Exercise Training and Glucose Metabolism in Aging

This study has been completed.
Sponsor:
Collaborators:
University of Maryland
National Institutes of Health (NIH)
National Institute on Aging (NIA)
Information provided by (Responsible Party):
VA Office of Research and Development
ClinicalTrials.gov Identifier:
NCT00701051
First received: June 18, 2008
Last updated: March 23, 2015
Last verified: March 2015
  Purpose
Diabetes and its associated complications affect more than 20 million Americans, and the prevalence of type 2 diabetes and impaired glucose tolerance rises dramatically with age such that 40% of Americans over age 60 are affected. In older adults, glucose metabolism may be affected by reduced skeletal muscle capillary supply, which limits insulin, glucose, and oxygen delivery to skeletal muscle. Reduced capillary supply to skeletal muscle is found in older individuals with impaired glucose tolerance and we hypothesize that this is due to reduced vascular growth factor expression, and chronic inflammation. Further, we hypothesize that reversal of a sedentary lifestyle through aerobic exercise training will increase insulin signaling and vascular growth factor expression, as well as decrease inflammation, to increase capillary supply to skeletal muscle, which contributes to improved glucose metabolism in older adults. This study will: 1) Determine the mechanisms underlying reduced skeletal muscle capillarization in older adults with impaired glucose tolerance; and 2) Determine the effect of aerobic exercise training-induced increases in skeletal muscle capillarization on glucose metabolism in older adults.

Condition Intervention
Type 2 Diabetes Mellitus
Impaired Glucose Tolerance (Prediabetes)
Behavioral: Aerobic exercise training
Behavioral: Detraining (cessation of exercise)

Study Type: Interventional
Study Design: Allocation: Non-Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Prevention
Official Title: Aging, Angiogenesis and Metabolic Responses to Aerobic Exercise

Resource links provided by NLM:


Further study details as provided by VA Office of Research and Development:

Primary Outcome Measures:
  • Baseline Glucose Utilization [ Time Frame: baseline ] [ Designated as safety issue: No ]
    Insulin-stimulated glucose uptake

  • Glucose Utilization (Pre/Post Intervention) [ Time Frame: baseline, 24 weeks, 26 weeks ] [ Designated as safety issue: No ]
    Insulin-stimulated glucose uptake

  • Baseline Skeletal Muscle Capillarization [ Time Frame: baseline ] [ Designated as safety issue: No ]
  • Skeletal Muscle Capillarization (Pre/Post Intervention) [ Time Frame: baseline, 24 weeks, 26 weeks ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Baseline 2-hour Postprandial Glucose [ Time Frame: baseline ] [ Designated as safety issue: No ]
  • 2-hr Post-prandial Plasma Glucose Level [ Time Frame: baseline, 24 weeks, 26 weeks ] [ Designated as safety issue: No ]
  • Baseline Cardiorespiratory Fitness [ Time Frame: baseline ] [ Designated as safety issue: No ]
    maximal oxygen consumption

  • Cardiorespiratory Fitness [ Time Frame: baseline, 24 weeks, 26 weeks ] [ Designated as safety issue: No ]
    Maximal oxygen consumption

  • Body Composition (%Fat) [ Time Frame: baseline, 24 weeks ] [ Designated as safety issue: No ]

Enrollment: 90
Study Start Date: October 2006
Study Completion Date: June 2012
Primary Completion Date: June 2012 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Arm 1
Older adults, normal glucose tolerance
Behavioral: Aerobic exercise training
24 weeks of aerobic exercise training: 3 times per week, 60 minutes per session, at 70% of maximal aerobic capacity
Behavioral: Detraining (cessation of exercise)
Cessation of exercise for 2 weeks
Experimental: Arm 2
Older adults, impaired glucose tolerance
Behavioral: Aerobic exercise training
24 weeks of aerobic exercise training: 3 times per week, 60 minutes per session, at 70% of maximal aerobic capacity
Behavioral: Detraining (cessation of exercise)
Cessation of exercise for 2 weeks

  Eligibility

Ages Eligible for Study:   50 Years to 75 Years   (Adult, Senior)
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Age 50-75 years
  • Non-smoker >2 years
  • Body mass index = 18-35 kg/m2

Exclusion Criteria:

  • History of CAD or cerebrovascular disease that would preclude exercise
  • Implantable defibrillator
  • Active cancer
  • Chronic pulmonary, thyroid, renal, liver, or hematological disease
  • HIV positive or prone to malnutrition
  • Sickle cell anemia
  • Type 1 diabetes, or currently on medication to treat type 2 diabetes
  • Poorly-controlled type 2 diabetes
  • Poorly-controlled hypertension
  • Taking medications including: beta-blockers, oral steroids, warfarin, certain statins, hormone replacement therapy (HRT), oral contraceptives (OCP), thiazolidinediones (TZD), or chronic steroids or nonsteroidal analgesics (NSAIDS) that may not be safely discontinued temporarily for specific procedures (i.e. for 72 hours prior)
  • Allergic to lidocaine or heparin
  • Recent weight change (>5kg in 3 months)
  • Currently pregnant or nursing
  • Physical impairment limiting exercise
  • Dementia or unstable clinical depression
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00701051

Locations
United States, Maryland
VA Maryland Health Care System, Baltimore
Baltimore, Maryland, United States, 21201
Sponsors and Collaborators
VA Office of Research and Development
University of Maryland
National Institutes of Health (NIH)
National Institute on Aging (NIA)
Investigators
Principal Investigator: Steven J. Prior, PhD VA Maryland Health Care System, Baltimore
  More Information

Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: VA Office of Research and Development
ClinicalTrials.gov Identifier: NCT00701051     History of Changes
Other Study ID Numbers: CDA-2-039-08S  H-27940  5P30AG028747-05 
Study First Received: June 18, 2008
Results First Received: January 26, 2015
Last Updated: March 23, 2015
Health Authority: United States: Federal Government

Additional relevant MeSH terms:
Diabetes Mellitus
Diabetes Mellitus, Type 2
Glucose Intolerance
Prediabetic State
Glucose Metabolism Disorders
Metabolic Diseases
Endocrine System Diseases
Hyperglycemia

ClinicalTrials.gov processed this record on July 27, 2016