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Insulin Resistance and Central Nervous System (CNS) Function in Type 2 Diabetes

Primary Purpose

Insulin Resistance, Type 2 Diabetes Mellitus

Status

Completed

Phase

Phase 4

Locations

United States

Study Type

Interventional

Intervention

pioglitazone

nateglinide

placebo

About this trial

This is an interventional treatment trial for Insulin Resistance focused on measuring impaired glucose tolerance

Eligibility Criteria

55 Years - undefined (Adult, Older Adult)All SexesAccepts Healthy Volunteers

Inclusion Criteria: Impaired glucose tolerance OR mild type 2 diabetes mellitus OR normal blood sugar regulation Stable weight and activity level Exclusion Criteria: Medications for diabetes Dementia Medications with known effects on memory Serious neurologic disease or head trauma Serious systemic illness (e.g., renal failure or uncontrolled hypertension) Serious psychiatric illness (e.g., schizophrenia or bipolar disorder) Allergy to pioglitazone or nateglinide

Sites / Locations

VA Puget Sound Health Care System (Seattle Campus)
VA Puget Sound Health Care System (American Lake Campus)

Outcomes

Primary Outcome Measures

Verbal memory (main study)

Selective attention (main study)

Plasma beta-amyloid levels (main study)

Cerebral glucose metabolism (sub-study)

Inflammatory markers in spinal fluid (sub-study)

Beta-amyloid in spinal fluid (sub-study)

Secondary Outcome Measures

Psychomotor speed

Verbal fluency

Blood levels of insulin, insulin degrading enzyme, cortisol and inflammatory markers

Full Information

NCT ID

NCT00212290

First Posted

September 20, 2005

Last Updated

February 12, 2010

Sponsor

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

1. Study Identification

Unique Protocol Identification Number

NCT00212290

Brief Title

Insulin Resistance and Central Nervous System (CNS) Function in Type 2 Diabetes

Study Type

Interventional

2. Study Status

Record Verification Date

February 2010

Overall Recruitment Status

Completed

Study Start Date

November 2002 (undefined)

Primary Completion Date

undefined (undefined)

Study Completion Date

December 2006 (Actual)

3. Sponsor/Collaborators

Name of the Sponsor

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

4. Oversight

5. Study Description

Brief Summary

The purpose of this study is to examine the effects of treating insulin resistance on memory and attention, brain glucose utilization, and proteins in spinal fluid.

Detailed Description

Insulin resistant conditions such as impaired glucose tolerance, type 2 diabetes mellitus, and hyperinsulinemia have been associated with an increased risk for memory decline and for Alzheimer's disease. The main study will determine whether treatment with pioglitazone or nateglinide will improve verbal memory and selective attention for older adults with impaired glucose tolerance or mild type 2 diabetes. The main study will also characterize changes in blood concentrations of insulin, inflammatory markers, and the beta-amyloid peptides that are related to Alzheimer's disease. In one sub-study, participants will undergo brain positron emission tomography (PET) imaging before and after 16 weeks of treatment with pioglitazone, nateglinide, or placebo. The purpose of this sub-study is to determine the effects of treatment on brain glucose utilization. In a second sub-study, participants will undergo a lumbar puncture procedure before and after treatment. The purpose of this sub-study is to determine the effects of treatment on spinal fluid concentrations of insulin, inflammatory markers, and beta-amyloid peptides. Together these main and sub-studies should characterize the effects of insulin resistance on cognition and suggest a mechanism by which insulin resistant conditions increase risk for memory decline and for Alzheimer's disease.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study

Insulin Resistance, Type 2 Diabetes Mellitus

Keywords

impaired glucose tolerance

7. Study Design

Primary Purpose

Treatment

Study Phase

Phase 4

Interventional Study Model

Parallel Assignment

Masking

Double

Allocation

Randomized

Enrollment

140 (Anticipated)

8. Arms, Groups, and Interventions

Intervention Type

Drug

Intervention Name(s)

pioglitazone

Intervention Type

Drug

Intervention Name(s)

nateglinide

Intervention Type

Drug

Intervention Name(s)

placebo

Primary Outcome Measure Information:

Title

Verbal memory (main study)

Title

Selective attention (main study)

Title

Plasma beta-amyloid levels (main study)

Title

Cerebral glucose metabolism (sub-study)

Title

Inflammatory markers in spinal fluid (sub-study)

Title

Beta-amyloid in spinal fluid (sub-study)

Secondary Outcome Measure Information:

Title

Psychomotor speed

Title

Verbal fluency

Title

Blood levels of insulin, insulin degrading enzyme, cortisol and inflammatory markers

10. Eligibility

Sex

All

Minimum Age & Unit of Time

55 Years

Accepts Healthy Volunteers

Eligibility Criteria

Overall Study Officials:

First Name & Middle Initial & Last Name & Degree

Suzanne Craft, PhD

Organizational Affiliation

VA Puget Sound Health Care System, University of Washington

Official's Role

Principal Investigator

Facility Information:

Facility Name

VA Puget Sound Health Care System (Seattle Campus)

City

Seattle

State/Province

Washington

ZIP/Postal Code

98108

Country

United States

Facility Name

VA Puget Sound Health Care System (American Lake Campus)

City

Tacoma

State/Province

Washington

ZIP/Postal Code

98493

Country

United States

12. IPD Sharing Statement

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Insulin Resistance and Central Nervous System (CNS) Function in Type 2 Diabetes

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