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

February 12, 2010 updated by: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
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.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

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.

Study Type

Interventional

Enrollment (Anticipated)

140

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Washington
      • Seattle, Washington, United States, 98108
        • VA Puget Sound Health Care System (Seattle Campus)
      • Tacoma, Washington, United States, 98493
        • VA Puget Sound Health Care System (American Lake Campus)

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

55 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

What is the study measuring?

Primary Outcome Measures

Outcome Measure
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

Outcome Measure
Psychomotor speed
Verbal fluency
Blood levels of insulin, insulin degrading enzyme, cortisol and inflammatory markers

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

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

Investigators

  • Principal Investigator: Suzanne Craft, PhD, VA Puget Sound Health Care System, University of Washington

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

November 1, 2002

Study Completion (Actual)

December 1, 2006

Study Registration Dates

First Submitted

September 20, 2005

First Submitted That Met QC Criteria

September 20, 2005

First Posted (Estimate)

September 21, 2005

Study Record Updates

Last Update Posted (Estimate)

February 15, 2010

Last Update Submitted That Met QC Criteria

February 12, 2010

Last Verified

February 1, 2010

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • DK61606 (completed)

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Type 2 Diabetes Mellitus

Clinical Trials on placebo

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Ecuador

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe