Exercise Capacity and Association with Quality of Life in Peritoneal Dialysis Patients

BACKGROUND: Muscle wasting, common and progressive in uremic patients, is associated with a high probability for morbidity, lower health-related quality of life (HRQOL), and mortality. However, exercise tolerance in peritoneal dialysis (PD) patients has not been fully elucidated. The aim of this study was to evaluate exercise capacity, its determinants, and its association with HRQOL in PD patients. METHODS: Outpatients treated with PD at Keio University Hospital from December 2016 to March 2018 were included in this single-center cross-sectional observational study. Exercise capacity was assessed by incremental shuttle walking test (ISWT) and handgrip and quadriceps strength. In addition to evaluation of PD-related parameters, HRQOL was assessed by the Kidney Disease Quality of Life-Short Form questionnaire. RESULTS: Among the 50 recruited PD outpatients, age and PD vintage were 63.8 ± 9.6 and 3.8 ± 2.8 years, respectively. Physical examination revealed ISWT of 312.0 ± 138.2 m, handgrip strength of 27.5 ± 6.9 kg, and quadriceps strength of 23.3 ± 10.0 kg. Multivariate analysis showed that younger age and male sex were significantly associated with higher ISWT and handgrip and quadriceps strength. Skeletal mass index (SMI) remained a significant predictor of handgrip and quadriceps strength. Moreover, only ISWT was strongly correlated with higher HRQOL scores, including physical, mental, and kidney-specific domains, even after adjustment for age and sex. CONCLUSIONS: Exercise tolerance in PD patients was partially determined by age, sex, and SMI. Moreover, this is the first study to demonstrate the strong relationship between aerobic capacity and HRQOL in PD patients.