Assessment of the physiological characteristic of extramyocellular lipid in older individuals

2019 Fiscal Year Final Research Report

• Project/Area Number: 19K21519
• Project/Area Number (Other): 18H06448 (2018)
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund (2019); Single-year Grants (2018)
• Review Section: 0909:Sports sciences, physical education, health sciences, and related fields
• Research Institution: Chukyo University
• Principal Investigator: Yoshiko Akito 中京大学, 国際教養学部, 助教 (70825124)
• Project Period (FY): 2018-08-24 – 2020-03-31
• Keywords: 高齢者 / 筋細胞外脂肪 / サイトカイン / 電気刺激

Outline of Final Research Achievements

We aimed to investigate 1) the relationships of extramyocellular lipid (EMCL) with blood biochemical parameters, muscle and physical functions and daily physical activities, and 2) the reaction of EMCL against acute neuromuscular electrical stimulation. Thirty-five older men and women participated in this study (age: 71 ± 4 years). EMCL was measured from vastus lateralis using 3T magnetic resonance spectroscopy. Firstly, we found that EMCL was explained by muscle echo intensity and muscle thickness of thigh using stepwise regression analysis. EMCL did not have relationships with blood biochemical parameters, physical functions and daily physical activities. Although blood lipid (e.g., total cholesterol, triglyceride and so on), glucose and adipocytokine changed after 30 min neuromuscular electrical stimulation, EMCL did not change before and after the stimulation. These results suggest that EMCL does not respond to acute metabolic change with muscle contraction.

Free Research Field

スポーツ生理学

Academic Significance and Societal Importance of the Research Achievements

筋内部の脂肪や結合組織の増加によって，いわゆる筋量だけでは判断できない「筋の質的変化」が生じる．高齢者では筋細胞外における脂肪の量が若齢者よりも多いが，筋細胞外脂肪がどのような特徴や性質を持つかは不明であった．本研究では筋細胞外脂肪と関連する要因の詮索や筋を動かした前後での筋細胞外脂肪の変化を明らかにした．特に筋を動かした前後で筋細胞外脂肪に変化が見られなかったことから，筋細胞外脂肪が筋を動かすエネルギー基質として活用されなかったことが示唆された．