[Relation between insulin resistance and insulin receptor gene methylation in the endometrium of patients with polycystic ovary syndrome].

ABSTRACT

OBJECTIVE: To study the relationship between insulin resistance and methylation of insulin receptor (INSR) gene in the endometrium of women with polycystic ovary syndrome (PCOS). METHODS: Based on the HOMA index, 35 patients with PCOS were divided into insulin resistant group (IR group, n=18) and non-resistant group (NIR group, n=18). The patients age, serum estriol, testosterone, FSH and LH, fasting insulin and fasting blood glucose were compared between the two groups. The endometrial samples were obtained from the patients to examine DNA methylation status of INSR gene in the endometrial cells using methylation-specific PCR. RESULTS: The BMI, WHR, fasting glucose, fasting insulin, and HOMA index differed significantly between the two groups (P<0.05). PCR analysis showed partial methylation in the promoter region of INSR gene in 13 samples in IR group and 11 samples in NIR group, without detection of full methylation of the INSR gene in either group. The methylation status showed no significant difference between the two groups (P=0.328). CONCLUSION: Partial methylation of the INSR gene occurs in the endometria of PCOS patients, but this study does not provide a strong evidence supporting the relationship between insulin resistance and INSR gene methylation in women with PCOS.