECE2009

Impact of growth hormone receptor blockade on substrate metabolism during short-term fasting in healthy subjects

Moller Louise , Norrelund Helene , Frystyk Jan , Moller Niels , Jorgensen Jens OL

Context and objective: During fasting growth hormone (GH) promotes lipolysis, attenuates glucose oxidation and preserves protein. Previous studies have primarily been conducted in GH deficient patients or during somatostatin-suppression of GH secretion. We aimed to study the impact of the fasting associated increase in GH without concomitant changes in other hormones, by the means of GH receptor (GHR) blockade.Design: Ten healthy young men participated i...

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...

ea0014p231 | (1) | ECE2007

Pioglitazone treatment significantly decreases 5-alpha reductase activity and improves metabolic risk factors in PCOS

Glintborg Dorte , Hermann Anne Pernille , Hagen Claus , Veldhuis Johannes , Schmedes Anne , Frystyk Jan , Flyvbjerg Allan , Andersen Marianne

Objective: To investigate the effect of pioglitazone on cortisol metabolism in PCOS.Design: Thirty insulin resistant PCOS patients were randomized to either 16 weeks of pioglitazone (30 mg/day) or placebo treatment. Before and after intervention, patients underwent 24 h 20 min.-integrated blood sampling for measurement of cortisol and 24 h excretion of cortisol, cortisone and steroid metabolites (cortisol, corticosteron, androgen, and 17-hydroxyprogester...

ea0041oc13.2 | Pituitary Clinical | ECE2016

Growth hormone and insulin signalling after acute GH exposure in patients with controlled acromegaly: impact of surgery versus somatostatin analog treatment

Dal Jakob , Lundby Hoyer Katrine , Pedersen Steen B , Magnusson Nils , Bjerrring Peter , Frystyk Jan , Moller Niels , Jessen Niels , Jorgensen Jens Otto L

Background: Somatostatin analogue treatment (SA) is used in acromegaly to suppress GH secretion and tumour growth. In addition, SA also suppresses insulin secretion and may impact on GH signalling in peripheral tissues.Objective: To compare GH and insulin signalling in skeletal muscle and adipose tissue in vivo before and after a single exogenous GH bolus in patients with acromegaly controlled by either surgery alone or by ongoing treatment with a slow-r...

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...

ea0070aep748 | Pituitary and Neuroendocrinology | ECE2020

Soluble klotho: A possible predictor of quality of life in acromegaly patients

Coopmans Eva , El-Sayed Nour , Frystyk Jan , Erik Magnusson Nils , Otto Jorgensen Jens , Jan Van der Lely Aart , Janssen Joseph AM , Muhammad Ammar , Neggers Sebastian

Purpose: Although quality of life (QoL) is improved in patients with acromegaly after disease control, QoL correlates only weakly with traditional biomarkers. Our objective is to investigate a potential relation between the new serum biomarker soluble Klotho (sKlotho), GH and insulin-like growth factor 1 (IGF-1) levels and QoL.Methods: In this prospective cohort study, we investigated 54 acromegaly patients biochemically well-controlled on combination tr...

ea0030p8 | (1) | BSPED2012

The effect of homozygosity versus heterozygosity for IGFALS gene mutations on growth, bone strength and insulin resistance

Hogler Wolfgang , Martin David , Crabtree Nicola , Barrett Timothy , Frystyk Jan , Tomlinson Jeremy , Metherell Lou , Rosenfeld Ron , Hwa Vivian , Rose Stephen , Walker Joanna , Shaw Nick

Background: Acid-labile subunit (ALS) deficiency inhibits ternary complex formation leading to primary IGF1 deficiency and short stature. Potential metabolic consequences such as diabetes and low bone mass are not well studied.Objective: This study measured insulin sensitivity, lipid profile, bone density and structure in members of 4 affected families and explore possible gene-dose effects.Methods: Four patients (7–21 years) ...