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Pioglitazone Incretin Study

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00656864
Recruitment Status : Completed
First Posted : April 11, 2008
Last Update Posted : February 2, 2011
Information provided by:
University of Vermont

Brief Summary:

Incretin hormones are hormones produced by the gut in response to food intake. These hormones help the body to control the metabolism of glucose (sugar). In particular, two incretin hormones (GLP-1 and GIP) cause the pancreas to secrete more insulin in response to high blood glucose levels. This helps the body to metabolize the glucose more effectively, lowering blood sugar levels. GLP-1 and GIP do not work as well in patients with type 2 diabetes (T2DM) as in subjects who do not have diabetes. This study tests whether a medicine called pioglitazone (Actos), which is commonly used to treat T2DM, improves the ability of GIP to increase insulin secretion.

To address this question the investigators will recruit patients with T2DM whose diabetes is controlled with either diet and exercise or with metformin (another medicine commonly used to treat T2DM). Subjects will undergo measurement of body fat by DEXA scanning and a series of studies to characterize their metabolism. These studies include an oral glucose tolerance test (a test sometimes used to diagnose diabetes), a mixed-meal challenge (to measure how much GLP-1 and GIP are produced in response to a meal) and measurement of insulin secretion in response to glucose and GIP given through a vein. The investigators will also obtain small samples of fat (from just under the skin of the belly) using a needle to measure levels of the receptor for GIP. Subjects will then be randomly assigned to 12 weeks of treatment with either pioglitazone or matching placebo (an inactive tablet that does not contain medication). The dose of pioglitazone will be increased during the first 4 weeks to the maximum prescribed dose of 45 mg per day. Subjects will be seen every 2-4 weeks during the treatment phase of the study. After 12 weeks of treatment all studies performed at the beginning of the study will be repeated. The pioglitazone treatment will continue until the end of testing, approximately 4 weeks.

The results of this study may give us information about why glucose control deteriorates in T2DM. This information might also lead to new ways to prevent or treat T2DM.

Condition or disease Intervention/treatment Phase
Diabetes Mellitus, Type 2 Drug: Pioglitazone Drug: Placebo Phase 4

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 24 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Basic Science
Official Title: Effects of Pioglitazone on the Regulation of Insulin Secretion in Patients With Type 2 Diabetes
Study Start Date : May 2008
Actual Primary Completion Date : November 2010
Actual Study Completion Date : November 2010

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Active Comparator: 1
Pioglitazone arm
Drug: Pioglitazone
Starting dose at 15 mg for two weeks, then titrated up to 45 mg in the subsequent 2 weeks.
Other Name: Actos (brand name for pioglitazone)

Placebo Comparator: 2
Placebo arm
Drug: Placebo

Primary Outcome Measures :
  1. Change in incretin-mediated insulin secretion and receptor regulation of glucose-dependent insulinotropic peptide (GIP) in patients with type 2 diabetes. [ Time Frame: 12 weeks per subject ]

Secondary Outcome Measures :
  1. Change in active GIP in response to an oral glucose tolerance test and mixed meal challenge [ Time Frame: 12 weeks ]
  2. Change in active GLP-1 in response to the oral glucose tolerance test and the mixed meal challenge [ Time Frame: 12 weeks ]
  3. Change in glucose response during the oral glucose tolerance test and mixed meal challenge [ Time Frame: 12 weeks ]
  4. Change in insulin secretion during the oral glucose tolerance test and the mixed meal challenge [ Time Frame: 12 weeks ]
  5. Change in the acute insulin response to glucose, insulin sensitivity and the disposition index during the IV glucose tolerance test. [ Time Frame: 12 weeks ]
  6. Change in adipocyte GIP receptor mRNA expression levels. [ Time Frame: 12 weeks ]

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 75 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Type 2 diabetes controlled with diet+exercise or metformin monotherapy
  • HbA1c less than or equal to 7%
  • Women will be non-fertile or practicing birth control

Exclusion Criteria:

  • Acute or chronic medical conditions that would contraindicate participation
  • Class III or IV heart failure
  • Pregnant or nursing women
  • Patients taking antidiabetic medications other than metformin, oral or chronic topical steroids, weight loss agents, antipsychotics, or other drugs that could affect insulin sensitivity or secretion.
  • AST or ALT more than 2.5 times the upper limit of normal
  • Active alcohol or drug abuse
  • Weight greater than 300 pounds

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00656864

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United States, Vermont
University of Vermont
South Burlington, Vermont, United States, 05403
Sponsors and Collaborators
University of Vermont
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Principal Investigator: Richard E Pratley, MD University of Vermont
Publications automatically indexed to this study by Identifier (NCT Number):
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Responsible Party: Richard Pratley, MD, University of Vermont College of Medicine Identifier: NCT00656864    
Other Study ID Numbers: 08-107
First Posted: April 11, 2008    Key Record Dates
Last Update Posted: February 2, 2011
Last Verified: January 2010
Keywords provided by University of Vermont:
Additional relevant MeSH terms:
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Diabetes Mellitus, Type 2
Diabetes Mellitus
Glucose Metabolism Disorders
Metabolic Diseases
Endocrine System Diseases
Hypoglycemic Agents
Physiological Effects of Drugs