Phase angle as a new indicator of muscle quality and Its application for sarcopenia evaluation

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K11691
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 59040:Nutrition science and health science-related
• Research Institution: Department of Clinical Research, National Hospital Organization Kyoto Medical Center
• Principal Investigator: Kusakabe Toru 独立行政法人国立病院機構(京都医療センター臨床研究センター), 内分泌代謝高血圧研究部, 研究室長 (60452356)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: サルコペニア / 筋質 / Phase Angle / 肥満症 / サルコペニア肥満

Outline of Final Research Achievements

At present, early detection and therapeutic intervention for sarcopenia are warranted in Japan. For the diagnosis of sarcopenia, it is important to assess not only skeletal muscle mass but also muscle quality. In this study, Phase Angle (PhA), obtained by bioelectrical impedance method, was shown to be useful as an evaluation index of muscle quality. Furthermore, PhA alone was able to diagnose sarcopenia. The study also showed that sarcopenic obesity diagnosed by a combined index of waist circumference and muscle quality was at higher risk of cerebro-cardiovascular disease (CVD). A Body Shape Index (ABSI), an obesity assessment index, was positively correlated with waist circumference and negatively correlated with muscle quality and predicted an accumulation of CVD risks, suggesting that the ABSI alone is useful for the diagnosis of sarcopenic obesity.

Free Research Field

代謝、内分泌学

Academic Significance and Societal Importance of the Research Achievements

世界有数の長寿国となった日本において、サルコペニアは、要支援・要介護の原因疾患の一つとして注目されており、健康寿命延伸のために、サルコペニアの早期発見と治療介入が必要と考えられている。本研究により、生体電気インピーダンス法により得られるPhase Angle（PhA）は推定式や変換アルゴリズムを必要とせず、簡便かつ正確に筋質を評価できることが示された。筋質は、筋肉内への脂肪浸潤や筋肉の線維化に影響される。これらは加齢や肥満症、2型糖尿病、骨粗鬆症などの生活習慣病に伴って増加してくることから、PhAはこれら生活習慣病における病態の把握にも有用であると考えられ、本研究の成果の学術的意義は大きい。