Clinical trial NCT01062711: Dose Response of Whey and Soy Protein Ingestion With and Without Resistance Exercise in Elderly Men
Official title: Responses of Muscle and Whole-body Protein Turnover to Ingestion of Differing Doses of Whey and Soy Protein With and Without Resistance Exercise in Elderly Men
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Sarcopenia
Keywords: sarcopenia
muscle
protein
muscle protein synthesis
muscle protein breakdown
whey
soy
casein
dose response
resistance exercise
unilateral
knee extension
whole body protein
Lead sponsor: McMaster University
Sponsor class: OTHER
Collaborators: name: National Dairy Council
First posted: 2010-02-04
Enrollment: 81
Sex: MALE
Minimum age (years): 60
Maximum age (years): 80
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

Brief summary: When we age, we lose muscle. It is not exactly clear why this happens, but we do know that this muscle loss can increase health risks and lead to health problems. Lifting weights (i.e. performing resistance exercise) and proper nutrition, in particular eating enough high quality protein, can help slow the loss of muscle mass or potentially even reverse it. Protein and resistance exercise are thought to do this by stimulating your muscle to make more proteins and/or potentially by slowing down the rate at which your body breaks proteins down. Whey protein is a high quality protein isolated from milk and is known to stimulate new protein synthesis for all proteins in your body. However, to date, the effect that whey protein has on muscle protein synthesis, particularly in the elderly has yet to be determined. Thus the purposes of this study are: 1) to determine if whey is an effective source of protein that will stimulate muscle protein synthesis in the elderly, similar to what we have previously seen in young persons; 2) to determine the smallest amount of whey protein to consume to maximally stimulate your muscle to make new proteins; 3) to see if performing resistance exercise will augment the increase in new muscle protein synthesis with whey consumption; and 4) to try and found out if whey is more effective than soy protein in stimulating new muscle protein synthesis and suppressing muscle protein breakdown in the elderly, similar to what we have previously seen in young persons


Eligibility criteria: Inclusion Criteria:

* Male
* Aged 60 to 80 years old
* Non-smoker
* Generally healthy and can tolerate the resistance exercise and protein drink

Exclusion Criteria:

* Allergies to whey, casein or soy
* Health problems such as: heart disease, rheumatoid arthritis of the knee joint, diabetes, poor lung function, uncontrolled hypertension, or any health conditions that might put participants at risks for this study
* Failed clearance for exercise participation by their medical doctor
* Failed an exercise stress test
* Taking metformin and/or other medications for the control of blood glucose even though one might not be classified as diabetic
* Taking prescribed blood thinners such as warfarin and heparin but excluding aspirin
* Taking medications for lung and kidney conditions but excluding medication for asthma that is under control

Primary outcomes:
measure: Muscle protein synthesis
timeFrame: Acute within the day
measure: whole body amino acid oxidation
timeFrame: acute within the day
Secondary outcomes:
measure: muscle protein breakdown
timeFrame: Acute within the day
measure: serum insulin
timeFrame: acute within the day
measure: plasma amino acid concentrations
timeFrame: acute within the day
Other outcomes:
Locations:
city: Hamilton
country: Canada
facility: McMaster University
state: Ontario
Study officials:
affiliation: McMaster University
name: Stuart Phillips, Ph.D.
role: PRINCIPAL_INVESTIGATOR
References: