AGE-RELATED-CHANGES IN MALE GONADAL-FUNCTION - IMPLICATIONS FOR THERAPY

In contrast with women, who experience a complete and abrupt cessation of ovarian function during the menopause, aging men largely maintain their testicular androgen production. Nevertheless, most cross-section al studies indicate that there is a partial decrease in testosterone l evels with aging, although this has not been confirmed by other studie s. The disparity among studies stems from differences in study design, patient numbers, assay techniques and inclusion criteria. Proposed me chanisms for an age-associated decline in testosterone production incl ude: (i) defects in the hypothalamic-pituitary-testicular axis; (ii) a n increase in sex hormone binding globulin levels; (iii) environmental factors; (iv) medication use; and (v) chronic illness. The potential beneficial effects of testosterone replacement therapy in hypogonadal men include increased bone density, increased muscle strength, an impr oved feeling of well-being and an improved metabolic profile. These be nefits need to be weighed against the potential risks of androgen ther apy, such as erythrocytosis, sleep apnoea, and the stimulation of beni gn prostatic hypertrophy or an occult prostate malignancy. Consequentl y, androgen replacement should be used with caution in elderly men wit h hypogonadism until the results of well-controlled prospective studie s are available.