Exercise Training and Glucose Metabolism in Aging

This study has been completed.
Sponsor:
Collaborators:
University of Maryland
Information provided by (Responsible Party):
Department of Veterans Affairs
ClinicalTrials.gov Identifier:
NCT00701051
First received: June 18, 2008
Last updated: June 29, 2012
Last verified: June 2012
  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 with IGT. 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 with impaired glucose tolerance.


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: Single Group 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 Department of Veterans Affairs:

Primary Outcome Measures:
  • Glucose utilization [ Time Frame: baseline, 24 weeks, 26 weeks ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • 2-hr post-prandial plasma glucose level [ Time Frame: baseline, 24 weeks, 26 weeks ] [ Designated as safety issue: No ]
  • skeletal muscle capillarization [ Time Frame: baseline, 24 weeks, 26 weeks ] [ Designated as safety issue: No ]
  • vascular growth factor expression [ Time Frame: baseline, 24 weeks, 26 weeks ] [ Designated as safety issue: No ]
  • phosphorylation of insulin signaling proteins [ Time Frame: baseline, 24 weeks, 26 weeks ] [ Designated as safety issue: No ]
  • Skeletal muscle glucose transporter-4 expression and glycogen synthase activity [ Time Frame: baseline, 24 weeks, 26 weeks ] [ Designated as safety issue: No ]
  • body composition (%fat) [ Time Frame: baseline, 24 weeks, 26 weeks ] [ Designated as safety issue: No ]
  • cardiorespiratory fitness [ Time Frame: baseline, 24 weeks, 26 weeks ] [ Designated as safety issue: No ]

Enrollment: 218
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
Experimental: Arm 3
Athletes, normal glucose tolerance
Behavioral: Detraining (cessation of exercise)
Cessation of exercise for 2 weeks

  Eligibility

Ages Eligible for Study:   50 Years to 75 Years
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
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
University of Maryland
Investigators
Principal Investigator: Steven J. Prior, PhD VA Maryland Health Care System, Baltimore
  More Information

No publications provided

Responsible Party: Department of Veterans Affairs
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
Last Updated: June 29, 2012
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 April 17, 2014