Endocrine Abstracts

Introduction: Autoimmunity is an important etiological factor of premature ovarian insufficiency (POI, menopause <40 years). It has been estimated that 4-50 % of POI cases are of autoimmune origin. Only a few studies, with sample sizes of dozens to hundreds POI cases, have investigated the prevalence of autoimmune diseases in women with POI. We aimed to assess in an essentially larger data set the prevalence of severe autoimmune diseases treated in tertiary care prior to POI diagnosis compared to matched controls.

Materials and Methods: Women diagnosed with POI between the years 1988-2017 (n=5,714) in Finland were identified from the reimbursement registry of the Social Insurance Institution by their right for hormone replacement therapy. Women with a history of cancer or bilateral oophorectomy (n=1,742), were excluded leaving 3,972 women spontaneous POI cases into the study population. Four population controls matched by age and municipality of residence (n= 15,708) were searched for each POI case. Severe autoimmune disease diagnoses for years 1970-2017 were identified from the Hospital Discharge Registry. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using binary logistic regression for having autoimmune diseases preceding the index date (the date when reimbursement for HRT was granted for the POI case in the case-control set) among POI cases compared to controls.

Results: In women with POI, 5.6% had a severe autoimmune disease before the index date. The prevalence of having any severe autoimmune disease prior to the index date was higher among women with POI (OR 2.6, 95% CI 2.2–3.0). Women with POI had an increased prevalence of several specific autoimmune diseases: polyglandular autoimmune diseases (OR 25.8, 95% CI 9.0-74.1), Addison´s disease (OR 22.9, 95% CI 7.9-66.1), vasculitis (OR 10.2, 95% 4.3-24.5), systemic lupus erythematosus (OR 6.2 95% CI 4.2-20.3), rheumatoid arthritis (OR 2.3, 95% CI 1.7-3.2), sarcoidosis (OR 2.3, 95% CI 1.2-4.5), inflammatory bowel diseases (OR 2.2, 95% CI 1.5-3.3), and hyperthyroidism (OR 1.9, 95% CI 1.2-3.1). The prevalence of diabetes type 1 and ankylosing spondylitis did not differ between cases and controls.

Conclusion: Women with severe autoimmune diseases have a more than two-fold increased risk of developing POI, smggesting that immunological mechanisms play a pivotal role in POI. Future studies should focus on specific autoimmune mechanisms behind POI from a preventive perspective.