Abstract

MOTTA, Rachel Souza Thompson; CASTANHO, Ivany Alves  and  VELARDE, Luis Guillermo Coca. Cutoff point of the phase angle in pre-radiotherapy cancer patients. Nutr. Hosp. [online]. 2015, vol.32, n.5, pp.2253-2260. ISSN 1699-5198.  https://dx.doi.org/10.3305/nh.2015.32.5.9626.

Introduction: malnutrition is a common complication for cancer patients. The phase angle (PA), direct measurement of bioelectrical impedance analysis (BIA), has been considered a predictor of body cell mass and prognostic indicator. Cutoff points for phase angle (PA) associated with nutritional risk in cancer patients have not been determined yet. Objectives: assess the possibility of determining the cutoff point for PA to identify nutritional risk in pre-radiotherapy cancer patients. Methods: sample group: Patients from both genders diagnosed with cancer and sent for ambulatory radiotherapy. Variables studied: body mass index (BMI), percentage of weight loss (% WL), mid-arm circumference (MAC), triceps skinfold thickness (TST), mid-arm muscle circumference (MAMC), mid-arm muscle area (MAMA), score and categorical assessment obtained using the Patient-Generated Subjective Global Assessment (PG-SGA) form, PA and standardized phase angle (SPA). Kappa coefficient was used to test the degree of agreement between the diagnoses of nutritional risk obtained from several different methods of nutritional assessment. Cutoff points for the PA through anthropometric indicators and PG-SGA were determined by using Receiver Operating Characteristic (ROC) curves, and patient survival was analyzed with the Cox regression method. Results: the cutoff points with the greatest discriminatory power were those obtained from BMI (5.2) and the categorical assessment of PG-SGA (5.4). The diagnosis obtained using these cutoff points showed a significant association with risk of death for the patients in the sample group. Conclusion: we recommend using the cutoff point 5.2 for the PA as a criterion for identifying nutritional risk in pre-radiotherapy cancer patients.

Keywords : Bioelectrical impedance; Cancer; Nutritional assessment; Anthropometry.

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