Background: It is difficult to define the laboratory finding of hyperandrogenism and associate it with clinical findings in children and adolescents. Androgen levels can be high in obesity, hirsutism, and PCOS. The free androgen index (FAI) is a simple ratio used to evaluate the biologically active testosterone
Objective and hypotheses: Our aim was to determine the FAI in adolescent females and to evaluated how this index is influenced in adolescents diagnosed with obesity, hirsutism, and PCOS.
Methods: A total of 75 female patients aged 1222 years, consisting of 25 patients each followed-up with diagnoses of obesity, hirsutism, and PCOS were included in the study. The control group consisted of healthy adolescents. The obesity group consisted of patients whose BMI was over SDS 2 and the hirsutismus group consisted of cases with a FerrimanGallwey score of 8 or over. The PCOS patient group consisted of patients who met all the PCOS Amsterdam 2013 diagnostic criteria for adolescents. Morning total testosterone and SHBG were measured in all patients. The FAI was calculated with the following formula: FAI=(total testosterone in nmol/l/SHBG in nmol/l)×100
Results: FAI values were 2.3±1.3 (range, 0.26.4) in healthy adolescent females, 10.1±6.1 (range, 1.727.3) in obese patients and 14.9±9.3 (range, 2.74.3) in PCOS cases. There was a statistically significant difference between healthy adolescents and the patients. The difference between the obese and hirsutism groups was not significant while that between the other groups was. The ROC analysis performed to differentiate the FAI in healthy adolescents from the values in the patient group showed a sensitivity of 80.6% and specificity of 97.8% when the cut off value was accepted as 4.85.
Conclusion: An FAI value over 4.85 can be used as a simple ratio that is inexpensive to measure with high sensitivity and specificity in defining hyperandrogenism.
20 - 22 Sep 2014
European Society for Paediatric Endocrinology