Program in Physical Therapy, Washington University School of Medicine, St. Louis, MO, USA.
Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, USA.
Gait Posture. 2024 Jul;112:159-166. doi: 10.1016/j.gaitpost.2024.05.016. Epub 2024 May 14.
Decreased muscle volume and increased muscle-associated adipose tissue (MAAT, sum of intra and inter-muscular adipose tissue) of the foot intrinsic muscle compartment are associated with deformity, decreased function, and increased risk of ulceration and amputation in those with diabetic peripheral neuropathy (DPN).
What is the muscle quality (normal, abnormal muscle, and adipose volumes) of the DPN foot intrinsic compartment, how does it change over time, and is muscle quality related to gait and foot function?
Computed tomography was performed on the intrinsic foot muscle compartment of 45 subjects with DPN (mean age: 67.2 ± 6.4 years) at baseline and 3.6 years. Images were processed to obtain volumes of MAAT, highly abnormal, mildly abnormal, and normal muscle. For each category, annual rates of change were calculated. Paired t-tests compared baseline and follow-up. Foot function during gait was assessed using 3D motion analysis and the Foot and Ankle Ability Measure. Correlations between muscle compartment and foot function during gait were analyzed using Pearson's correlations.
Total muscle volume decreased, driven by a loss of normal muscle and mildly abnormal muscle (p<0.05). MAAT and the adipose-muscle ratio increased. At baseline, 51.5% of the compartment was abnormal muscle or MAAT, increasing to 55.0% at follow-up. Decreased total muscle volume correlated with greater midfoot collapse during gait (r = -0.40, p = 0.02). Greater volumes of highly abnormal muscle correlated with a lower FAAM score (r = -0.33, p = 0.03).
Muscle volume loss may progress in parallel with MAAT accumulation, impacting contractile performance in individuals with DPN. Only 48.5% of the DPN intrinsic foot muscle compartment consists of normal muscle and greater abnormal muscle is associated with worse foot function. These changes identify an important target for rehabilitative intervention to slow or prevent muscle deterioration and poor foot outcomes.
足部内在肌间隙的肌肉体积减少和与肌肉相关的脂肪组织（MAAT，即肌内和肌间脂肪之和）增加与糖尿病周围神经病变（DPN）患者的畸形、功能下降以及溃疡和截肢风险增加有关。
DPN 足部内在肌间隙的肌肉质量（正常、异常肌肉和脂肪体积）如何，它随时间如何变化，以及肌肉质量与步态和足部功能是否相关？
对 45 名 DPN 患者（平均年龄：67.2±6.4 岁）的足部内在肌间隙进行了计算机断层扫描，分别在基线和 3.6 年后进行。对图像进行处理以获得 MAAT、高度异常、轻度异常和正常肌肉的体积。对于每个类别，计算了年度变化率。采用配对 t 检验比较了基线和随访时的结果。使用三维运动分析和足踝能力测量评估步态时的足部功能。采用 Pearson 相关分析评估肌肉间隙与步态时足部功能之间的相关性。
总肌肉体积减少，主要是由于正常肌肉和轻度异常肌肉的减少（p<0.05）。MAAT 和脂肪-肌肉比增加。基线时，51.5%的肌间隙为异常肌肉或 MAAT，随访时增加到 55.0%。总肌肉体积减少与步态时中足塌陷增加相关（r = -0.40，p = 0.02）。高度异常肌肉体积增加与 FAAM 评分降低相关（r = -0.33，p = 0.03）。
肌肉体积的减少可能与 MAAT 的积累平行进展，影响 DPN 患者的收缩性能。只有 48.5%的 DPN 足部内在肌间隙由正常肌肉组成，异常肌肉越多，足部功能越差。这些变化确定了一个重要的治疗靶点，以减缓或预防肌肉恶化和不良的足部结果。
