Combined in vivo muscle mass, muscle protein synthesis and muscle protein breakdown measurement: a ‘Combined Oral Stable Isotope Assessment of Muscle (COSIAM)’ approach

• DOI: 10.1007/s11357-021-00386-2
• Publication Date: 2021-05-27T21:02:37Z
• Authors: Jessica Cegielski; Daniel J. Wilkinson; Matthew S. Brook; Catherine Boereboom; Bethan E. Phillips; John F. R. Gladman; Kenneth Smith; Philip J. Atherton
• Keywords: Myofibril; Protein turnover; Vastus lateralis muscle

Abstract Optimising approaches for measuring skeletal muscle mass and turnover that are widely applicable, minimally invasive cost effective is crucial in furthering research into sarcopenia cachexia. Traditional measurement of protein require infusion expensive, sterile, isotopically labelled tracers which limits the applicability these certain populations (e.g. clinical, frail elderly). To concurrently quantify i.e. synthesis (MPS) breakdown (MPB), elderly human volunteers using stable-isotope Methyl-[D 3 ]-creatine (D -Cr), deuterium oxide 2 O), ]-3-methylhistidine -3MH), to measure mass, MPS MPB, respectively. We recruited 10 older males (71 ± 4 y, BMI: 25 kg . m , mean SD) a 4-day study, with DXA consumption D O -Cr on day 1. -3MH was consumed 3, 24 h prior returning lab. From urine, saliva blood samples, single biopsy (vastus lateralis), we determined MPB. derived positively correlated appendicular fat-free (AFFM) estimated by (r = 0.69, P 0.027). Rates cumulative myofibrillar over days were 0.072%/h (95% CI, 0.064 0.081%/h). Whole-body MPB 6 0.052 0.038 0.067). These rates similar previous literature. demonstrate potential be used alongside concurrent MPS, design, applicable clinical populations.