High Prevalence of Anti Thyroid Antibodies in an Albanian Cohort of Patients

Abstract

Introduction: Albania is classified as iodine deficient region and endemic goiter in this country has been a concern for public health. A salt iodization program has been implemented in Albania since 2008. Most of regions still remain with a mild or moderate iodine deficiency there are no studies on prevalence of thyroid autoimmune disorders. The purpose of this study was to assess thyroid function and the presence of thyroid antibodies in subjects that were not previously diagnosed or treated for thyroid disorders. Methods: This is a cross-sectional study performed in a cohort of patients in Albania during a 2 year period (january 2018-january 2020). We assessed the prevalence of thyroid function disorders and presence of thyroid antibodies in 5047 subjects (81% females and 19% males). Individuals previously diagnosed or treated for thyroid disease were excluded from the study. TSH, Free T4, total T3, Anti TPO(thyroid peroxidase) and anti TG (thyroglobulin) were measured with electrochemiluminescence method with Cobas 6000 Roche Diagnostics. We calculated the frequency of thyroid antibodies and the abnormal thyroid function. Statistical analysis was performed to see if there was a difference between individuals with positive antibodies and those negative for antibodies. Results: 91 % (4596) of subjects resulted euthyroid. We found a low prevalence of overt thyroid dysfunction (hyperthyroidism 0.48% and hypothyroidism 1.69%). The rates of subclinical hypothyroidism and hyperthyroidism were 5.5% and 1.4% respectively. The prevalence of positive thyroid antibodies, at least one of them was 28% in females and 14% in males (2:1 ratio). 97.3 % of subjects who testet negative for antibodies had normal thyroid function compared to 73.5% in antibodies positive group. There was a significant difference for subclinical hypothyroidism and other thyroid disorders between antibodies positive group and antibodies negative group (p value <0.0000119% of individuals(from 5047 examined) had normal thyroid function and resulted positive for anti TPO or anti TG. Conclusions: Undiagnosed biochemical thyroid dysfunctions were common in subjects living in a mild to moderate iodine-deficient area especially subclinical hypothyroidism. TSH level correlated well with the presence of antibodies resulting in significant difference in thyroid function between 2 groups. We found a high prevalence (19%) of thyroid antibodies in euthyroid subjects. TPO antibodies in euthyroid subjects can be used to identify subjects with increased risk for hypothyroidism such as women who are pregnant (to predict first trimester or postpartum thyroid dysfunction), patients with other autoimmune diseases, subjects on drugs like amiodarone or relatives of patients with autoimmune thyroid diseases.