Fatty acid-binding protein-4 plasma levels are associated to metabolic abnormalities and response to therapy in girls and young women with androgen excess

OBJECTIVE: To assess the usefulness of circulating fatty acid-binding protein 4 (FABP4) as a predictive marker of long-term therapeutic outcome in girls with ovarian androgen excess and a history of precocious pubarche (PP) and low birth weight (LBW) and in young women with polycystic ovary syndrome (PCOS). METHODS: We included 97 patients. Thirty-nine had a history of LBW-PP and were randomized to remain untreated (n = 13) or to receive metformin (n = 26). PCOS women (n = 58) received low-dose flutamide-metformin plus an oral contraceptive. Auxology, androgens, glucose, insulin, homeostasis model assessment (HOMA)-insulin resistance (IR), lipid profile, FABP4, and body composition (by dual-energy X-ray absorptiometry) were assessed at baseline and after 2 years. RESULTS: At baseline, FABP4 was associated with anthropometric measurements and fat body mass (all P < 0.05). FABP4 levels increased less after follow-up in the PP-treated girls (P < 0.05); in the PCOS patients, basal FABP4 levels were inversely associated with changes in systolic blood pressure, HOMA-IR, and total fat mass (all P < 0.05). Body mass index-standard deviation scores was the main independent predictor of FABP4 variations (33%, P < 0.001). CONCLUSION: FABP4 is a strong clinical biomarker of adiposity, IR, and the presence of the components of the metabolic syndrome in non-obese hyperandrogenic girls and young women; pretreatment FABP4 levels appear to predict therapeutic long-term response.