Kyoto University, Kyoto, Research Fellow of Japan Society for the Promotion of Science, Tokyo, Japan.
Kyoto University, Kyoto, Japan.
Arthritis Care Res (Hoboken). 2024 Dec;76(12):1696-1702. doi: 10.1002/acr.25412. Epub 2024 Sep 4.
We aimed to examine whether lower-limb muscle quantity and quality assessed by bioelectric impedance analysis (BIA) were associated with knee extension strength and whether the association differed with knee osteoarthritis (OA) severity.
We included 1,525 participants (63.6% women; mean ± SD age 68.0 ± 5.3 years) from the Nagahama Prospective Cohort. Knee extension strength was measured during maximum voluntary isometric contraction. Lower-limb muscle mass and the extracellular water (ECW)-to-intracellular water (ICW) ratio were used as indicators of muscle quantity and quality, respectively, and assessed via a BIA device. We executed multiple linear regression analyses to investigate the association of muscle quantity and quality with knee extension strength. Additionally, participants were classified into three groups with respect to OA severity and symptoms: control, early OA, and advanced OA groups; subgroup analyses were also executed.
The muscle mass (P < 0.001) and ECW-to-ICW ratio (P = 0.009) were significantly associated with knee extension strength. In the subgroup analysis, the muscle mass was significantly associated with knee extension strength (P < 0.001), but there was no association between ECW-to-ICW ratio and knee extension strength (P = 0.731) in the control group. In the early OA and advanced OA groups, the muscle mass (both P < 0.001) and ECW-to-ICW ratio (early OA, P = 0.034; advanced OA, P = 0.015) were significantly associated with knee extension strength.
Lower-limb muscle quality was associated with knee extension strength, and the association was stronger in patients with knee OA. These findings suggest that both muscle quantity and quality should be assessed to better understand muscle function in patients with knee OA.
本研究旨在探讨通过生物电阻抗分析（BIA）评估的下肢肌肉量和质量与膝关节伸肌力量的关系，以及这种关系是否因膝骨关节炎（OA）严重程度而异。
我们纳入了来自长滨前瞻性队列的 1525 名参与者（63.6%为女性；平均年龄 68.0 ± 5.3 岁）。在最大自主等长收缩期间测量膝关节伸肌力量。通过 BIA 设备评估下肢肌肉量和细胞外水（ECW）与细胞内水（ICW）比值，分别作为肌肉量和质量的指标。我们进行了多元线性回归分析，以探讨肌肉量和质量与膝关节伸肌力量的关系。此外，根据 OA 严重程度和症状将参与者分为三组：对照组、早期 OA 组和晚期 OA 组；并进行了亚组分析。
肌肉量（P < 0.001）和 ECW-ICW 比值（P = 0.009）与膝关节伸肌力量显著相关。在亚组分析中，肌肉量与膝关节伸肌力量显著相关（P < 0.001），但在对照组中，ECW-ICW 比值与膝关节伸肌力量无相关性（P = 0.731）。在早期 OA 和晚期 OA 组中，肌肉量（均 P < 0.001）和 ECW-ICW 比值（早期 OA，P = 0.034；晚期 OA，P = 0.015）与膝关节伸肌力量显著相关。
下肢肌肉质量与膝关节伸肌力量相关，在膝 OA 患者中这种相关性更强。这些发现表明，为了更好地理解膝 OA 患者的肌肉功能，应同时评估肌肉量和质量。
