Chronic Muscle Disuse in the Elderly
The purpose of this study is to define the effects of chronic disuse on skeletal muscle structure and function in elderly individuals at the cellular and molecular level by examining elderly characterized by chronic muscle disuse (patients with knee osteoarthritis) and healthy elderly no evidence of knee osteoarthritis and normal physical activity levels.
|Study Design:||Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Basic Science
|Official Title:||Muscle Disuse and Contractile Dysfunction in the Elderly|
- Single muscle fiber structure/function [ Time Frame: Baseline ] [ Designated as safety issue: No ]
- Single muscle fiber structure/function [ Time Frame: 3.5 months (post-training) ] [ Designated as safety issue: No ]
|Study Start Date:||October 2010|
|Estimated Study Completion Date:||June 2015|
|Estimated Primary Completion Date:||June 2015 (Final data collection date for primary outcome measure)|
Resistance exercise training
Exercise is being used as an experimental tool to determine if remediation of muscle disuse counteracts cellular/molecular defects in muscle structure/function.
Behavioral: Resistance exercise training
Lower extremity resistance exercise training 3x/wk
Skeletal muscle disuse is an important contributing factor to physical disability. Disuse is more frequent in the elderly and they are more susceptible to its debilitating effects because of their diminished physiological reserve. Despite these facts, the mechanisms whereby disuse promotes skeletal muscle contractile dysfunction in this population remain largely undetermined. Therefore, the investigators will systematically test for modifications of single skeletal muscle fiber structure and function that underlie contractile dysfunction. Elderly individuals characterized by chronic muscle disuse (patients with knee osteoarthritis) will be compared to carefully-matched controls with no clinical evidence of knee osteoarthritis and normal activity levels. Thereafter, elderly with chronic disuse will undergo an exercise intervention to remediate muscle disuse. The investigators hypothesize that muscle disuse impairs contractile function, in part, through alterations in myosin kinetics, myofilament protein content and the mechanical properties of the myofilament lattice and that exercise rehabilitation will counteract these deficits. The investigators will specifically examine the effect of disuse on mechanical, kinetic and structural properties and molecular composition of single muscle fibers in cases and controls, as well as determine how increasing muscle use in elderly with chronic disuse via exercise training affects muscle fiber mechanical, kinetic and structural properties and molecular composition. These translational studies will provide the first comprehensive evaluation of the cellular and molecular mechanisms through which muscle disuse alters skeletal muscle structure and contractile function in elderly humans. This knowledge can assist in the development and refinement of preventative and corrective therapies for disability by tailoring these approaches to address specific molecular defects.
|Contact: Michael J. Toth, Ph.D.||firstname.lastname@example.org|
|United States, Vermont|
|University of Vermont and State Agricultural College||Recruiting|
|Burlington, Vermont, United States, 05405|
|Principal Investigator:||Michael J. Toth, Ph.D.||University of Vermont and State Agricultural College|