An emerging relationship between circulating estradiol and thyroid autoimmunity in polycystic ovarian syndrome

Objectives: To find an association between circulating Estradiol and thyroid autoimmunity in females with polycystic ovarian syndrome (PCOS) and its impact on their health.

Materials and Methods: This study was conducted at Aziz Fatimah Medical and Dental College, after obtaining ethical approval from Institutional Ethical Committee (letter No. DME/568-19) from April to September 2017. Hundred PCOS females enrolled in the age range 17-35 years were taken who fulfilled inclusion and exclusion criteria. Blood samples were drawn and stored at Aziz Fatima Hospital, Faisalabad. All blood samples were analyzed for the levels of Estradiol, thyroid stimulat-ing hormone (TSH), free triiodothyronine (FT3), free tetra-iodothyronine (FT4), and thyroid peroxidase antibody (TPO-Ab). The data was analyzed using SPSS 23.

Results: Of the total population, TPO-Ab was positive in 26% of study participants. It was observed that 64% and 40% of TPO-Ab positive subjects were in the Estradiol quartiles E3 and E4 respectively and none of them were found to be in E1 and E2 quartiles. We have found a significant association of the E2 with TSH, FT4, and TPO-Ab, however, no significant correlation was found between TSH and TPO-Ab. Beta coefficient (β) of 1.006 shows that higher E2 was significantly related to higher TPO-Ab titer with p-value = 0.002. Similarly, a significant but weak positive association was found between E2 and TSH. E2 was significantly negatively associated with FT4.

Conclusion: OEstradiol is positively associated with TPO antibodies and TSH and negatively associated with FT4 in PCOS patients. Our findings suggest that thyroid autoimmunity is commonly found in PCOS females.