Prevalence of thyroid autoimmune disease in patients with systemic erythematosus

Introduction: Thyroid autoimmune diseases have been associated with a variety of rheumatologic diseases, including systemic lupus erythematosus (SLE). Objective: To estimate the prevalence of thyroid autoimmune diseases in patients with SLE. Methods: Transversal study to compare the prevalence of thyroid disorders in 106 patients with SLE and a control group of 102 patients. The patients were submitted to a clinical and a laboratorial evaluation; the tests included antiperoxidase and antithyroglobulin antibodies, TSH, free T4 and T3. Results: We detected high prevalence of subclinical hypothyroidism (11%) and clinical hypothyroidism (13%) in the group of patients with SLE when they were compared to the control group, 7% and 1%, respectively (p < 0,001). The hyperthyroidism occurred in a same frequency in the two groups. The positivity of antithyroid antibodies was higher in the group with SLE (23% versus 19%, p = 0,025). The relative risk of the patients with SLE to develop thyroid dysfunctions was 1,6. Conclusion: The thyroid disorders were more prevalent in patients with LES than in general population.