Leucine-Enriched EAA's to Mitigate Inactivity Induced Muscle Atrophy
Research type
Research Study
Full title
The Effects of Leucine Enriched Essential Amino Acid Supplementation on Skeletal Muscle Protein Synthesis, Mitochondrial Function and Glycaemic Control During Two Weeks of Step Reduction Healthy in Older Adults
IRAS ID
290789
Contact name
Leigh Breen
Contact email
Sponsor organisation
University of Birmingham
Duration of Study in the UK
2 years, 0 months, 0 days
Research summary
Unavoidable periods of inactivity (i.e. during injury/illness) result in large declines of muscle mass and function. In otherwise healthy individuals, protracted disuse events may accumulate over the lifespan and contribute to the devastating loss of muscle protein mass and strength observed with ageing. Mechanistically, the disuse-induced loss of muscle mass is related to alterations in muscle protein synthesis and muscle protein breakdown. Therefore, supplementing the diet with essential amino acids (EAA), which contains a high amount of the amino acid Leucine, may offer a potential solution to alleviate inactivity-induced muscle loss and maintain muscle metabolic function.
Twenty-four (non-obese, non-diabetic, non-smokers) male and female subjects aged 60-85-years will undergo a 14-day period of reduced activity, by means of reducing step count to <1,000 steps per day. Participants will be randomly allocated to receive either leucine-enriched EAA’s (Leu-EAA; n=12) or an isonitrogenous placebo (PLA; n=12) supplementation throughout the 14-day intervention. Body composition (via the us of dual-energy X-ray absorptiometry, DXA) and muscular strength assessments will be completed before and immediately following the period of inactivity. A saliva sample will be obtained prior to a single bolus of ‘heavy labelled’ water will be ingested each morning from three days prior to until the end of the intervention. A standard oral glucose tolerance test (OGTT) will be performed pre, during, and post 14-day invention to understand the effects of inactivity on glycemic control and insulin sensitivity. Furthermore, prior to (i.e. day 0), during (i.e. day 7), and immediately following the period of inactivity (i.e. day 14) a small muscle biopsy will be acquired from the thigh of the participants to understand the rate in which new muscle protein is synthesized. A dose of D3-Methylhistidine will also be consumed and 24-hour urine collected during the protocol to provide information about muscle protein breakdown.
REC name
Wales REC 4
REC reference
21/WA/0187
Date of REC Opinion
7 Jun 2021
REC opinion
Unfavourable Opinion