Leeds Vascular Institute, Leeds General Infirmary, Leeds Teaching Hospitals NHS Trust, Great George Street, Leeds, LS1 3EX, United Kingdom.
Leeds Institute of Cardiovascular and Metabolic Medicine, The University of Leeds, Clarendon Way, Leeds, LS2 9JT, United Kingdom.
Br J Radiol. 2020 Jul;93(1111):20200136. doi: 10.1259/bjr.20200136. Epub 2020 May 27.
The measurement of muscle area is routinely utilised in determining sarcopaenia in clinical research. However, this simple measure fails to factor in age-related morphometric changes in muscle quality such as myosteatosis. The aims of this study were to: firstly investigate the relationship between the masseter area (quantity) and density (quality), and secondly compare the prognostic clinical relevance of each parameter.
Cross-sectional CT head scans were reviewed for patients undergoing carotid endarterectomy. The masseter was manually delineated and the total masseter area (TMA) and the total masseter density (TMD) calculated. Measurements of the TMA were standardised against the cranial circumference. Observer variability in measurements were assessed using Bland-Altman plots. The relationship between TMA and TMD were evaluated using Pearson's correlation and linear regression analyses. The prognostic value of TMA and TMD were assessed using receiver operator curves and cox-regression analyses.
In total, 149 patients who had undergone routine CT scans prior to a carotid endarterectomy were included in this study. No significant observer variations were observed in measuring the TMA, TMD and cranium circumference. There was a significant positive correlation between standardised TMA and TMD (Pearson's correlation 0.426, < 0.001, adjusted R-squared 17.6%). The area under the curve for standardised TMA in predicting all-cause mortality at 30 days, 1 year and 4 years were higher when compared to TMD. Standardised TMA was only predictive of post-operative overall all-cause mortality (adjusted hazard ratio 0.38, 95% confidence interval 0.15-0.97, = 0.043).
We demonstrate a strong relationship between muscle size and density. However, the utilisation of muscle area is likely to be limited in routine clinical care.
Our study supports the utilisation of muscle area in clinical sarcopaenia research. We did not observe any additional prognostic advantage in quantifying muscle density.
肌肉面积的测量在临床研究中常用于确定肌肉减少症。然而，这种简单的测量方法未能考虑到与年龄相关的肌肉质量形态变化，如肌内脂肪增多症。本研究的目的是：首先研究咬肌面积（数量）和密度（质量）之间的关系，其次比较每个参数的预后临床相关性。
对行颈动脉内膜切除术的患者进行横断面 CT 头部扫描。手动描绘咬肌，并计算总咬肌面积（TMA）和总咬肌密度（TMD）。TMA 的测量值与头围标准化。使用 Bland-Altman 图评估测量的观察者变异性。使用 Pearson 相关和线性回归分析评估 TMA 与 TMD 之间的关系。使用接收器操作曲线和 Cox 回归分析评估 TMA 和 TMD 的预后价值。
共纳入 149 例行颈动脉内膜切除术的患者。在测量 TMA、TMD 和头围时，未观察到明显的观察者变异性。标准化 TMA 与 TMD 之间存在显著正相关（Pearson 相关 0.426，<0.001，调整后的 R 平方值为 17.6%）。与 TMD 相比，标准化 TMA 在预测 30 天、1 年和 4 年全因死亡率方面的曲线下面积更高。标准化 TMA 仅预测术后全因死亡率（调整后的危险比 0.38，95%置信区间 0.15-0.97， = 0.043）。
我们证明了肌肉大小和密度之间存在很强的关系。然而，在常规临床护理中，肌肉面积的使用可能受到限制。
我们的研究支持在临床肌肉减少症研究中使用肌肉面积。我们没有观察到量化肌肉密度的任何额外预后优势。
