[Is determination of the "free androgen index" for hormone screening in polycystic ovaries of value?].
In 82 females with hyperandrogenism and polycystic ovaries, the sensitivity and diagnostic accuracy of the free-androgen index (FAI) were compared with those of testosterone (T), free testosterone (fT), androstenedione (A), LH and the LH/FSH ratio. Normal ranges for each parameter were derived as 95th percentile in 53 healthy controls of similar age. T, fT, A, FAI, LH and LH/FSH were significantly (p < 0.001) higher in patients than controls. The sensitivity and diagnostic accuracy of the FAI (0.46 and 0.64) were lower than those of T (0.67 and 0.78) and A (0.56 and 0.73) and similar to those of fT and LH/FSH. The overall variance of the FAI was highest among all parameters. The FAI was significantly (p = 0.05) elevated in a subgroup with obesity (n = 34), whereas T and fT did not differ in obese and nonobese subjects with polycystic-ovary syndrome. We cannot recommend the routine measurement of the FAI in the rational laboratory evaluation of female hyperandrogenism for the following reasons. (1) The adequate normal range for the FAI (< 8.7) is substantially higher than previously thought in normal individuals, which has serious consequences for the accuracy of the test. (2) The values of the FAI showed the widest overlap with controls. (3) The significant positive correlation between FAI and fT allows the prediction of the FAI from the measurement of fT, rendering the determination of a second parameter for the free bioactive T unnecessary. (4) The FAI as well as sex-hormone-binding globulin are influenced by body weight, whereas T and fT are markers for hyperandrogenism independent of obesity.
Steck
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T
Universitäts-Frauenklinik Würzburg, BRD.
Wernze
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H
D000328:Adult; D000727:Androgen-Binding Protein / Q000097:blood*; D000728:Androgens / Q000097:blood*; D015415:Biomarkers; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood; D011085:Polycystic Ovary Syndrome / Q000097:blood / Q000175:diagnosis*
D000727:Androgen-Binding Protein; D000728:Androgens; D015415:Biomarkers; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone
Ist die Bestimmung des "freien Androgenindexes" zum Hormonscreening bei polyzystischen Ovarien sinnvoll?