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Altitudeexposureinsports:theAthleteBiologicalPassportstandpoint

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HeliosPareja-Galeano

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GiuseppeLippi

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PerspectiveDrug Testing

and Analysis

Received: 26 June 2013 Revised: 14 August 2013 Accepted: 14 August 2013 Published online in Wiley Online Library

(www.drugtestinganalysis.com) DOI 10.1002/dta.1539

Altitude exposure in sports: the AthleteBiological Passport standpointFabian Sanchis-Gomar,a,b* Helios Pareja Galeano,a,b Thomas Brioche,a,b,c

Vladimir Martinez-Bellod and Giuseppe Lippie

The Athlete Biological Passport (ABP) is principally founded on monitoring an athlete’s biological variables over time, to iden-tify abnormal biases on a longitudinal basis. Several factors are known to influence the results of these markers. However, themanner in which the altitude factor is taken into account still needs to be standardized. Causal relationships betweenhaematological variables should be correctly integrated into ABP software. In particular, modifications of haematologicalparameters during and after exposure to different altitudes/hypoxic protocols need to be properly included within detectionmodels. Copyright © 2013 John Wiley & Sons, Ltd.

Keywords: haemoglobin; haematocrit; reticulocytes; hypoxia exposure; blood doping

* Correspondence to: Fabian Sanchis-Gomar, Department of Physiology, Facultyof Medicine, University of Valencia, Av. Blasco Ibañez, 15, Valencia 46010Spain. E-mail: fabian.sanchis@uv.es

a Faculty of Medicine, Department of Physiology, University of Valencia, Spain

b Fundación Investigación Hospital Clínico Universitario/INCLIVA, Spain

c Laboratory M2S (Movement, Sport and Health Sciences), UFR-APS, RennesCedex, France

d Faculty of Teaching, Department of Teaching of Musical, Visual and CorporalExpression, University of Valencia, Spain

e Clinical Chemistry and Hematology Laboratory, Department of Pathology andLaboratory Medicine, Academic Hospital of Parma, Italy

Introduction

Rather than using direct techniques to detect illicit drugs or sub-stances, the Athlete Biological Passport (ABP) is founded on mon-itoring an athlete’s biological variables over time to identifyabnormal biases on a longitudinal basis[1] and, more specifically,in Bayesian networks through a mathematical formalism basedon probabilities shown on a graph.[2] The blood variables usedto define the ABP include haematocrit, haemoglobin (Hb), redblood cell count, mean corpuscular volume, mean corpuscularHb, mean corpuscular Hb concentration, reticulocyte count, andpercentage of reticulocytes.[3] In addition, the multiparametricmarkers OFF-Hr score (index of stimulation) and ABPS (abnormalblood profile score) are calculated from this set of parameters.[4,5]

Several and heterogeneous factors are known to influence theresult of these markers, including ethnic origin, age, gender, theanalyzer used for measurement, the sport discipline, the seasonalchanges of the haematological parameters and exposure to alti-tude.[2,6–8] This information can be easily recorded during bloodanalysis, with the possible exception of altitude. The manner inwhich the altitude factor is taken into account still needs to bestandardized.[6] Recent publications reflect concern about howhypoxic environment (natural or artificially induced exposure)may be misinterpreted by the ABP software as heterogeneousand confounding factors,[9] since altitude exposure and trainingare not adequately weighted within the ABP software/algorithm.The time course for normalization of parameters after exposureto different altitudes/hypoxia protocols needs to be properlyaddressed in detection models. Intermittent hypoxia training orexposure consists of brief periods of daily exposure to severe nat-ural or artificial hypoxia (e.g. altitude exposure, nitrogen houses,hypoxia tents, breathing apparatuses for inspiratory hypoxia).[10]

The living high, training low method (LHTL) is another approachwhich entails living at a high/moderate altitude (2500 m) andtraining at a low altitude (1250 m).[11,12] Other alternatives exist,such as the so-called living high, training high (LHTH) and livinglow, training high (LLTH).[13,14] Therefore, all these different hyp-oxic exposure protocols, with potential heterogeneous effects

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on the components of the ABP, should be accurately considered,along with hypoxic stimulation in combination with training.

Sottas et al. concluded that athletes’ exposition to altitude wasidentified using the whereabouts forms as determined in thethree-week pre-competition profile of each athlete tested duringthe 2005 and 2007 World Athletics Championships (3444 en-tries).[15] Although the whereabouts forms currently consider alti-tude simulation systems, devices, and protocols,[3] it isnoteworthy that the whereabouts forms at that time (between2005 and 2007) had some drawbacks since: (1) they did not con-sider the possibility of an athlete using altitude simulation sys-tems, or the type of device or protocol applied; (2) they did notcontain accurate information about training sessions and/or com-petitions before sample collection; (3) they did not take into ac-count other confounding factors listed in the operatingguidelines.[3] Even today the whereabouts forms do not properlyconsider these last two points. It is also assumed that the effect ofaltitude exposure is appropriately interpreted according to therecommendations of the World Health Organization (WHO) fordiagnosis of anaemia. [16] These recommendations are based ona paper published in 1945 and are mostly related to normal in-creases of haemoglobin and haematocrit values related to long-term altitude exposure (Table 1).

Copyright © 2013 John Wiley & Sons, Ltd.

Table 1. Normal increases of haemoglobin and haematocrit valuesrelated to long-term altitude exposure. (Extracted from WHO.16)

Altitude (metres) Increase inhaemoglobin (g/l)

Increase inhaematocrit (l/l)

<1000 0 0

1000 +2 +0.005

1500 +5 +0.015

2000 +8 +0.025

2500 +13 +0.040

3000 +19 +0.060

3500 +27 +0.085

4000 +35 +0.110

4500 +45 +0.140

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New findings in this field

Recent scientific findings show broad heterogeneity and differentresponses when subjects are exposed to natural altitude vs artifi-cial hypoxia, also displaying rather different and controversialhaematological results.[12,17–19] In an excellent review publishedrecently by Lundby et al., the authors focused on altitude trainingand the increase of performance in elite athletes. Interestingly,after a careful review and despite the lack of rigorous scientificstudies, these authors concluded that LHTH and LHTL may in-crease exercise performance in some, but not all, athletes. How-ever, LLTH and intermittent hypoxic breathing at rest do notimprove endurance capacity more than normoxic training. Thus,the use of intermittent hypoxic exposure was not recommendedsince it would not increase sea-level performance.[20] Moreover,Robach and Lundby recently reported that LHTL may only in-crease Hbmass, and possibly VO2max, in athletes with an initiallow Hbmass value, and that the potential response seems to bereduced in athletes with an already high Hbmass or red bloodcell volume (RCV).[21] Therefore, although individual studies sup-port the hypothesis that exposure to hypoxia induces improvedendurance performance, the current literature does not supportthis common notion for athletes with an already high Hbmass.Neither the postulated hypoxia-induced effects nor its putativelyunderlying mechanisms have yet been convincingly proven.Unfortunately, some of the current literature suffers from variousmethodological shortcomings including a small number ofsubjects, non-randomized study designs, neither single nordouble-blinded design, heterogeneous populations, and vari-ous hypoxic methods or training modalities within as well asbetween studies.[22]

The function of the Expert Panel

An expert is someone with knowledge in a particular field, ischosen by the Anti-Doping Organization (ADO), and isresponsible for providing an evaluation of the ABP. For thehaematological module, experts will have knowledge in one ormore of the fields of clinical haematology, sports medicine, orexercise physiology.[23]

The Expert Panel is responsible for (1) reviewing ABP data andresults from the adaptive model provided by the ADO in order toidentify any possible pathological or confounding conditions; (2)recommending any follow-up testing or suggesting possible clin-ical testing that may be required to confirm assessment or to col-lect further evidence to support or confirm possible pathologies;

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(3) reviewing any athlete’s explanations and providing opinionson whether any atypical finding was highly probable given thata prohibited substance or method had been used; (4) workingwith the relevant ADO as required and providing evidentiarysupport as necessary throughout any results managementprocess.[23] A final report of the ABP containing data with a highchance of being attributable to the use of one or more prohibitedsubstances or methods is typically defined as an ‘adversepassport finding’.[23]

Nevertheless, the haematological system of an athlete issubjected to potential changes induced by unusual environmen-tal conditions such as the hypoxia of altitude.[24] Therefore, alti-tude is a confounding factor for blood variables, becausehypoxia might affect both red blood cell production and vascularvolumes. The time of exposure and the degree of hypoxia(altitude) must be evaluated on an individual basis, also consider-ing specific information about the time of collection in relation tothe sojourn at high altitude. Two leading experts in this field,Schumacher and d’Onofrio, both recognize that any abnormalityin a profile should be scrutinized in view of the question ‘Can theabnormal result of the profile be explained by the environmentalconditions to which the athlete was exposed prior to providingthe sample?’[24] Thus, the expert evaluation is broadly dependenton the right timing of blood tests.[24] In fact, times of blood draw-ings are also important for a correct evaluation and interpreta-tion. The effect of altitude, if present, shows a typical delayfrom exposure to increase of Hb. In addition, the experts pointout that specific issues with the schedule of each athlete suchas altitude exposure must be considered. [24] The evaluation ofthe athlete’s personal profile could aid the experts in consideringthem a responder or a non-responder.[25]

Yet the altitude factor has not been standardized in the adap-tive model/algorithm so far. All these variables should be in-cluded in the anti-doping model, considering the large numberof athletes that are currently being screened. A crucial point forinterpreting ABP blood profile is the use of special tents or cham-bers, where hypoxia can be artificially reproduced. It is notewor-thy that the use of artificial hypoxia could be reproduced eitherat home or at sea level. The registration of athletes’ data with AD-AMS software only includes permanence at natural altitude, butnot the use of artificial hypoxia and the corresponding degreeof artificial altitude. Moreover, in the case of an adverse passportfinding, the alleged use of this method is subject to the arbitraryinterpretation of the experts.

Concluding remarks

The precision of the ABP could be improved by intensifyingthe direct participation of laboratory experts in (1) creatingand validating algorithms; (2) recognizing biologically validthresholds for the different sports, training regimens, and envi-ronmental conditions; and (3) identifying reliable laboratoryinstrumentation, protocols, and quality assurance programmesfor haematological testing.[26]

The chance of obtaining false-positive and false-negative testresults is crucial in an anti-doping context, wherein this special di-agnostic area carries important forensic implications and a largenumber of disqualifications are now taken to court. Athleteswho live or train regularly at high altitudes may be unfairly notpenalized or even unjustly sanctioned. Thus, athletes could even-tually use the altitude exposure explanation to elude elevatedresults in haematological abnormalities. The cut-off limit is in fact

13 John Wiley & Sons, Ltd. Drug Test. Analysis (2013)

Altitude and ABP

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and Analysis

lower when an altitude model was explicitly considered, i.e. ahigher sensitivity to blood doping.[27] A model that is based onthe distribution of altitudes during the two weeks before the testmay offer a reasonable alternative.[2] Likewise, thresholds arehigher when the athlete is tested at a high altitude, i.e. a lowerprobability of a false-positive.[27] To date, ABP software classifiedthe altitude exposure taking into account the total meters ofaltitude as follow: <1000 m; 1000–1500 m; 1500–2000 m;2000–2500 m; 2500–3000 m; >3000 m. Moreover, prior to bloodcollection, the athlete must answer the following questions:[2] (1)Have they spent any time at high altitudes (>1000 m) during theprevious two weeks? If yes, when and at what altitude? (2) Havethey used a hypoxia tent (>1000 m) during the previous twoweeks? If yes, when and what PiO2 was used? However, theimpact of altitude or hypoxia exposure is still overlooked in thecurrent ABP model. All the variables should be transparentlycharacterized and describe how they influence the calculationof the likelihood percentage of abnormal variation of data inthe Bayesian/adaptive model. Altitude is the most commonlymodified variable over time in an athlete’s profile and mustalways be correctly considered in the calculation, but also byexperts who interpret the ABP data.[24]

Causal relationships between different altitudes/hypoxic proto-cols and the variation of haematological variables should be ap-propriately integrated in ABP software, as follows:

1) Type of altitude exposure protocol: LLTH, LHTL, LHTH, or inter-mittent hypoxic breathing at rest since LHTH and LHTL mayinduce higher haematological adaptations than LLTH or inter-mittent hypoxic breathing at rest.

2) Even though Hbmass has some drawbacks (i.e. problems instandardization), it could be included in the procedure to ob-tain baseline values before altitude exposure. Members of theAthlete Passport Management Unit (APMU) could benefitfrom this additional information. Consequently, it is crucialto establish an initial or basal Hbmass and Hb concentrationbefore altitude exposure since the potential response is se-verely reduced in athletes with an already high Hbmass, Hbconcentration, or RCV. For this purpose, screening for Hblevels and Hbmass in athletes before engaging in hypoxic ex-posure protocols may be a potential and innovative perspec-tive, for example including a baseline Hb level obtained withthree determinations off-season and at least one monthbefore and after altitude/hypoxic exposure. As previouslymentioned, Hbmass for anti-doping purposes should beassessed always in combination with haemoglobin and bloodvolume.[28]

3) The Expert Panel should be aware of the athlete’s baselinehaematological values (before hypoxic exposure) for accurateinterpretation of blood profile fluctuations due to hypoxicexposure. For example, an increase of 10 g/L of Hb can beachievable after an exposure to altitude or hypoxia (LHTL,2500m/21 days) in a male athlete with a baseline Hb level of130 g/L, whereas the same extent of increase is virtuallyunachievable by another male athlete with a baseline Hblevel of 155 g/L. Surprisingly, this aspect is embarrassinglyoverlooked in the complex algorithm of the ABP software,which has been developed according to WHO recommenda-tions (Figure 1).[16]

Finally, it has recently been demonstrated that it is possible toabuse recombinant human erythropoietin (rHuEpo) withouttriggering ABP thresholds.[29] Accordingly, additional and more

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sensitive markers are needed to detect rHuEpo abuse by meansof the ABP model. For this purpose, several markers such as totalhaemoglobin mass (Hbmass), bilirubin, ferritin, Hbmr, RBCHb/RetHb ratio, and/or Serum Epo concentration should be consid-ered for integration.[2,30–34]

References[1] S. Gilbert. The biological passport. Hastings Cent. Rep. 2010, 40, 18.[2] P.E. Sottas, N. Robinson,M. Saugy. The athlete’s biological passport and

indirect markers of blood doping. Handb. Exp. Pharmacol. 2010, 195,305.

[3] WADA. The World Anti-Doping Code. Athlete Biological Passport Op-erating Guidelines and Compilation of Required Elements, Version3.1, 2012, pp 1–52. Available at: www.wada-ama.org [5 August 2013]

[4] C.J. Gore, R. Parisotto, M.J. Ashenden, J. Stray-Gundersen, K. Sharpe,W. Hopkins, et al. Second-generation blood tests to detect erythro-poietin abuse by athletes. Haematologica 2003, 88, 333.

[5] P.E. Sottas, N. Robinson, S. Giraud, F. Taroni, M. Kamber, P. Mangin,et al. Statistical classification of abnormal blood profiles in athletes.Int. J. Biostat. 2006, 2, 3.

[6] P.E. Sottas, N. Robinson, M. Saugy. A forensic approach to the inter-pretation of blood doping markers. Law Probab. Risk 2008, 7, 191.

[7] G. Banfi. Limits and pitfalls of athlete’s biological passport. Clin.Chem. Lab. Med. 2011, 49, 1417.

[8] G. Lippi, C. Mattiuzzi, G. Banfi. Controlling sources of preanalyticalvariability in doping samples: Challenges and solutions. Bioanalysis2013, 5, 1571.

[9] F. Sanchis-Gomar, V.E. Martinez-Bello, M.C. Gomez-Cabrera, J. Vina.Current limitations of the athlete’s biological passport use in sports.Clin. Chem. Lab. Med. 2011, 49, 1413.

[10] E.A. Hinckson, W.G. Hopkins, J.S. Edwards, P. Pfitzinger, J. Hellemans.Sea-level performance in runners using altitude tents: A field study.J. Sci. Med. Sport 2005, 8, 451.

[11] J. Stray-Gundersen, R.F. Chapman, B.D. Levine. ’Living high-traininglow’ altitude training improves sea level performance in male andfemale elite runners. J. Appl. Physiol. 2001, 91, 1113.

[12] J. Stray-Gundersen, B.D. Levine. Live high, train low at natural alti-tude. Scand. J. Med. Sci. Spor. 2008, 18, 21.

[13] B.D. Levine, J. Stray-Gundersen. ’Living high-training low’: Effect ofmoderate-altitude acclimatization with low-altitude training on per-formance. J. Appl. Physiol. 1997, 83, 102.

[14] J.P. Wehrlin, P. Zuest, J. Hallen, B. Marti. Live high-train low for 24days increases hemoglobin mass and red cell volume in elite endur-ance athletes. J. Appl. Physiol. 2006, 100, 1938.

[15] P.E. Sottas, N. Robinson, G. Fischetto, G. Dolle, J.M. Alonso, M. Saugy.Prevalence of blood doping in samples collected from elite track andfield athletes. Clin. Chem. 2011, 57, 762.

[16] World Health Organisation. Iron Deficiency Anemia: Assessment, pre-vention and control, a guide for programme managers. WHO Publica-tions, Geneva, 2001.

[17] J.P. Richalet, C.J. Gore. Live and/or sleep high:train low, usingnormobaric hypoxia. Scand. J. Med. Sci. Spor. 2008, 18, 29.

[18] P. Bartsch, C. Dehnert, B. Friedmann-Bette, V. Tadibi. Intermittenthypoxia at rest for improvement of athletic performance. Scand. J.Med. Sci. Spor. 2008, 18, 50.

[19] G.P. Millet, B. Roels, L. Schmitt, X. Woorons, J.P. Richalet. Combininghypoxic methods for peak performance. Sports Med. 2010, 40, 1.

[20] C. Lundby, G.P. Millet, J.A. Calbet, P. Bartsch, A.W. Subudhi. Does ’al-titude training’ increase exercise performance in elite athletes? Brit.J. Sports Med. 2012, 46, 792.

[21] P. Robach, C. Lundby. Is live high-train low altitude training relevantfor elite athletes with already high total hemoglobin mass? Scand. J.Med. Sci. Spor. 2012, 22, 303.

[22] P. de Paula, J. Niebauer. Effects of high altitude training on exercisecapacity: Fact or myth. Sleep Breath. 2010, 16, 233.

[23] WADA. The World Anti-Doping Code. Athlete Biological PassportOperating Guidelines and Compilation of Required Elements.2012, pp. 1–52. Available at: www.wada-ama.org [20 May 2013]

[24] Y.O. Schumacher, G. d’Onofrio. Scientific expertise and the athletebiological passport: 3 years of experience. Clin. Chem. 2012, 58, 979.

[25] R.F. Chapman, J. Stray-Gundersen, B.D. Levine. Individual variation inresponse to altitude training. J. Appl. Physiol. 1998, 85, 1448.

& Sons, Ltd. wileyonlinelibrary.com/journal/dta

F. Sanchis-Gomar et al.

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[26] G. Lippi, M. Plebani, F. Sanchis-Gomar, G. Banfi. Current limitationsand future perspectives of the athlete blood passport. Eur. J. Appl.Physiol. 2012, 112, 3693.

[27] N. Robinson, P.E. Sottas, P. Mangin, M. Saugy. Bayesian detectionof abnormal hematological values to introduce a no-start rulefor heterogeneous populations of athletes.Haematologica 2007, 92, 1143.

[28] F. Sanchis-Gomar, G. Lippi. Hb(mass) for anti-doping purposesshould be assessed in combination with hemoglobin and bloodvolume. Int. J. Sport Med. 2012, 33, 502.

[29] M. Ashenden, C.E. Gough, A. Garnham, C.J. Gore, K. Sharpe. Currentmarkers of the athlete blood passport do not flag microdose EPOdoping. Eur. J. Appl. Physiol. 2011, 111, 2307.

[30] J. Morkeberg, K. Sharpe, B. Belhage, R. Damsgaard, W. Schmidt,N. Prommer, et al. Detecting autologous blood transfusions: A

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comparison of three passport approaches and four bloodmarkers. Scand. J. Med. Sci. Spor. 2009, 21, 235.

[31] W. Jelkmann, C. Lundby. Blood doping and its detection. Blood 2011,118, 2395.

[32] T. Pottgiesser, T. Echteler, P.E. Sottas, M. Umhau, Y.O. Schumacher.Hemoglobin mass and biological passport for the detec-tion of autologous blood doping. Med. Sci. Sport Exer.2012, 44 , 835.

[33] J. Morkeberg. Detection of autologous blood transfusions inathletes: A historical perspective. Transfus. Med. Rev. 2012, 26, 199.

[34] F. Sanchis-Gomar, V.E. Martinez-Bello, M.C. Gomez-Cabrera,J. Vina. The hybrid algorithm (Hbmr) to fight against blooddoping in sports. Scand. J. Med. Sci. Spor. 2010, 20, 789,author reply 792.

13 John Wiley & Sons, Ltd. Drug Test. Analysis (2013)