[Testosterone substitution in patients with hypogonadism]

After the age of 60, 20-35% of men present with androgen deficiency. Clinical symptoms of hypogonadism in older men are often more difficult to interpret than in younger men. Knowledge of physiological actions of testosterone and its metabolites are important prerequisites for diagnosis, drug selection and surveillance of therapy. Another question is whether any type of interventions, such as hormone replacement therapy, may play a role in improving the quality of life as proven in post-menopausal women.

To understand testosterone supplementation in the aging male, this review will discuss the following important topics: physiology of male hormonal balance, changes in reproductive organs in elderly men, endocrine evaluation of the male, pharmacological effects of testosterone on target organs, available preparations for testosterone and testosterone supplementation.

Testosterone deficiency may induce organic symptoms such as loss of muscular strength, decreased libido and loss of bone density and have psychological consequences such as fatigue or depression. Controlled clinical trials show that therapy with natural testosterone results in clinical improvements in elderly men that cover androgenic effects.

With the current status of knowledge short acting, low dose testosterone preparations seem to be best tailored for substitution of older hypogonadal men. Only intensive research in the future can satisfy these requirements.