Altitude and Erythropoietin: Comparative Evaluation of Their Impact on Key Parameters of the Athlete Biological Passport: A Review

The hematological module of the Athlete's Biological Passport (ABP) identifies doping methods and/or substances used to increase the blood's capacity to transport or deliver oxygen to the tissues. Recombinant human erythropoietin (rhEPOs) are doping substances known to boost the production of red blood cells and might have an effect on the blood biomarkers of the ABP. However, hypoxic exposure influences these biomarkers similarly to rhEPOs. This analogous impact complicates the ABP profiles' interpretation by antidoping experts. The present study aimed to collect and identify, through a literature search, the physiological effects on ABP blood biomarkers induced by these external factors. A total of 43 studies were selected for this review. A positive correlation (R² = 0.605, r = 0.778, p < 0.001) was identified between the hypoxic dose and the increase in hemoglobin concentration (HGB) percentage. In addition, the change in the reticulocyte percentage (RET%) has been identified as one of the most sensitive parameters to rhEPO use. The mean effects of rhEPO on blood parameters were greater than those induced by hypoxic exposure (1.7 times higher for HGB and RET% and 4 times higher for hemoglobin mass). However, rhEPO micro-doses have shown effects that are hardly distinguishable from those identified after hypoxic exposure. The results of the literature search allowed to identify temporal and quantitative evolution of blood parameters in connection with different hypoxic exposure doses, as well as different rhEPOs doses. This might be considered to provide justified and well-documented interpretations of physiological changes in blood parameters of the Athlete Biological Passport.

Relation between Exercise Performance and Blood Storage Condition and Storage Time in Autologous Blood Doping

Professional athletes are expected to continuously improve their performance, and some might also use illegal methods-e.g., autologous blood doping (ABD)-to achieve improvements. This article applies a systematic literature review to investigate differences in the ABD methods and the related performance and blood parameters owing to different storage conditions-cryopreservation (CP) and cold storage (CS)-and different storage durations. The literature research resulted in 34 original articles. The majority of currently published studies employed CS during ABD. This contrasts to the applied storage technique in professional sports, which was mainly reported to be CP. The second outcome of the literature research revealed large differences in the storage durations applied, which were in the range of one day to 17 weeks between blood sampling and re-infusion, which might affect recovery of the red blood cell mass and thus performance outcome related to ABD. Data revealed that performance parameters were positively affected by ABD when a minimal storage duration of four weeks was adhered. This article identified a need for further research that reflect common ABD practice and its real effects on performance parameters, but also on related blood parameters in order to develop valid and reliable ABD detection methods.

Influence of chronic training workload on the hematological profile: a pilot study in sedentary people, amateur and professional cyclists

Background and aim:

The assessment of hematological profile requires to identify possible sources of biological variability, including exercise-related variations. This study was hence aimed to evaluate hematological profile variations in amateur and professional athletes, and establish their possible dependence on cumulative training volume.

Materials and Methods:

The study population consisted of 59 sedentary male subjects, 78 amateur and 80 professional male cyclists, in whom a large number of hematological variables were measured at rest.

Results:

Red blood cell (RBC) count and hemoglobin were decreased in the two athlete cohorts compared to sedentary subjects, but did not differ between amateur and professional cyclists. Hematocrit was gradually and significantly decreased in parallel with cumulative training volume. Amateur cyclists displayed higher mean corpuscular volume (MCV) and lower mean corpuscular hemoglobin concentration (MCHC) values than sedentary subjects and professional cyclists, whilst mean corpuscular hemoglobin (MCH) was higher in professional cyclists. The reticulocyte count and soluble transferrin receptor (sTFR) values were similar across all groups. Serum ferritin was higher in professional cyclists than in the other two groups, whilst transferrin gradually decreased from sedentary group to the two cohorts of amateur and professional cyclists. In univariate analysis, cumulative training volume was inversely associated with age, body mass index (BMI), RBC count, hematocrit, hemoglobin and transferrin, whilst a positive association was found with ferritin. In multivariate analysis, BMI, RBC count and ferritin remained significantly associated with training volume.

Conclusions:

These results show that the volume of endurance training may affect some hematological variables. (www.actabiomedica.it)

Athlete Biological Passport: Need and Challenges

The Athlete Biological Passport programme was initiated in 2009 by the World Anti-Doping Agency for making the anti-doping programme more effective and stronger. There are three modules in this ABP programme: haematological, steroidal and endocrinological. Currently, the first two modules have been implemented. The newer products such as recombinant human erythropoietin, recombinant proteins, and peptides are similar to those produced naturally. Hence, detection of these substances even with advanced techniques is difficult. Therefore, the concept of ABP came into existence which is based on longitudinal monitoring of biological markers and their variations over a period of time. The ABP does not rely upon the detection of a particular prohibited substance but it reflects the changes in biological markers collated over an athlete's career. Hence, athletes can be monitored through constant interpretation of the passport data. There are many advantages with the implementation of this programme; however, there are various issues which may lead to false interpretation of passport data that must be taken into consideration.

Geolocalisation of athletes for out-of-competition drug testing: ethical considerations. Position statement by the WADA Ethics Panel

Through the widespread availability of location-identifying devices, geolocalisation could potentially be used to place athletes during out-of-competition testing. In light of this debate, the WADA Ethics Panel formulated the following questions: (1) should WADA and/or other sponsors consider funding such geolocalisation research projects?, (2) if successful, could they be proposed to athletes as a complementary device to Anti-Doping Administration and Management System to help geolocalisation and reduce the risk of missed tests? and (3) should such devices be offered on a voluntary basis, or is it conceivable that they would be made mandatory for all athletes in registered testing pools? In this position paper, the WADA Ethics Panel concludes that the use of geolocalisation could be useful in a research setting with the goal of understanding associations between genotype, phenotype and environment; however, it recognises that the use of geolocalisation as part of or as replacement of whereabouts rules is replete with ethical concerns. While benefits remain largely hypothetical and minimal, the potential invasion of privacy and the data security threats are real. Considering the impact on privacy, data security issues, the societal ramifications of offering such services and various pragmatic considerations, the WADA Ethics Panel concludes that at this time, the use of geolocalisation should neither be mandated as a tool for disclosing whereabouts nor implemented on a voluntary basis.

Validation of a blood marker for plasma volume in endurance athletes during a live-high train-low altitude training camp

Altitude is a confounding factor within the Athlete Biological Passport (ABP) due, in part, to the plasma volume (PV) response to hypoxia. Here, a newly developed PV blood test is applied to assess the possible efficacy of reducing the influence of PV on the volumetric ABP markers; haemoglobin concentration ([Hb]) and the OFF-score. Endurance athletes (n=34) completed a 21-night simulated live-high train-low (LHTL) protocol (14 h.d-1 at 3000 m). Bloods were collected twice pre-altitude; at days 3, 8, and 15 at altitude; and 1, 7, 21, and 42 days post-altitude. A full blood count was performed on the whole blood sample. Serum was analysed for transferrin, albumin, calcium, creatinine, total protein, and low-density lipoprotein. The PV blood test (consisting of the serum markers, [Hb] and platelets) was applied to the ABP adaptive model and new reference predictions were calculated for [Hb] and the OFF-score, thereby reducing the PV variance component. The PV correction refined the ABP reference predictions. The number of atypical passport findings (ATPFs) for [Hb] was reduced from 7 of 5 subjects to 6 of 3 subjects. The OFF-score ATPFs increased with the PV correction (from 9 to 13, 99% specificity); most likely the result of more specific reference limit predictions combined with the altitude-induced increase in red cell production. Importantly, all abnormal biomarker values were identified by a low confidence value. Although the multifaceted, individual physiological response to altitude confounded some results, the PV model appears capable of reducing the impact of PV fluctuations on [Hb].

The athlete's hematological response to hypoxia: A meta-analysis on the influence of altitude exposure on key biomarkers of erythropoiesis

Altitude training is associated with changes in blood markers, which can confound results of the Athlete?s Biological Passport (ABP). This meta-analysis aims to describe the fluctuations during- and post-altitude in key ABP variables; hemoglobin concentration ([Hb]), square-root transformed reticulocyte percentage (sqrt(retic%)) and the OFF-score. Individual de-identified raw data were provided from 17 studies. Separate linear mixed effects analyses were performed for delta values from baseline for [Hb], sqrt(retic%) and OFF-score, by altitude phase (during and post). Mixed models were fitted with the hierarchical structure: study and subject within study as random effects. Delta values as response variables and altitude dose (in kilometer hours; km.hr = altitude (m) / 1000 x hours), sex, age, protocol and baseline values as fixed effects. Allowances were made for potential autocorrelation. Within two days at natural altitude [Hb] rapidly increased. Subsequent delta [Hb] values increased with altitude dose, reaching a plateau of 0.94 g/dL [95%CI (0.69, 1.20)] at ~1000 km.hr. Delta sqrt(retic%) and OFF-score were the first to identify an erythrocyte response, with respective increases and decreases observed within 100 to 200 km.hr. Post-altitude, [Hb] remained elevated for two weeks. Delta sqrt(retic%) declined below baseline, the magnitude of change was dependent on altitude dose. Baseline values were a significant covariate (p<0.05). The response to altitude is complex resulting in a wide range of individual responses, influenced primarily by altitude dose and baseline values. Improved knowledge of the plausible hematological variations during- and post-altitude provides fundamental information for both the ABP expert and sports physician.

Influence of combined iron supplementation and simulated hypoxia on the haematological module of the athlete biological passport

The integrity of the athlete biological passport (ABP) is underpinned by understanding normal fluctuations of its biomarkers to environmental or medical conditions, for example, altitude training or iron deficiency. The combined impact of altitude and iron supplementation on the ABP was evaluated in endurance-trained athletes (n = 34) undertaking 3 weeks of simulated live-high: train-low (14 h.d^-1 , 3000 m). Athletes received either oral, intravenous (IV) or placebo iron supplementation, commencing 2 weeks prior and continuing throughout hypoxic exposure. Venous blood was sampled twice prior, weekly during, and up to 6 weeks after altitude. Individual ABP thresholds for haemoglobin concentration ([Hb]), reticulocyte percentage (%retic), and OFF score were calculated using the adaptive model and assessed at 99% and 99.9% specificity. Eleven athletes returned values outside of the calculated reference ranges at 99%, with 8 at 99.9%. The percentage of athletes exceeding the thresholds in each group was similar, but IV returned the most individual occurrences. A similar frequency of abnormalities occurred across the 3 biomarkers, with abnormal [Hb] and OFF score values arising mainly during-, and %retic values mainly post- altitude. Removing samples collected during altitude from the model resulted in 10 athletes returning abnormal values at 99% specificity, 2 of whom had not triggered the model previously. In summary, the abnormalities observed in response to iron supplementation and hypoxia were not systematic and mostly in line with expected physiological adaptations. They do not represent a uniform weakness in the ABP. Nevertheless, altitude training and iron supplementation should be carefully considered by experts evaluating abnormal ABP profiles.