Increased serum erythropoietin but not red cell production after 4 wk of intermittent hypobaric hypoxia (4,000-5,500 m)

• Published in: Journal of applied physiology (1985) Vol. 101; no. 5; pp. 1386 - 1393
• Main Authors: Gore, Christopher J, Rodriguez, Ferran A, Truijens, Martin J, Townsend, Nathan E, Stray-Gundersen, James, Levine, Benjamin D
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Am Physiological Soc 01.11.2006; American Physiological Society
• Subjects: Adaptation, Physiological - physiology; Altitude; Biological and medical sciences; Double-Blind Method; Erythrocyte Volume - physiology; Erythrocytes; Erythropoiesis - physiology; Erythropoietin - blood; Female; Fundamental and applied biological sciences. Psychology; Hematologic Tests; Hemoglobin; Hormones; Humans; Hypoxia; Hypoxia - blood; Male; Placebo effect; Running - physiology; Swimming - physiology; Erythropoiesis; High altitude; Oxygen; Erythropoietin; Red blood cell; Environmental factor; Blood cell; Vertebrata; Mammalia; hemoglobin mass; Polypeptide; Intermittent; Hemoglobin; Hypoxia; red cell volume; Cell volume
• DOI: 10.1152/japplphysiol.00342.2006
• ISSN: 8750-7587

1 Australian Institute of Sport, Canberra, Australia; 2 Institute for Exercise and Environmental Medicine, Presbyterian Hospital of Dallas and University of Texas Southwestern Medical Center at Dallas, Dallas, Texas; 3 Institut Nacional d'Educació Física de Catalunya, Universitat de Barcelona, Barcelona, Spain; 4 Faculty of Human Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands; and 5 New South Wales Institute of Sport, Sydney, Australia Submitted 21 March 2006 ; accepted in final form 16 June 2006 This study tested the hypothesis that athletes exposed to 4 wk of intermittent hypobaric hypoxia exposure (3 h/day, 5 days/wk at 4,000–5,500 m) or double-blind placebo increase their red blood cell volume (RCV) and hemoglobin mass (Hb mass ) secondary to an increase in erythropoietin (EPO). Twenty-three collegiate level athletes were measured before (Pre) and after (Post) the intervention for RCV via Evans blue (EB) dye and in duplicate for Hb mass using CO rebreathing. Hematological indexes including EPO, soluble transferrin receptor, and reticulocyte parameters were measured on 8–10 occasions spanning the intervention. The subjects were randomly divided among hypobaric hypoxia (Hypo, n = 11) and normoxic (Norm, n = 12) groups. Apart from doubling EPO concentration 3 h after hypoxia there was no increase in any of the measures for either Hypo or Norm groups. The mean change in RCV from Pre to Post for the Hypo group was 2.3% (95% confidence limits = –4.8 to 9.5%) and for the Norm group was –0.2% (–5.7 to 5.3%). The corresponding changes in Hb mass were 1.0% (–1.3 to 3.3%) for Hypo and –0.3% (–2.6 to 3.1%) for Norm. There was good agreement between blood volume (BV) from EB and CO: EB BV = 1.03 x CO BV + 142, r 2 = 0.85, P < 0.0001. Overall, evidence from four independent techniques (RCV, Hb mass , reticulocyte parameters, and soluble transferrin receptor) suggests that INTERMITTENT HYPOBARIC HYPOXIA EXPOSURE did not accelerate erythropoiesis despite the increase in serum EPO. high altitude; erythropoiesis; red cell volume; hemoglobin mass Address for reprint requests and other correspondence: C. J. Gore, Physiology Dept., Australian Institute of Sport, Leverrier Crescent, Bruce, ACT 2617, Australia or Exercise Physiology Laboratory, School of Education, Flinders University, GPO Box 2100, Adelaide, SA 5001, Australia (e-mail: chris.gore{at}ausport.gov.au )