Intradialytic Exercise: Effects on Arterial Stiffness and Gait Speed in Patients Undergoing Hemodialysis

Abstract

BACKGROUND The benefits of exercise for vascular and physical health in patients on chronic hemodialysis (CHD) are controversial. This study evaluated the outcomes of an intradialytic aerobic exercise program on carotid-femoral pulse wave velocity (cfPWV, an index of arterial stiffness), gait speed, and a sit-to-stand test in patients with CHD. MATERIAL AND METHODS A total of 114 CHD patients were randomly assigned to the exercise or the control (regular care) group. Patients performed intradialytic cycling exercises (3 sessions/week for 12 months) for 20 minutes in a supine position and the exercise protocol was set at a low-to-moderate intensity, defined as activities eliciting 3 to 5.9 metabolic equivalents. Data on cfPWV, gait speed, and the 5-times sit-to-stand test were collected. cfPWV was determined from the time taken for the arterial pulse to propagate from the carotid to the femoral artery and were compared between the 2 groups. RESULTS Arterial stiffness was improved, as evidenced by a significant decrease in cfPWV, in the exercise group compared to the control group (p<0.001). Generalized estimating equations analysis revealed a reduction in cfPWV at 6 and 12 months after the exercise intervention (p<0.001). Gait speed was significantly faster in the exercise group than in the control group (p=0.019). No exercise-related adverse events were reported. Results of 5-times sit-to-stand and body composition did not differ significantly between the 2 study groups. CONCLUSIONS Intradialytic cycling exercise significantly improved cfPWV and gait speed in CHD patients during the 12-month study period.

Figure 1

Participant flow chart.

Figure 2

Changes in carotid–femoral pulse wave velocity (cfPWV) in the exercise and control groups from baseline to 6-month and 12-month follow-up. cfPWV was determined from the time taken for the arterial pulse to propagate from the carotid to the femoral artery. cfPWV was calculated using the elapsed time and the distance of the point of maximum upslope between the 2 recording points. Independent-sample t test revealed that cfPWV in the exercise group was improved at these 2 follow-up timepoints.

Figure 3

Changes in gait speed in exercise and control groups from baseline to 6-month and 12-month follow-up. Gait speed was measured with the participant walking a 6-meter distance. Independent-sample t test revealed that carotid–femoral pulse wave velocity (cfPWV) in the exercise group was improved at these 2 follow-up timepoints.