Development of detection methods for early knee osteoarthritis through evaluation of muscle quality

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K19376
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 59010:Rehabilitation science-related
• Research Institution: Kyoto University
• Principal Investigator: Taniguchi Masashi 京都大学, 医学研究科, 助教 (00827701)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 早期変形性膝関節症 / 骨格筋変性 / 筋質低下 / 筋内脂肪

Outline of Final Research Achievements

Knee osteoarthritis (KOA) is one of major musculoskeletal disorders in the older individuals, significantly impairing daily function. Given the irreversible nature of joint deformities associated with KOA, early detection and preventative interventions are important. Recent studies have suggested that functional impairment in KOA is closely linked to qualitative decline in skeletal muscle, namely increased intramuscular fat (intraMAT), rather than muscle atrophy. Therefore, this study aimed to clarify the characteristics of muscle degeneration in early KOA and elucidate the association of muscle degeneration with knee dysfunction. The results revealed significant the intraMAT accumulation, particularly in the vastus medialis (VM) muscle, and this accumulation was associated with functional impairment and loss of cartilage quality in early KOA. These findings suggested that higher VM intraMAT is an imaging biomarker for detecting early KOA.

Free Research Field

リハビリテーション科学

Academic Significance and Societal Importance of the Research Achievements

変形性膝関節症（膝OA）は、加齢変性疾患の一つといえ、高齢化とともに有病者数が増加している。膝OAに対する根治療法は確立されていないため、膝OAの早期発見、早期介入の重要性が指摘されている。本研究の成果は、膝OAの早期段階を筋質低下、特に筋内脂肪の増加によって検出できるだけでなく、その変化は機能障害・軟骨の質的低下と関連することを明らかにした。サルコペニアを代表とする骨格筋の変性は、従来、筋量に着目されてきたが、筋質を評価することが疾患の早期段階を捉えることが他でも指摘されつつあり、同様の知見を新たに早期膝OAで見出した点は学術的意義が高いものといえる。