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| 22. |
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| 23. |
- Ahrén, Bo, et al.
(author)
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Changes in Prandial Glucagon Levels after 2-year Treatment with Vildagliptin or Glimepiride in Patients with Type 2 Diabetes Mellitus Inadequately Controlled with Metformin Monotherapy.
- 2010
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In: Diabetes Care. - : American Diabetes Association. - 1935-5548 .- 0149-5992. ; 33:4, s. 730-732
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Journal article (peer-reviewed)abstract
- Objective - To determine if the dipeptidyl peptidase 4 inhibitor vildagliptin more effectively than the sulfonylurea glimepiride inhibits glucagon levels during meal. Research design and methods - Glucagon responses to a standard meal were measured at baseline and study endpoint (mean 1.8 years) in a trial evaluating add-on therapy to metformin with vildagliptin 50 mg bid compared to glimepiride up to 6 mg qd in type 2 diabetes (baseline HbA1c 7.3+/-0.6%). Results - HbA(1c) and prandial glucose AUC(0-2h) were reduced similarly in both groups, while prandial insulin AUC(0-2h) increased to a greater extent by glimepiride. Prandial glucagon AUC(0-2h) (baseline 66.6+/-2.3 pmol.h/l) decreased by 3.4+/-1.6 pmol.h/l by vildagliptin group (n=137) and increased by 3.8+/-1.7 pmolh/l by glimepiride group (n=121). The between-group difference was 7.3+/-2.1 pmol.h/l (p<0.001). Conclusion - Vildagliptin therapy but not glimepiride improves post-prandial alpha-cell function, which persists for at least 2 years.
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| 24. |
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| 25. |
- Ahrén, Bo, et al.
(author)
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Characterization of GLP-1 effects on beta-cell function after meal ingestion in humans.
- 2003
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In: Diabetes Care. - : American Diabetes Association. - 1935-5548 .- 0149-5992. ; 26:10, s. 2860-2864
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Journal article (peer-reviewed)abstract
- OBJECTIVE—Glucagon-like peptide 1 (GLP-1) is an incretin that augments insulin secretion after meal intake and is developed for treatment of type 2 diabetes. As a novel therapeutic agent, characteristics of its β-cell effects are important to establish. Previously, β-cell effects of GLP-1 have been characterized in humans during graded intravenous infusions of glucose, whereas its effects after more physiological stimuli, like meal intake, are not known. RESEARCH DESIGN AND METHODS—Eight women (aged 69 years, fasting glucose 3.7–10.3 mmol/l, BMI 22.4–43.9 kg/m2) who had fasted overnight were served a breakfast (450 kcal) with intravenous infusion of saline or synthetic GLP-1 (0.75 pmol · kg–1 · min–1), and β-cell function was evaluated by estimating the relationship between glucose concentration and insulin secretion (calculated by deconvolution of C-peptide data). RESULTS—GLP-1 markedly augmented insulin secretion, despite lower glucose. Total insulin secretion was 29.7 ± 4.2 nmol/m2 with GLP-1 versus 21.0 ± 1.6 nmol/m2 with saline (P = 0.048). GLP-1 increased the dose-response relationship between glucose concentration and insulin secretion (70 ± 26 with GLP-1 versus 38 ± 16 pmol insulin · min−1 · m2 · mmol−1 glucose · l without, P = 0.037) and augmented the potentiation factor that modulates the dose response (2.71 ± 0.42 with GLP-1 versus 0.97 ± 0.17 without, P = 0.005). The potentiation factor correlated to GLP-1 concentration (r = 0.53, P < 0.001); a 10-fold increase in GLP-1 levels produced a twofold increase in the potentiation factor. These effects of GLP-1 did not correlate with fasting glucose levels or BMI. CONCLUSIONS—Administration of GLP-1 along with ingestion of a meal augments insulin secretion in humans by a dose-dependent potentiation of the dose-response relationship between plasma glucose and insulin secretion.
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| 26. |
- Ahrén, Bo, et al.
(author)
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Clinical evidence and mechanistic basis for vildagliptin's action when added to metformin.
- 2011
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In: Diabetes, Obesity and Metabolism. - : Wiley. - 1462-8902. ; 13:3, s. 193-203
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Journal article (peer-reviewed)abstract
- Several new oral antidiabetic agents, known as 'gliptins' or 'enzyme dipeptidyl peptidase-IV (DPP-4) inhibitors', have been developed for the treatment of type 2 diabetes and a key clinical use of the gliptins is in combination with metformin. There are important differences in the kinetics of the interaction of different gliptins with the catalytic site of DPP-4, which may lead to varying pharmacokinetics, pharmacodynamics and dosing regimens. Therefore, individual gliptins need to be characterized and here we discuss the extensively studied DPP-4 inhibitor vildagliptin, which has binding characteristics that ensure inhibition of the enzyme beyond the presence of detectable drug levels in plasma. As vildagliptin has been used most often at doses of 50 mg once or twice daily, in combination with metformin, this review focuses on these dose regimens. All clinical trials employing vildagliptin (50 mg once or twice daily) as an add-on therapy to metformin (identified by MEDLINE search using keywords vildagliptin and metformin or known by authors to be in press) are reviewed, as is current knowledge of the mechanism of action of vildagliptin. Vildagliptin added to a stable dose of metformin elicits a dose-related decrease in both HbA1c and fasting plasma glucose. The additional efficacy seen with 50 mg twice daily [ΔHbA1c ∼- 1.1% (-12.1 mmol/mol)] relative to 50 mg once daily [ΔHbA1c ∼- 0.7% (-7.7 mmol/mol)] is attributable to an overnight effect of the evening dose of vildagliptin, with prolonged DPP-4 inhibition and elevated fasting levels of the intact and insulinotropic form of glucagon-like peptide-1 (GLP-1). Vildagliptin's therapeutic actions are primarily mediated by GLP-1 and metformin enhances vildagliptin's effect to raise plasma levels of intact GLP-1. Vildagliptin is weight-neutral and has a very low hypoglycaemic potential, explained by its remarkable ability to enhance both α-cell and β-cell sensitivity to glucose. Therefore, vildagliptin offers a clinically important outcome when added to metformin with a twice daily dose regimen, taking advantage of its tight binding and slow dissociation characteristics that lead to a sustained overnight effect.
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| 27. |
- Ahrén, Bo, et al.
(author)
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Clinical measures of islet function: usefulness to characterize defects in diabetes.
- 2008
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In: Current Diabetes Reviews. - 1573-3998. ; 4:2, s. 129-145
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Journal article (peer-reviewed)abstract
- In healthy individuals, the ability of the pancreatic islets to sense and respond appropriately to changes in plasma glucose levels maintains plasma glucose levels within a narrow range despite broad fluctuations in nutrient intake and variable "demand" for insulin imposed by changes in insulin sensitivity. This ability of the pancreatic islets is lost in type 2 diabetes (T2DM). For studies on the pathophysiology of T2DM, methods for analyzing islet function are therefore required. Many methods of varying degrees of complexity have been developed and used to measure pancreatic beta-cell function in humans and to characterize the defects existing in patients with T2DM or precursors thereof (impaired fasting glucose [IFG] and impaired glucose tolerance [IGT]). Significant, although perhaps less progress has been made toward development of methods to characterize alpha-cell function. This work presents an overview of clinical measures of islet function, from simple static measures such as HOMA-beta to the more complex dynamic measures such as those utilizing stepped hyperglycemic clamps and acute administration of arginine to obtain more detailed information regarding the interaction of glucose and non-glucose secretagogues. We emphazise the need for accurate measures of alpha-cell function, and we discuss the strengths and limitations of the various methods, highlighting the many aspects of both alpha- and beta-cell function that become impaired during development of T2DM.
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| 28. |
- Ahrén, Bo
(author)
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Clinical results of treating type 2 diabetic patients with sitagliptin, vildagliptin or saxagliptin - diabetes control and potential adverse events
- 2009
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In: Best Practice and Research in Clinical Endocrinology and Metabolism. - : Elsevier BV. - 1521-690X. ; 23:4, s. 487-498
-
Journal article (peer-reviewed)abstract
- Inhibition of dipeptidyl peptidase-4 (DPP-4) is a novel oral treatment for type 2 diabetes. DPP-4 inhibition increases insulin secretion and reduces glucagon secretion by preventing the inactivation of glucagon-like peptide-1 (GLP-1), thereby lowering glucose levels. Several DPP-4 inhibitors are in clinical development; more studies exist for sitagliptin and vildagliptin. They improve metabolic control in type 2 diabetes in monotherapy and also in combination with metformin, sulphonylurea and thiazolidinediones. HbA(1c) is reduced by approximately 0.6-1.1% in studies up to 52 weeks. Similar, although more limited, results were obtained for saxagliptin. DPP-4 inhibitors are safe and tolerable with no increased risk of adverse events compared to placebo and have a low risk of hypoglycaemia. DPP-4 inhibitors are body weight-neutral. The DPP-4 inhibitors are recommended for use in the early stage of type 2 diabetes, in combination with metformin in subjects with inadequate glycaemic control. DPP-4 inhibition may also be used in combination with sulphonylurea and thiazolidinediones and potentially also in combination with insulin. The durability and long-term safety of DPP-4 inhibitors remain to be established.
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| 29. |
- Ahrén, Bo
(author)
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Contribution of GIP and GLP-1 to the Insulin Response to Oral Administration of Glucose in Female Mice
- 2023
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In: Biomedicines. - : MDPI AG. - 2227-9059. ; 11:2
-
Journal article (peer-reviewed)abstract
- It has previously been shown that the incretin effect accounts for ≈50% of the insulin response to oral glucose in normal mice. Now, I have proceeded and studied the contribution of glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) to the insulin response to oral glucose in female mice by using receptor antagonists. A specific GIP receptor antagonist (mGIP(3-30); 50 or 500 nmol/kg), a specific GLP-1 receptor antagonist (exendin(9-39); 3 or 30 nmol/kg), the combination of mGIP (500 nmol/kg) and exendin(9-39) (30 nmol/kg), or saline was given intravenously four minutes after administration of glucose (50 mg) through a gastric tube in anesthetized C57/BL6J mice (n = 95) with samples obtained before glucose administration and after 15, 30 and 60 min. The insulinogenic index, determined as the area under the 60 min curve for insulin (AUCinsulin) divided by the AUCglucose, was used to reflect the insulin response. It was found that the insulinogenic index was reduced by 67 ± 4% by mGIP(3-30) (p < 0.001), by 60 ± 14% by exendin(9-39) (p = 0.007) and by 61 ± 14% by the combination of mGIP(3-30) and exendin(9-39) (p = 0.043), both at their highest doses, compared to animals injected with glucose in the same experimental series. It is concluded that both GIP and GLP-1 are required for a normal incretin effect in female mice, that they contribute similarly to the insulin response, and that it is unlikely that there is another incretin hormone in this species.
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| 30. |
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