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Effects of the correction of renal anaemia by erythropoietin on physiological changes during exercise
Author(s) -
LEWIS N. P.,
MACDOUGALL I. C.,
WILLIS N.,
COLES G. A.,
WILLIAMS J. D.,
HENDERSON A. H.
Publication year - 1993
Publication title -
european journal of clinical investigation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.164
H-Index - 107
eISSN - 1365-2362
pISSN - 0014-2972
DOI - 10.1111/j.1365-2362.1993.tb00785.x
Subject(s) - anaerobic exercise , erythropoietin , bicarbonate , pco2 , medicine , arterial blood , respiratory minute volume , heart rate , ventilation (architecture) , anesthesia , endocrinology , cardiology , blood pressure , respiratory system , physiology , mechanical engineering , engineering
. The effects of treating the anaemia of end‐stage renal failure with erythropoietin were studied in nine dialysis patients. The increase in haemoglobin concentration (by 59% from 7.0 ± 1.2 to 11.1 ± 1.1 g dl ‐1 ) was associated with increases in exercise duration (by 41%) and maximum oxygen consumption (by 34%). Treatment reduced resting heart rate but did not significantly alter heart rate at maximum exercise, nor resting or exercise blood pressure. Resting arterial potassium concentrations were slightly increased after treatment, but they increased similarly in relation to minute ventilation during exercise. Lactic acidaemia developed during exercise at both levels of haemoglobin, and was accompanied by similar reductions in arterial pH and bicarbonate levels but constant Pao 2 and Paco 2 . Ventilation was coupled to the metabolic rate of carbon dioxide production, ventilatory dead‐space and arterial Pco 2 before and after treatment of anaemia, the ventilatory requirement for carbon dioxide elimination being unchanged. Treatment of anaemia did not alter resting arterial lactate concentration; the concentration of lactate at maximum exercise was increased slightly following treatment but this increase did not reach statistical significance. The rate of increase in arterial lactate concentration as a function of oxygen consumption, assessed both with respect to the ‘lactate threshold’ and ‘lactate slope index’, was significantly delayed by treatment. Treatment of anaemia also delayed the ‘anaerobic threshold’, and there was good correlation between lactate and anaerobic thresholds. Treatment of renal anaemia by erythropoietin thus results in improved tissue oxygen supply during exercise, reflected by delay in the onset of lactic acidaemia.