Age-related pelvic floor muscle (PFM) dysfunction is a critical defect in the progression to pelvic floor disorders (PFDs). Despite dramatic prevalence of PFDs in older women, the underlying pathophysiology of age-related PFM dysfunction remains poorly understood. Using cadaveric specimens, we quantified aging effects on functionally relevant PFM properties and compared PFMs with the appendicular muscles from the same donors. PFMs, obturator internus, and vastus lateralis were procured from younger (N = 4) and older (N = 11) donors with known obstetrical and medical history. Our findings demonstrate that PFMs undergo degenerative, rather than atrophic, alterations. Importantly, age-related fibrotic degeneration disproportionally impacts PFMs compared to the appendicular muscles. We identified intramuscular lipid accumulation as another contributing factor to the pathological alterations of PFMs with aging. We observed a fourfold decrease in muscle stem cell (MuSC) pool of aged relative to younger PFMs, but the MuSC pool of appendicular muscles from the same older donors was only twofold lower than in younger group, although these differences were not statistically significant. Age-related degeneration appears to disproportionally impact PFMs relative to the appendicular muscles from the same donors. Knowledge of tissue- and cell-level changes in aged PFMs is essential to promote our understanding of the mechanisms governing PFM dysfunction in older women.
Bibliographical noteFunding Information:
This research was partially funded by NIH/NIA Grant R03HDO75994, and NIH/NICHD (R21HD094566, R01HD092515, R01HD102184). PD was supported through a NIH F31 Predoctoral fellowship (F31HD098007).
The authors wish to thank individuals who donated their bodies to the University of Minnesota?s Anatomy Bequest Program for the advancement of education and research. This research was partially funded by NIH/NIA Grant R03HDO75994, and NIH/NICHD (R21HD094566, R01HD092515, R01HD102184). PD was supported through a NIH F31 Predoctoral fellowship (F31HD098007). MA: Medical Advisory Board, Renovia, Inc.; Editorial stipend - American Journal of Obstetrics and Gynecology. KLC: co-founder, consultant, board member, receives income, and holds equity interest in Ventrix, Inc. All other authors report no conflict of interest.
© 2021, Biomedical Engineering Society.
- Pelvic floor disorders
- Pelvic floor muscles