Evaluating phase angle in malnutrition risk assessment using nutritional screening tools

<h2>Summary</h2><h3>Background & aims</h3> Malnutrition is a common complication in patients with breast cancer and is associated with adverse clinical outcomes. Phase angle (PhA), a parameter derived from bioelectrical impedance analysis (BIA) may reflect nutritional status, but its value versus standard tools remains unclear. This study aims to evaluate the utility of PhA in detecting malnutrition risk in breast cancer patients, compared with four validated screening tools. <h3>Methods</h3> This cross-sectional observational study included 98 female patients with breast cancer. Nutritional status was assessed using the Nutritional Risk Screening 2002 (NRS-2002), Patient-Generated Subjective Global Assessment Short Form (PG-SGA SF), Malnutrition Universal Screening Tool (MUST), and Malnutrition Screening Tool (MST). PhA was measured using single-frequency (50 kHz) BIA. Receiver Operating Characteristic (ROC) analysis was used to determine the optimal PhA cut-off for malnutrition risk. Associations between PhA and malnutrition risk were examined univariate and multivariate logistic regression analyses. <h3>Results</h3> PhA was significantly associated with nutritional risk across all four screening tools. The optimal PhA cut-off for malnutrition risk based on NRS-2002 was 5.04 degrees (AUC = 0.83), with 73% sensitivity and 87% specificity. In crude logistic regression, a PhA <5.04 degrees significantly increased malnutrition risk across all screening tools: NRS-2002 (OR = 0.178, p < 0.001), MUST (OR = 0.338, p=0.005), MST (OR = 0.308, p < 0.001), and PG-SGA SF (OR = 0.481, p=0.037). These associations remained statistically significant after adjustment for age and fat mass index in three models (excluding PG-SGA SF). <h3>Conclusion</h3> PhA, appears to be a practical and supportive indicator for identifying malnutrition risk in breast cancer patients, particularly when used alongside validated screening tools. The identified cut-off value (5.04 degrees) may serve as a useful threshold in clinical practice.