Muscle Morphology, Mechanics, and Performance Laboratory, Department of Physical Medicine and Rehabilitation, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA.
Muscle Morphology, Mechanics, and Performance Laboratory, Department of Physical Medicine and Rehabilitation, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA; Department of Physical Therapy and Athletic Training, University of Utah, Salt Lake City, UT 84108, USA.
J Sport Health Sci. 2024 Nov;13(6):820-840. doi: 10.1016/j.jshs.2024.05.005. Epub 2024 May 15.
Assessment and quantification of skeletal muscle within the aging population is vital for diagnosis, treatment, and injury/disease prevention. The clinical availability of assessing muscle quality through diagnostic ultrasound presents an opportunity to be utilized as a screening tool for function-limiting diseases. However, relationships between muscle echogenicity and clinical functional assessments require authoritative analysis. Thus, we aimed to (a) synthesize the literature to assess the relationships between skeletal muscle echogenicity and physical function in older adults (≥60 years), (b) perform pooled analyses of relationships between skeletal muscle echogenicity and physical function, and (c) perform sub-analyses to determine between-muscle relationships.
CINAHL, Embase, MEDLINE, PubMed, and Web of Science databases were systematically searched to identify articles relating skeletal muscle echogenicity to physical function in older adults. Risk-of-bias assessments were conducted along with funnel plot examination. Meta-analyses with and without sub-analyses for individual muscles were performed utilizing Fisher's Z transformation for the most common measures of physical function. Fisher's Z was back-transformed to Pearson's r for interpretation.
Fifty-one articles (n = 5095, female = ∼2759, male = ∼2301, 72.5 ± 5.8 years, mean ± SD (1 study did not provide sex descriptors)) were extracted for review, with previously unpublished data obtained from the authors of 13 studies. The rectus femoris (n = 34) and isometric knee extension strength (n = 22) were the most accessed muscle and physical qualities, respectively. The relationship between quadriceps echogenicity and knee extensor strength was moderate (n = 2924, r = -0.36 (95% confidence interval: -0.38 to -0.32), p < 0.001), with all other meta-analyses (grip strength, walking speed, sit-to-stand, timed up-and-go) resulting in slightly weaker correlations (r: -0.34 to -0.23, all p < 0.001). Sub-analyses determined minimal differences in predictive ability between muscle groups, although combining muscles (e.g., rectus femoris + vastus lateralis) often resulted in stronger correlations with maximal strength.
While correlations are modest, the affordable, portable, and noninvasive ultrasonic assessment of muscle quality is a consistent predictor of physical function in older adults. Minimal between-muscle differences suggest that echogenicity estimates of muscle quality are systemic. Therefore, practitioners may be able to scan a single muscle to estimate full-body skeletal muscle quality/composition, while researchers should consider combining multiple muscles to strengthen the model.
评估和量化老龄化人群的骨骼肌对于诊断、治疗和预防损伤/疾病至关重要。通过诊断超声评估肌肉质量的临床可用性为其提供了一个机会，使其可以作为功能受限疾病的筛查工具。然而，肌肉回声与临床功能评估之间的关系需要权威分析。因此，我们的目的是：(a) 综合文献评估老年人（≥60 岁）骨骼肌回声与身体功能之间的关系；(b) 对骨骼肌回声与身体功能之间的关系进行汇总分析；(c) 进行亚分析以确定肌肉之间的关系。
系统检索 CINAHL、Embase、MEDLINE、PubMed 和 Web of Science 数据库，以确定与老年人骨骼肌回声与身体功能相关的文章。同时进行风险偏倚评估和漏斗图检查。对于最常见的身体功能测量指标，利用 Fisher's Z 转换对具有和不具有肌肉亚分析的元分析进行了分析。为了便于解释，Fisher's Z 通过反变换转换为 Pearson's r。
共提取了 51 篇文章（n=5095，女性=2759，男性=2301，72.5±5.8 岁，平均值±标准差（1 项研究未提供性别描述））进行综述，从 13 项研究的作者处获得了以前未发表的数据。股直肌（n=34）和等长膝关节伸展力量（n=22）是使用最广泛的肌肉和身体质量。股四头肌回声与膝关节伸肌力量之间的关系为中度（n=2924，r=-0.36（95%置信区间：-0.38 至 -0.32），p<0.001），所有其他元分析（握力、步行速度、坐站、计时起立行走）的相关性稍弱（r：-0.34 至 -0.23，均 p<0.001）。亚分析确定了肌肉群之间预测能力的差异很小，尽管组合肌肉（例如股直肌+股外侧肌）通常与最大力量的相关性更强。
虽然相关性适中，但经济实惠、便携和非侵入性的超声肌肉质量评估是老年人身体功能的一致预测指标。肌肉之间的差异很小，这表明肌肉质量的回声估计是全身性的。因此，临床医生可能能够扫描单个肌肉来估计全身骨骼肌质量/组成，而研究人员则应考虑组合多个肌肉以增强模型。
