Prevalence of thyroid dysfunction in patients with systemic lupus erythematosus: A descriptive cross sectional study

Background: Estimate of prevalence of thyroid dysfunction in systemic lupus erythematosus (SLE) patients from India is scarce. The present study evaluated the prevalence of thyroid dysfunction and anti-thyroid peroxidase (TPO) antibodies in SLE patients, and the most prominent clinical features of thyroid dysfunction were noted. Materials and Methods: This descriptive, cross-sectional study involved 100 adult patients diagnosed with SLE at a tertiary teaching hospital, Bengaluru, India. The study excluded patients on medications that are known to cause thyroid dysfunctions, those with a history of thyroidectomy, and those with other systemic autoimmune diseases. Results: Among the 100 recruited patients, 99 were females, and most (47%) belonged to the age group of 20-30 years, the median duration of lupus was 24 months. Thyroid dysfunction was observed in 42% (n = 42), and hypothyroidism was the most common thyroid abnormality. None of the patients had hyperthyroidism. Among the patients with thyroid dysfunction, the corresponding number of patients with clinical hypothyroidism and subclinical hypothyroidism were 71% (n = 30) and 29% (n = 12). Of 25 patients with elevated anti-TPO, 48% (n = 12) had clinical hypothyroidism, 20% (n = 5) had subclinical hypothyroidism, and 32% (n = 8) had normal thyroid-stimulating hormone and free T4. Most of the patients with thyroid dysfunction were newly diagnosed, and the predominant symptoms noted were fatigue (75%), hair loss (75%), and joint pain (63%). Conclusions: The prevalence of thyroid dysfunction was found to be higher in SLE than previously published cohorts in India and the rest of the world. It does not affect lupus activity.