SARCOPENIA-PATHOGENESIS

SUMMARY

1. Associated with accelerated loss of fast motor units.

2. Loss and atrophy of type II fibers and adaptive conversion of fiber II into fiber I (usually with reduction in high intensity activities).

3. Significant amount of inter- and intra-fiber fat infiltration (myosteatosis).

4. High levels of circulating inflammatory cytokines.

5. Motor neuron loss.

6. Hormonal decline (reproductive & hypothalamic-GH-insulin like growth factor-1 axis).

7. Reductions in satellite cell counts.

8. Age-induced mitochondrial dysfunction.

Reference(s)

Cifu, D.X. (2020). Braddom’s physical medicine and rehabilitation. Elsevier. Get it on Amazon.
Cuccurullo, S. (2019). Physical medicine and rehabilitation board review. New York: Demosmedical. Get it on Amazon.
O’Young, B., Young, M.A. and Stiens, S.A. (2008). Physical Medicine and Rehabilitation Secrets. Mosby. Get it on Amazon.