Paixão Elemárcia Martins da Silva, Gonzalez Maria Cristina, Ito Marina Kiyomi
Postgraduate Program in Human Nutrition, University of Brasília, Brasilia 70910-900, Distrito Federal, Brazil.
Postgraduate Program in Health and Behavior, Catholic University of Pelotas, Pelotas, Rio Grande do Sul, Brazil.
Clin Nutr. 2015 Jun;34(3):496-500. doi: 10.1016/j.clnu.2014.05.012. Epub 2014 Jun 8.
BACKGROUND & AIMS: Standardized phase angle (SPA) is a value derived from bioelectrical impedance phase angle analysis and has been recognized as marker of nutritional risk and clinical status of cancer patients. This study aimed to evaluate the changes in SPA during radiation therapy of cancer patients and identify possible nutritional and clinical determinants of these changes.
Nutritional assessment was performed before the initiation and at the end of the radiotherapy. It included anthropometrics and bioelectrical impedance analysis. A generalized linear mixed model was used to evaluate the effects of selected independent variables on the changes in standardized phase angle.
A total of 104 patients entered the study and those with complete information were included in the analysis (n = 62). Most patients (61%) were at clinical stage I and II, the most prevalent irradiation site was the pelvis (39%) and 98% were well nourished or overweight. According to the regression analysis, changes in body weight and irradiation at head and neck/upper abdomen and thorax were associated with standardized phase angle modifications during radiotherapy. Clinical stage and radiation dose were not associated with changes in standardized phase angle. Compared to baseline values, for every 1 kg weight reduction during the radiation therapy, the standardized phase angle also decreased by 0.107 (p < 0.0001).
In well nourished or overweight patients, weight loss during radiation therapy is closely associated with decrease in standard phase angle.
标准化相位角（SPA）是通过生物电阻抗相位角分析得出的值，已被公认为癌症患者营养风险和临床状态的标志物。本研究旨在评估癌症患者放疗期间SPA的变化，并确定这些变化可能的营养和临床决定因素。
在放疗开始前和结束时进行营养评估。评估内容包括人体测量学和生物电阻抗分析。使用广义线性混合模型评估选定自变量对标准化相位角变化的影响。
共有104例患者进入研究，其中具有完整信息的患者纳入分析（n = 62）。大多数患者（61%）处于临床I期和II期，最常见的照射部位是骨盆（39%），98%的患者营养良好或超重。根据回归分析，体重变化以及头颈部/上腹部和胸部的照射与放疗期间标准化相位角的改变有关。临床分期和放射剂量与标准化相位角的变化无关。与基线值相比，放疗期间体重每减轻1 kg，标准化相位角也降低0.107（p < 0.0001）。
在营养良好或超重的患者中，放疗期间体重减轻与标准相位角降低密切相关。
