Objective:To investigate the serum irisin levels and its association with insulin resistance(IR)in patients with polycystic ovary syndrome(PCOS). Methods:Sixty patients diagnosed as PCOS and eighty healthy female volunteers were enrolled in this study.Serum hormone and irisin levels were measured. Homeostasis model of insulin resistance(HOMA-IR)was performed to evaluate IR

and HOMA-β

△Ins30/△Glu30

AUCIns/Gluwere used to assess β-cell function

and the relation between irisin and IR was analyzed by Pearson’s correlation and multiple stepwise regression. Results:The level of serum irisin in patients with PCOS was higher than that of control group(P<0.05). Serum irisin levels were positively correlated with BMI(r=0.381

P=0.003)

fasting blood glucose(r=0.565

P=0.000)

fasting insulin(r=0.551

P=0.000)

2-hour post-load insulin(r =0.299

P =0.020)

LH/FSH(r =0.802

P =0.000)

progesterone(r=0.349

P=0.006)

TG(r=0.306

P=0.018)

HOMA-IR(r=0.632

P=0.000)and AUCIns/Glu(r=0.317

P=0.014). Multiple stepwise regression analysis indicated that irisin was associated with HOMA-IR

but had no correlation with β-cell function(HOMA-β

△Ins30/△Glu30

AUCIns/Glu)in PCOS patients(F=169.05

R2=0.945

P=0.000). Conclusion:Serum irisin is elevated in patients with PCOS and may play a role in the pathogenesis of IR.