Standardized phase angle indicates nutritional status in hospitalized preoperative patients.

There is currently no criterion standard to assess nutritional status, and different methods have been used in hospitalized patients. The aim of this study was to investigate the agreement and the association between bioelectrical impedance analysis derived by standardized phase angle (SPA) and other methods used for the nutritional assessment of body composition, metabolic status, and functional status in surgical patients. The hypothesis was that the SPA is effective for evaluating nutritional status in surgical patients; therefore, it could be used when the application of other assessment methods is not possible. The sample consisted of 125 patients (20-94 years of age) before elective gastrointestinal or hernia repair. The participants were from the Surgical Clinic 1 at the University Hospital of the Federal University of Santa Catarina, Florianópolis, SC, Brazil. Nutritional status was evaluated during the preoperative period based on the triceps skinfold thickness, mid-arm circumference, body mass index, percent weight loss, nutritional risk screening 2002 (NRS 2002), subjective global assessment (SGA), and SPA. The agreement between the SPA and the other methods was assessed with the k coefficient. The agreement between the SPA and the methods of nutritional assessment that were investigated for diagnosing malnutrition was moderate for NRS 2002 and SGA, weak for percent weight loss, and poor for triceps skinfold thickness, mid-arm circumference, and body mass index. There was a significant association between SPA and both NRS 2002 and SGA (P < .001). Our results suggest that SPA is able to indicate the risk of nutritional deficiency in the patients assessed. However, good agreement between SPA and the methods investigated was not observed.