Hsiao CC; Chang Gung Memorial Hospital, New Taipei, Taiwan,
Chou CY; Fang JT; Chang SC; Liu KC; Huang SC

Kidney & Blood Pressure Research. 49(1):735-744, 2024.

INTRODUCTION: Disparities in physical fitness between immediately before
dialysis (pre-D) and the day following dialysis (non-D) have not been
investigated despite potential adverse factors such as fluid status,
uremia, and electrolyte levels in the pre-dialysis period. The effect of
acute exercise immediately before hemodialysis (HD) on HD-related
hypotension remains unclear. We hypothesized that cardiopulmonary
performance and muscular strength would be inferior in the immediate pre-D
period compared to those non-D.

METHODS: Twenty patients receiving chronic HD treatments underwent
symptom-limited incremental cardiopulmonary exercise testing (CPET) and
isokinetic testing both 1-2 h prior to dialysis (pre-D) and non-D. This
investigation was a sub-study of a clinical trial assessing the efficacy
of a pre-D exercise training program. Blood pressure profiles during HD
post-CPET and pre-D exercise training were compared with those during
usual HD sessions.

RESULTS: No adverse events were observed during the 80 exercise tests.
Prior to dialysis, the nadir of the ventilatory equivalent of CO2 was
slightly elevated, the resting heart rate was lower, and the peak systolic
blood pressure was higher than those non-D. Contrary to our hypothesis,
peak <inline-formula>VO2</inline-formula> and quadriceps peak torque
showed no differences. Blood pressure profiles during HD post-exercise
were similar to those during sessions without prior exercise, except for a
lower resting systolic blood pressure at the beginning of HD.

CONCLUSION: Cardiopulmonary response and muscular strength in the 1-2 h
prior to HD were comparable with those on the day following HD, with only
minor clinically insignificant differences. Acute exercise prior to HD did
not affect the magnitude of hypotension during HD. This study suggests a
potential alternative timing for exercise training or testing in patients
undergoing chronic HD.