Discovering pathways of sarcopenia in older adults: a role for insulin resistance on mitochondria dysfunction.

The precise cause of sarcopenia, skeletal muscle loss and strength, in older persons is unknown. However, there is a strong evidence for muscle loss due to insulin resistance as well as mitochondrial dysfunction over aging. Considering that epidemiological studies have underlined that insulin resistance may have a specific role on skeletal muscle fibre atrophy and mitochondrial dysfunction has also been extensively shown to have a pivotal role on muscle loss in older persons, a combined pathway may not be ruled out. Considering that there is growing evidence for an insulin-related pathway on mitochondrial signaling, we hypothesize that a high degree of insulin resistance will be associated with the development of sarcopenia through specific alterations on mitochondrial functioning. This paper will highlight recent reviews regarding the link between skeletal muscle mitochondrial dysfunction and insulin resistance. We will specifically emphasize possible steps involved in sarcopenia over aging, including potential biomolecular mechanisms of insulin resistance on mitochondrial functioning.