Impedance-derived phase angle is associated with muscle mass, strength, quality of life, and clinical outcomes in maintenance hemodialysis patients

Introduction: We aimed to evaluate the association between the phase angle and muscle mass, muscle strength, physical performance tests, quality-of-life scales, mood scales, or patient and hospitalization-free survival rates in hemodialysis (HD) patients. Methods: We included 83 HD patients. The patients were divided into tertiles based on phase angle value. The phase angle was measured using a bioimpedance analysis machine. Thigh muscle area per height squared (TMA/Ht2), handgrip strength (HGS), nutritional indicators, physical performance, quality-of-life, depression or anxiety status, and the presence of hospitalization or death regardless of cause were evaluated. Results: In our study, no significant differences were observed in the serum albumin level and body mass index according to tertiles of phase angle. The phase angle tertiles were associated with TMA/Ht2 and HGS. The phase angle was also associated with physical performance measurements and depression or anxiety status. Subgroup analyses according to sex, age, and diabetes mellitus showed similar trends to those of the total cohort. Furthermore, the hospitalization-free survival rate and patient survival rate were favorable in patients with high values for the phase angle. Conclusion: The present study demonstrated that the phase angle is associated with muscle mass, strength, physical performance, quality-of-life scale, and hospitalization-free survival in maintenance HD patients.