The age-related loss of skeletal muscle mass and function: measurement and mechanisms of muscle fibre atrophy and muscle fibre loss in humans.

The age-related loss of skeletal muscle mass and function: measurement and mechanisms of muscle fibre atrophy and muscle fibre loss in humans. Ageing Res Rev. 2018 Jul 23;: Authors: Wilkinson DJ, Piasecki M, Atherton PJ Abstract Age-related loss of skeletal muscle mass and function, sarcopenia, is associated with physical frailty and increased risk of morbidity (chronic diseases), in addition to all-cause mortality. The loss of muscle mass occurs incipiently from middle-age (~1%/year), and in severe instances can lead to a loss of ~50% by the 8-9th decade of life. This review will focus on muscle deterioration with ageing and highlight the two underpinning mechanisms regulating declines in muscle mass and function: muscle fibre atrophy and muscle fibre loss (hypoplasia) - and their measurement. The mechanisms of muscle fibre atrophy in humans relate to imbalances in muscle protein synthesis (MPS) and breakdown (MPB); however, since there is limited evidence for basal alterations in muscle protein turnover, it would appear that "anabolic resistance' to fundamental environmental cues regulating diurnal muscle homeostasis (namely physical activity and nutrition), underlie age-related catabolic perturbations in muscle proteostasis. While the 'upstream' drivers of the desensitization of aged muscle to anabolic stimuli are poorly defined, they most likely relate to impaired efficiency of the conversion of nutritional/exercise stimuli into ...
Source: Ageing Research Reviews - Category: Genetics & Stem Cells Authors: Tags: Ageing Res Rev Source Type: research