[Value of laboratory parameters in androgenization in the female with special reference to the "free androgen index"]

The degree of androgynism (A) in women can be assessed via clinical data and by determining the levels of testosterone (T), dehydroepiandrosterone sulfate (DHEA-S) and testosterone binding globulin (TBG) in the blood. The determination of the "free androgen index" (FAI), the ratio of total T and TBG, helpful in estimating the level of free T in serum, conveys valuable additional information: in case of FAI below 1, a mild kind of A without elevation of free testosterone can be assumed. However, severe A with elevation of free testosterone and absolute hyperandrogynism is associated with FAI values above 1. In 63 women with signs of A the parameters mentioned above and the FAI were used to determine the degree of severity of A. These data were compared with the corresponding data of a control group. It could be shown that in women whose A was due to idiopathic hirsutism the increased level of bonded T played a causal role. The mean FAI in this group was 0.41. In contrast, in women with POC syndrome and androgynous cycle disturbances, the absolute hyperandrogynism with elevation of free T levels predominated. In these groups the mean FAI was above 1. However, women with male pattern bolding as single sign of A did not exhibit any significant difference in comparison to the control group. In this disease, the increased response of androgen receptors in the skin despite normal androgen levels seems to play a causal role. Two cases of androgen producing ovarial tumours and one case of adrenogenital syndrome were analysed separately.