Abstract: [Abstract] Objective   To compare the relationship between secretory characteristics of serum ghrelin and mechanism of metabolic syndrome in obese and non-obese patients with polycystic ovarian syndrome (PCOS). Methods   Based on the body mass index (BMI), 60 PCOS patients were divided into two groups, 30 cases in obese group（BMI≥25 kg/m2）and 30 cases in non-obese group (BMI＜25 kg/m2). Thirty infertile patients with tubal factor and normal menstruation were the control group. The serum levels of ovarian sex steroid hormones were detected by fully automatic chemiluminescence method,and the experiment of sugar metabolism was carried out in three groups. The serum ghrelin level was detected by enzyme linked immunosorbent assay (ELISA). The correlation between ghrelin level and biochemical metabolic indexes was analyzed by simple correlation analysis. Results  (1) The serum ghrelin level was significantly lower in obese group (1.84±0.46) and non-obese group (2.13±0.52) than that of control group (2.52±0.78，P < 0.05)，and the level was significantly lower in obese group than that of non-obese group. (2) The values of fasting insulin (FIN), homeostasis model assessment insulin resistance index (HOMA-IR), and serum INS levels of 2 h and 3 h oral glucose tolerance test (OGTT) were significantly higher in obese group than those of non-obese group and control group (P < 0.05). In non-obese group, the serum values of LH and LH/FSH were markedly higher than those of obese group and control group. (3) The serum ghrelin level was negatively correlated with FIN and HOMA-IR (r=-0.542 and -0.503,P < 0.05). In non-obese group, the serum ghrelin level was negatively correlated with testosterone (r=-0.568，P <0.05). Conclusion   The serum ghrelin levels may play a significant role in pathogenesis mechanisms in PCOS patients，especially in obese ones.

Key words: polycystic ovarian syndrome, Insulin Resistence, Ghrelin, obesity, body mass index