Clinical trial NCT00701051: Exercise Training and Glucose Metabolism in Aging
Official title: Aging, Angiogenesis and Metabolic Responses to Aerobic Exercise
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Type 2 Diabetes Mellitus
Impaired Glucose Tolerance (Prediabetes)
Lead sponsor: VA Office of Research and Development
Sponsor class: FED
Collaborators: name: University of Maryland
name: National Institutes of Health (NIH)
name: National Institute on Aging (NIA)
First posted: 2008-06-19
Enrollment: 90
Sex: ALL
Minimum age (years): 50
Maximum age (years): 75
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: NON_RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

Brief 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.


Eligibility 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

Primary outcomes:
measure: Baseline Glucose Utilization
timeFrame: baseline
measure: Glucose Utilization (Pre/Post Intervention)
timeFrame: baseline, 24 weeks, 26 weeks
measure: Baseline Skeletal Muscle Capillarization
timeFrame: baseline
measure: Skeletal Muscle Capillarization (Pre/Post Intervention)
timeFrame: baseline, 24 weeks, 26 weeks
Secondary outcomes:
measure: Baseline 2-hour Postprandial Glucose
timeFrame: baseline
measure: 2-hr Post-prandial Plasma Glucose Level
timeFrame: baseline, 24 weeks, 26 weeks
measure: Baseline Cardiorespiratory Fitness
timeFrame: baseline
measure: Cardiorespiratory Fitness
timeFrame: baseline, 24 weeks, 26 weeks
measure: Body Composition (%Fat)
timeFrame: baseline, 24 weeks
Other outcomes:
Locations:
city: Baltimore
country: United States
facility: VA Maryland Health Care System, Baltimore
state: Maryland
Study officials:
affiliation: VA Maryland Health Care System, Baltimore
name: Steven J. Prior, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Prior SJ, Goldberg AP, Ortmeyer HK, Chin ER, Chen D, Blumenthal JB, Ryan AS. Increased Skeletal Muscle Capillarization Independently Enhances Insulin Sensitivity in Older Adults After Exercise Training and Detraining. Diabetes. 2015 Oct;64(10):3386-95. doi: 10.2337/db14-1771. Epub 2015 Jun 11.