Aging Is Accompanied by a Blunted Muscle Protein Synthetic Response to Protein Ingestion

• Published in: PloS one Vol. 10; no. 11; p. e0140903
• Main Authors: Wall, Benjamin Toby, Gorissen, Stefan H., Pennings, Bart, Koopman, René, Groen, Bart B. L., Verdijk, Lex B., van Loon, Luc J. C.
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 04.11.2015; Public Library of Science (PLoS)
• Subjects: Absorptivity; Aged; Aging; Care and treatment; Cross-Sectional Studies; Development and progression; Diet; Dietary Proteins - metabolism; Global health; Humans; In vivo methods and tests; Ingestion; Laboratories; Male; Men; Muscle Proteins - metabolism; Muscles; Nanowires; Nutrition; Patient outcomes; Postprandial Period; Protein biosynthesis; Protein Biosynthesis - physiology; Protein folding; Protein synthesis; Retrospective Studies; Sarcopenia; Sarcopenia - metabolism; Sarcopenia - pathology; Skeletal muscle; Stable isotopes; Young Adult; United States; Netherlands
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0140903

Progressive loss of skeletal muscle mass with aging (sarcopenia) forms a global health concern. It has been suggested that an impaired capacity to increase muscle protein synthesis rates in response to protein intake is a key contributor to sarcopenia. We assessed whether differences in post-absorptive and/or post-prandial muscle protein synthesis rates exist between large cohorts of healthy young and older men. We performed a cross-sectional, retrospective study comparing in vivo post-absorptive muscle protein synthesis rates determined with stable isotope methodologies between 34 healthy young (22±1 y) and 72 older (75±1 y) men, and post-prandial muscle protein synthesis rates between 35 healthy young (22±1 y) and 40 older (74±1 y) men. Post-absorptive muscle protein synthesis rates did not differ significantly between the young and older group. Post-prandial muscle protein synthesis rates were 16% lower in the older subjects when compared with the young. Muscle protein synthesis rates were >3 fold more responsive to dietary protein ingestion in the young. Irrespective of age, there was a strong negative correlation between post-absorptive muscle protein synthesis rates and the increase in muscle protein synthesis rate following protein ingestion. Aging is associated with the development of muscle anabolic inflexibility which represents a key physiological mechanism underpinning sarcopenia.