| 1. |
- Forslund, Sofia K., et al.
(author)
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Combinatorial, additive and dose-dependent drug–microbiome associations
- 2021
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In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 600:7889, s. 500-505
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Journal article (peer-reviewed)abstract
- During the transition from a healthy state to cardiometabolic disease, patients become heavily medicated, which leads to an increasingly aberrant gut microbiome and serum metabolome, and complicates biomarker discovery1–5. Here, through integrated multi-omics analyses of 2,173 European residents from the MetaCardis cohort, we show that the explanatory power of drugs for the variability in both host and gut microbiome features exceeds that of disease. We quantify inferred effects of single medications, their combinations as well as additive effects, and show that the latter shift the metabolome and microbiome towards a healthier state, exemplified in synergistic reduction in serum atherogenic lipoproteins by statins combined with aspirin, or enrichment of intestinal Roseburia by diuretic agents combined with beta-blockers. Several antibiotics exhibit a quantitative relationship between the number of courses prescribed and progression towards a microbiome state that is associated with the severity of cardiometabolic disease. We also report a relationship between cardiometabolic drug dosage, improvement in clinical markers and microbiome composition, supporting direct drug effects. Taken together, our computational framework and resulting resources enable the disentanglement of the effects of drugs and disease on host and microbiome features in multimedicated individuals. Furthermore, the robust signatures identified using our framework provide new hypotheses for drug–host–microbiome interactions in cardiometabolic disease.
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| 2. |
- Molinaro, Antonio, et al.
(author)
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Imidazole propionate is increased in diabetes and associated with dietary patterns and altered microbial ecology
- 2020
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In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723 .- 2041-1723. ; 11:1
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Journal article (peer-reviewed)abstract
- Microbiota-host-diet interactions contribute to the development of metabolic diseases. Imidazole propionate is a novel microbially produced metabolite from histidine, which impairs glucose metabolism. Here, we show that subjects with prediabetes and diabetes in the MetaCardis cohort from three European countries have elevated serum imidazole propionate levels. Furthermore, imidazole propionate levels were increased in subjects with low bacterial gene richness and Bacteroides 2 enterotype, which have previously been associated with obesity. The Bacteroides 2 enterotype was also associated with increased abundance of the genes involved in imidazole propionate biosynthesis from dietary histidine. Since patients and controls did not differ in their histidine dietary intake, the elevated levels of imidazole propionate in type 2 diabetes likely reflects altered microbial metabolism of histidine, rather than histidine intake per se. Thus the microbiota may contribute to type 2 diabetes by generating imidazole propionate that can modulate host inflammation and metabolism.
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| 3. |
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| 4. |
- DeFronzo, Ralph A., et al.
(author)
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Type 2 diabetes mellitus
- 2015
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In: Nature Reviews Disease Primers. - : Springer Science and Business Media LLC. - 2056-676X. ; 1
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Journal article (peer-reviewed)abstract
- Type 2 diabetes mellitus (T2DM) is an expanding global health problem, closely linked to the epidemic of obesity. Individuals with T2DM are at high risk for both microvascular complications (including retinopathy, nephropathy and neuropathy) and macrovascular complications (such as cardiovascular comorbidities), owing to hyperglycaemia and individual components of the insulin resistance (metabolic) syndrome. Environmental factors (for example, obesity, an unhealthy diet and physical inactivity) and genetic factors contribute to the multiple pathophysiological disturbances that are responsible for impaired glucose homeostasis in T2DM. Insulin resistance and impaired insulin secretion remain the core defects in T2DM, but at least six other pathophysiological abnormalities contribute to the dysregulation of glucose metabolism. The multiple pathogenetic disturbances present in T2DM dictate that multiple antidiabetic agents, used in combination, will be required to maintain normoglycaemia. The treatment must not only be effective and safe but also improve the quality of life. Several novel medications are in development, but the greatest need is for agents that enhance insulin sensitivity, halt the progressive pancreatic β-cell failure that is characteristic of T2DM and prevent or reverse the microvascular complications. For an illustrated summary of this Primer, visit: http://go.nature.com/V2eGfN.
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| 5. |
- Færch, Kristine, et al.
(author)
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Insulin resistance is accompanied by increased fasting glucagon and delayed glucagon suppression in individuals with normal and impaired glucose regulation
- 2016
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In: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 65:11, s. 3473-3481
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Journal article (peer-reviewed)abstract
- Hyperinsulinemia is an adaptive mechanism that enables the maintenance of normoglycemia in the presence of insulin resistance. We assessed whether glucagon is also involved in the adaptation to insulin resistance. A total of 1,437 individuals underwent an oral glucose tolerance test with measurements of circulating glucose, insulin, and glucagon concentrations at 0, 30 and 120 min. Early glucagon suppression was defined as suppression in the period from 0 to 30 min, and late glucagon suppression as 30 to 120 min after glucose intake. Insulin sensitivity was estimated by the validated insulin sensitivity index. Individuals with screen-detected diabetes had 30% higher fasting glucagon levels and diminished early glucagon suppression, but greater late glucagon suppression when compared with individuals with normal glucose tolerance (P 0.014). Higher insulin resistance was associated with higher fasting glucagon levels, less early glucagon suppression, and greater late glucagon suppression (P < 0.001). The relationship between insulin sensitivity and fasting glucagon concentrations was nonlinear (P < 0.001). In conclusion, increased fasting glucagon levels and delayed glucagon suppression, together with increased circulating insulin levels, develop in parallel with insulin resistance. Therefore, glucose maintenance during insulin resistance may depend not only on hyperinsulinemia but also on the ability to suppress glucagon early after glucose intake.
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| 6. |
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| 7. |
- Frid, Anders, et al.
(author)
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Influence of whey supplementation on glycaemic and hormonal excursions at breakfast and lunch in type II diabetic subjects
- 2005
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In: American Journal of Clinical Nutrition. - 1938-3207. ; 82:1, s. 69-75
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Journal article (peer-reviewed)abstract
- Background:Whey proteins have insulinotropic effects and reduce the postprandial glycemia in healthy subjects. The mechanism is not known, but insulinogenic amino acids and the incretin hormones seem to be involved. Objective:The aim was to evaluate whether supplementation of meals with a high glycemic index (GI) with whey proteins may increase insulin secretion and improve blood glucose control in type 2 diabetic subjects. Design:Fourteen diet-treated subjects with type 2 diabetes were served a high-GI breakfast (white bread) and subsequent high-GI lunch (mashed potatoes with meatballs). The breakfast and lunch meals were supplemented with whey on one day; whey was exchanged for lean ham and lactose on another day. Venous blood samples were drawn before and during 4 h after breakfast and 3 h after lunch for the measurement of blood glucose, serum insulin, glucose-dependent insulinotropic polypeptide (GIP), and glucagon-like peptide 1 (GLP-1). Results:The insulin responses were higher after both breakfast (31%) and lunch (57%) when whey was included in the meal than when whey was not included. After lunch, the blood glucose response was significantly reduced [–21%; 120 min area under the curve (AUC)] after whey ingestion. Postprandial GIP responses were higher after whey ingestion, whereas no differences were found in GLP-1 between the reference and test meals. Conclusions:It can be concluded that the addition of whey to meals with rapidly digested and absorbed carbohydrates stimulates insulin release and reduces postprandial blood glucose excursion after a lunch meal consisting of mashed potatoes and meatballs in type 2 diabetic subjects.
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| 8. |
- Halim, Abdul, 1983-, et al.
(author)
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Glucagon-like peptide-1 inhibits prandial gastrointestinal motility through myenteric neuronal mechanisms in humans
- 2018
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In: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 103:2, s. 575-585
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Journal article (peer-reviewed)abstract
- Context: Glucagon-like peptide-1 (GLP-1) secretion from L-cells and postprandial inhibition of gastrointestinal motility.Objective: Investigate whether physiological plasma concentrations of GLP-1 can inhibit human postprandial gastrointestinal motility; determine target mechanism of GLP-1 and analogue ROSE-010 action.Design: Single-blind parallel study.Setting: University research laboratory.Participants: Healthy volunteers investigated with antroduodenojejunal manometry. Human gastric, intestinal and colonic muscle strips.Interventions: Motility indices (MI) obtained before and during infusion of saline or GLP-1 were compared. Plasma GLP-1 and glucagon-like peptide-2 (GLP-2) measured by radioimmunoassay. Gastrointestinal muscle strips, pre-contracted with bethanechol/electric field stimulation (EFS), investigated for GLP-1- or ROSE-010-induced relaxation. GLP-1, GLP-2 and their receptors localized by immunohistochemistry. Action mechanisms studied employing exendin(9-39)amide, Lω-nitro-monomethylarginine (L-NMMA), 2´,5´-dideoxyadenosine (DDA), tetrodotoxin (TTX).Main outcome measures: Hypothesize postprandial gastric relaxation induced by GLP-1, the mechanism of which intrinsic neuronally-mediated.Results: Food intake increased MI to 6.4±0.3 (antrum), 5.7±0.4 (duodenum) and 5.9±0.2 (jejunum). GLP-1 administered intravenously raised plasma GLP-1, but not GLP-2. GLP-1 0.7 pmol/kg·min significantly suppressed MI to 4.6±0.2, 4.7±0.4 and 5.0±0.2, respectively, while 1.2 pmol/kg·min suppressed corresponding MI to 5.4±0.2, 4.4±0.3 and 5.4±0.3 (p<0.0001-0.005). GLP-1 and ROSE-010 prevented bethanechol- or EFS-induced muscle contractions (p <0.005-0.05). Inhibitory responses to GLP-1 and ROSE-10 were blocked by exendin(9-39)amide, L-NMMA, DDA or TTX (all p <0.005-0.05). GLP-1 and GLP-2 were localized to epithelial cells; GLP-1 also in myenteric neurons. GLP-1R and GLP-2R were localized at myenteric neurons but not muscle, GLP-1R also in epithelial cells.Conclusions: GLP-1 inhibits postprandial motility through GLP-1R at myenteric neurons, involving nitrergic and cAMP-dependent mechanisms.
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| 9. |
- Halim, Md. Abdul, 1983-, et al.
(author)
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Glucagon-like peptide-1 inhibits prandial gastrointestinal motility through myenteric neuronal mechanisms in humans
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Journal article (peer-reviewed)abstract
- ContextGlucagon-like peptide-1 (GLP-1) secretion from L-cells and postprandial inhibition of gastrointestinal motility.ObjectiveInvestigate whether physiological plasma concentrations of GLP-1 can inhibit human postprandial gastrointestinal motility; determine target mechanism of GLP-1 and analogue ROSE-010 action.DesignSingle-blind parallel study.SettingUniversity research laboratory.ParticipantsHealthy volunteers investigated with antroduodenojejunal manometry. Human gastric, intestinal and colonic muscle strips.InterventionsMotility indices (MI) obtained before and during infusion of saline or GLP-1 were compared. Plasma GLP-1 and glucagon-like peptide-2 (GLP-2) measured by radioimmunoassay. Gastrointestinal muscle strips, pre-contracted with bethanechol/electric field stimulation (EFS), investigated for GLP-1- or ROSE-010-induced relaxation. GLP-1, GLP-2 and their receptors localized by immunohistochemistry. Action mechanisms studied employing exendin(9-39)amide, Lω-nitro-monomethylarginine (L-NMMA), 2´,5´-dideoxyadenosine (DDA), tetrodotoxin (TTX).Main outcome measuresHypothesize postprandial gastric relaxation induced by GLP-1, the mechanism of which intrinsic neuronally-mediated.ResultsFood intake increased MI to 6.4±0.3 (antrum), 5.7±0.4 (duodenum) and 5.9±0.2 (jejunum). GLP-1 administered intravenously raised plasma GLP-1, but not GLP-2. GLP-1 0.7 pmol/kg·min significantly suppressed MI to 4.6±0.2, 4.7±0.4 and 5.0±0.2, respectively, while 1.2 pmol/kg·min suppressed corresponding MI to 5.4±0.2, 4.4±0.3 and 5.4±0.3 (p<0.0001-0.005). GLP-1 and ROSE-010 prevented bethanechol- or EFS-induced muscle contractions (p <0.005-0.05). Inhibitory responses to GLP-1 and ROSE-10 were blocked by exendin(9-39)amide, L-NMMA, DDA or TTX (all p <0.005-0.05). GLP-1 and GLP-2 were localized to epithelial cells; GLP-1 also in myenteric neurons. GLP-1R and GLP-2R were localized at myenteric neurons but not muscle, GLP-1R also in epithelial cells.ConclusionsGLP-1 inhibits postprandial motility through GLP-1R at myenteric neurons, involving nitrergic and cAMP-dependent mechanisms.
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| 10. |
- Hansen, Lea B.S., et al.
(author)
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A low-gluten diet induces changes in the intestinal microbiome of healthy Danish adults
- 2018
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In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723 .- 2041-1723. ; 9:1
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Journal article (peer-reviewed)abstract
- © 2018, The Author(s). Adherence to a low-gluten diet has become increasingly common in parts of the general population. However, the effects of reducing gluten-rich food items including wheat, barley and rye cereals in healthy adults are unclear. Here, we undertook a randomised, controlled, cross-over trial involving 60 middle-aged Danish adults without known disorders with two 8-week interventions comparing a low-gluten diet (2 g gluten per day) and a high-gluten diet (18 g gluten per day), separated by a washout period of at least six weeks with habitual diet (12 g gluten per day). We find that, in comparison with a high-gluten diet, a low-gluten diet induces moderate changes in the intestinal microbiome, reduces fasting and postprandial hydrogen exhalation, and leads to improvements in self-reported bloating. These observations suggest that most of the effects of a low-gluten diet in non-coeliac adults may be driven by qualitative changes in dietary fibres.
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| 11. |
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| 12. |
- Jujic, Amra, et al.
(author)
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Endogenous incretin levels and risk of first incident cancer : a prospective cohort study
- 2023
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In: Scientific Reports. - : Springer Nature. - 2045-2322. ; 13
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Journal article (peer-reviewed)abstract
- Concerns have been raised regarding a potentially increased risk of cancer associated with treatment with glucagon-like peptide-1 (GLP-1) receptor agonists. Here, we explored whether fasting and oral glucose tolerance test post-challenge glucose-dependent insulinotropic peptide (GIP) and GLP-1 levels were associated with incident first cancer. Within the cardiovascular re-examination arm of the population-based Malmo Diet Cancer study (n = 3734), 685 participants with a previous cancer diagnosis were excluded, resulting in 3049 participants (mean age 72.2 +/- 5.6 years, 59.5% women), of whom 485 were diagnosed with incident first cancer (median follow-up time 9.9 years). Multivariable Cox-regression and competing risk regression (death as competing risk) were used to explore associations between incretin levels and incident first cancer. Higher levels of fasting GLP-1 (462 incident first cancer cases/2417 controls) showed lower risk of incident first cancer in competing risk regression (sub-hazard ratio 0.90; 95% confidence interval 0.82-0.99; p = 0.022). No association was seen for fasting GIP, post-challenge GIP, or post-challenge GLP-1 and incident first cancer. In this prospective study, none of the fasting and post-challenge levels of GIP and GLP-1 were associated with higher risk of incident first cancer; by contrast, higher levels of fasting GLP-1 were associated with lower risk of incident first cancer.
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| 13. |
- Jujić, Amra, et al.
(author)
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Glucose-Dependent Insulinotropic Peptide in the High-Normal Range Is Associated With Increased Carotid Intima-Media Thickness
- 2021
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In: Diabetes Care. - : American Diabetes Association. - 0149-5992 .- 1935-5548. ; 44:1, s. 224-230
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Journal article (peer-reviewed)abstract
- OBJECTIVE While existing evidence supports beneficial cardiovascular effects of glucagon-like peptide 1 (GLP-1), emerging studies suggest that glucose-dependent insulinotropic peptide (GIP) and/or signaling via the GIP receptor may have untoward cardiovascular effects. Indeed, recent studies show that fasting physiological GIP levels are associated with total mortality and cardiovascular mortality, and it was suggested that GIP plays a role in pathogenesis of coronary artery disease. We investigated the associations between fasting and postchallenge GIP and GLP-1 concentrations and subclinical atherosclerosis as measured by mean intima-media thickness in the common carotid artery (IMTmeanCCA) and maximal intima-media thickness in the carotid bifurcation (IMTmaxBulb).RESEARCH DESIGN AND METHODS Participants at reexamination within the Malmö Diet and Cancer–Cardiovascular Cohort study (n = 3,734, mean age 72.5 years, 59.3% women, 10.8% subjects with diabetes, fasting GIP available for 3,342 subjects, fasting GLP-1 available for 3,299 subjects) underwent oral glucose tolerance testing and carotid ultrasound.RESULTS In linear regression analyses, each 1-SD increment of fasting GIP was associated with increased (per mm) IMTmeanCCA (β = 0.010, P = 0.010) and IMTmaxBulb (β = 0.014; P = 0.040) in models adjusted for known risk factors and glucose metabolism. In contrast, each 1-SD increment of fasting GLP-1 was associated with decreased IMTmaxBulb (per mm, β = −0.016, P = 0.014). These associations remained significant when subjects with diabetes were excluded from analyses.CONCLUSIONS In a Swedish elderly population, physiologically elevated levels of fasting GIP are associated with increased IMTmeanCCA, while GLP-1 is associated with decreased IMTmaxBulb, further emphasizing diverging cardiovascular effects of these two incretin hormones.
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| 14. |
- Manell, Elin, et al.
(author)
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Exploring the GLP-1-GLP-1R axis in porcine pancreas and gastrointestinal tract in vivo by ex vivo autoradiography
- 2021
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In: BMJ Open Diabetes Research & Care. - : BMJ Publishing Group Ltd. - 2052-4897. ; 9
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Journal article (peer-reviewed)abstract
- Introduction Glucagon-like peptide-1 (GLP-1) increases insulin secretion from pancreatic beta-cells and GLP-1 receptor (GLP-1R) agonists are widely used as treatment for type 2 diabetes mellitus. Studying occupancy of the GLP-1R in various tissues is challenging due to lack of quantitative, repeatable assessments of GLP-1R density. The present study aimed to describe the quantitative distribution of GLP-1Rs and occupancy by endogenous GLP-1 during oral glucose tolerance test (OGTT) in pigs, a species that is used in biomedical research to model humans.Research design and methods GLP-1R distribution and occupancy were measured in pancreas and gastrointestinal tract by ex vivo autoradiography using the GLP-1R-specific radioligand 177Lu-exendin-4 in two groups of pigs, control or bottle-fed an oral glucose load. Positron emission tomography (PET) data from pigs injected with 68Ga-exendin-4 in a previous study were used to retrieve data on biodistribution of GLP-1R in the gastrointestinal tract.Results High homogenous uptake of 177Lu-exendin-4 was found in pancreas, and even higher uptake in areas of duodenum. Low uptake of 177Lu-exendin-4 was found in stomach, jejunum, ileum and colon. During OGTT, there was no increase in plasma GLP-1 concentrations and occupancy of GLP-1Rs was low. The ex vivo autoradiography results were highly consistent with to the biodistribution of 68Ga-exendin-4 in pigs scanned by PET.Conclusion We identified areas with similarities as well as important differences regarding GLP-1R distribution and occupancy in pigs compared with humans. First, there was strong ligand binding in the exocrine pancreas in islets. Second, GLP-1 secretion during OGTT is minimal and GLP-1 might not be an important incretin in pigs under physiological conditions. These findings offer new insights on the relevance of porcine diabetes models.
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| 15. |
- Manell, Hannes, 1987-
(author)
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Impaired Glucose Tolerance in Childhood Obesity : Contribution of Glucagon, GLP-1 and Inflammation
- 2019
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Doctoral thesis (other academic/artistic)abstract
- In the wake of increased obesity prevalence, impaired glucose tolerance (IGT) and type 2 diabetes (T2D) in childhood and adolescence is increasingly common. Given the negative impacts these conditions have on health over time, understanding the pathophysiology in those affected early in life is important. Both the proglucagon-derived peptides and low-grade inflammation have been implicated in the development of obesity-related complications. The aim of this thesis was to study across the glucose tolerance spectrum in children and adolescents with obesity 1) proglucagon-derived peptides glucagon, GLP-1 and glicentin, 2) dipeptidyl peptidase-4 (DPP-4) and its degradation of GLP-1 and 3) novel inflammatory markers. To this end, children and adolescents of the Uppsala Longitudinal Study of Childhood Obesity were studied. Children and adolescents with obesity had higher fasting plasma glucagon concentrations than lean controls. In particular visceral adiposity, hyperinsulinemia, triglycerides and free fatty acids (FFAs) were associated with high plasma glucagon concentrations. In isolated islets elevated FFAs caused hypersecretion of glucagon. In children and adolescents with IGT or T2D, fasting plasma glucagon was further elevated and the GLP-1 and glicentin response to an oral glucose tolerance test (OGTT) was decreased. In T2D plasma glucagon increased during the first 15 minutes of OGTT. Plasma DPP-4 concentrations were elevated in obesity and associated with lower proportion of intact GLP-1 but not with IGT. Several pro-inflammatory markers were elevated in children and adolescents with obesity but not further elevated in IGT or T2D with the exception of low plasma Tumor necrosis factor-related weak inducer of apoptosis (TWEAK) levels, which were associated with IGT, hyperinsulinemia and hyperglucagonemia. High plasma hepatocyte growth factor (HGF) concentration was associated with increased risk of further weight gain in children and adolescents with obesity.In conclusion, elevated glucagon concentration at fasting, a hyperglucagonemic response to OGTT and reduced GLP-1 and glicentin are characteristics of IGT and T2D development in childhood obesity reflecting altered usage of the proglucagon gene. DPP-4 concentrations are elevated in childhood obesity but not associated with IGT. Reduced circulating TWEAK was identified as a novel marker of IGT early in life. Children with obesity and high HGF are less likely to respond well to lifestyle intervention.
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| 16. |
- Munch Roager, Henrik, et al.
(author)
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Whole grain-rich diet reduces body weight and systemic low-grade inflammation without inducing major changes of the gut microbiome: A randomised cross-over trial
- 2019
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In: Gut. - : BMJ. - 1468-3288 .- 0017-5749. ; 68:1, s. 83-93
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Journal article (peer-reviewed)abstract
- Objective T o investigate whether a whole grain diet alters the gut microbiome and insulin sensitivity, as well as biomarkers of metabolic health and gut functionality. Design 60 Danish adults at risk of developing metabolic syndrome were included in a randomised cross-over trial with two 8-week dietary intervention periods comprising whole grain diet and refined grain diet, separated by a washout period of =6 weeks. The response to the interventions on the gut microbiome composition and insulin sensitivity as well on measures of glucose and lipid metabolism, gut functionality, inflammatory markers, anthropometry and urine metabolomics were assessed. Results 50 participants completed both periods with a whole grain intake of 179±50 g/day and 13±10 g/day in the whole grain and refined grain period, respectively. Compliance was confirmed by a difference in plasma alkylresorcinols (p<0.0001). Compared with refined grain, whole grain did not significantly alter glucose homeostasis and did not induce major changes in the faecal microbiome. Also, breath hydrogen levels, plasma short-chain fatty acids, intestinal integrity and intestinal transit time were not affected. The whole grain diet did, however, compared with the refined grain diet, decrease body weight (p<0.0001), serum inflammatory markers, interleukin (IL)-6 (p=0.009) and C-reactive protein (p=0.003). The reduction in body weight was consistent with a reduction in energy intake, and IL-6 reduction was associated with the amount of whole grain consumed, in particular with intake of rye. Conclusion C ompared with refined grain diet, whole grain diet did not alter insulin sensitivity and gut microbiome but reduced body weight and systemic lowgrade inflammation.
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| 17. |
- Otten, Julia, 1973-, et al.
(author)
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The liver-alpha-cell axis after a mixed meal and during weight loss in type 2 diabetes
- 2021
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In: Endocrine Connections. - : Bioscientifica. - 2049-3614. ; 10:9, s. 1101-1110
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Journal article (peer-reviewed)abstract
- Objective: Glucagon and amino acids may be regulated in a feedback loop called the liver-alpha-cell axis with alanine or glutamine as suggested signal molecules. We assessed this concept in individuals with type 2 diabetes in the fasting state, after ingestion of a protein-rich meal, and during weight loss. Moreover, we investigated if postprandial glucagon secretion and hepatic insulin sensitivity were related.Methods: This is a secondary analysis of a 12-week weight-loss trial (Paleolithic diet ± exercise) in 29 individuals with type 2 diabetes. Before and after the intervention, plasma glucagon and amino acids were measured in the fasting state and during 180 min after a protein-rich mixed meal. Hepatic insulin sensitivity was measured using the hyperinsulinemic-euglycemic clamp with [6,6-2H2]glucose as a tracer.Results: The postprandial increase of plasma glucagon was associated with the postprandial increase of alanine and several other amino acids but not glutamine. In the fasted state and after the meal, glucagon levels were negatively correlated with hepatic insulin sensitivity (rS = −0.51/r = −0.58, respectively; both P < 0.05). Improved hepatic insulin sensitivity with weight loss was correlated with decreased postprandial glucagon response (r = −0.78; P < 0.001).Conclusions: Several amino acids, notably alanine, but not glutamine could be key signals to the alpha cell to increase glucagon secretion. Amino acids may be part of a feedback mechanism as glucagon increases endogenous glucose production and ureagenesis in the liver. Moreover, postprandial glucagon secretion seems to be tightly related to hepatic insulin sensitivity.
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| 18. |
- Witte, Anne-Barbara, et al.
(author)
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Involvement of endogenous glucagon-like peptide-1 in regulation of gastric motility and pancreatic endocrine secretion
- 2011
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In: Scandinavian Journal of Gastroenterology. - : Informa UK Limited. - 0036-5521 .- 1502-7708. ; 46:4, s. 428-435
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Journal article (peer-reviewed)abstract
- Objective. To study the role of endogenous glucagon-like peptide-1 (GLP-1) on gastric emptying rates of a solid meal as well as postprandial hormone secretion and glucose disposal. Material and methods. In nine healthy subjects, gastric emptying of a 310-kcal radio-labelled solid meal and plasma concentrations of insulin, glucagon and glucose were measured during infusion of saline or the GLP-1 receptor antagonist exendin(9-39)amide (Ex(9-39)) at 300 pmol·kg−1·min−1. Results. Ex(9-39) infusion had no effect on the total gastric emptying curve, but changed the intra-gastric distribution of the meal. During infusion of Ex(9-39), more content stayed in the upper stomach (79.1 ± 2.5% of total during Ex(9-39) compared to 66.6 ± 5.7% during saline at 5 min). During Ex(9-39) infusion, higher concentrations of plasma glucagon were measured both before (after 40 min of Ex(9-39) infusion the glucagon level was 15.1 ± 0.7 pmol·L−1 compared to 5.4 ± 1.4 during saline) and after the meal, and postprandial GLP-1 levels increased. Basal insulin and glucose levels were not affected by Ex(9-39), but the postprandial rise of insulin and glucose enhanced during Ex(9-39). Conclusions. Endogenous GLP-1 is involved in the regulation of gastric motility in relation to meal intake and also in the regulation of postprandial insulin and glucose levels. Furthermore, endogenous GLP-1 seems to tonically restrain glucagon secretion.
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