Factors influencing exercise tolerance in maintenance hemodialysis patients

Objective  To observe the level of exercise tolerance among maintenance hemodialysis (MHD) patients using the cardiopulmonary exercise test (CPET) and analysis the factors influencing it.

Methods  From December 2019 to April 2021, 121 maintenance hemodialysis (MHD) patients were recruited for cardiopulmonary exercise testing. General profiles, medical history, laboratory indicators and parameters of CPET were recorded to establish a data set. Take peak respiratory uptake as the dependent variable and other indicators of CPET as independent variables for multiple liner regressions analysis.

Results  A total of 121 patients were recruited. There were 85 males and 36 females with an age range of (28-78) years. Peak respiratory uptake was (12.17±2.56)mL·kg⁻¹·min⁻¹ . Multiple linear regression model as constructed by “stepwise method” indicated that the fitted multiple liner regression equation was statistically significant (F=44.345, P<0.001). Furthermore, average peak power (β=0.063, P<0.001), breathing reserve (β=−0.105, P<0.001), peak heart rate (β=0.024, P=0.003) and slope of VE-VCO₂ curve (β=−0.153, P<0.001) were all significant independent predictors of peak respiratory uptake.

Conclusions  Skeletal muscle power, pulmonary ventilation, ventilation efficiency and cardiac function are independent predictors for exercise tolerance in MHD patients.