Endocrine Abstracts

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...

Background: Growth hormone (GH) potently stimulates lipolysis, and after GH exposure, levels of serum free fatty acids (FFAs) increase in a distinct temporal pattern characterized by a 1-hour lag phase and a peak after 3 hours followed by a gradual return to baseline. This effect predominantly operates during fasting and promotes utilization of lipids from adipose tissue (AT) at the expense of glucose and protein. Prolonged fasting also downregulates the expression of the G0/G...

Context: Obesity is accompanied by blunted GH secretion but relatively normal serum IGF-I levels, which suggests increased GH sensitivity. This, however, remains to be tested at the level of GH signaling in human subjects.Objective: To compare the effects of an acute intravenous GH bolus in obese vs normal weight subjects on GH signaling pathways in adipose and muscle tissue, substrate metabolism and insulin sensitivity.Subjects an...

Background: GH secretion and action change with age in adult human subjects, and this play an important role in substrate metabolism in aging subjects. Targeted disruption of the GH receptor in mice extends longevity, and this is associated with decreased expression of apoptosis-related genes including caspase-9 (CASP9) in skeletal muscle.Aim: To study DNA methylation of putative GH target genes in skeletal muscle of adult male subjects in relation to bo...

Background: The impact of GH on insulin sensitivity is ambiguous since both long standing GH-deficiency as well as acute GH exposure and prolonged GH-excess are associated with insulin resistance.Aim: To test the hypotheses that the insulin antagonistic effect of GH i) is dynamic and depend on ambient GH levels and ii) subsides gradually with time after GH exposure.Methods: Eight GHDA participated in a randomised crossover study. E...

Background: Active acromegaly induces insulin resistance despite a lean phenotype, both of which reverse by curative surgery. The impact of somatostatin analogue treatment on insulin sensitivity is less certain and may be offset by its anti-lipogenic effects.Aim: To study insulin sensitivity, body composition and extopic lipid content in newly diagnosed patients with acromegaly before and ≥6 months after successful surgical or medical treatment.</p...

Background: Growth Hormone (GH) reversibly suppresses insulin-stimulated glucose uptake in skeletal muscle, but less is known about GH effects on glucose metabolism in the basal state. Somatostatin suppresses GH as well as insulin, and may also exert direct effects in skeletal muscle. This may have therapeutic implications in the treatment of acromegalic patients with a somatostatin analogue (SA).Aim: To study basal and insulin-stimulated glucose metabol...

Background and aim: Insulin resistance is associated with type 2 diabetes and obesity but recent studies suggest that it may also be associated with type 1 diabetes (T1D), which may affect glycemic control. Hypoglycemia is a dreaded condition among patients with T1D and may also limit optimal glycemic management. We aimed to investigate insulin sensitivity and metabolic adaptions in healthy control subjects and T1D subjects.Material and methods: <!--SUB:...

Introduction: The presence of brown adipose tissue (BAT) in humans has recently been demonstrated by histology and positron emission tomography (PET). In previous reports, BAT in adults is primarily confined to the upper chest and neck. Here, we report a case of massive BAT infiltration of the visceral adipose tissue in a patient with catecholamine secreting paraganglioma.Methods: The patient was evaluated with [18F]-FDG PET/CT at three occasi...

Background: Physiological elevations of free fatty acids (FFAs) occur in a dynamic bell-shaped fashion lasting some hours, e.g. nocturnally and during exercise. In order to define the metabolic role of physiological elevations in relation to diurnal fluctuations in insulin sensitivity, the present study was designed to identify the metabolic effects of a dynamic 4 hour elevation of FFAs during a glucose clamp.Materials and methods: 8 lean, healthy men we...