Endocrine Abstracts

Low-carbohydrate/high-fat diets (LC–HFD) are a popular way of dieting among the general population as several reports in humans indicate that LC–HFD induce weight loss in overweight subjects without caloric restriction and may improve glucose metabolism. However, regarding this type of diet there is also much controversy in scientific literature because clinical studies and data from animal experiments suggest severe side effects and thus warrant caution. Furthermore...

Measuring circulating concentrations of GH and insulin-like growth factor (IGF1) is crucial to biochemically establish the diagnosis of GH-related disorders such as acromegaly and GH deficiency. Many commercial or in-house immunoassays are in use. Controlled studies and regular external quality assessment schemes document considerable disparities in GH and IGF1 concentrations reported when different assays are used. Among the reasons for the differences are the molecular heter...

Recombinant human growth hormone (rhGH) is abused as a performance enhancing drug, but our knowledge about this is mainly based on rumours, confessions of former athletes and on actions of the police. For many years, the detection of rhGH application by biochemical methods was thought to be impossible. Physiological and biochemical properties of hGH made the development of a test method difficult. rhGH is identical in amino acid sequence and chemical properties to the main, 22...

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The purpose of our study was to establish an assay for the measurement of aldosterone in saliva which utilises a simple, non-invasive sampling technique on an out-patient basis. For this we have developed a non-isotopic, time-resolved fluorescence immunoassay. The assay only requires a volume of 100 μl for each duplicate value obtained and involves an overnight incubation after extraction of samples. Cross-reactivity with potentially interfering steroids is below 0.01%. T...

We previously have reported that short-term treatment of mice with recombinant hGH leads to significant increases in bodyweight (BW), lean body mass (LBM) and liver weight, but – unlike in humans – does not robustly increase circulating levels of IGF1. We now tested the hypothesis that formation of neutralizing antibodies in mice treated with rhGH could explain the lack of IGF1 response. Therefore, we intentionally induced antibody formation against hGH in female FVB...

Performance enhancing substances enjoy considerable popularity among athletes, particularly if deemed undetectable. Doping with growth hormone has been considered undetectable until recently. Two strategies have been pursued to detect GH doping: Pharmacological endpoints and GH isoform composition.For the former approach the consortium GH 2000/2004 has identified markers of GH action and found a combination of parameters from the IGF-system and collagen ...

The OGTT is the gold standard for confirmation or exclusion of acromegaly in treatment-naïve patients as well as after surgery. According to former guidelines, acromegaly is ruled out if the growth hormone (GH) nadir lies below 1.0 μg/l and 0.4 μg/l pre- and postoperatively, respectively. We present the case of a 40-year-old man who presented to the outpatient clinic in 2014 for endocrinological evaluation after an elevated IGF-I concentration had occasionally b...

Metabolic diseases are among the most important diseases in western societies and usually related to obesity. Dietary interventions are recommended for treatment and include both strategies with reduced caloric intake and alterations in macronutrient composition. Metabolism must be assumed to be regulated differently in females and males. In previous studies we demonstrated that low carbohydrate high fat (LCHF) diets affect GH/IGF-I axis in male rats. We know investigated whet...

Low-carbohydrate/high fat diets (LC-HFD) effectively induce body weight loss in both animals and humans; however, in rats this is paralleled by increased visceral adiposity contributing to impaired glucose tolerance. Estrogen inhibits adipose tissue accumulation, with estrogen deficient female animals displaying increased body weight and visceral adiposity with reduced insulin sensitivity, which can be reversed with estrogen replacement. Consistent with the effects seen in fem...