P. Barany et al., TREATMENT OF ANEMIA IN HEMODIALYSIS-PATIENTS WITH ERYTHROPOIETIN - LONG-TERM EFFECTS ON EXERCISE CAPACITY, Clinical science, 84(4), 1993, pp. 441-447
1. The effects of correcting anaemia on exercise capacity were evaluat
ed in 21 haemodialysis patients (aged 39 +/- 12 years) before starting
treatment with recombinant human erythropoietin (Hb concentration, 73
+/- 10 g/l; total Hb, 59 +/- 12% of expected), after correction of th
e anaemia to a Hb concentration of 108 +/- 7 g/l and a total Hb 82 +/-
10% of expected, and in 13 of the patients after 12 months on mainten
ance recombinant human erythropoietin treatment (Hb concentration 104
+/- 14 g/l, total Hb 79 +/- 17% of expected). Fifteen healthy subjects
(aged 41 +/- 9 years), who took no regular exercise, constituted the
control group. Maximal exercise capacity was determined on a bicycle e
rgometer. Oxygen uptake, respiratory quotient, blood lactate concentra
tion, heart rate and blood pressure were measured at rest and at maxim
al workload. 2. After 6 +/- 3 months on recombinant human erythropoiet
in, maximal exercise capacity increased from 108 +/- 27 W to 130 +/- 3
6 W (P<0.001) and the maximal oxygen uptake increased from 1.24 +/- 0.
39 litres/min to 1.50 +/- 0.45 litres/min (P<0.001). No significant ch
anges in respiratory quotient (1.16 +/- 0.13 versus 1.18 +/- 0.13) and
blood lactate concentration (4.0 +/- 1.8 versus 3.6 +/- 1.1 mmol/1) a
t maximal workload were observed, but the blood lactate concentration
in the patients was significantly lower than that in the control subje
cts (6.7 +/- 2.3 mmol/l, P<0.01). After the correction of anaemia, the
aerobic power was still 38% lower in the patients than in the control
subjects and 17% lower than the reference values. 3. After 12 months
on maintenance recombinant human erythropoietin treatment (17 +/- 3 mo
nths from the start of the study), no further significant changes were
observed in maximal exercise capacity (before start, 112 +/- 31 W, 6
+/- 3 months, 134 +/- 42 W, 17 +/- 3 months, 134 +/- 50 W), maximal ox
ygen uptake (before start, 1.33 +/- 0.45 litres/min; 6 +/- 3 months, 1
.59 +/- 0.54 litres/min; 17 +/- 3 months, 1.75 +/- 0.78 litres/min) or
blood lactate concentration (before start, 4.4 +/- 1.9 mmol/l; 6 +/-
3 months, 4.0 +/- 1.0 mmol/l; 17 +/- 3 months, 4.7 +/- 2.0 mmol/l). 4.
Thus, in haemodialysis patients the improvement in maximal aerobic po
wer after the correction of anaemia persists without marked changes du
ring long-term treatment with recombinant human erythropoietin. We did
not observe any effects on exercise capacity that could be attributed
to a spontaneous increase in physical activity after treatment of ana
emia.