Hashimoto's thyroiditis might increase polycystic ovary syndrome and associated comorbidities risks in Asia

Background: To investigate whether increased the comorbidities such as coronary artery disease (CAD) and risks between Hashimoto's thyroiditis (HT) and polycystic ovary syndrome ( PCOS) in Taiwanese women. Methods: Patients newly diagnosed as having HT during 2000-2012 were assigned to the case group. Cases and controls were matched for age and comorbidities at a 1:2 ratio using propensity score matching. Incidence was calculated in the unit of 1000 person-year. Univariate and multivariate Cox proportional hazard regression, multivariate Cox, logistic regression, and Kaplan-Meier analyses were performed. Results: Among 3,996 participants, 2,664 constituted the control group and 1,332 constituted the case group. The PCOS risk in patients with HT increased by 2.37 times [95% confidence interval (CI): 1.22-4.62] compared with the controls. Hypertension (HTN) [adjusted odds ratio (OR): 1.31, 95% CI: 1.03-1.66] and hyperlipidemia (adjusted OR: 1.55, 95% CI: 1.2-1.9) were more common in HT patients without PCOS than in other patients. The adjusted OR for CAD in patients with HT was 1.51 (95% CI: 1.11-2.06), whereas that in patients with HT and PCOS was 5.92 (95% CI: 1.32-26.53). Conclusions: In our study, the PCOS risk in patients with HT increased by 2.37 times, which is lower than the increase in HT risk in Asian patients with PCOS (4.56 times). The proportion of CAD increased significantly by 5.92 times in patients with HT and PCOS compared with patients with HT only.