Free androgen index and Irisin in polycystic ovary syndrome

Purpose PCOS is associated with hyperandrogenism and insulin resistance (IR). Recent studies have shown that circulating Irisin levels increase in PCOS women. However, no report has demonstrated a relationship between Irisin and hyperandrogenism in PCOS women. The purpose of the study was to compare interrelationship between Irisin or androgen excess with IR in PCOS and normal subjects. Methods 166 PCOS and 103 control women were prospectively studied. Euglycemic-hyperinsulinemic clamps were preformed to assess their insulin sensitivity, which was expressed as M value. Circulating Irisin was determined by ELISA kit. Circulating androgens were measured using ultrasensitive assays. Results PCOS women with high FAI had significantly higher BMI, FAT%, TC, DHEA-S and HOMA-IR, and significantly lower levels of M values and SHBG than PCOS women with low FAI or the controls. Pearson correlations showed that in the entire population, FAI correlated positively with BMI, WHR, FAT%, blood pressure, TG, DHEA-S, LH/FSH, AUCinsulin, HOMA-IR and Irisin, and negatively with M values. In multiple stepwise regression analysis, only FAT%, DHEA-S and LH/FSH were independent related factors with FAI. Conclusion The elevated Irisin levels in PCOS women were associated with androgen excess. Circulating Irisin is a primary predictor of hyperandrogenism, MetS and IR in PCOS women.