Department of Clinical Medicine and Surgery, School of Medicine, Federico II University, Naples, Italy.
Department of Clinical Medicine and Surgery, School of Medicine, Federico II University, Naples, Italy.
Clin Nutr. 2021 May;40(5):3052-3061. doi: 10.1016/j.clnu.2020.10.048. Epub 2020 Nov 1.
BACKGROUND & AIMS: Bioelectrical impedance analysis-derived phase angle (PhA) has been gaining attention in the clinical evaluation of nutritional status because it is thought to be a proxy of water distribution and body cell mass; it is also associated to muscle strength and is an effective predictor of different clinical outcomes. Since an association may be expected between PhA and sarcopenia (defined by low skeletal muscle mass and impaired muscle function), the aim of this systematic review was to evaluate: a) changes in PhA due to sarcopenia; b) prevalence of sarcopenia according to PhA values; c) derivation of phase angle cut-offs for detecting sarcopenia; d) sarcopenia and PhA as predictors of clinical outcomes.
A systematic research on electronic databases (PubMed, Embase, Scopus and Web of Science) from inception to January 31st, 2020 was performed according to PRISMA checklist. Using PICOS strategy, "P" corresponded to participants of any age, gender or ethnicity, "I" designated diagnosis of sarcopenia, "C" indicated subjects without sarcopenia, "O" corresponded to PhA, and "S" selected all study types. Methodological quality was assessed using the National Institute of Health (NIH) quality assessment tool.
Through the initial literature search and after removing duplicates and excluding papers by screening titles and abstracts, 79 potentially relevant studies were examined. Thirteen studies (7668 subjects) met the inclusion criteria. The overall risk of bias was low. Sarcopenia was associated with a significant lower PhA in seven studies out of eight, while five studies out of six reported a high prevalence of sarcopenia was in patients with low PhA. Different cut-off point values from 4.05 to 5.05° have been derived for the identification of sarcopenia. PhA and sarcopenia were independent predictors of survival in cancer patients and geriatric hospitalized patients.
Data from the selected papers demonstrate that PhA is decreased in sarcopenic subjects and the prevalence of sarcopenia is higher in subjects with low PhA. Further studies are needed to determine to what extent PhA may be valuable in detecting low muscle quality and/or identifying sarcopenia.
生物电阻抗分析衍生的相位角（PhA）在营养状况的临床评估中越来越受到关注，因为它被认为是水分布和细胞质量的替代指标；它还与肌肉力量相关，是不同临床结果的有效预测指标。由于 PhA 可能与肌肉减少症（定义为骨骼肌量低和肌肉功能受损）相关，本系统评价的目的是评估：a）肌肉减少症引起的 PhA 变化；b）根据 PhA 值确定肌肉减少症的患病率；c）衍生 PhA 检测肌肉减少症的截断值；d）肌肉减少症和 PhA 作为临床结果的预测指标。
根据 PRISMA 清单，从成立到 2020 年 1 月 31 日，对电子数据库（PubMed、Embase、Scopus 和 Web of Science）进行了系统研究。使用 PICOS 策略，“P”对应于任何年龄、性别或种族的参与者，“I”指定肌肉减少症的诊断，“C”表示没有肌肉减少症的受试者，“O”对应于 PhA，“S”选择所有研究类型。使用美国国立卫生研究院（NIH）质量评估工具评估方法学质量。
通过初步文献检索，在去除重复项并通过筛选标题和摘要排除论文后，共检查了 79 篇潜在相关的研究。13 项研究（7668 名受试者）符合纳入标准。总体偏倚风险较低。在八项研究中有七项研究表明肌肉减少症与 PhA 显著降低相关，而在六项研究中有五项研究表明 PhA 较低的患者肌肉减少症患病率较高。已得出 4.05 至 5.05°的不同截断值用于识别肌肉减少症。PhA 和肌肉减少症是癌症患者和老年住院患者生存的独立预测指标。
从入选论文中得出的数据表明，PhA 在肌肉减少症患者中降低，PhA 较低的患者中肌肉减少症的患病率更高。需要进一步的研究来确定 PhA 在检测低肌肉质量和/或识别肌肉减少症方面的价值。
