Association of Phase Angle with Body Composition in Hemodialysis Patients: A Case-Control Study

Patients on hemodialysis (HD) often experience changes in body composition due to metabolic disorders. Phase angle (PhA) is a marker of tissue integrity and may reflect overall functional condition. This study evaluated body composition and its relationship with PhA in 53 HD patients (27 women, 26 men) over 40 years old, compared with 106 age- and sex-matched healthy controls. Body composition was assessed using bioelectrical impedance analysis (BIA), measuring skeletal muscle mass (SMM), fat tissue, total bone mass (BM), and PhA. HD patients had significantly lower fat mass and PhA than controls (p < 0.001). The prevalence of low SMM and BM was higher in patients, though not statistically significant. Sex differences were generally not significant, except for a higher prevalence of low BM in female controls (p < 0.001). After adjusting for age and sex, PhA was positively associated with SMM% (p = 0.021) and BM (p = 0.035) in HD patients only. These results indicate that PhA-body composition relationships differ between HD patients and healthy individuals, highlighting PhA as a potential marker of body composition disturbances in HD.