Phase Angle as a Sarcopenia Marker in Hospitalized Elderly Patients.

BACKGROUND: Phase angle (PhA) has been proposed as a parameter to predict clinical outcomes and mortality for various diseases. Several studies have considered it an important nutrition assessment tool. However, the usefulness of this parameter as a sarcopenia marker has not yet been evaluated. This study was developed to evaluate the performance of PhA as a sarcopenia marker in hospitalized elderly patients.

MATERIALS AND METHODS: This was a cross-sectional study involving elderly patients admitted to a hospital in northeastern Brazil. The PhA was obtained from resistance and reactance measurements by bioelectrical impedance. Sarcopenia was defined as a decrease in muscle mass associated with a reduced muscle strength or physical performance.

RESULTS: The sample consisted of 148 patients with a mean age of 71.6 (±7.6) years and a 62.8% prevalence of sarcopenia. The average PhA was 5.9 ± 2.0°, similar for men and women (5.9 ± 2.3 vs 5.9 ± 1.8; P = .946). In men, sarcopenic patients had a lower average PhA (5.6 ± 2.3°) when compared with patients without this condition (6.8 ± 1.9°; P = .024). When comparing the value of PhA regarding the degree of sarcopenia, it was found that patients from both sexes with severe sarcopenia had lower averages. The PhA had a low predictive capacity in relation to the diagnostic components of sarcopenia (physical performance, muscle mass, and strength).

CONCLUSION: PhA was an inaccurate marker to identify sarcopenia and presented low predictive capacity to explain muscle mass, muscle strength, and functional capacity, components involved in the diagnosis of sarcopenia.