Thyroid dysfunction in rheumatoid arthritis
F. Mohammadi, S. Zayeni, A. Jafarnejhad, M Hedayati Omami & N. Amini
Introduction: Rheumatoid arthritis, the most common inflammatory arthritis, is commonly seen with thyroid hormone autoantibodies and thyroid dysfunction.In this survey we evaluate the thyroid function and the prevalence of thyroid autoantibody, autoimmune thyroiditis and other forms of thyroid dysfunction to determine whether these patients should be screened for thyroid disease.
Material and methods: Our study included 224 rheumatoid arthritis patients (195 female, 29 male), all fulfilling the revised ACR criteria for the diagnosis of RA who consecutively admitted to Rheumatology clinic of university based, internal medicine centre of Razi hospital in Rasht, the capital city of Guilan province in north of Iran. Mean age was 49.05±13.53. For each patient, demographic data were recorded. Each patient was evaluated for the personal and family history of thyroid disease. All patients underwent tests for Free T4, Free T3, TSH, Anti Thyroid Peroxidase (Anti TPO), and Anti Thyroglobulin (Anti Tg).
Result: (19.6%) patients had positive family history for thyroid disease. Laboratory evidence for thyroid dysfunction in the form of hypothyroidism was obtained in 42 (18.8%) patients who all were women. Hypothyroidism was more common in Patient with a positive family history of thyroid disease which was statistically significant. We could not detect such a relation regarding to sex and age. In this study no case of hyperthyroidism was detected. Autoimmunity was detected in 39 (17.4%) patients. All cases were women which was statistically significant (P<0.008).Physical examination and thyroid sonography revealed simple goitre, multinodular goitre, simple nodule in 3(1.3%), 3(1.3%) and 2(0.8%) cases respectively.
In 19 (43.2%) patients with thyroid disease, the family history for thyroid disease was positive. When contrasting patients with positive family history of thyroid diseases with patients without such a family history, the results were statistically significant only in the case of hypothyroidism (P<0.02). A statistically significant relationship between sex and thyroid abnormalities was found only in the case of autoimmunity (P<0.008).
Conclusion: Thyroid dysfunctions are common in rheumatoid arthritis. It seems wise to evaluate these patients for the investigated abnormality especially the autoimmunity.
Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector