Dietary Strategies to Promote Muscle Protein Anabolism in the Elderly - Full Text View

Purpose

Aging is associated with the loss of lean muscle mass, termed sarcopenia. Food intake and in particular the ingestion of protein or amino acids has been shown to be a powerful stimulus to promote net muscle protein anabolism. However this anabolic response following a meal-like protein bolus seems to be blunted in the elderly as compared to young adults.

The first aim of this proposal is to investigate the post-prandial muscle protein synthesis rates in young and elderly men in response to a meal-like protein bolus after a period of rest or physical activity (study A). The rest trial (REST) will act as a proof-of-principle study to examine the blunted protein synthetic response in the elderly, and as a control trial in comparison with the exercise trial (EXC) to establish the surplus value of physical activity prior to protein intake on muscle protein synthesis.

The second aim of this proposal is to determine the surplus value of an increased quantity of the ingested protein bolus (study B). Large amounts of protein (40 and 60 g) will be compared to a meal-like amount of protein (20 g) as a means to maximize plasma amino acid availability and/or to stimulate muscle protein anabolism.

The third aim of this proposal is to study the differences in quality of the ingested protein bolus (study C). Instead of significantly increasing the quantity of the protein bolus, we will also apply a more practical approach to augment skeletal muscle protein synthesis rates; modifying the digestibility or amino acid composition of a meal-like protein bolus.

Condition	Intervention
Sarcopenia	Dietary Supplement: Protein/Amino Acids Other: Physical exercise

Study Type:	Interventional
Study Design:	Allocation: Randomized Intervention Model: Parallel Assignment Masking: Double Blind (Subject, Outcomes Assessor) Primary Purpose: Prevention
Official Title:	Dietary Strategies to Promote Muscle Protein Anabolism in the Elderly

Resource links provided by NLM:

MedlinePlus related topics: Exercise and Physical Fitness

Drug Information available for: Amino acids

U.S. FDA Resources

Further study details as provided by Maastricht University Medical Center:

Primary Outcome Measures:

All interventions will affect muscle protein synthesis. With the application of amino acid tracer methodology we are able to determine muscle protein synthesis. [ Time Frame: 6 hours ] [ Designated as safety issue: No ]

Secondary Outcome Measures:

Differences in rate of uptake/absorption from the intestine. [ Time Frame: 6 hours ] [ Designated as safety issue: No ]

Enrollment:	120
Study Start Date:	December 2007
Study Completion Date:	November 2010
Primary Completion Date:	November 2010 (Final data collection date for primary outcome measure)

Arms	Assigned Interventions
Experimental: 1 Young men 18-30 years, BMI < 27 kg/m2	Dietary Supplement: Protein/Amino Acids Casein Whey Leucine Other: Physical exercise The physical exercise protocol will consist of low intensity cycling and light resistance-type exercise; after 5 minutes of self-paced cycling, subjects will perform 6 sets of 10 repetitions on the horizontal leg press machine (Technogym BV, Rotterdam, The Netherlands) and 6 sets of 10 repetitions on the leg extension machine (Technogym BV, Rotterdam, The Netherlands). The first 2 sets of both resistance exercises will be performed at 40% of the subjects' 1RM. Sets 3-4, and 5-6 will be performed at 55% and 75% of 1RM, respectively, with 2 minutes rest intervals between sets.
Experimental: 2 Young men 18-30 years, BMI < 27 kg/m2	Dietary Supplement: Protein/Amino Acids Casein Whey Leucine
Experimental: 3 Old men 70-85 years, BMI < 27 kg/m2	Dietary Supplement: Protein/Amino Acids Casein Whey Leucine Other: Physical exercise The physical exercise protocol will consist of low intensity cycling and light resistance-type exercise; after 5 minutes of self-paced cycling, subjects will perform 6 sets of 10 repetitions on the horizontal leg press machine (Technogym BV, Rotterdam, The Netherlands) and 6 sets of 10 repetitions on the leg extension machine (Technogym BV, Rotterdam, The Netherlands). The first 2 sets of both resistance exercises will be performed at 40% of the subjects' 1RM. Sets 3-4, and 5-6 will be performed at 55% and 75% of 1RM, respectively, with 2 minutes rest intervals between sets.
Experimental: 4 Old men 70-85 years, BMI < 27 kg/m2	Dietary Supplement: Protein/Amino Acids Casein Whey Leucine
Experimental: 5 Old men 70-85 years, BMI < 27 kg/m2	Dietary Supplement: Protein/Amino Acids Casein Whey Leucine
Experimental: 6 Old men 70-85 years, BMI < 27 kg/m2	Dietary Supplement: Protein/Amino Acids Casein Whey Leucine
Experimental: 7 Old men 70-85 years, BMI < 27 kg/m2	Dietary Supplement: Protein/Amino Acids Casein Whey Leucine
Experimental: 8 Old men 70-85 years, BMI < 27 kg/m2	Dietary Supplement: Protein/Amino Acids Casein Whey Leucine
Experimental: 9 Old men 70-85 years, BMI < 27 kg/m2	Dietary Supplement: Protein/Amino Acids Casein Whey Leucine
Experimental: 10 Old men 70-85 years, BMI < 27 kg/m2	Dietary Supplement: Protein/Amino Acids Casein Whey Leucine

Eligibility

Ages Eligible for Study:	18 Years to 85 Years
Genders Eligible for Study:	Male
Accepts Healthy Volunteers:	Yes

Criteria

Inclusion Criteria:

In study A, non-obese male subjects (BMI <27) between the age of 18-30 yrs and 70-85 yrs will be selected.
In studies B and C, non-obese male subjects (BMI <27) between the age of 70-85 yrs will be selected.

Exclusion Criteria:

Type II diabetes or other known diseases
Use of medication
Female
Other ages or BMI than indicated above
Participation in any regular exercise program.

Contacts and Locations

Please refer to this study by its ClinicalTrials.gov identifier: NCT00557388

Locations

Netherlands
University of Maastricht
Maastricht, Limburg, Netherlands, 6200 MD

Sponsors and Collaborators

Maastricht University Medical Center

National Nutrition and Food Technology Institute

Investigators

Principal Investigator:

Luc van Loon, Phd

Maastricht University

More Information

No publications provided by Maastricht University Medical Center

Additional publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):

Pennings B, Groen B, de Lange A, Gijsen AP, Zorenc AH, Senden JM, van Loon LJ. Amino acid absorption and subsequent muscle protein accretion following graded intakes of whey protein in elderly men. Am J Physiol Endocrinol Metab. 2012 Apr;302(8):E992-9. doi: 10.1152/ajpendo.00517.2011. Epub 2012 Feb 14.

Pennings B, Boirie Y, Senden JM, Gijsen AP, Kuipers H, van Loon LJ. Whey protein stimulates postprandial muscle protein accretion more effectively than do casein and casein hydrolysate in older men. Am J Clin Nutr. 2011 May;93(5):997-1005. Epub 2011 Mar 2.

Pennings B, Koopman R, Beelen M, Senden JM, Saris WH, van Loon LJ. Exercising before protein intake allows for greater use of dietary protein-derived amino acids for de novo muscle protein synthesis in both young and elderly men. Am J Clin Nutr. 2011 Feb;93(2):322-31. Epub 2010 Nov 17.

Responsible Party:	Maastricht University Medical Center
ClinicalTrials.gov Identifier:	NCT00557388 History of Changes
Other Study ID Numbers:	MEC 07-3-086, TIFN A-1002
Study First Received:	November 13, 2007
Last Updated:	September 13, 2011
Health Authority:	Netherlands: The Central Committee on Research Involving Human Subjects (CCMO)

Keywords provided by Maastricht University Medical Center:

muscle loss
aging
protein

amino acids
exercise
protein synthesis

Additional relevant MeSH terms:

Sarcopenia
Muscular Atrophy
Neuromuscular Manifestations
Neurologic Manifestations

Nervous System Diseases
Atrophy
Pathological Conditions, Anatomical
Signs and Symptoms

ClinicalTrials.gov processed this record on May 16, 2013