Correlation Between Phase Angle and Nutritional Status in Hospitalized Patients at Nutritional Risk

Abstract

Background & Aims: This study evaluated the correlations between phase angle (PA) and muscle mass (MM), which can contribute to an accurate nutritional diagnosis. Methods: Retrospective cross-sectional study, conducted from July 2020 to July 2021, included patients classified as at-risk based on their initial nutritional assessments. Bioelectrical impedance analysis was used to evaluate body composition and determine the phase angle (PA). Data on nutritional status and hospital stay were also obtained. Results: Among the 1.012 evaluated patients, 55% (557) were male, the median age was 71.8 years, and the median body mass index (BMI) was 22.7 kg/m 2 . A total of 60.1% (606) of the patients had low MM. The PA cut-off for reduced MM was 4.30º for the total population and for men, and 3.76º for women. Patients with reduced PA were older (61.8 [23] vs. 76.4 [19] years; p<0.001), had a longer hospital stay (14 [20] vs. 11[15]; p<0.001) and lower BMI (24.1 [6.0] vs 22.3 [4.8] kg/m 2 ; p<0.001). Patients with a hospital stay >11 days were twice as likely to have a reduced PA (odds ratio [OR] = 2.00, 95% confidence interval [CI] 1.37–2.93). In addition, patients from critical units were almost twice as likely to have a reduced PA (OR = 1.87, 95% CI 1.22–2.87). Conclusion: Patients with reduced MM presented a lower PA cut-off than that for patients with normal MM; thus, the PA represents a good marker to detect MM reduction. A reduced PA also increased the likelihood of malnutrition and prolonged hospital stay.