The role of androgen therapy.

The concept of a female androgen insufficiency syndrome, although not new, remains somewhat controversial. Androgens are quantitatively the predominant sex steroid in women, circulating in the micromolar and nanomolar concentration range, compared with picomolar levels of oestrogens. The most significant biologically active androgen is testosterone (T), which circulates bound tightly to sex-hormone-binding globulin (SHBG) and loosely to albumin. It is generally held that the non-SHBG-bound fraction is the bioavailable moiety. Hence, clinically useful T measurements require data on total concentrations as well as SHBG level. Testosterone insufficiency occurs in a number of circumstances, including hypopituitarism, premature ovarian failure, adrenal failure, exogenous corticosteroid use and oral oestrogen therapy (causing elevation of SHBG and suppression of gonadotrophins). Clinical symptoms of androgen insufficiency include loss of libido, diminished well-being, fatigue and blunted motivation and have been reported to respond well to T replacement, generally without significant side-effects.