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Context Incretins are crucial stimulators of insulin secretion following food intake. Data on incretin secretion and action during pregnancy are sparse. Objective The aim of the study was to investigate the incretin response during an oral glucose tolerance test (OGTT) in pregnant women with and without gestational diabetes mellitus (GDM). Design We analyzed data from the ongoing observational PREG study (NCT 04270578). Setting The study was conducted at the University Hospital Tübingen. Participants We examined 167 women (33 with GDM) during gestational week 27 ± 2.2. Intervention Subjects underwent 5-point OGTT with a 75-g glucose load. Main outcome measures We assessed insulin secretion and levels of total glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), glicentin, and glucagon during OGTT. Linear regression was used to analyze the relation of GLP-1 and glucose with insulin secretion and the association of incretin levels on birth outcome. Results Insulin secretion was significantly lower in women with GDM (P Conclusions The more pronounced GLP-1 increase in women with GDM could be part of a compensatory mechanism counteracting GLP-1 resistance. Higher GLP-1 levels might be protective against fetal overgrowth.

Fat accumulation outside subcutaneous adipose tissue often has unfavourable effects on systemic metabolism. In addition to non-alcoholic fatty liver disease, which has received considerable attention, pancreatic fat has become an important area of research throughout the past 10 years. While a number of diagnostic approaches are available to quantify pancreatic fat, multi-echo Dixon MRI is currently the most developed method. Initial studies have shown associations between pancreatic fat and the metabolic syndrome, impaired glucose metabolism and type 2 diabetes mellitus. Pancreatic fat is linked to reduced insulin secretion, at least under specific circumstances such as prediabetes, low BMI and increased genetic risk of type 2 diabetes mellitus. This Review summarizes the possible causes and metabolic consequences of pancreatic fat accumulation. In addition, potential therapeutic approaches for addressing pancreatic fat accumulation are discussed. There is growing evidence that fat accumulation in the pancreas can have consequences for metabolic health. This Review discusses the methods for detecting pancreatic fat and the potential causes and pathogenic consequences of pancreatic fat accumulation.

While oral glucose ingestion typically leads to a decrease in circulating glucagon levels, a substantial number of persons display stable or rising glucagon concentrations when assessed by radioimmunoassay (RIA). However, these assays show cross-reactivity to other proglucagon cleavage products. Recently, more specific assays became available, therefore we systematically assessed glucagon and other proglucagon cleavage products and their relation to metabolic health. We used samples from 52 oral glucose tolerance tests (OGTT) that were randomly selected from an extensively phenotyped study cohort.Glucagon concentrations quantified with RIA were non-suppressed at 2 hours of the OGTT in 36 % of the samples. Non-suppressors showed lower fasting glucagon levels compared to suppressors (p=0.011). Similar to RIA measurements, ELISA-derived fasting glucagon was lower in non-suppressors (psuppressors and non-suppressors (p=0.004 and p=0.002, respectively) with higher concentrations of both hormones in non-suppressors. Levels of insulin, C-peptide, and free fatty acids were comparable between groups. Non-suppressors were leaner and had lower plasma glucose concentrations (p=0.03 and p=0.047, respectively). Despite comparable liver fat content and insulin sensitivity (p≥0.3), they had lower 2-hour post-challenge glucose (p=0.01).Glucagon 1-61, glicentin and GLP-1 partially account for RIA-derived glucagon measurements due to cross-reactivity of the assay. However, this contribution is small, since the investigated proglucagon cleavage products contribute less than 10% to the variation in RIA measured glucagon. Altered glucagon levels and higher post-challenge incretins are associated with a healthier metabolic phenotype that is known to be indicative for reduced cardiovascular risk, cancer incidence, and mortality.

Prevalence of both type 1 and type 2 diabetes mellitus is growing worldwide and one major cause for morbidity and mortality. However, not every patient develops diabetes-related complications, but causes for the individual susceptibility are still not fully understood. As a platform to address this, we initiated the TUDID (TUebingen DIabetes Database) study, a prospective, monocentric, observational study that includes adults with diabetes mellitus who are treated in the inpatient clinic of a University Hospital in southern Germany. Besides a thorough clinical examination and extensive laboratory tests (with integrated biobanking), major study focuses are the kidneys, the eyes, the vasculature as well as cognition and mood where standardized investigations for early stages for diabetes complications are performed. Analyses of the data generated by this precise characterization of diabetes-related complications will contribute to our understanding of the development and course of such complications, and thus facilitate the implementation of tailored treatment options that can reduce the risk and severity of diabetes-related complications.

AIMS/HYPOTHESIS: Besides insulin resistance, type 2 diabetes associates with decreased hepatic insulin clearance (HIC). We now tested for causal relationship of HIC to liver fat accumulation or features of the metabolic syndrome. METHODS: HIC was derived from oral glucose tolerance tests with the "Oral C-peptide and Insulin Minimal Models" (n = 3311). Liver fat was quantified by magnetic resonance spectroscopy (n = 1211). Mendelian Randomization was performed using established single nucleotide polymorphisms (SNPs; 115 for liver fat, 155 alanine-aminotransferase, 37 insulin sensitivity, 37 insulin secretion, 72 fasting insulin, 5285 BMI, 163 visceral fat, 270 waist circumference, 442 triglycerides, 620 HDL-Cholesterol, 193C-reactive protein, 53 lipodystrophy-like phenotypes). RESULTS: HIC associated inversely with liver fat (p

Background and Aims: Incretins are crucial for an adequate insulin secretion in response to ingestions of nutrients. In patients with diabetes, prediabetes or a specific genetic background, this incretin effect is blunted. Data on incretin secretion and action during pregnancy are scarce. Here we investigated the incretin response during an oral glucose tolerance test (OGTT) in pregnant women with and without gestational diabetes. Methods: Pregnant women from the ongoing PREG study underwent 5-point OGTT with 75 g glucose. We measured plasma glucose, insulin and C-peptide at all time points and total GLP-1 at minute 0, 30 and 120. Indices of insulin secretion and GLP-1 increase were calculated from the difference at min 0 and 30. We used linear regression to analyze the relation of GLP-1 and glucose with insulin secretion. Results: We examined 163 women during gestational week 26.8 (±2.0 SD), GDM was present in 30 (18.4%) women. Insulin secretion was significantly lower in women with GDM (p=0.04, adjusted for BMI, age, week of gestation, insulin sensitivity). GLP-1 levels increased after glucose intake with a peak at 30 min. GLP-1 levels at minute 30 and AUCGLP-1 was significantly higher in women with GDM (by ∼20%, both p=0.03, adjusted for age, BMI and week of gestation). The GLP-1 increase was associated with insulin secretion only in GDM, but not in women with normal glucose tolerance. This association remained significant even after adjustment for increase of glucose and basal insulin levels (GDM group: p Conclusion: Women with GDM had lower insulin secretion despite increased GLP-1 levels during OGTT. The more pronounced GLP-1 increase in women with GDM could be part of a compensatory mechanism counteracting GLP-1 resistance. In addition to incretin resistance, this phenomenon suggests a dysfunction of glucose stimulated insulin secretion. Disclosure L. Fritsche: None. M. Heni: Research Support; Self; Boehringer Ingelheim Pharmaceuticals, Inc., Sanofi. Speaker’s Bureau; Self; Novo Nordisk A/S. S.S. Eckstein: None. M.J. Winzenried: None. J. Hummel: None. A.L. Birkenfeld: None. H. Preissl: None. H. Haering: None. A. Peter: None. A. Fritsche: None. R. Wagner: Advisory Panel; Self; Novo Nordisk A/S. Speaker’s Bureau; Self; Novo Nordisk A/S. Other Relationship; Self; Eli Lilly and Company. Funding German Federal Ministry of Education and Research (01GI0925)

Introduction: Type 2 diabetes is not only associated with insulin resistance but also with decreased insulin clearance. Insulin is mostly eliminated from portal blood during the first pass through the liver. The magnitude of this effect is closely related to systemic insulin sensitivity. As insulin resistance is often accompanied by fatty liver, we here investigated whether there is a causal link between liver fat and hepatic insulin clearance (IC). Methods: We computed IC using data from oral glucose tolerance tests in 3391 non diabetic individuals and the oral C-peptide and Insulin Minimal Models. Liver fat was quantified by 1H-MR-spectroscopy in 1211 participants. We performed Mendelian randomization analyses to test for causal determination of IC by liver fat and potentially related traits using established single nucleotide polymorphisms (liver fat: 115 SNPs, alanine-aminotransferase: 155 SNPs, insulin sensitivity: 37 SNPs, C-reactive protein: 193 SNPs). Results: IC associated inversely with liver fat content (β=-0.1±0.03, p Conclusion: This study supports the hypothesis that systemic effects such as inflammatory activity and/or genetic factors determining insulin resistance might modulate insulin extraction in the liver. Disclosure A. Lamprinou: None. J. Machann: None. F. Schick: None. S.S. Eckstein: None. C. Dalla Man: Research Support; Self; Sanofi-Aventis Deutschland GmbH. R. Visentin: None. N. Stefan: None. A.L. Birkenfeld: None. A. Peter: None. H. Haering: None. A. Fritsche: None. M. Heni: Research Support; Self; Boehringer Ingelheim Pharmaceuticals, Inc., Sanofi. Speaker’s Bureau; Self; Novo Nordisk A/S. R. Wagner: Advisory Panel; Self; Novo Nordisk A/S. Speaker’s Bureau; Self; Novo Nordisk A/S. Other Relationship; Self; Eli Lilly and Company. Funding German Center of Diabetes Research (01GI0925)

Das Gehirn ist ein wichtiges insulinsensitives Organ. Die zerebrale Wirkung von Insulin ist in die Gedachtnisfunktion involviert, aber auch fur die Regulation des Essverhaltens und des Korpergewichts wichtig. Zudem beeinflusst sie die Regulation des Stoffwechsels im gesamten Korper auch direkt. Insulinresistenz im peripheren Gewebe ist eine der wichtigsten Ursachen des Typ-2-Diabetes. Doch auch im Gehirn wurde eine Insulinresistenz nachgewiesen, die durch verschiedene Faktoren, wie Alter, Korpergewicht, viszerales Fettgewebe, gesattigte Fettsauren und genetischen Hintergrund beeinflusst wird. Entsprechend der physiologischen zerebralen Wirkungen des Insulins fuhrt eine Einschrankung der Insulinsignalkaskade im Gehirn zu Veranderungen des Essverhaltens und des Gewichts und konnte damit wiederum eine Rolle bei der Entstehung von Typ-2-Diabetes spielen. Die zerebrale Insulinresistenz zu verhindern oder gar ruckgangig zu machen, steht daher im Fokus aktueller Forschung.