Clinical Trial: Insulin and Sarcopenia in the Elderly
Study Status: Completed
Recruit Status: Completed
Study Type: Interventional
Official Title: Insulin and Sarcopenia in the Elderly
Brief Summary: Muscle loss with aging is a significant contributor to disability in older people. Our general hypothesis is that loss of muscle with aging, known as sarcopenia, may be due to inability of muscle to grow in response to insulin. Our goal is to determine the mechanisms underlying this age-related insulin resistance of muscle proteins, which will allow us to define in the future specific interventions to target this defect and provide the scientific basis for the prevention and treatment of sarcopenia.
Detailed Summary:
Our general hypothesis is that a reduced response of muscle protein anabolism to insulin plays an important role in the loss of muscle mass with aging. Our goal is to determine the mechanisms underlying the age-related insulin resistance of muscle proteins, which will allow us to define specific interventions to target this defect and provide the scientific basis for the prevention and treatment of sarcopenia.
Our previous studies indicate that the response of muscle proteins to the anabolic action of insulin is impaired in healthy older adults as compared to younger controls, which hampers the anabolic effect of mixed feeding on muscle proteins. These changes are associated with an age-related reduction in the vasodilatory response to insulin, which, from our data, appears to be a potentially important mediator of the physiological anabolic effect of insulin on muscle proteins. Preliminary data from our laboratory also suggest that in older subjects a single bout of aerobic exercise may restore the normal response of blood flow, muscle protein synthesis and anabolism to insulin.
Therefore, we will test in healthy subjects the following specific hypotheses:
- Insulin-induced increases in blood flow and muscle perfusion are necessary for the physiological stimulation of muscle protein synthesis and anabolism by insulin.
- Aging reduces the vascular sensitivity to insulin, which prevents the physiological increase in blood flow and muscle perfusion in response to insulin, thereby decreasing the response of muscle protein synthesis and net balance to the anabolic action of insulin and mixed feeding.
- Aerobic exercise can restore, in older subjects, the insulin-induced increase in b
Sponsor: The University of Texas Medical Branch, Galveston
Current Primary Outcome: muscle protein synthesis [ Time Frame: 5 and 8 hours ]
Original Primary Outcome: Same as current
Current Secondary Outcome: blood flow [ Time Frame: 5 and 8 hours ]
Original Secondary Outcome: Same as current
Information By: The University of Texas Medical Branch, Galveston
Dates:
Date Received: May 27, 2008
Date Started: September 2005
Date Completion:
Last Updated: December 8, 2016
Last Verified: January 2015
