Abstract
The effects of exercise training on exercise capacity were evaluated in 8 regular hemodialysis patients whose anemia was partially improved by treatment with recombinant human erythropoietin (rEPO). A 12-week exercise training program was started using a bicycle ergometer. A symptom-limited exercise tolerance test was performed before and after the program. Serial measurements of blood gases, arterial lactate values and expiratory gas were made during the test. Hemoglobin values were maintained constant. PaO2 and PaCO2 did not change significantly during the test. Exercise time was lengthened from 13.2±1.8 to 15.8±1.2 min (p<0.01), but maximum O2 uptake did not increase significantly. Maximum arterial lactate values rose significantly from 3.6±2.0 to 4.4±1.4mM (p<0.05). Although the exercise capacity of regular hemodialysis patients treated with rEPO improved, their aerobic exercise capacity did not improve significantly. Maximum arterial lactate values, on the other hand, did increase. These results indicate that improved exercise capacity was not the result of an improvement in aerobic energy production but in anaerobic energy production. A surprisingly low O2 uptake in terms of a markedly increased O2 supply indicates that hemodialysis patients have (a) defect (s) in the aerobic energy production system of their skeletal muscle.
