Functional impact of sarcopenia in respiratory muscles.

摘要: The risk for respiratory complications and infections is substantially increased in old age, which may be due, part, to sarcopenia (aging-related weakness atrophy) of the diaphragm muscle (DIAm), reducing its force generating capacity impairing ability perform expulsive non-ventilatory motor behaviors critical airway clearance. aging-related reduction DIAm due selective atrophy higher type IIx and/or IIb fibers, whereas lower I IIa fiber sizes are preserved. Fiber specific also seen following unilateral phrenic nerve denervation other neurodegenerative disorders. Accordingly, effect aging on function resembles that neurodegeneration suggests possible common mechanisms, such as involvement several neurotrophic factors mediating sarcopenia. This review will focus changes two signaling pathways represent potential mechanisms underlying atrophy.