Hemoglobin mass response to simulated hypoxia “blinded” by noisy measurement?
2012; American Physiological Society; Volume: 112; Issue: 10 Linguagem: Inglês
10.1152/japplphysiol.00212.2012
ISSN8750-7587
AutoresLaura A. Garvican, Philo U. Saunders, David B. Pyne, David T. Martin, Eileen Y. Robertson, Christopher J. Gore,
Tópico(s)Cardiovascular and exercise physiology
ResumoLetters to the EditorHemoglobin mass response to simulated hypoxia "blinded" by noisy measurement?Laura A. Garvican, Philo U. Saunders, David B. Pyne, David T. Martin, Eileen Y. Robertson, and Christopher J. GoreLaura A. GarvicanPhysiology, Australian Institute of Sport, Canberra; , Philo U. SaundersPhysiology, Australian Institute of Sport, Canberra; , David B. PynePhysiology, Australian Institute of Sport, Canberra; , David T. MartinPhysiology, Australian Institute of Sport, Canberra; , Eileen Y. RobertsonSouth Australian Sports Institute, Adelaide; and , and Christopher J. GorePhysiology, Australian Institute of Sport, Canberra; Exercise Physiology Laboratory, Flinders University, Adelaide, AustraliaPublished Online:15 May 2012https://doi.org/10.1152/japplphysiol.00212.2012MoreSectionsPDF (78 KB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInEmailWeChat to the editor: Siebenmann and colleagues (13) found that 4 wk of simulated altitude (16 hr/day, 3,000 m) failed to increase Hbmass. We believe their methodology to quantify Hbmass was suboptimal, which confounds interpretation.In the mid-1990s, Finnish scientists reported increased red cell mass following 3–4 wk of simulated altitude (8). Subsequent attempts by our group failed to reproduce these findings (2). In 2004, Rusko (11) suggested that an adequate hypoxic stimulus required >12 hr/day, >2,000 m, >3 wk. Indeed, since 2006, using the optimized CO-rebreathing technique (9), we have consistently observed mean increases in Hbmass of 3–5% after exposures of 14 hr/day, 3,000 m, 21 days in elite athletes (3, 6, 10, 12) and furthermore demonstrated this response as reproducible (10). We also quantified that individual variation of the Hbmass response to this hypoxic dose is of similar magnitude to the mean increase (10). We therefore disagree with the assertion of Siebenmann that "the presence of an effect on Hbmass crucially depends on the random composition of the subject groups," as our nonresponders can usually be explained by illness, injury, or training stress. By using duplicate measures, we have demonstrated a mean increase in Hbmass of ∼1% per 100 h to both simulated (3, 6) and natural altitude (4). On the basis of these findings we would expect a 4–5% increase in Siebenmann's study.It is difficult to directly compare initial Hbmass values to other recently published studies in elite athletes (4, 10), because the CO-rebreathing method used by Siebenmann, results in an ∼2% overestimation of Hbmass because CO loss to myoglobin is unaccounted for (5). We consider it unlikely that the lack of increase is due to high baseline values. We are also concerned by Siebenmann's relatively high typical error of 2.6% and contend that a likely explanation for the absence of an Hbmass response is a relatively poor signal-to-noise ratio. We have published extensively on ways to reduce error in Hbmass measurement (1, 5, 7) and suggest that the optimized method is superior for minimizing measurement error (5). We encourage all researchers to adopt this methodology. Specifically, in regard to Siebenmann's method, HbCO% values of venous blood must be corrected for oxygen saturation and CO mixed completely throughout all vascular compartments before sampling (5). HbCO content of venous blood rises slowly following the onset of rebreathing and does not converge to a plateau until ∼10 min. Additionally, if venous blood is sampled prematurely (i.e., at 8 min as described by Siebenmann), this method may yield spuriously high Hbmass values (5).In our experience, on the basis of many Hbmass measurements of elite athletes using the optimized CO-rebreathing method, most athletes who are sufficiently fueled, iron supplemented, not sick or injured, and appropriately trained, typically show an increased Hbmass following an adequate hypoxic stimulus. More research is required to understand why some athletes fail to increase Hbmass. However, insights into this topic are best made when Hbmass is quantified with the highest precision technique available. Unlike Siebenmann's approach, the optimized CO-rebreathing method (9), with recent refinements (5), holds more promise for quantifying small mean effects and individual responses to altitude.DISCLOSURESNo conflicts of interest, financial or otherwise, are declared by the authors.AUTHOR CONTRIBUTIONSAuthor contributions: L.A.G., P.U.S., D.T.M., E.Y.R., and C.J.G. conception and design of research; L.A.G., P.U.S., D.T.M., E.Y.R., and C.J.G. performed experiments; L.A.G., P.U.S., D.B.P., E.Y.R., and C.J.G. analyzed data; L.A.G., P.U.S., D.B.P., D.T.M., and C.J.G. interpreted results of experiments; L.A.G. drafted manuscript; L.A.G., P.U.S., D.B.P., D.T.M., E.Y.R., and C.J.G. edited and revised manuscript; L.A.G., P.U.S., D.B.P., D.T.M., E.Y.R., and C.J.G. approved final version of manuscript.REFERENCES1. Alexander AC , Garvican LA , Burge CM , Clark SA , Plowman JS , Gore CJ. Standardising analysis of carbon monoxide rebreathing for application in anti-doping. J Sci Med Sport 14: 100–105, 2011.Crossref | ISI | Google Scholar2. Ashenden MJ , Gore CJ , Dobson GP , Hahn AG. "Live high, train low" does not change the total haemoglobin mass of male endurance athletes sleeping at a simulated altitude of 3000 m for 23 nights. Eur J Appl Physiol Occup Physiol 80: 479–484, 1999.Crossref | ISI | Google Scholar3. Clark SA , Quod MJ , Clark MA , Martin DT , Saunders PU , Gore CJ. Time course of haemoglobin mass during 21 days live high:train low simulated altitude. Eur J Appl Physiol 106: 399–406, 2009.Crossref | ISI | Google Scholar4. Garvican L , Martin D , Quod M , Stephens B , Sassi A , Gore C. Time course of the hemoglobin mass response to natural altitude training in elite endurance cyclists. Scand J Med Sci Sports 22: 95–103, 2012.Crossref | ISI | Google Scholar5. Garvican LA , Burge CM , Cox AJ , Clark SA , Martin DT , Gore CJ. Carbon monoxide uptake kinetics of arterial, venous and capillary blood during CO rebreathing. Exp Physiol 95: 1156–1166, 2011.Crossref | ISI | Google Scholar6. Garvican LA , Pottgiesser T , Martin DT , Schumacher YO , Barras M , Gore CJ. The contribution of haemoglobin mass to increases in cycling performance induced by simulated LHTL. Eur J Appl Physiol 111: 1089–1101, 2011.Crossref | ISI | Google Scholar7. Gough CE , Sharpe K , Ashenden MJ , Anson JM , Saunders PU , Garvican LA , Bonetti DL , Gore CJ , Prommer N. Quality control technique to reduce the variability of longitudinal measurement of hemoglobin mass. Scand J Med Sci Sports 21: e365–e371, 2011.Crossref | ISI | Google Scholar8. Laitinen H , Alopaeus K , Heikkinen R , Hietanen L , Mikkelsson L , Tikkanen HO , Rusko HK. Acclimatization to living in normobaric hypoxia and training in normoxia at sea level in runners. Med Sci Sports Exerc 27: S109, 1995.Crossref | Google Scholar9. Prommer N , Schmidt W. Loss of CO from the intravascular bed and its impact on the optimised CO-rebreathing method. Eur J Appl Physiol 100: 383–391, 2007.Crossref | PubMed | ISI | Google Scholar10. Robertson EY , Saunders PU , Pyne DB , Aughey RJ , Anson JM , Gore CJ. Reproducibility of performance changes to simulated live high/train low altitude. Med Sci Sports Exerc 42: 394–401, 2010.Crossref | ISI | Google Scholar11. Rusko HK , Tikkanen HO , Peltonen JE. Altitude and endurance training. J Sports Sci 22: 928–944; discussion 945, 2004.Crossref | ISI | Google Scholar12. Saunders PU , Ahlgrim C , Vallance B , Green DJ , Robertson EY , Clark SA , Schumacher YO , Gore CJ. An attempt to quantify the placebo effect from a three-week simulated altitude training camp in elite race walkers. Int J Sports Physiol Perform 5: 521–534, 2010.Crossref | ISI | Google Scholar13. Siebenmann C , Robach P , Jacobs RA , Rasmussen P , Nordsborg N , Diaz V , Christ A , Olsen NV , Maggiorini M , Lundby C. "Live high-train low" using normobaric hypoxia: a double-blinded, placebo-controlled study. J Appl Physiol 112: 106–117, 2012.Link | ISI | Google ScholarAUTHOR NOTESAddress for reprint requests and other correspondence: L. A. Garvican, Australian Institute of Sport, PO Box 176, Belconnen, ACT 2616, Australia (e-mail: laura.[email protected]gov.au). Download PDF Previous Back to Top Next FiguresReferencesRelatedInformationRelated ArticlesReply to Garvican, Saunders, Pyne, Martin, Robertson, and Gore 15 May 2012Journal of Applied PhysiologyCited ByHypoxic Training Is Beneficial in Elite AthletesMedicine & Science in Sports & Exercise, Vol. 52, No. 2Is live high – train low altitude training relevant for elite athletes? Flawed analysis from inaccurate data15 December 2017 | British Journal of Sports Medicine, Vol. 53, No. 15"Live High-Train Low" Paradigm: Moving the Debate ForwardExercise and Sport Sciences Reviews, Vol. 46, No. 4The Effects of Altitude Training on Erythropoietic Response and Hematological Variables in Adult Athletes: A Narrative Review11 April 2018 | Frontiers in Physiology, Vol. 9Stage racing at altitude induces hemodilution despite an increase in hemoglobin massLaura A. Garvican-Lewis, Yorck O. Schumacher, Sally A. Clark, Ryan Christian, Paolo Menaspà, Jamie Plowman, Brian Stephens, Jiliang Qi, Rongyun Fan, Yingying He, David T. Martin, Kevin G. Thompson, Christopher J. Gore, and Fuhai Ma1 September 2014 | Journal of Applied Physiology, Vol. 117, No. 5Year-to-year variability in haemoglobin mass response to two altitude training camps26 November 2013 | British Journal of Sports Medicine, Vol. 47, No. Suppl 1 More from this issue > Volume 112Issue 10May 2012Pages 1797-1798 Copyright & PermissionsCopyright © 2012 the American Physiological Societyhttps://doi.org/10.1152/japplphysiol.00212.2012PubMed22589495History Received 15 February 2012 Accepted 28 February 2012 Published online 15 May 2012 Published in print 15 May 2012 Metrics
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