Cognitive Effects of Aerobic Exercise for IGT Adults
Condition: Impaired Glucose Tolerance
MeSH terms: Glucose Intolerance
Study type: Interventional
Phase: Phase 2

Summary: 
      The specific aims for the study will be to determine if aerobic exercise enhances cognition
      for older adults who are at risk for developing type II diabetes mellitus (T2DM), and to
      evaluate whether change in insulin sensitivity predicts cognitive performance for subjects
      randomized to the aerobic exercise group. Sedentary older adults diagnosed with impaired
      glucose tolerance using an oral glucose tolerance test will participate in a 6-month
      supervised protocol of either aerobic exercise or stretching. Cognitive testing and blood
      collection will occur at baseline, and months 3 and 6. Before and after the 6-month
      intervention, insulin sensitivity, maximum aerobic capacity, and body fat composition and
      distribution (via CT scan) will be assessed for all subjects. The results of this study may
      provide support for a relatively simple and inexpensive treatment strategy that specifically
      targets many of the health factors that directly influence risk of cognitive decline
      associated with T2DM for older adults.
    

Detailed description: 
      The benefits of exercise on cognition have been demonstrated both in animals and humans.
      Exercise has salutary effects on glucoregulation and visceral adiposity, an important link
      for adults with impaired glucose tolerance (IGT) and type 2 diabetes mellitus (T2DM).
      Exercise also upregulates neurotrophic activity, an effect that serves to increase neuronal
      viability in the same brain regions that support complex cognitive functions affected by
      metabolic disease. In this proposed controlled intervention trial, the hypothesis is that
      aerobic exercise will have a beneficial effect on cognition and several biomarkers that index
      disease progression for older adults with IGT. 40 older subjects (age: >55 yrs) with IGT,
      confirmed by OGTT, will be randomized to an aerobic fitness or stretching program for 6
      months. Cognitive measures and fasting blood samples will be obtained at baseline, month 3,
      and month 6. Cognitive tests will evaluate abilities affected by age and by significant
      glucoregulatory dysregulation. In addition, all subjects will undergo a
      hyperinsulinemic-euglycemic clamp protocol, a cardiopulmonary fitness assessment, and body
      fat quantification procedures, immediately before and after the intervention. The specific
      aims of the study will be to determine if aerobic exercise enhances cognition for older
      adults with IGT, to evaluate whether exercise-induced change in insulin sensitivity predicts
      cognitive performance, and to relate exercise effects on insulin sensitivity and cognition to
      changes in specified biomarkers. The results of this study may provide support for a
      relatively simple and inexpensive treatment strategy that targets many of the health factors
      that influence risk of cognitive decline.
    

Intervention name(s): Aerobic exercise
Intervention type(s): Behavioral
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single
Primary purpose: Treatment
Keywords: IGT; exercise; cognition; insulin; aging; aerobic