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

B.T. Wall, S.H. Gorissen, B. Pennings, R. Koopman, Bart B.L. Groen, Lex B. Verdijk, Luc J.C. van Loon

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

PURPOSE: 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. PROCEDURES: 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. FINDINGS: 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. CONCLUSIONS: Aging is associated with the development of muscle anabolic inflexibility which represents a key physiological mechanism underpinning sarcopenia.
Original languageEnglish
Article numbere0140903
JournalPLOS ONE
Volume10
Issue number11
DOIs
Publication statusPublished - 1 Jan 2015

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