Endocrine Abstracts

JOINT1200

Objective: Autoimmunity could be part of the pathogenesis of polycystic ovary syndrome (PCOS), but data regarding risk of autoimmune diseases in population based cohorts are limited.

Aim: To investigate incidence rates of autoimmune diseases in Danish women with PCOS before and after PCOS diagnosis compared to controls.

Design: National register-based study in Danish women with PCOS (PCOS Denmark, n=30,340) and age-matched controls (n=151,520). Type 1 diabetes, thyroid disease or other autoimmune diseases were study outcomes (defined by ICD10 diagnosis and/or medical treatment for type 1 diabetes or thyroid disease). Baseline was the date for PCOS diagnosis.

Results: The median age at PCOS diagnosis was 28 years (interquartile range (IQR) 23; 35). Before baseline (mean risk time 11.4 years), the incidence rate of type 1 diabetes (IRR=2.18 (1.33; 3.55), thyroid disease (IRR=1.81 (1.68; 1.96) and other autoimmune disease (IRR=1.12 (1.03; 1.22) was significantly higher in women with PCOS compared to controls (all P<0.001). In PCOS, the prevalence of T1D before baseline was 0.09%, thyroid disorder 3.25% and other autoimmune disease 2.6%. The mean risk time after the index date was 9.8 years. After baseline, the incidence rate of type 1 diabetes (IRR=3.41 (3.02; 3.86), thyroid disease (IRR=1.49 (1.41; 1.59) and other autoimmune disease (IRR=1.13 (1.04; 1.22) was significantly higher in women with PCOS compared to controls (all P≤0.003).

Conclusion: The incidence rate of autoimmune disease was higher in women with PCOS compared to controls before and after PCOS diagnosis.