Endocrine Abstracts

Traditionally, male hypogonadism is classified into hypogonadotrophic (the archetype being Kallmann syndrome) and hypergonadotrophic (the archetype being Klinefelter syndrome). Late-onset hypogonadism (LOH) constitutes a separate entity that can be defined as the state where men of advanced age demonstrate low serum testosterone (T) concentrations in combination with a spectrum of symptoms reminiscent of those of ‘classic’ male hypogonadism (e.g. reduced sexual function, loss of vigor, muscle weakness and depression). In obese men, hypogonadism can further worsen the metabolic profile.

The cornerstone of the treatment of male hypogonadism is testosterone replacement therapy (TRT) in the form of intramuscular injections or transdermal preparations (gel, patches). Important TRT issues include:

• Indications (undisputable diagnosis of hypogonadism).

• Contra-indications (absolute: prostate cancer breast cancer; relative: sleep apnea syndrome, benign prostate hyperplasia with obstructive symptoms).

• Adverse effects (polycythemia, prostate hyperplasia, gynecomastia, alteration of serum lipid profile, liver toxicity, impairment of spermatogenesis).

• Follow-up program [recording of clinical (e.g. symptom improvement including sexual function, natural history of sleep apnea, blood pressure, digital rectal examination) and biochemical (e.g. PSA, fasting lipid profile, complete blood count, liver function tests) parameters on pre-determined time intervals].

TRT is expected to re-establish sexual functioning and libido, improve mood and muscle mass, prevent osteoporosis and maintain mental acuity and virilization. A most debated issue is that TRT in LOH. Despite the evidence TRT may increase the incidence of cardiovascular disease, a critical review of the available literature suggests that TRT is effective and safe treatment for male hypogonadism, when applied in carefully selected populations. In symptomatic men with LOH, metabolic impairment and obesity, the combination of TRT with lifestyle modifications can result in better outcomes.