Thyroid autoimmunity markers in women with polycystic ovary syndrome and controls

This study was performed to compare the prevalence of autoimmune thyroid disease (AITD) assessed by thyroid peroxidase antibody (anti-TPO Ab) and thyroid ultrasonography (USG) in Korean women with polycystic ovary syndrome (PCOS) (n = 210) and age-matched controls (n =343). We also compared the clinical features of women with PCOS according to the presence of AITD. Patients and controls were enrolled from a population who visited a screening centre for a general health check-up. There was no difference in the frequency of anti-TPO Ab positivity between the women with PCOS and the controls (4.8% (5/104) in patients and 7.6% (18/238) in controls). The frequency of heterogeneous or hypoechoic parenchyma on USG also did not differ between the patients and controls (9.3% (11/118) in patients and 12.3% (40/325) in controls). Within the PCOS group, the subjects with AITD (who had either Ab positivity or sonographic findings compatible with thyroiditis) showed significantly higher body mass indexes, waist circumferences and homeostasis model assessment for insulin resistance levels than the patients without AITD. In conclusion, AITD was not more prevalent in women with PCOS than in controls. However, among women with PCOS, subjects with AITD showed significantly higher adiposity and insulin resistance index than those without AITD.