Male hypogonadism: therapeutic choices and pharmacological management

Management of male infertility is always a difficult task, and the pathologic process is often poorly understood. Even though modern assisted reproduction techniques (ART) can help overcome severe male factor infertility, the application of these methods in all infertile couples would definitely represent over-treatment. Several conditions can interfere with spermatogenesis and reduce sperm quality and production. A careful diagnostic work-up is necessary before any andrological treatment can be initiated so that adequate treatment options can be selected for individual patients. Most hormonal imbalances can be readily identified and successfully treated nonsurgically. However, the treatment of men with unexplained idiopathic infertility remains a challenge. In the absence of a correctable etiology, patients are managed with either empirical medical therapy or ART. Empiric medical therapy continues as a viable option. However, physicians and patients must understand that the success rates with any of the pharmacological therapies remain suboptimal.

An increasing number of research studies in men indicate endurance exercise training has significant effects upon the major male reproductive hormone, testosterone, and the hypothalamic-pituitary-testicular axis that regulates reproductive hormone production. This review article addresses a relatively new reproductive endocrine dysfunction found in exercising men, what has been deemed the "exercise-hypogonadal male condition". Specifically, men with this condition exhibit basal (resting-state) free and total testosterone levels that are significantly and persistently reduced. The exact physiological mechanism inducing the reduction of testosterone is currently unclear, but is postulated to be a dysfunction (or perhaps a readjustment) within the hypothalamic-pituitary-testicular regulatory axis. The time course for die development of the exercise-hypogonadal condition or the threshold of exercise training necessary to induce the condition remains unresolved. The potential exists for these reduced testosterone levels within the exercise-hypogonadal male to be disruptive and detrimental to some anabolic or androgenic testosterone-dependent physiological processes. Regrettably, few research studies have addressed whether such processes are affected; thus, findings are equivocal. Conversely, the alterations in circulating testosterone brought about by endurance exercise training have the potential for cardiovascular protective effects and could be beneficial to the health of these men. Present evidence suggests this condition is limited to men who have been persistently involved in chronic endurance exercise training for extended periods of time (i.e., years) and is not a prevalent occurrence. Nonetheless, many questions regarding the male reproductive endocrine adaptive process to exercise training still remain unanswered, necessitating the need for much further research.