Assessing the Dose-response of Muscle Protein Synthesis to "Super-whey" in Older Adults
ConditionSarcopenia
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexMale
Age65-85
SponsorUniversity of Nottingham
About this trial
Skeletal muscle accounts for approximately 45-55% of total body mass in healthy adults and plays a pivotal role in whole-body metabolic health, locomotion and physical independence. Undesirable loss of skeletal muscle mass (atrophy) is, however, a common feature of many diseases and scenarios including ageing, bed rest/immobilisation, cancer and physical inactivity. Despite the exact mechanisms causing muscle atrophy being not yet fully understood, "anabolic resistance" (reduced muscle building in response to protein feeding and exercise) is thought to be key, especially for age-related skeletal muscle losses (known as sarcopenia). As such, the search for optimal strategies (e.g., exercise and/ or nutritional interventions) to combat this anabolic blunting remains a hot-topic in scientific research.
Leucine, an essential and branched chain amino acid (EAA/BCAA), is thought to be the most potent AA for stimulating muscle protein synthesis (MPS; the muscle building process). Although, as a stand-alone supplement, leucine is unlikely to provoke a robust and prolonged state of MPS, low doses of leucine-enriched mixed-EAAs can elicit similar increases in MPS as compared to a large dose of whey protein. As reduced appetite and increased satiety (feeling fuller) are common with advancing age, supplementation of a low-dose protein (i.e., leucine-enriched) that can adequately stimulate MPS may contribute to muscle health maintenance in older adults and reduce satiation following a meal.
This study aims to examine which of three doses of a novel leucine-enriched whey protein ("super-whey") best stimulates muscle building in older adults
Eligibility criteria
This trial accepts healthy volunteersQualifiers
Participant is in the desired age-ranges (young adults: 18-35 years; older adults: 65+ years).
Participant is willing and able to give informed consent for participation in the study.
Participant is physically able to perform resistance exercise
Disqualifiers
A BMI <18 or >35 kg/m2
Active cardiovascular, cerebrovascular or respiratory disease: e.g. uncontrolled hypertension (BP > 160/100), angina, heart failure (class III/IV), arrhythmia, right to left cardiac shunt, recent cardiac event, COPD, pulmonary hypertension or recent (6 mo) stroke
Any metabolic disease
Clotting dysfunction
Trial design
Design model
Parallel
Treatments tested in this trial
Dietary protein supplement
Other intervention3 different doses of super-whey protein supplements will be given in a randomised crossover fashion to participants
Treatment groups
30 Participants
are divided into 3 treatment groupsGroup A: Super-Whey protein Dose 1Experimental treatment 1 intervention
Group B: Super-Whey protein Dose 2Experimental treatment 1 intervention
Group C: Super-Whey protein Dose 3Experimental treatment 1 intervention
Trial outcomes
Primary outcomes
1
Muscle protein fractional synthetic rate (postabsorptive)
Postabsorptive measures of muscle protein synthesis assessed in muscle tissue (collected by muscle biopsy). This outcome will be assessed prior to administering a protein drink to obtain muscle protein fractional synthetic rate in the fasted state.
Time frame
Assessed at 3 hour mark2
Muscle protein fractional synthetic rate (postprandial)
Postprandial measures of muscle protein synthesis assessed in muscle tissue (collected by muscle biopsy). This outcome will be assessed following administering a protein drink to obtain muscle protein fractional synthetic rate in the fed state.
Time frame
Assessed at 6 hour markSecondary outcomes
1
Plasma amino acid concentrations
During the fasted and fed states of the study, blood samples are collected every 20 minutes to capture the plasma amino acid concentrations in the blood at that time-point (24 timepoints assessed). Future analysis using mass-spectroscopy will allow determination of the different amino acid concentrations in the blood plasma collected.
Time frame
Assessed over 7.5 hoursSponsors and contacts
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Source ClinicalTrials.gov