Muscle's structural composition is an important factor underlying muscle strength and physical function in older adults. There is an increasing amount of research to support the clear disassociation between the loss of muscle lean tissue mass and strength with aging. This disassociation implies that factors in addition to lean muscle mass are responsible for the decreases in strength and function seen with aging. Intermuscular adipose tissue (IMAT) is a significant predictor of both muscle function and mobility function in older adults and across a wide variety of comorbid conditions such as stroke, spinal cord injury, diabetes, and COPD. IMAT is also implicated in metabolic dysfunction such as insulin resistance. The purpose of this narrative review is to provide a review of the implications of increased IMAT levels in metabolic, muscle, and mobility function. Potential treatment options to mitigate increasing levels of IMAT will also be discussed.

中文翻译：

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肌间脂肪：后果和原因回顾

肌肉的结构组成是影响老年人肌肉力量和身体机能的重要因素。越来越多的研究支持肌肉瘦肉组织质量的损失和力量与衰老之间的明显分离。这种分离意味着除了瘦肌肉质量之外的其他因素也是导致随着年龄增长而出现的力量和功能下降的原因。肌间脂肪组织 (IMAT) 是老年人和各种合并症（如中风、脊髓损伤、糖尿病和 COPD）的肌肉功能和运动功能的重要预测指标。IMAT 还涉及代谢功能障碍，例如胰岛素抵抗。这篇叙述性综述的目的是回顾 IMAT 水平在代谢、肌肉、和移动功能。还将讨论减轻 IMAT 水平升高的潜在治疗方案。