The correlation of muscle thickness and pennation angle assessed by ultrasound with sarcopenia in elderly Chinese community dwellers

Background: Sarcopenia is typically defined as the loss of muscle mass, strength and low physical performance with aging. Ultrasound is a safe and easy method for evaluating muscle mass and quality by muscle thickness (MT) and pennation angle (PA), respectively. Although the positive correlations between MT and muscle mass and handgrip strength were observed, the relationship between MT, PA and physical performance remains unclear.Purpose: This study aimed to investigate the correlation of aforementioned ultrasound parameters with muscle mass, muscle strength and physical performance and explore the utility of ultrasound in predicting sarcopenia.Patients and methods: A total of 265 elderly Chinese community dwellers were included. MT of both forearm and lower leg as well as PA of gastrocnemius was assessed by ultrasound. Muscle mass was assessed by dual-energy X-ray absorptiometry. Muscle strength was measured by a Jamar hand dynamometer. Physical performance was assessed by the Short Physical Performance Battery (SPPB).Results: Anterior radial MT in men and regional MTs except posterior fibula in women were negatively correlated with the age. No significant correlation was observed between PA and the age in both genders. Posterior tibial MT and posterior fibula MT were positively correlated with the relative appendicular skeletal muscle mass in men and women, respectively. Anterior ulnar MT was positively correlated with grip strength in both genders. Moreover, gastrocnemius medialis PA showed a positive association with gait speed and SPPB in women but not in men.Conclusion: A combination of posterior fibula MT, anterior ulnar MT and gastrocnemius medialis PA measured by muscle ultrasound is helpful for the assessment of sarcopenia in Chinese elderly women. In addition, a combination of posterior tibial MT and anterior ulnar MT measured by muscle ultrasound is helpful for the assessment of sarcopenia in Chinese elderly men.

背景：肌肉减少症通常被定义为随着年龄增长肌肉质量、力量下降以及身体机能降低。超声是一种通过肌肉厚度（MT）和羽状角（PA）分别评估肌肉质量和质量的安全且简便的方法。尽管观察到MT与肌肉质量和握力之间存在正相关，但MT、PA与身体机能之间的关系仍不清楚。 目的：本研究旨在探讨上述超声参数与肌肉质量、肌肉力量和身体机能的相关性，并探索超声在预测肌肉减少症中的应用。 患者和方法：共纳入265名中国老年社区居民。通过超声评估前臂和小腿的MT以及腓肠肌的PA。通过双能X线吸收法评估肌肉质量。通过贾马尔握力计测量肌肉力量。通过简易体能状况量表（SPPB）评估身体机能。 结果：男性的桡骨前侧MT以及女性除腓骨后侧外的区域MT与年龄呈负相关。在两性中，PA与年龄之间均未观察到显著相关性。男性的胫骨后侧MT和女性的腓骨后侧MT分别与相对四肢骨骼肌质量呈正相关。两性的尺骨前侧MT与握力呈正相关。此外，女性的内侧腓肠肌PA与步速和SPPB呈正相关，而男性则无此相关性。 结论：通过肌肉超声测量腓骨后侧MT、尺骨前侧MT和内侧腓肠肌PA的组合有助于评估中国老年女性的肌肉减少症。此外，通过肌肉超声测量胫骨后侧MT和尺骨前侧MT的组合有助于评估中国老年男性的肌肉减少症。