Divided by more than a common language
Apparently, the need for effective intervention is more critical than one would necessarily assume. Not only is there a hypogonadism ‘epidemic’, linked to the fattening of our population, but there is no globally approved treatment for secondary hypogonadism (2HG) i.e. that form not associated with testicular failure. Epidemiologists warn that 2HG is in fact the predominant clinical representation, being roughly six times as common as primary hypogonadism.
The conclusions of the recent consensus panel are neither more nor less appropriate nor scholarly than those of other groups, e.g. the Endocrine Society, BAUS, AUA or SMSNA, but their value is as a timely reminder that unless there is clinical consensus on the disorder it is practically impossible to design regulatory authority-proof clinical trials to ensure drug approval. Ironically the most effective treatment strategy in many instances would be lifestyle intervention, but we all know how compliant men are when diet and exercise are recommended.
Returning to drug treatment, the panel does emphasize the critical importance of distinguishing between the different aetiologies of primary hypogonadism and 2HG. Although testosterone replacement therapy is usually appropriate in the treatment of primary hypogonadism, it may be inappropriate in the treatment of 2HG. Because of negative feedback in this situation testosterone replacement can reduce spermatogenesis and testicular function. This clinical phenomenon is exemplified by the phase III data from two clinical trials presented by Kim et al. [2] in this issue of BJUI. Compared with placebo, testosterone replacement produced substantial reductions in spermatogenesis and testicular function. Bearing in mind that many men with androgen deficiency may well wish to preserve fertility, testosterone replacement could therefore in fact be counterproductive. The trials by Kim et al. also showed that, by comparison, the selective, centrally active, oestrogen antagonist, enclomiphene, could normalize testosterone levels while maintaining testicular function and spermatogenesis.
In many ways, assuming eventual regulatory approval, enclomiphene could represent the optimum therapy for 2HG, preferably as an adjunct to lifestyle modification, i.e. dietary manipulation and exercise. Unfortunately, at least in the USA, the regulatory authority appear not to recognize 2HG as a condition that merits treatment. Pressure from the clinical community could influence this attitude.