The Diagnostic Value of Free Androgen Index in Obese Adolescent Females with Idiopathic Hirsutism and Polycystic Ovary Syndrome

Abstract

Objective: The free androgen index (FAI) is the ratio between total testosterone and sex hormone binding globulin (SHBG), and it has been proposed as a marker. FAI is increasingly used in the definitive diagnosis of patients with hyperandrogenism. Although the reference range of FAI in adult females has been identified, there are no adequate studies on the reference range for adolescent girls. We determined the diagnostic value of FAI in adolescent girls diagnosed with obesity, idiopathic hirsutism (IH) and polycystic ovary syndrome (PCOS). Methods: Patients aged 12 to 21 years and diagnosed with obesity, IH and PCOS were included in the study. FAI was found by calculating the ratio of total testosterone to SHBG. Results: According to receiver-operating characteristic (ROC) analysis results, FAI level under 3.45 indicated that the participants were healthy. ROC analysis was also used to determine the usefulness of FAI in distinguishingbetween healthy participants and those diagnosed withPCOS, obesity, IH. It was determined that patients with FAI above 6.15 should be evaluated for PCOS. Conclusion: We concluded that FAI is a reliable marker to identify and followup patients with hyperandrogenism and the reference values we found in our study can be used in clinical practice.