A recent commentary by Rosner emphasized that direct radioimmunoassay of free testosterone by the tracer analog method may underestimate its concentration.
ANDROGEN DEFICIENCY STATES IN WOMEN
Currently, there is no consensus on a clinical or biochemical definition of androgen deficiency in women. A physical and behavioral symptom complex termed “female androgen deficiency syndrome” includes impaired sexual function, loss of energy and depression.
Based on the distribution of serum total and free testosterone concentrations in healthy, menstruating
15 ng/dl, the lower end of the normal female range in our laboratory.
The causes of androgen deficiency in women can be divided into ovarian, adrenal, central
and systemic causes. Ovarian causes include premature ovarian failure, Turner’s syndrome and
surgical or chemical ovariectomy. Turner’s syndrome is characterized by gonadal dysgenesis, streak gonads, estrogen deficiency and low circulating levels of androstenedione, testosterone,
free testosterone and SHBG.
Most of these women are receiving estrogen and progesterone replacement, which further decreases their free androgen levels by increasing the SHBG concentrations; in addition, LH suppression by the hormone replacement therapy may further decrease the stimulus for ovarian androgen production.
It is possible that the reduction in free androgen levels induced by the traditional hormone replacement therapy might adversely affect sexual function in post-menopausal women. Primary adrenal insufficiency is associated with deficiencies of glucocorticoids as well as adrenal androgens.
Central causes of androgen deficiency include disorders affecting the pituitary or the hypothalamus. Panhypopituitarism affects androgen secretion from both adrenal and ovarian sources; not surprisingly, patients with panhypopituitarism have lower circulating concentrations of total and free testosterone, and androstenedione than those found in patients with either adrenal or ovarian failure alone.