From the Department of Movement Sciences and Wellbeing, "Parthenope" University, Naples, Italy.
the Department of Public Health, Federico II University, Naples, Italy.
J Pediatr Gastroenterol Nutr. 2022 Aug 1;75(2):120-130. doi: 10.1097/MPG.0000000000003488. Epub 2022 Jun 1.
Phase angle (PhA), a directly-measured bioelectrical impedance analysis variable, is suggested to be a proxy of body cell mass as well as extracellular/intracellular water ratio, and is related to cellular integrity and functions. The aim of this systematic review was to evaluate PhA in healthy youths in relation to sex, age, weight status, physical fitness, and sports activities. A systematic literature search (preferred reporting items for systematic reviews and meta-analyses criteria) until January 2022 was performed using PubMed, Embase, Scopus, and Web of Science regarding studies on PhA in healthy children and adolescents 4-18 years of age. Quality was assessed according to the National Institute of Health. After removing duplicates and studies not fulfilling the inclusion criteria, 22 cross-sectional and 1 longitudinal were considered appropriate. As for quality, 14 articles were rated fair and 9 good. Ten studies found that PhA increases with age: the increase was more marked after puberty, whereas changes in younger subjects are by far less defined. A clear sex difference was found in adolescents, likely due to pubertal development. Limited evidence suggests that PhA increases in participants with very high BMI. Limited data were reported on physically active youths without convincing findings. Positive associations of PhA with physical fitness and fat-free mass were found in few studies. In conclusion, partial and limited evidence suggests that changes in PhA over the first 2 decades of life reflect modification in body composition and fat-free mass composition. Further studies are needed for confirming PhA as a relevant marker of nutritional status in youths.
相位角（PhA）是一种直接测量的生物电阻抗分析变量，它被认为是身体细胞质量以及细胞外/细胞内水分比例的替代指标，与细胞完整性和功能有关。本系统评价的目的是评估健康年轻人的 PhA 与性别、年龄、体重状况、身体状况和体育活动的关系。使用 PubMed、Embase、Scopus 和 Web of Science 进行了系统的文献搜索（系统评价和荟萃分析的首选报告项目标准），直到 2022 年 1 月，检索了关于 4-18 岁健康儿童和青少年 PhA 的研究。根据美国国立卫生研究院的标准评估质量。在去除重复项和不符合纳入标准的研究后，考虑了 22 项横断面研究和 1 项纵向研究。就质量而言，有 14 篇文章被评为中等，9 篇文章被评为良好。有 10 项研究发现 PhA 随年龄增长而增加：青春期后增加更为明显，而年轻受试者的变化远不那么明确。在青少年中发现了明显的性别差异，这可能是由于青春期发育。有有限的证据表明，PhA 在非常高 BMI 的参与者中增加。关于没有令人信服发现的活跃年轻人的有限数据。少数研究报告了 PhA 与身体状况和去脂体重呈正相关。总之，部分和有限的证据表明，生命头 20 年中 PhA 的变化反映了身体成分和去脂体重成分的改变。需要进一步的研究来确认 PhA 作为年轻人营养状况的一个相关指标。
