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

NCT ID: NCT00212290

Last Updated: 2010-02-15

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: PHASE4
• Total Enrollment: 140 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2002-11-30
• Study Completion Date: 2006-12-31

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.

Conditions

Insulin Resistance; Type 2 Diabetes Mellitus

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: DOUBLE

Interventions

pioglitazone

Intervention Type: DRUG

nateglinide

Intervention Type: DRUG

placebo

Intervention Type: DRUG

Eligibility Criteria

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

• Minimum Eligible Age: 55 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

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

NIH

Sponsor Role: lead

Principal Investigators

Suzanne Craft, PhD

Role: PRINCIPAL_INVESTIGATOR

VA Puget Sound Health Care System, University of Washington

Locations

VA Puget Sound Health Care System (Seattle Campus)

Seattle, Washington, United States

VA Puget Sound Health Care System (American Lake Campus)

Tacoma, Washington, United States

Countries

United States

Other Identifiers

DK61606 (completed)

Identifier Type: -

Identifier Source: org_study_id