Sabatino Alice, Broers Natascha J H, van der Sande Frank M, Hemmelder Marc H, Fiaccadori Enrico, Kooman Jeroen P
Nephrology Unit, Department of Medicine and Surgery, Parma University Hospital, University of Parma, Parma, Italy.
Division on Nephrology, Department of Internal Medicine, Maastricht University Medical Centre, Maastricht, Netherlands.
Front Nutr. 2021 Aug 16;8:697523. doi: 10.3389/fnut.2021.697523. eCollection 2021.
Assessment of muscle mass (MM) or its proxies, lean tissue mass (LTM) or fat-free mass (FFM), is an integral part of the diagnosis of protein-energy wasting (PEW) and sarcopenia in patients on hemodialysis (HD). Both sarcopenia and PEW are related to a loss of functionality and also increased morbidity and mortality in this patient population. However, loss of MM is a part of a wider spectrum, including inflammation and fluid overload. As both sarcopenia and PEW are amendable to treatment, estimation of MM regularly is therefore of major clinical relevance. Whereas, computer-assisted tomography (CT) or dual-energy X-ray absorptiometry (DXA) is considered a reference method, it is unsuitable as a method for routine clinical monitoring. In this review, different bedside methods to estimate MM or its proxies in patients on HD will be discussed, with emphasis on biochemical methods, simplified creatinine index (SCI), bioimpedance spectroscopy (BIS), and muscle ultrasound (US). Body composition parameters of all methods are related to the outcome and appear relevant in clinical practice. The US is the only parameter by which muscle dimensions are measured. BIS and SCI are also dependent on either theoretical assumptions or the use of population-specific regression equations. Potential caveats of the methods are that SCI can be influenced by residual renal function, BIS can be influenced by fluid overload, although the latter may be circumvented by the use of a three-compartment model, and that muscle US reflects regional and not whole body MM. In conclusion, both SCI and BIS as well as muscle US are all valuable methods that can be applied for bedside nutritional assessment in patients on HD and appear suitable for routine follow-up. The choice for either method depends on local preferences. However, estimation of MM or its proxies should always be part of a multidimensional assessment of the patient followed by a personalized treatment strategy.
评估肌肉量（MM）或其替代指标，即瘦组织量（LTM）或去脂体重（FFM），是诊断血液透析（HD）患者蛋白质 - 能量消耗（PEW）和肌肉减少症的重要组成部分。肌肉减少症和PEW均与功能丧失相关，并且在该患者群体中发病率和死亡率也会增加。然而，MM的丧失是更广泛范围的一部分，包括炎症和液体过载。由于肌肉减少症和PEW都可通过治疗改善，因此定期评估MM具有重要的临床意义。虽然计算机断层扫描（CT）或双能X线吸收法（DXA）被认为是参考方法，但它不适用于常规临床监测。在本综述中，将讨论在HD患者中估计MM或其替代指标的不同床边方法，重点是生化方法、简化肌酐指数（SCI）、生物电阻抗光谱法（BIS）和肌肉超声（US）。所有方法的身体成分参数均与结果相关，并且在临床实践中似乎具有相关性。US是唯一用于测量肌肉尺寸的参数。BIS和SCI也依赖于理论假设或使用特定人群的回归方程。这些方法的潜在问题在于，SCI可能受残余肾功能影响，BIS可能受液体过载影响，尽管使用三室模型可能避免后者的影响，并且肌肉超声反映的是局部而非全身的MM。总之，SCI、BIS以及肌肉超声都是可用于HD患者床边营养评估的有价值方法，并且似乎适用于常规随访。选择哪种方法取决于当地偏好。然而，MM或其替代指标的估计应始终作为患者多维评估的一部分，随后制定个性化治疗策略。
