Exercise Training and Glucose Metabolism in Aging

Summary

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.

Conditions

• Type 2 Diabetes Mellitus
• Impaired Glucose Tolerance (Prediabetes)

Interventions

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

Sponsors & Collaborators

• University of Maryland

  collaborator OTHER

• National Institutes of Health (NIH)

  collaborator NIH

• National Institute on Aging (NIA)

  collaborator NIH

• US Department of Veterans Affairs

  lead FED

Principal Investigators

• Steven J. Prior, PhD · VA Maryland Health Care System, Baltimore

Study Design

Allocation

NON_RANDOMIZED

Purpose

PREVENTION

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

50 Years

Max Age

75 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2006-10-31

Primary Completion

2012-06-30

Completion

2012-06-30

Countries

• United States

Study Locations