Hyperandrogenism controversy in elite women’s sport: an examination and critique of recent evidence

Hyperandrogenism controversy in elite women’s sport: an examination and critique of recent evidence

Peter H Sőnksen,1,2 L Dawn Bavington,3 Tan Boehning,1
David Cowan,4 Nishan Guha,5 Richard Holt,1 Katrina Karkazis,6
Malcolm Andrew Ferguson-Smith,7 Jovan Mircetic,8 Dankmar Bőhning9


In July 2017, the International Associa-tion of Athletics Federations (IAAF) was expected to return to the Court of Arbi-tration for Sport (CAS) with evidence to justify reinstatement of their contro-versial hyperandrogenism rule. CAS has granted IAAF a 2-month extension for their response, which was due by the end of September. CAS suspended the IAAF Hyperandrogenism Regulations 2 years earlier following the successful appeal by the Indian runner Dutee Chand. IAAF advisors have published two recent arti-cles in this journalto support their claims that women with high endogenous testosterone levels have such a significant performance advantage over women with lower levels that it is necessary to exclude them from competing in the female category.

Both papers have examined the rela-tionship between blood testosterone concentration and athletic performance using a cross-sectional design. While such studies can show the presence of associa-tion, they do not prove causality and no mention is made of the possible impor-tance of associated androgen insensitivity, while in some there may be a contribution from exogenous testosterone. The paper by Eklund et al compared a spectrum of androgen-related endocrine variables in a group of 106 elite Swedish female athletes with 117 sedentary controls. They found no difference in testosterone concen-trations between the two groups, and most importantly no correlation between testosterone concentration and indices of performance in the elite female athletes.

The paper by Bermon and Garnier (funded by the IAAF and WADA) examined the results of endocrine variables in 1332 blood samples from elite female athletes who took part in the 2011 and 2013 IAAF World Athletic Champi-onships; 17.3% of these athletes were sampled at both events.

The hyperandrogenism rule concerns total endogenous blood testosterone, but Bermon and Garnier concentrated on the derived ‘free testosterone’(fT) and found that there were five (of 21) events where athletes whose fT was in the highest tertile appeared to do better than those whose fT was in the lowest tertile. On the other hand, although not statistically significant, those with fT in the lowest tertile appeared to perform better than those in the highest tertile in nine events. Furthermore, for the total endogenous testosterone levels, only three running events showed significant differences in performance between high and low testosterone tertiles.

We view the comparison between the‘tertile groups’using the unpaired t-test as statistically inappropriate and the lack of adjustment for multiple comparisons a major flaw of the analysis. A better approach would have been to look for a direct and statistically significant correlation between endogenous testosterone and performance as in the study by Eklund et al ; in that case there was no correlation. Correlation anal-ysis is the appropriate analysis tool, particu-larly for a cross-sectional study such as this where causal inference is not possible.

In the absence of a statistically significant correlation between androgens and performance, the evidence that either total testosterone or free testosterone predicts performance in women is not supported. A further criticism of the paper is the consid-erable controversy and concerns about the validity of various methods of calculating (rather than measuring) fT. Both papers provide useful information about the association between androgens and athletic performance in women but do not come close to addressing the issue of causality. Furthermore, their findings cannot be extrapolated to the extraordinarily high but largely non-functional testosterone levels that are seen in women with the androgen insensitivity syndrome.


The IAAF was tasked by CAS with providing sufficient evidence that female athletes with androgen levels in the so-called male range have a competitive advantage over their peers, comparable to that men have over women, previously identified as 10%–12% [2; Para 526]. These studies do not provide this evidence. Both papers provide some new data but do not directly tackle the issues articulated by the CAS.

As the CAS panel noted, a competi-tive advantage in the range of 1%–3% suggested by the IAAF advisors is a rela-tively marginal one ‘…given the many other relevant variables that also legiti-mately affect athletic performance’ (para 527). One of the difficulties in quantifying the performance advantage that any indi-vidual athlete (male or female) derives from high endogenous testosterone levels is that it fails to account for these other variables. The IAAF acknowledged this fact in their previous study to determine whether unusually high levels of testos-terone in women provide a competitive advantage, which used the same data from the 2011 World Athletic Championships in Daegu. They stated that they were unable to exclude other variables that ‘…in some unknown way may bring an advantage to female athletes’ (see also Ferguson-Smith and Bavington).

Ethicists (including several authors of this editorial) have argued that even if the IAAF were able to prove a performance advantage of a high endogenous testos-terone in elite female athletes, this would not be unfair.

In conclusion, even considering the methodical limitations, these two new papers present no new evidence to support the regulation beyond what the CAS reviewed before reaching their deci-sion on the Dutee Chand case.



2017年7月、国際陸上競技連盟(IAAF)は、同性高アンドロゲン過剰症規則の復活を正当化する証拠を得て、スポーツ仲裁裁判所(CAS)に戻ることを期待されていました。 CASはIAAFに対し、9月末までに2ヵ月の延長を認めました。 CASはIAAF高アンドロゲン症規制を中断
2年前、インドのランナーDutee Chandによるアピールが成功した。内因性テストステロン値が高い女性は、レベルが低い女性よりもパフォーマンス上の優位性が非常に高いため、女性カテゴリーでの競争から除外する必要があるという主張を裏付けるために、IAAFアドバイザーはこのジャーナルに最近2件の論文を掲載しました。

どちらの論文も、断面デザインを用いて血中テストステロン濃度と運動能力の関係を調べました。そのような研究は関連性の存在を示すことができますが、因果関係を証明するものではなく、関連するアンドロゲン不感受性の重要性については言及されていませんが、外因性テストステロンからの寄与があるかもしれません。 Eklundらによる論文は、117人の座りがちな対照を有する106人のエリートスウェーデン女性アスリートのグループにおけるアンドロゲン関連内分泌変数のスペクトルを比較した。彼らは、2つのグループ間でテストステロン濃度に差は見られず、そして最も重要なことには、エリートの女性アスリートにおいてテストステロン濃度と成績の指標との間に相関がないことを見出しました。



対応のないt検定を使用した「従属グループ」の統計的な不適当性と多重比較の調整の欠如との比較は、分析の大きな欠陥です。 Eklundらによる研究のように、より良いアプローチは、内因性テストステロンとパフォーマンスの間の直接的で統計的に有意な相関関係を探すことでした。その場合、相関関係はありませんでした。特に因果推論が不可能なこのような横断的研究には、相関分析が適切な分析ツールです。




CAS委員会が指摘したように、IAAFアドバイザーが提案する1%〜3%の範囲における競争上の優位性は、比較的運動能力に合法的に影響を与える関連変数を考えると、比較的限界的なものである。第527項)個々のアスリート(男性または女性)が高い内因性テストステロンレベルから得られるパフォーマンス上の利点を定量化する際の困難の1つは、それがこれらの他の変数を説明できないことです。 IAAFは以前の研究でこの事実を認め、女性における異常に高いレベルのテストステロンが競争優位性を提供するかどうかを決定した。それは大邱での2011年世界陸上競技選手権からの同じデータを使用した。彼らは、「…未知の方法で女性アスリートに利益をもたらすかもしれない」という他の変数を除外することはできないと述べた(Ferguson-SmithとBavingtonも参照)。


結論として、方法論的な制限を考慮しても、これら2つの新しい論文は、Dutee Chand事件に関する決定に達する前にCASが検討した以上に規制を支持する新しい証拠を提示していない。