サルコペニアとインスリン抵抗性・ミトコンドリア機能障害

サルコペニアとインスリン抵抗性・ミトコンドリア機能障害に関するレビュー論文を紹介します。

Abbatecola AM, Paolisso G, Fattoretti P, Evans WJ, Fiore V, Dicioccio L, Lattanzio F. Discovering pathways of sarcopenia in older adults: a role for insulin resistance on mitochondria dysfunction. J Nutr Health Aging. 2011;15(10):890-5.

サルコペニアの正確な原因は不明ですが、インスリン抵抗性と加齢によるミトコンドリア機能障害が骨格筋減少の一因であることは明らかです。そこで仮説として、高度のインスリン抵抗性がミトコンドリアの機能変化を介してサルコペニアと関連していることを提唱しています。

インスリン抵抗性とミトコンドリア機能障害の関連は確かなようですが、どちらが原因でどちらが結果か、因果関係にないのかは不明です。インスリン抵抗性に対して食事・運動・薬物療法を行いますが、加齢によるサルコペニアを認める高齢者にそのまま食事・運動・薬物療法を行えばよいかどうかは今後の研究課題ですね。

Abstract
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.