Background: Exercise training improves blood pressure (BP) in the general population, but prior studies in hemodialysis (HD) patients only used pill counts or treatment-related BPs. We evaluated the effect of 3 to 6 months of intradialytic exercise training on ambulatory blood pressure (ABP) and treatment-related pre- and postdialysis BP.
Patients and methods: Nineteen chronic HD patients trained with an exercise bicycle for 30 to 60 min in the first 1 to 2 hr of each of thrice weekly HD. Interdialytic 44-hr ABP was performed a week before training began and repeated at 3 and 6 months. Pre- and post-HD systolic and diastolic BP and pre- and post-HD weight were recorded for 2 months prior to training, throughout the training, and, if available, for the 2 months after training ended. BP medications were recorded throughout. Body composition by bioimpedance, and norepinephrine and epinephrine levels by RIA were done at 0, 3, and 6 months.
Results: Thirteen subjects who completed at least 3 months of training exercised 90% of HD sessions for 56 min +/- 23 SD each. Systolic and diastolic 44-hr interdialytic ABP fell during training (systolic 138.4 mmHg +/- 19.6 vs. 125.7 mmHg +/- 20.0 vs. 125.9 mmHg +/- 22.9; diastolic 83.2 mmHg +/- 10.2 vs. 74.7 mmHg +/- 9.0 vs. 73.9 mmHg +/- 11.8 at 0, 3, and 6 months; p < .05 ANOVA). Norepinephrine and epinephrine levels did not independently predict systolic BP. Pre-HD systolic BP was stable during the pretraining period, fell significantly during the training period (p < .03), and returned toward preexercise levels during the posttraining period (p < .001). Pre- or postweight, erythropoietin dose, total body water, and number of BP meds were unchanged.
Conclusion: Exercise training during HD significantly improves both interdialytic ABP and treatment-related BP.