Sarcopenia
Conditions
Brief summary
This study will examine the effect of leucine-enriched protein supplementation, alone and in combination with long chain n-3 polyunsaturated fatty acids (LC n-3 PUFA), on muscle mass and function in older adults at risk of sarcopenia. The investigators hypothesize that LC n-3 PUFA supplementation will further enhance the efficacy of the leucine-enriched protein.
Detailed description
The progressive loss of skeletal muscle mass and function with advancing age, termed sarcopenia, contributes substantially to disability, physical dependence, and mortality among older adults. Aging is associated with an attenuated muscle protein synthetic response to the ingestion of small to moderate protein doses compared to younger persons. Several studies have reported that the acute, postprandial muscle protein synthesis (MPS) response to a suboptimal protein dose is enhanced when the leucine content of the protein bolus is increased. This indicates that supplementing the lower-protein daily meals (i.e., breakfast and lunch) with leucine may represent a practical strategy to augment the MPS response to these meals and, subsequently, attenuate sarcopenic muscle mass loss over time. In addition, LC n-3 PUFA supplementation has been shown to enhance the MPS response to amino acid infusion older adults suggesting that combined leucine and LC n-3 PUFA supplementation be particularly effective for improving daily MPS, muscle mass and function in older adults.
Interventions
DIETARY_SUPPLEMENTPlacebo
Protein-free, LC n-3 PUFA-free juice based supplement
DIETARY_SUPPLEMENTLeucine-enriched protein
Leucine-enriched whey protein
DIETARY_SUPPLEMENTLC n-3 PUFA
LC n-3 PUFA
Sponsors
University College Dublin
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
65 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* Age: ≥65 y * Sex: males and females * Low muscle mass (assessed via bioelectrical impedance analysis using cut-offs from Janssen, 2004) and/or low handgrip strength (\< 30 kg men, \<20kg women)
Exclusion criteria
* BMI \>35 kg/m2 * Cancer - malignancy in the past 5 years * Multiple Sclerosis, Parkinsons Disease * Chronic kidney disease * Liver failure * Diabetes * Conditions that will affect ability to consume, digest and/or absorb the study drink (i.e. cows milk protein allergy, inflammatory bowel disease) * Smokers * Cognitive function \< 21 on Mini-Mental State Examination * Excess alcohol intake * Regular resistance training * Total walking incapacity * Musculoskeletal or neuromuscular impairments that could interfere with strength testing * Medications interfering with muscle metabolism * Adherence to a high energy or high protein diet three months before starting and during the study. Use of protein containing or amino acid containing nutritional supplements three months before starting and during the study. * High consumers of oily fish. * Weight change \> 3 kg past 3 months
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Appendicular skeletal muscle mass | 6 months | Assessed via dual energy x-ray absorptiometry |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Physical performance | 6 months | Short physical performance battery, single leg stand, timed up and go |
| Metabolomics | 6 months | Assessed using nuclear magnetic resonance (NMR) spectroscopy |
| Isometric knee extension strength | 6 months | Maximal voluntary contraction |
| Thigh muscle mass | 6 months | Assessed in dominant leg via MRI in sub cohort (n=39) |
| Muscle protein synthesis | 6 months | Measured as fractional synthetic rate (%/day) over a 3-d period at baseline and end of study |
| Transcriptomics | 6 months | Assessed via RNA Sequencing |
Countries
Ireland
Outcome results
None listed