Evaluating thyroid disorders in patients with rheumatoid arthritis:a cross-sectional study

Introduction: The prevalence of autoimmune thyroid disease (AITD) in RA varies considerably; and there is no recommendation for routine population screening for thyroid diseases in RA. In this study, we assessed the prevalence of thyroid disorders in RA patients referred to the Razi Hospital, Rasht, Iran. Patients and Methods: This was ananalytical cross-sectional study. The prevalence of thyroid abnormalities in 224 patients diagnosed with RA was evaluated according to ACR criteria who referred to the Razi hospital rheumatology clinic during 2008-2010, Rasht, Iran. All patients were checked for free T4, free T3, Thyroidstimulating hormone (TSH), Anti-thyroid peroxidase (Anti-TPO) and Anti-Thyroglobulin. Results: Generally, 224 patients were included in the study and 87.1% were female;the mean age was 49.05±13.53 years (CI: 18-80). Sixty-four patients (28.6%) had thyroid disorders. There was no significant relationship between the existence of thyroid disorder and age, familial history of thyroid or RA diseases (P>0.05) but there was a significant relationship between the existence of thyroid disorder and gender (P<0.001) and it was more in women. In the clinical examination results, the existence of nodule was a significant predictor of thyroid dysfunction (OR: 1.12, CI: 0.6-0.98; P<0.001). Conclusion: Our study confirmed an increase in the prevalence of thyroid dysfunction in patients with RA associated with a low prevalence of hormonal alterations. The most thyroid dysfunction was hypothyroidism.