Prevalence of Undiagnosed Autoimmune Thyroid Disease and Thyroid Dysfunction in Filipino Patients with Autoimmune Rheumatic Disorders

Abstract

Objectives. (1) To determine the prevalence of autoimmune thyroid disease among patients with autoimmune rheumatic disorders seen at the Philippine General Hospital. (2) To determine clinical features that are associated with the occurrence of autoimmune thyroid disease in these patients. Methodology. This is a cross sectional analytical study that included 155 adult Filipinos diagnosed with an autoimmune rheumatic disorder. Clinical characteristics were recorded. Serum thyrotropin, thyroxine, triiodothyronine, anti-thyroid peroxidase antibody, anti-thyroglobulin antibody and urinary iodide excretion were determined. The prevalence of autoimmune thyroid disease was computed. Associations between clinical factors and autoimmune thyroid disease were determined. Results. Overall 21.94% of the population had autoimmune thyroid disease. There was significant association between duration of the autoimmune rheumatic disorder and autoimmune thyroid disease (p-= 0.018). No significant association was noted with the other clinical factors although there was an almost significant association observed for the presence of goiter (p=0.054). Conclusion. Autoimmune thyroid disease commonly occurs in patients with autoimmune rheumatic disorders. As such, it is important to consider screening these patients for the coexistence of thyroid disease to help prevent the complications associated with thyroid dysfunction and avoid adding up to the morbidity of the existing autoimmune rheumatic disorder.