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Sponsored by: |
Department of Veterans Affairs |
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Information provided by: | Department of Veterans Affairs |
ClinicalTrials.gov Identifier: | NCT00469833 |
The objective of this project is to understand defects in insulin secretion that contribute to abnormal glucose metabolism in patients with diabetes.
Condition | Intervention |
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Diabetes Hyperglycemia |
Drug: Exendin-(9-39); 0.9% Saline; 20% Dextrose; Carnation Instant Breakfast; 95% Orleate Drug: Exendin-(9-39); 20% Dextrose; 75g oral glucose; 0.9% Saline Drug: Insulin Glargine; 20% Dextrose; 75g oral glucose; 0.9% Saline |
Study Type: | Interventional |
Study Design: | Basic Science, Non-Randomized, Open Label, Placebo Control, Crossover Assignment, Pharmacodynamics Study |
Official Title: | Pathogenesis of the Impaired Incretin Effect in Type 2 Diabetes |
Estimated Enrollment: | 20 |
Study Start Date: | April 2008 |
Estimated Study Completion Date: | April 2013 |
Estimated Primary Completion Date: | April 2010 (Final data collection date for primary outcome measure) |
Arms | Assigned Interventions |
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1
Within subjects comparison; before and after treatment.
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Drug: Exendin-(9-39); 0.9% Saline; 20% Dextrose; Carnation Instant Breakfast; 95% Orleate
20% dextrose will be infused to achieve a hyperglycemic clamp. Subjects will ingest instant breakfast in skim milk during the clamp. The clamp will be performed on 2 occasions, once with and once without an infusion of Exendin-(9-39).
Drug: Exendin-(9-39); 20% Dextrose; 75g oral glucose; 0.9% Saline
20% dextrose will be infused to achieve a hyperglycemic clamp. Subjects will ingest oral glucose solution during the clamp. The clamp will be performed on 2 occasions, once with and once without an infusion of Exendin-(9-39).
Drug: Insulin Glargine; 20% Dextrose; 75g oral glucose; 0.9% Saline
20% dextrose will be infused to achieve a hyperglycemic clamp. Subjects will ingest oral glucose solution during the clamp. The clamp will be performed on 2 occasions, once at baseline and once after 2 months of treatment with nightly insulin glargine, titrated to reduce fasting glucose levels.
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The objective of this project is to understand defects in insulin secretion that contribute to abnormal glucose metabolism in patients with diabetes.
Diabetes is a major problem for patients receiving care at VA medical centers among whom 20% are affected. Specifically, this project will seek to determine the mechanism(s) by which the incretin effect is impaired in diabetic patients. The incretin effect refers to the action of GI hormones and neural stimuli to increase insulin secretion after food intake, and accounts for approximately 50% of postprandial insulin secretion in nondiabetic humans. There are several studies indicating that this response is severely impaired in patients with type 2 diabetes. The mechanism(s) by which this occurs has not been explained. There is some evidence to suggest that secretion of the important incretins, glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), may be impaired in diabetic individuals. There is also some data to suggest that the -cells in persons with diabetes are insensitive to the incretins. The problem with the current state of knowledge in this area is that previous work has involved small numbers of diabetic subjects, and did not directly test mechanisms by which the incretin effect is altered in diabetes.
In this project we will: 1) determine the role of reduced GIP and GLP-1 levels in mediating postprandial insulin secretion in diabetic subjects. Subjects with type 2 diabetes and nondiabetic controls will have the incretin effect measured on separate occasions using test meals that cause different levels of circulating incretins. This will allow the role of reduced incretin levels in diabetes to be assessed; 2) determine the role of endogenous GLP-1 to stimulate insulin secretion in diabetic subjects. Subjects with type 2 diabetes and nondiabetic controls will have the incretin effect measured on two occasions, with and without infusion of a GLP-1 receptor antagonist. This study will compare the role of GLP-1 signaling to stimulate postprandial insulin secretion in diabetic and nondiabetic humans; 3) determine the role of hyperglycemia to impair the incretin effect. Groups of type 2 diabetic subjects will have the incretin effect measured before and after intensified diabetes treatment. This study will test the effect of chronic hyperglycemia on incretin mediated insulin secretion. In all studies, the incretin effect will be measured before and after these interventions using studies with a within subjects design. A combined glucose clamp/meal tolerance test protocol will be used to quantify the incretin effect.
These studies will allow the role of incretin secretion, incretin action, and overall metabolic milieu, on postprandial insulin secretion to be defined.
The results of these studies will add important new information for understanding abnormal -cell function in diabetes. By identifying the sites where the incretin effect is impaired this project will provide the basis for new approaches to treat diabetic patients. This is especially relevant with the recent availability of new medications that target the incretin pathways to lower blood glucose.
The blood samples will be drawn and processed in the GCRC. The samples will be frozen and stored in Building 15, Room 401. Samples will be shipped to the Genome Research Institute by staff trained in IATA shipping procedures.
Ages Eligible for Study: | 30 Years to 65 Years |
Genders Eligible for Study: | Both |
Accepts Healthy Volunteers: | Yes |
Inclusion Criteria:
Aim 1:
(non-diabetics)
(diabetics)
Exclusion Criteria:
Contact: Colleen Rogge, RN | (513) 475-6478 | MaryColleen.Rogge@va.gov |
United States, Ohio | |
VA Medical Center, Cincinnati | Recruiting |
Cincinnati, Ohio, United States, 45220 | |
Contact: Colleen Rogge, RN 513-475-6478 MaryColleen.Rogge@va.gov | |
Principal Investigator: David D'Alessio, MD |
Principal Investigator: | David D'Alessio, MD | Cincinnati VA Medical Center |
Responsible Party: | Department of Veterans Affairs ( D'Alessio, David - Principal Investigator ) |
Study ID Numbers: | ENDA-010-06S |
Study First Received: | May 4, 2007 |
Last Updated: | March 30, 2009 |
ClinicalTrials.gov Identifier: | NCT00469833 History of Changes |
Health Authority: | United States: Federal Government; United States: Food and Drug Administration |
Diabetes Glucose Tolerance Incretin Insulin |
Hypoglycemic Agents Metabolic Diseases Hyperglycemia Diabetes Mellitus, Type 2 Incretins Glargine |
Diabetes Mellitus Endocrine System Diseases Endocrinopathy Glucose Metabolism Disorders Metabolic Disorder Insulin |
Hypoglycemic Agents Metabolic Diseases Hyperglycemia Physiological Effects of Drugs Glargine |
Diabetes Mellitus Endocrine System Diseases Glucose Metabolism Disorders Pharmacologic Actions Insulin |