Diaphragm Muscle Sarcopenia is Present in Both Male and Female Mice

Abstract

The diaphragm muscle (DIAm) must be able to generate sufficient forces to sustain ventilatory and non‐ventilatory behaviors throughout the lifespan. Age‐related decreases in DIAm fiber cross‐sectional area and specific force, i.e., sarcopenia, may impair the ability to generate transdiaphragmatic pressures (Pdi) necessary to accomplish expulsive, non‐ventilatory behaviors essential for airway clearance. We examined the effects of aging on DIAm function in both male and female mice at 6 and 24 months of age (n=79). Maximum DIAm specific force was 30% lower in old mice (P蠄0.001) and Pdi generated during non‐ventilatory behaviors was ~40% less in old mice (P蠄0.001). No differences in either DIAm force or Pdi were found between males and females. Collectively, these results indicate that DIAm sarcopenia is present in both sexes and significantly affects the ability to generate Pdi needed for airway clearance in old age.Supported by R01‐AG044615, T32‐HL105355, and the Mayo Clinic.