Ghrelin Infusion in Humans Induces Acute Insulin Resistance and Lipolysis Independent of Growth Hormone Signaling

OBJECTIVE—Ghrelin is a gut-derived peptide and an endogenous ligand for the growth hormone (GH) secretagogue receptor. Exogenous ghrelin stimulates the release of GH (potently) and adrenocorticotropic hormone (ACTH) (moderately). Ghrelin is also orexigenic, but its impact on substrate metabolism is controversial. We aimed to study direct effects of ghrelin on substrate metabolism and insulin sensitivity in human subjects

Development of ACRODAT®, a new software medical device to assess disease activity in patients with acromegaly

Despite availability of multimodal treatment options for acromegaly, achievement of long-term disease control is suboptimal in a significant number of patients. Furthermore, disease control as defined by biochemical normalization may not always show concordance with disease-related symptoms or patient's perceived quality of life. We developed and validated a tool to measure disease activity in acromegaly to support decision-making in clinical practice. An international expert panel (n = 10) convened to define the most critical indicators of disease activity. Patient scenarios were constructed based on these chosen parameters. Subsequently, a panel of 21 renowned endocrinologists at pituitary centers (Europe and Canada) categorized each scenario as stable, mild, or significant disease activity in an online validation study. From expert opinion, five parameters emerged as the best overall indicators to evaluate disease activity: insulin-like growth factor I (IGF-I) level, tumor status, presence of comorbidities (cardiovascular disease, diabetes, sleep apnea), symptoms, and health-related quality of life. In the validation study, IGF-I and tumor status became the predominant parameters selected for classification of patients with moderate or severe disease activity. If IGF-I level was ≤1.2x upper limit of normal and tumor size not significantly increased, the remaining three parameters contributed to the decision in a compensatory manner. The validation study underlined IGF-I and tumor status for routine clinical decision-making, whereas patient-oriented outcome measures received less medical attention. An Acromegaly Disease Activity Tool (ACRODAT) is in development that might assist clinicians towards a more holistic approach to patient management in acromegaly

Ghrelin Does Not Directly Stimulate Secretion of Glucagon-like Peptide-1

Abstract Context The gastrointestinal hormone ghrelin stimulates growth hormone secretion and appetite, but recent studies indicate that ghrelin also stimulates the secretion of the appetite-inhibiting and insulinotropic hormone glucagon-like peptide-1 (GLP-1). Objective To investigate the putative effect of ghrelin on GLP-1 secretion in vivo and in vitro. Subjects and Methods A randomized placebo-controlled crossover study was performed in eight hypopituitary subjects. Ghrelin or saline was infused intravenously (1 pmol/min × kg) after collection of baseline sample (0 min), and blood was subsequently collected at time 30, 60, 90, and 120 minutes. Mouse small intestine was perfused (n = 6) and GLP-1 output from perfused mouse small intestine was investigated in response to vascular ghrelin administration in the presence and absence of a simultaneous luminal glucose stimulus. Ghrelin receptor expression was quantified in human (n = 11) and mouse L-cells (n = 3) by RNA sequencing and RT-qPCR, respectively. Results Ghrelin did not affect GLP-1 secretion in humans (area under the curve [AUC; 0–120 min]: ghrelin infusion = 1.37 ± 0.05 min × nmol vs. saline infusion = 1.40 ± 0.06 min × nmol [P = 0.63]), but induced peripheral insulin resistance. Likewise, ghrelin did not stimulate GLP-1 secretion from the perfused mouse small intestine model (mean outputs during baseline/ghrelin infusion = 19.3 ± 1.6/25.5 ± 2.0 fmol/min, n = 6, P = 0.16), whereas glucose-dependent insulinotropic polypeptide administration, used as a positive control, doubled GLP-1 secretion (P < 0.001). Intraluminal glucose increased GLP-1 secretion by 4-fold (P < 0.001), which was not potentiated by ghrelin. Finally, gene expression of the ghrelin receptor was undetectable in mouse L-cells and marginal in human L-cells. Conclusions Ghrelin does not interact directly with the L-cell and does not directly affect GLP-1 secretion

Hypercortisolism in Newly Diagnosed Type 2 Diabetes:A Prospective Study of 384 Newly Diagnosed Patients

Clinical epidemiolog