Muscle Insulin Resistance in Aging (Mirage)
|Insulin Resistance Sarcopenia||Behavioral: Exercise Behavioral: Energy Restriction-Induced Weight Loss|
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Basic Science
|Official Title:||Muscle Insulin Resistance In Aging|
- Measure of intramyocellular lipids [ Time Frame: Visit 3 ~22 hours ]A percutaneous muscle biopsy of the vastus lateralis will be obtained, and the intramyocellular lipids will be measured by high-performance liquid chromatography-tandem mass spectrometry.
- Measure of insulin sensitivity [ Time Frame: Visit 3 ~22 hours ]Insulin sensitivity will be measured using an intravenous catheter (glucose clamps) that will be placed in the antecubital vein for subsequent insulin and glucose infusions and for stable isotope infusions. This will measure insulin-stimulated changes in insulin signaling proteins and metabolism.
- Measure muscle strength and power [ Time Frame: Visit 2 (baseline) and 6 months ]
Muscle strength and power will be measured in participants who have successfully completed all screening procedures.
Measurement is obtained using a short physical performance battery, knee extension, and muscle power testing using a pneumatic-driven dynamometer.
|Study Start Date:||June 2014|
|Estimated Primary Completion Date:||November 2018 (Final data collection date for primary outcome measure)|
|Experimental: Exercise training protocol||
Participants will complete a progressive 6-month exercise training program, 4-5 days per week, 45 min per session (180 min per week), consisting mostly of walking (both outside and on an indoor treadmill) but with the option to include stationary cycling, elliptical and rowing machines, similar to what we have utilized previously to elicit significant improvements in insulin sensitivity in both middle-age and older adults (52-55). Beginning at week 8, these subjects will also perform 2 non-consecutive resistance exercise sessions per week, 30 min per session, focused on major muscle groups using resistance machines (total days of exercise will still be 4 to 5).
|Experimental: Energy restriction-induced weight loss||
Behavioral: Energy Restriction-Induced Weight Loss
The goal of the weight loss intervention will be to produce a weight loss of 10% body weight. A reduction of 500-1000 kcal/day - based on baseline weight -and low fat (<30% of calories from fat) diet will be used as part of the weight loss intervention.
|No Intervention: Health Education|
- To determine the effects of diet-induced weight loss with and without the addition of exercise on mitochondrial biogenesis and energetic capacity, cellular redox state and insulin resistance.
- To determine the effects of diet-induced weight loss with and without the addition of exercise on intramyocellular lipid profiles.
- To determine the effects of diet-induced weight loss with and without exercise on skeletal muscle proteins mediating a program of autophagy and either loss or maintenance of muscle mass.
Please refer to this study by its ClinicalTrials.gov identifier: NCT02230839
|Contact: Patty Fordfirstname.lastname@example.org|
|United States, Florida|
|Translational Research Institute for Metabolism and Diabetes||Recruiting|
|Orlando, Florida, United States, 32804|
|Contact: Patty Ford 407-303-7100|
|Sub-Investigator: Steven Smith, MD|
|Sub-Investigator: Richard Pratley, MD|
|Sub-Investigator: Paul Coen, PhD|
|Principal Investigator:||Bret Goodpaster, PhD||Translational Research Institute for Metabolism and Diabetes|