Muscle Regrowth During Physical Rehabilitation and Amino Acid Supplementation
The general hypothesis is that in older adults muscle regrowth after an acute musculoskeletal stress will be positively influenced by traditional physical rehabilitation, and further enhanced by nutritional supplementation. Using state-of-the-art stable isotope methodologies for the study of muscle metabolism and methodologies for the measurement of cell signaling, we will test the following specific hypotheses: 1) Total knee arthroplasty (TKA) induces an acute net protein catabolism mainly by reducing muscle protein synthesis; 2) TKA induced catabolism is attenuated by the ingestion of essential amino acids (EAA); 3) EAA supplementation in combination with physical therapy (PT) will stimulate muscle protein synthesis and mTOR signaling to a greater extent than PT with Placebo; and 4) EAA supplementation during TKA PT rehabilitation will improve muscle strength, muscle volume and functional outcomes to a greater extent than PT with Placebo.
Public Benefit: This research will focus rehabilitation efforts on specific and currently unresolved mechanisms responsible for muscle loss following total knee replacement in older adults. While knee pain due to bone arthritis is often alleviated after knee replacement, complete return of physical function and independence is difficult to achieve. This research will help to restore physical function and independence in the rapidly growing population of older adults with knee arthritis.
|Osteoarthritis||Dietary Supplement: Essential amino acids Dietary Supplement: Alanine|
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Treatment
|Official Title:||Muscle Regrowth During Physical Rehabilitation and Amino Acid Supplementation|
- Stair Time up [ Time Frame: 6 weeks ]
- Quadriceps Muscle Strength [ Time Frame: 6 weeks ]
- Mid-thigh Muscle Volume [ Time Frame: 6 weeks ]Analysis was performed using the Analyze 11 software package with semi-automated delineation of quadriceps, hamstrings, and adductors boarders. Using thresholding methods, the software can differentiate operator-delineated parameters set to distinguish muscle from non-muscle (i.e., adipose tissue) using voxel intensity within each border region for quantitative determination of muscle volume.
|Study Start Date:||June 2008|
|Study Completion Date:||December 2013|
|Primary Completion Date:||December 2013 (Final data collection date for primary outcome measure)|
20 g EAA daily for 7 days prior to TKA surgery and for 14 days after surgery.
Dietary Supplement: Essential amino acids
Subjects will ingest 20 grams of essential amino acids (EAA) daily for 7 days prior to total knee arthroplasty (TKA) surgery and for 14 days after surgery daily. On the days they are seen by physical therapy (PT) they will ingest the EAA supplement 30 minutes after the end of each PT rehabilitation session.
Placebo Comparator: ALA+PT
20 g NEAA daily for 7 days prior to TKA surgery and for 14 days after surgery.
Dietary Supplement: Alanine
Subjects will ingest 20 grams of non-essential amino acid (NEAA) daily for 7 days prior to total knee arthroplasty (TKA) surgery and for 14 days after surgery daily. On the days they are seen by physical therapy (PT) they will ingest the NEAA supplement 30 minutes after the end of each PT rehabilitation session.
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Please refer to this study by its ClinicalTrials.gov identifier: NCT00760383
|United States, Oregon|
|University of Oregon|
|Eugene, Oregon, United States, 97401-1240|
|Slocum Center for Orthopedics and Sports Medicine|
|Eugene, Oregon, United States, 97401|
|Principal Investigator:||Hans C Dreyer, PT, PhD||Assistant Professor, Department of Human Physiology|