Investigation of age-related difference in muscle quality: focus on skeletal muscle oxidative capacity and intramyocellular lipid

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K19691
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 59040:Nutrition science and health science-related
• Research Institution: Chukyo University
• Principal Investigator: Yoshiko Akito 中京大学, 教養教育研究院, 講師 (70825124)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 筋細胞内脂肪 / 磁気共鳴分光装置 / 筋酸素化機能 / ミトコンドリア / 高齢者

Outline of Final Research Achievements

We aimed to investigate the physiological characteristics of muscle oxidative capacity in young and older individuals. On the firstly, we observed that muscle oxidative capacity had a relationship with walking speed (r=0.59, P<0.05) in older individuals. This finding indicated that muscle oxidative capacity would become a factor to relate the index of age-related decline of muscle function. Secondly, we investigated the relationship between muscle oxidative capacity and intramyocellular lipid in young and older individuals. We found that a relationship between muscle oxidative capacity and intramyocellular lipid was confirmed in young (r=-0.47, P<0.05) but not older individuals (r=0.22, P=0.45). Muscle oxidative capacity directly showed muscle mitochondria function. Therefore, this result speculated that intramyocellular lipid in young individuals has the potential to contribute to muscle lipid metabolism and generate energy in the mitochondria.

Free Research Field

老年医学

Academic Significance and Societal Importance of the Research Achievements

加齢に伴う骨格筋の変化はサルコペニアとして定義され，筋の量的・機能的な指標から評価されている．これに加え，筋の質的な指標の評価の重要性が認識されつつある．筋の質的指標には，筋内部の脂肪量やミトコンドリア機能などが挙げられているが，その詳細については不明な点が多い．本研究では，筋でのエネルギー代謝に重要なミトコンドリアの機能を反映する筋酸素化機能に着目し，特に高齢者における筋酸素化機能の意義を明らかにした．今後は，筋酸素化機能を向上させる方法を検討することで，高齢者の健康寿命の増進やADL維持に貢献する知見の獲得も期待される．