[Andropause and its management in the aged male]

Abstract

THE "ANDROPAUSE": Also called the "male menopause" or "partial androgen deficiency of the aging male" etc., corresponds to the age at which the progressive decrease in androgen activity reaches a pathogenic threshold. Surveys made in various countries since the seventies conclude that testosterone blood levels start to decrease after the age of 25 and that 20 to more than 50% of the male population no longer benefit from optimal androgen stimulation after the age of 60. THE CONSEQUENCES OF HYPOANDROGENISM: The subsequent progressive hypoandrogenism participates in inducing the commonly-observed clinical symptoms (fatigue, morosity, weight loss, lack of interest in sexual activity); the most specific of which is the disappearance or rarification of "automatic" nocturnal or matinal erections. This appears to influence the prostatic pathology and the frequent cardiovascular risk factors, which, far more than a problem of erection, is a major public health issue. A COMPLEX BIOLOGICAL DIAGNOSIS: Added to the abnormalities in production and transport of testosterone are the abnormalities in its metabolisation by the target tissues. These abnormalities are often undetected in present day blood controls and may explain the elevation in the hepatocyte of SHBG synthesis, the relative inhibition of GnRH pulses and LH secretion in the hypothalamus and the pituitary gland and, in the arterial wall (including penile vascularisation) and the prostate, some of the frequent functional and histological disorders. In current practice today, the best approximation of androgen potential is obtained by the comparison of total testosterone concentrations and SHBG, measurements that require relatively reliable standardised kits.

Therapeutic choice: Optimal replacement therapy, for some authors, must mimic the physiology of the young man and above all maintain or reinforce the estrogenic effects of testosterone, related to its aromatisation into estradiol and supposedly beneficial for the cardiovascular system and the bone. For other, the androgenic effects, enhanced by the 5 alpha reduction into dihydrotestosterone (DHT), should be reinforced in older men because the estrogenic effects are ineffective on bone and most of the other targets, and are probably pathogenic for the prostate. This debate is extremely important since the various formulations of androgens authorized by the French Medicines agency (AFSSAPS) induce clearly differing estradiol/DHT plasma ratios.