A landmark event took place in the world of sport last week. No, it wasn’t Kohli’s hundredth hundred on the cricket field, or another sensational victory of one of the Williams sisters on the tennis court. It wasn’t even a record breaking, Carl Lewis-type athletics performance. In fact, it did not take place on the sports ground at all. Rather, in an office in Lausanne, Switzerland, a heartbreaking judgment was handed out to the star South African athlete, twice Olympic gold medalist, Caster Semenya, denying her the right to compete in women’s sports unless her blood testosterone level was maintained below 5 nmol/L for at least 6 months.
The Court of Arbitration for Sport (CAS) rejected her appeal challenging International Association of Athletics Federations’ (IAAF) regulations. The decision shook the world of sport; Indians had a particular interest in this as our own athlete Dutee Chand had won a similar appeal (in April 2018 the IAAF withdrew hyperandrogenism regulations) which allowed participation in 100 and 200m without restrictions.
However, in a contentious move at the same time last year, the IAAF framed rules to allow only those with testosterone levels less than 5 nmol/L to participate in women’s track events from 400 m and up to a mile.
What exactly is testosterone, the blood level of which can make or mar careers of elite athletes? The mention of the word testosterone conjures up images of macho men, aggressive corporate tycoons, and Greek God like sport stars. Testosterone, the principal male hormone, has been attributed to have magical properties — not only does it impact libido and sexual function, it also adds to muscle and bone strength, and has an impact on behaviour. Sudden aggressive behaviour by men is sometimes referred to a ‘testosterone rush’. It is one of the reasons for superior physical abilities of men as compared to women. It has therefore been used/ misused for years by sportspersons in attempt to bulk up muscle, enhance strength and improve performance.
The source of testosterone in men is the testes. Interestingly, this classic male hormone is also made in women’s bodies, albeit in much smaller quantities. Typically, adult women have total testosterone levels of 0.5- 2.6 nmol/L. In men the levels are 4 to 10 fold higher (above 8.35 nmol/l). Some women can have higher levels of testosterone. A medical condition very commonly seen in adolescents and young women is PCOS (polycystic ovary syndrome).There is some evidence that even these girls may have enhanced athletic ability, but their levels are usually mildly elevated and almost never reach 5 nmol/L, the cut off level proposed by IAAF.
The other group of conditions that can cause high testosterone levels in women are rare disorders of sexual differentiation or ‘differences in sex development’ (DSD) as the IAAF eligibility rules state. That women with DSD could have an advantage over others is supported by the finding that DSD is found in almost 7 out of every 1,000 elite women athletes, which is dramatically greater than in the general population.
Caster Semenya and Dutee Chand belong to this category. In DSD there is a mismatch between the chromosome, gonads (testes or ovaries), and the external appearance. Many such women, reared as girls, might be totally unaware of their condition. This raises ethical issues about disqualifying them.The commonest among DSD are enzyme defects in the adrenal gland, called congenital adrenal hyperplasia (CAH).
The methods to reduce testosterone levels in DSD with CAH are the use of cortisone (and similar steroids). These cortisone like drugs have significant adverse effects, especially on the bone and muscle. For most other groups birth control pills are the mainstay of treatment. However, birth control pills can produce side effects like mood changes, weight gain and clotting problems. The testosterone level rises as soon as treatment is discontinued, so therapy has to be for prolonged periods and the possibility of side effects is serious and real.
Purely from the scientific standpoint, the IAAF rules have merit. In general there is a correlation between testosterone levels and athletic performance. The cutoff level proposed is not seen in common conditions. Most (but not all) women with such high testosterone levels have an advantage over others. So the rule is fair to those with normal testosterone levels. At the same time, it is unfair and discriminatory against DSD girls, who have naturally high testosterone levels for no fault of theirs, and some of them (those with testosterone resistance) might not be deriving benefit from those levels anyway. They will be forced to take medications that are not totally safe for prolonged periods of time.
Ultimately, it’s about being fair to the larger pool of women athletes versus being discriminatory to a small subset. There cannot be a completely satisfactory answer to this. Too many complexities and lack of proof in some areas further hinder our assessment.
Given the daunting task faced by the IAAF and CAS in this situation, they have gone with the science as it stands now. Personally I agree with the judgement, with the caveat that much more data should be collected in this field, and the stipulations should be revised from time to time as new information appears.
Dr Mithal is the chairman of endocrinology at Medanta, The Medicity.